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  • 1.
    Nazir, Uzma
    et al.
    Department of Chemistry, Quaid-i-Azam University, Islamabad, Pakistan.
    Akhter, Zareen
    Department of Chemistry, Quaid-i-Azam University, Islamabad, Pakistan.
    Janjua, Naveed Kausar
    Department of Chemistry, Quaid-i-Azam University, Islamabad, Pakistan.
    Asghar, Muhammad Adeel
    Department of Chemistry, Quaid-i-Azam University, Islamabad, Pakistan.
    Kanwal, Sehrish
    Department of Chemistry, Quaid-i-Azam University, Islamabad, Pakistan.
    Butt, Tehmeena Maryum
    Department of Chemistry, Quaid-i-Azam University, Islamabad, Pakistan.
    Sani, Asma
    Department of Chemistry, Quaid-i-Azam University, Islamabad, Pakistan.
    Liaqat, Faroha
    Department of Chemistry, Quaid-i-Azam University, Islamabad, Pakistan.
    Hussain, Rizwan
    Laboratory for Advanced Materials Processing (LAMP), NCP, Islamabad, Pakistan.
    Shah, Faiz Ullah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Biferrocenyl Schiff bases as efficient corrosion inhibitors for an aluminium alloy in HCl solution: a combined experimental and theoretical study2020In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 10, no 13, p. 7585-7599Article in journal (Refereed)
    Abstract [en]

    The corrosion inhibitive capabilities of some ferrocene-based Schiff bases on aluminium alloy AA2219-T6 in acidic medium were investigated using Tafel polarization, electrochemical impedance spectroscopy (EIS), weight loss measurement, FT-IR spectroscopy and scanning electron microscopic (SEM) techniques. The influence of molecular configuration on the corrosion inhibition behavior has been explored by quantum chemical calculation. Ferrocenyl Schiff bases 4,4′-((((ethane-1,2-diylbis(oxy))bis(4,1-phenylene))bis(methaneylylidene))bis(azaneylylidene))bisferrocene (Fcua), 4,4′-((((ethane-1,2-diylbis(oxy))bis(2-methoxy-1,4-phenylene))bis(methaneylylidene))bis(azaneylylidene))bisferrocene (Fcub) and 4,4′-((((ethane-1,2-diylbis(oxy))bis(2-ethoxy-1,4-phenylene))bis(methaneylylidene))bis(azaneylylidene))bisferrocene (Fcuc) have been synthesized and characterized by FT-IR, 1H and 13C NMR spectroscopic studies. These compounds showed a substantial corrosion inhibition against aluminium alloy in 0.1 M of HCl at 298 K. Fcub and Fcuc showed better anticorrosion efficiency as compared with Fcua due to the electron donating methoxy and ethoxy group substitutions, respectively. Polarization curves also indicated that the studied biferrocenyl Schiff bases were mixed type anticorrosive materials. The inhibition of the aluminium alloy surface by biferrocenyl Schiff bases was evidenced through scanning electron microscopy (SEM) studies. Semi-empirical quantum mechanical studies revealed a correlation between corrosion inhibition efficiency and structural functionalities.

  • 2.
    Rodina, Tatyana A.
    et al.
    Institute of Geology and Nature Management, Far Eastern Branch of the Russian Academy of Sciences, 675000 Blagoveschensk, Amur Region, Russia.
    Loseva, Olga V.
    Institute of Geology and Nature Management, Far Eastern Branch of the Russian Academy of Sciences, 675000 Blagoveschensk, Amur Region, Russia.
    Smolentsev, Anton I.
    Nikolaev Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences, 630090 Novosibirsk, Russia. Novosibirsk State University, 630090 Novosibirsk, Russia.
    Antzutkin, Oleg N.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering. Department of Physics, Warwick University, Coventry CV4 7AL, UK.
    Ivanov, Alexander V.
    Institute of Geology and Nature Management, Far Eastern Branch of the Russian Academy of Sciences, 675000 Blagoveschensk, Amur Region, Russia.
    Crystal structure, solid-state 13C and 15N NMR characterisation, chemisorption activity and thermal behaviour of new mercury(II) dipropyldithiocarbamate: Binuclear, pseudo-binuclear and heteronuclear complexes of [Hg2(PrDtc)4], [Hg(PrDtc)2]2 and [Au(PrDtc)2]2[Hg2Cl6]2020In: Inorganica Chimica Acta, ISSN 0020-1693, E-ISSN 1873-3255, Vol. 508, article id 119630Article in journal (Refereed)
    Abstract [en]

    Two polymorphs of a new mercury(II) N,N-dipropyldithiocarbamate represented by centrosymmetric binuclear and pseudo-binuclear molecules, [Hg2(PrDtc)4] (1) and [Hg(PrDtc)2]2 (2), have been isolated, identified using heteronuclear (13C, 15N) CP-MAS NMR and structurally characterised by single-crystal X-ray diffraction analysis. There are two pairs of inequivalent PrDtc ligands playing either terminal chelating or tridentate bridging structural functions in the former compound; while the latter complex comprises two pairs of structurally inequivalent chelating PrDtc ligands. The reaction of freshly precipitated mercury(II) N,N-dipropyldithiocarbamate (HgPrDtc) with a [AuCl4]−/2 M HCl solution results in the formation of the ionic complex [Au(PrDtc)2]2[Hg2Cl6] (3). There are two inequivalent centrosymmetric cations, [Au(PrDtc)2]+ (‘A’ and ‘B’), and a binuclear centrosymmetric anion, [Hg2Cl6]2− in the structure of 3. In the cationic part of the complex, each of the gold(III) cations has two pairs of the relatively weak inequivalent secondary Au···S bonds with two neighbours, therefore forming linear supramolecular cationic chains (⋯‘A’⋯‘B’⋯‘A’⋯‘B’⋯)n. To study the thermal behaviour of the compounds, simultaneous thermal analysis was also performed. The formation of HgS and reduced elemental gold was established during the thermolysis of 1/2 and 3, respectively.

  • 3.
    Zaeva, Anna S.
    et al.
    Institute of Geology and Nature Management, Far Eastern Branch of the Russian Academy of Sciences,Blagoveschensk, Amur Region, Russia.
    Ivanov, Maxim A.
    Institute of Geology and Nature Management, Far Eastern Branch of the Russian Academy of Sciences,Blagoveschensk, Amur Region, Russia.
    Gerasimenko, Andrey V.
    Institute of Chemistry, Far Eastern Branch of the Russian Academy of Sciences,Vladivostok, Russia.
    Ivanov, Alexander V.
    Institute of Geology and Nature Management, Far Eastern Branch of the Russian Academy of Sciences, Blagoveschensk, Amur Region, Russia.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering. Department of Physics, Warwick University, Coventry, UK.
    Dialkyldithiocarbamate platinum(II) complexes of [Pt(S2CNR2)2] (R = iso-C3H7iso-C4H9): Preparation, 13C CP-MAS NMR, molecular structure, supramolecular self-assembly and thermal behaviour2020In: Polyhedron, ISSN 0277-5387, E-ISSN 1873-3719, Vol. 175, article id 114166Article in journal (Refereed)
    Abstract [en]

    Two new dialkyldithiocarbamato platinum(II) complexes of [Pt(S2CNR)2], R = iso-C3H7 (1) and iso-C4H9 (2), have been prepared and characterised using 13C CP-MAS NMR. The crystal and molecular structures of the isolated compounds were established by single-crystal X-ray diffraction. The unit cell of 1 contains four centrosymmetric discrete molecules of [Pt{S2CN(iso-C3H7)2}2], of which the pairs are structurally inequivalent to each other (hereafter denoted as molecules 1a and 1b). At the supramolecular level, due to numerous intermolecular C–H···S hydrogen bonds, the 1a molecules form linear polymeric ribbons, whose interaction with the 1b molecules results in a two-dimensional polymeric network. In the structure of 2, the construction of supramolecular zigzag chains by non-centrosymmetric molecules of [Pt{S2CN(iso-C4H9)2}2] is determined by intermolecular C–H···Pt anagostic interactions. The thermal behaviour of crystalline compounds 1 and 2 was studied by simultaneous thermal analysis (STA), a combination of the TG and DSC techniques, under an argon atmosphere. In both cases, platinum(II) sulphide (PtS) was identified as the main end-product upon thermal decomposition of the complexes at 600 °C.

  • 4.
    Filippov, Andrei
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Bulat, Munavirov
    System and Component Design, KTH Royal Institute of Technology, Stockholm, Sweden.
    Sergei, Glavatskih
    System and Component Design, KTH Royal Institute of Technology, Stockholm, Sweden. Department of Electromechanical, Systems and Metal Engineering, Ghent University, Ghent, Belgium. School of Chemistry, University of New South Wales, Sydney, Australia.
    Shah, Faiz Ullah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering. Department of Physics, Warwick University, Coventry, United Kingdom.
    Diffusion of Ions in Phosphonium Orthoborate Ionic Liquids Studied by 1H and 11B Pulsed Field Gradient NMR2020In: Frontiers in Chemistry, E-ISSN 2296-2646, Vol. 8, article id 119Article in journal (Refereed)
    Abstract [en]

    Non-halogenated boron-based ionic liquids (ILs) composed of phosphonium cations and chelated orthoborate anions have high hydrolytic stability, low melting point and exceptional properties for various applications. This study is focused on ILs with the same type of cation, trihexyltetradecylphosphonium ([P6,6,6,14]+), and two orthoborate anions, such as bis(salicylato)borate ([BScB]−) and bis(oxalato)borate ([BOB]−). We compare the results of this study with our previous studies on ILs with bis(mandelato)borate ([BMB]−) and a variety of different cations (tetraalkylphosphonium, dialkylpyrrolidinium and dialkylimidazolium). The ion dynamics and phase behavior of these ILs is studied using 1H and 11B pulsed-field-gradient (PFG) NMR. PFG NMR is demonstrated to be a useful tool to elucidate the dynamics of ions in this class of phosphonium orthoborate ILs. In particular, the applicability of 11B PFG NMR for studying anions without 1H, such as [BOB]−, and the limitations of this technique to measure self-diffusion of ions in ILs are demonstrated and discussed in detail for the first time.

  • 5.
    Mushtaq, Irrum
    et al.
    Department of Chemistry, Quaid-i-Azam University, Islamabad, Pakistan.
    Mushtaq, Iram
    Department of Biochemistry, Quaid-i-Azam University, Islamabad, Pakistan.
    Akhter, Zareen
    Department of Chemistry, Quaid-i-Azam University, Islamabad, Pakistan.
    Murtaza, Iram
    Department of Biochemistry, Quaid-i-Azam University, Islamabad, Pakistan.
    Qamar, Samina
    Department of Chemistry, Quaid-i-Azam University, Islamabad, Pakistan.
    Ayub, Sidra
    Department of Biochemistry, Quaid-i-Azam University, Islamabad, Pakistan.
    Mirza, Bushra
    Department of Biochemistry, Quaid-i-Azam University, Islamabad, Pakistan.
    Butt, Tehmeena Maryum
    Department of Chemistry, Quaid-i-Azam University, Islamabad, Pakistan.
    Janjua, Naveed Kausar
    Department of Chemistry, Quaid-i-Azam University, Islamabad, Pakistan.
    Shah, Faiz Ullah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Zaman, Farasat
    Department of Women's and Children's Health, Karolinska Institutet and Pediatric Endocrinology Unit, Karolinska University Hospital, Solna, Sweden.
    Engineering electroactive and biocompatible tetra(aniline)-based terpolymers with tunable intrinsic antioxidant properties in vivo2020In: Materials science & engineering. C, biomimetic materials, sensors and systems, ISSN 0928-4931, E-ISSN 1873-0191, Vol. 108, article id 110456Article in journal (Refereed)
    Abstract [en]

    Under different pathological conditions, high levels of reactive oxygen species (ROS) cause substantial damage to multiple organs. To counter these ROS levels in multiple organs, we have engineered highly potent novel terpolymers. We found that combination of FDA-approved polyethylene glycol, fumaric acid moieties and electroactive tetra(aniline) by varying the content of tetra(aniline) results into a novel drug composition with biologically active tunable intrinsic antioxidant properties. To test tunable intrinsic antioxidative properties of these engineered novel terpolymers, we used alloxan to induce diabetes in rats where ROS generation is known to be higher. The systemic administration of terpolymers to the diabetic rats showed strong electroactive antioxidant behavior which normalized ROS levels, enzymatic antioxidants including superoxide dismutase, catalase, but also reduced glutathione. As a proof-of-principle, we here show TANI based novel drug composition of terpolymers with tunable intrinsic antioxidant effects confirmed in multiple organs.

  • 6.
    Shaikhullina, Milyausha
    et al.
    Institute of Physics, Kazan Federal University, 420008 Kazan, Russia.
    Khaliullina, Aliya
    Institute of Physics, Kazan Federal University, 420008 Kazan, Russia. Medical and Biological Physics, Kazan Medical University, 420012 Kazan, Russia.
    Gimatdinov, Rustam
    Medical and Biological Physics, Kazan Medical University, 420012 Kazan, Russia.
    Butakov, Anatoly
    Radiophysics and Electronics, Chelyabinsk State University, Chelyabinsk 454001, Russia.
    Chernov, Vladimir
    Radiophysics and Electronics, Chelyabinsk State University, Chelyabinsk 454001, Russia.
    Filippov, Andrei
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering. Medical and Biological Physics, Kazan Medical University, 420012 Kazan, Russia.
    NMR relaxation and self-diffusion in aqueous micellar gels of pluronic F-1272020In: Journal of Molecular Liquids, ISSN 0167-7322, E-ISSN 1873-3166, Vol. 306, article id 112898Article in journal (Refereed)
    Abstract [en]

    We studied the transverse NMR relaxation of protons of different chemical groups and diffusion of molecules in an aqueous pluronic F-127 system. The system was studied at concentrations of 15, 21 and 28 wt% and in the temperature range of 293–333 K. The dynamic peculiarities in different phases were analyzed based on the NMR relaxation and diffusion data. Our study demonstrated a correlation between phase states, T2 relaxation times of “solid-like” and “liquid” protons of selected chemical groups of polypropylene oxide (PPO) and polyethylene oxide (PEO) blocks, and diffusion coefficients. Transverse NMR relaxation established that the presence of a “solid-like” component of CH3 protons of PEO blocks is observed only at temperatures and concentrations corresponding to the rigid-gel phase, due to entanglements between micellar coronas. At all temperatures and concentrations, some CH3 protons of PPO blocks and some CH2 protons of PEO blocks show “liquid-like” transverse NMR relaxation. Under the conditions corresponding to formation of the rigid-gel phase of the pluronic, relaxation of the “liquid-like” protons additionally accelerates due to entanglements of micellar coronas. Transition of the system to the rigid-gel phase is accompanied by decrease of diffusion coefficients by a factor of 10–104 relative to the diffusivity of free-moving pluronic micelles in the sol phase. Diffusion measurements show that there are pre-transition phenomena, which are characteristic for temperatures and concentrations near sol-gel phase boundaries.

  • 7.
    Kanwal, Sehrish
    et al.
    Department of Chemistry, Quaid-i-Azam University, Islamabad, Pakistan.
    Ali, Naveed Zafar
    Federal Institute for Materials Research and Testing (BAM), Richard-Will, Berlin, Germany. National Center for Physics, Quaid-i-Azam University Campus, Islamabad, Pakistan.
    Hussain, Rizwan
    National Center for Physics, Quaid-i-Azam University Campus, Islamabad, Pakistan. Laboratory of Advance Materials & Processing (LAMP), University of Maryland, USA.
    Shah, Faiz Ullah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Akhter, Zareen
    Department of Chemistry, Quaid-i-Azam University, Islamabad, Pakistan.
    Poly-thiourea formaldehyde based anticorrosion marine coatings on Type 304 stainless steel2020In: Journal of Materials Research and Technology, ISSN 2238-7854Article in journal (Refereed)
    Abstract [en]

    In the present study, hexamethylene diisocyanate (HMDI) encapsulated poly-thiourea formaldehyde (PTF) (10 wt%) coating was developed in an epoxy-polyamine matrix and their anticorrosion studies on Type SS304 stainless steel substrate have been conducted using electrochemistry techniques. The compact and hydrophobic shell wall of PTF proved to be a potent shell wall material for HMDI encapsulation. The effect of temperature and pH values was found to be decisive factor in the synthesis of microcapsules. The PTF microcapsules were synthesized in acidic condition with a pH value of 3. Over 90% of the core fraction is retained in water after 21 days immersion. However, core content decreased with increasing temperature. The capsules were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy(SEM), thermogravimetric analysis (TGA) and Electrochemical Impedance spectroscopy (EIS). Scanning electron microscopic analysis depicts the uniform morphology of coating with a particle size in the range of 1.08 μm–22.06 μm. The vibrational band at 2271 cm−1 attributed to NCO signal further endorses the successful encapsulation of HMDI into the PTF capsules. Electrochemical testing on steel specifies the appreciable anticorrosion performance of the synthesized poly thiourea formaldehyde (PTF) coating against artificial sea water.

  • 8.
    Fan, Pengpeng
    et al.
    Herbert Gleiter Institute of Nanoscience, Department of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing, P. R. China.
    Qiu, Xiuhua
    Herbert Gleiter Institute of Nanoscience, Department of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing, P. R. China.
    Shah, Faiz Ullah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Ji, Qingmin
    Herbert Gleiter Institute of Nanoscience, Department of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing, P. R. China.
    An, Rong
    Herbert Gleiter Institute of Nanoscience, Department of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing, P. R. China. Center for Nanotechnology (CeNTech), Institute of Physics, Westfälische Wilhelms-Universität Münster, Münster, Germany.
    The effect of nanoscale friction of mesoporous carbon supported ionic liquids on the mass transfer of CO2 adsorption2020In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 22, no 3, p. 1097-1106Article in journal (Refereed)
    Abstract [en]

    Supported ionic liquids (ILs) are attractive alternatives for CO2 capture and the thickness of supported IL films plays a critical role in the CO2 mass transfer rate. However, the dependence of CO2 uptake on the IL film thickness differs as the system varies. In this work, atomic force microscopy (AFM) is employed to probe the ‘nanofriction coefficient’ to characterize the mobility of ILs at the solid interface, in which, the smaller the nanofriction coefficient, the faster are the ionic mobility and CO2 mass transfer. A monotonic and almost linear relationship for supported IL films is obtained between the resistance of CO2 mass transfer (1/k) and the nanofriction coefficient (μ), avoiding the controversy over the effect of supported IL film thickness on CO2 adsorption. The enhanced mass transfer of CO2 adsorption at IL-solid interfaces is observed at smaller resistance 1/k and friction coefficient μ. The low-friction driven local mobility (diffusion) of ILs at solid interfaces is enhanced, promoting the exchange mixing of the ILs adsorbing CO2 with the ‘blank-clean’ ions of the ILs, and thus accelerating the CO2 mass transfer. The proposed correlation links the nanoscale friction with the mass transfer of CO2 adsorption, providing a fresh view on the design of ultra-low frictional supported ILs for enhanced CO2 capture and separation processes.

  • 9.
    Filippov, Andrei
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering. Kazan State Medical University, Kazan, Russia.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering. Department of Physics, Warwick University, Coventry, U.K.
    Shah, Faiz Ullah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Understanding the Interaction of Boric Acid and CO2 with Ionic Liquids in Aqueous Medium by Multinuclear NMR Spectroscopy2020In: ACS Sustainable Chemistry & Engineering, E-ISSN 2168-0485, Vol. 8, no 1, p. 552-560Article in journal (Refereed)
    Abstract [en]

    Boric acid is known to enhance the kinetics of CO2 absorption by some active aqueous solutions. However, the mechanism of interaction of boric acid with CO2 in the presence of active molecules is not yet fully understood. In this work, the interaction and dynamics of ions in aqueous solutions of functionalized choline-based ionic liquids [N1,1,5,2OH][Threo] and [N1,1,5,2OH][Tau] in the presence of boric acid and CO2 was thoroughly investigated using a multinuclear NMR approach: 13C and 11B NMR spectroscopy, 11B NMR transverse relaxation, and 1H and 11B NMR diffusometry. 13C and 11B NMR spectroscopy revealed the formation of borate-based complexes as a result of a reaction between boric acid and the anions of the ILs at ionic liquid/boric acid molar ratios larger than ca. 0.15. The formation of these complexes and their dynamics were further investigated using 11B relaxation and 1H and 11B pulse-field-gradient (PFG) NMR. Plausible reaction mechanisms of boric acid with the anions of the ILs, formation of the borate complexes, and dissociation of these complexes facilitated by CO2 molecules are suggested.

  • 10.
    Korneeva, E.V.
    et al.
    Institute of Geology and Nature Management, Far-Eastern Branch of the Russian Academy of Sciences, Blagoveschensk, Russian Federation.
    Smolentsev, A. I.
    Nikolaev Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russian Federation. Novosibirsk State University, Novosibirsk, Russian Federation.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering. University of Warwick, Coventry, United Kingdom.
    Ivanov, A. V.
    Institute of Geology and Nature Management, Far-Eastern Branch of the Russian Academy of Sciences, Blagoveschensk, Russian Federation.
    Binding of gold(iii) with silver(i) dipropyldithiocarbamate: supramolecular self-assembly (role of secondary Au…S and Ag…S bonds) and thermal behavior of the ionic-polymer complex ([Au(S2CNPr2)2][AgCl2])n2019In: Russian chemical bulletin, ISSN 1066-5285, E-ISSN 1573-9171, Vol. 68, no 1, p. 40-47Article in journal (Refereed)
    Abstract [en]

    The double ionic-polymer complex ([Au(S2CNPr2)2][AgCl2])n (1) was prepared as an individual fixation form of gold(III) from NaCl solutions with silver(I) dipropyldithiocarbamate and was characterized by single-crystal X-ray diffraction and 13C magic-angle spinning (MAS) NMR spectroscopy. The structure of 1 comprises two nonequivalent centrosymmetric complex cations [Au(S2CNPr2)2]+ (A and B) and the discrete linear anion [AgCl2]. Gold(III) cations are linked by pairs of unsymmetrical secondary Au…S bonds to form linear supramolecular chains (…A…B…)n. Neighboring cations are additionally linked by [AgCl2] anions via secondary Ag…S and Cl…S bonds, the anions being involved in the overall stabilization of the supramolecular structure. The cation–anion interactions lead to a distortion of the linear configuration of the [AgCl2] anion. The character of thermolysis of 1 accompanied by quantitative regeneration of bound Au and Ag was established by simultaneous thermal analysis.

  • 11.
    Filippov, Andrei
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering. Institute of Physics, Kazan Federal University, Russia.
    Bhattacharyya, Shubhankar
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Shah, Faiz Ullah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    CO2 absorption and ion mobility in aqueous choline-based ionic liquids2019In: Journal of Molecular Liquids, ISSN 0167-7322, E-ISSN 1873-3166, Vol. 276, p. 748-752Article in journal (Refereed)
    Abstract [en]

    CO2 absorption and ion mobility are investigated in a series of 50/50 wt% aqueous solutions of choline-based ionic liquids with different cations and anions: [N1,1,4,2OH][Threo], [N1,1,5,2OH][Threo], [N1,1,6,2OH][Threo], [N1,1,5,2OH][β-ala] and [N1,1,5,2OH][Tau]. The process of CO2 absorption was completed in an hour reaching maximum of absorption capacity 0.07–0.10 wt% to ionic liquid (by 0.4–0.6 molar ratios). A rapid CO2 absorption is observed by the formation of solid product as a result of reaction between CO2 molecule and the ionic liquid. Diffusion coefficients of the cation and anion in the mixture are comparable while the diffusivity of water molecules is found to be quite different from the ions. In the process of CO2 absorption, an increase in the diffusivity of ions is observed due to the precipitation of solid products and depletion of ions contents in the liquid phase of the system. 13C NMR measurements of diffusivity of CO2 enriched with 13C isotope showed that a part of the absorbed CO2 remained in the liquid phase being physically and chemically bound to ions. The ionic liquid is re-cycled by evaporating water and releasing CO2 molecules using vacuum and temperature.

  • 12.
    Trublet, Mylene
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Scukins, Edvards
    Aeronautics, Department of Flight Data and Navigation, SAAB, Linköping, Sweden.
    Carabante, Ivan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Rusanova-Naydenova, Daniela
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Competitive Sorption of Metal Ions on Titanium Phosphate Sorbent(TiP1) in Fixed-Bed Columns: A Closed-Mine Waters Study2019In: ACS Sustainable Chemistry & Engineering, ISSN 2168-0485, Vol. 7, no 9, p. 8145-8154Article in journal (Refereed)
    Abstract [en]

    Sorptionfixed-bed column experiments were performed using atitanium phosphate ion-exchanger composed of−H2PO4units [TiO(OH)(H2PO4)·H2O]. Model mine water containingfive divalent metal ions (Cu2+,Zn2+,Mn2+,Ni2+,and Co2+) and a few closed-mine water samples were treated to evaluate the sorptionpreference of the material. For thefirst time, dynamic ion-exchange capacities(estimated to be between 3.2 and 4.2 mequiv g−1) and static ion-exchange uptakes(calculated to be between 3.1 and 3.5 mequiv g−1) were obtained for the same TiP1sorbent and data were discussed in terms of sorption behavior. It was found thatsorption processes on TiP1 in model and closed-mine waters during a columnexperiment could be accurately predicted from the corresponding batch experiment(including the sorbent’s capacities in different types of waters). A competitivesorption phenomenon in favor of Cu2+on TiP1 was established for all cases, pointingtoward the possibility of isolating pure copper concentrate from closed-mine waters.The relatively high amounts of calcium and magnesium ions present in mine waters did not appear to considerably affect theselectivity of TiP1 material. Exploratory experiments for sorbent regeneration and desorption using a low concentration of nitricacid were demonstrated.

  • 13.
    Arkhipov, Viktor P.
    et al.
    Kazan National Research Technological University, Kazan, Russia.
    Arkhipov, Ruslan V.
    Kazan Federal University, Kazan, Russia.
    Idiyatullin, Zamil Sh.
    Kazan National Research Technological University, Kazan, Russia.
    Filippov, Andrei
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Dynamic and structural properties, cloud point of mixed micelles of oxyethylated isononylphenols2019In: Journal of Dispersion Science and Technology, ISSN 0193-2691, E-ISSN 1532-2351Article in journal (Refereed)
    Abstract [en]

    We measured the self-diffusion coefficients of mixed micelles formed in binary mixtures of oxyethylated isononylphenols (neonols) AF9-2,3,4,6,8,9,10,12 by NMR diffusometry in aqueous 1 wt% solutions. The effective hydrodynamic radii of the micelles were calculated using the Stokes-Einstein relation. Cloud points of these solutions were determined visually and the relation between the cloud point and the composition of the mixture was suggested. Extraction of phenol from the solutions at their cloud points was also studied.

  • 14.
    Kotenkov, Sergey A.
    et al.
    Institute of Physics, Kazan Federal University, Kazan, Russia.
    Gnezdilov, Oleg I.
    Institute of Physics, Kazan Federal University, Kazan, Russia.
    Khaliullina, Aliya V.
    Institute of Physics, Kazan Federal University, Kazan, Russia;Kazan State Medical University, Kazan, Russia.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Gimatdinov, Roustam S.
    Kazan State Medical University, Kazan, Russia.
    Filippov, Andrei
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering. Institute of Physics, Kazan Federal University, Kazan, Russia.
    Effect of Cholesterol and Curcumin on Ordering of DMPC Bilayers2019In: Applied Magnetic Resonance, ISSN 0937-9347, E-ISSN 1613-7507, Vol. 50, no 1-3, p. 511-520Article in journal (Refereed)
    Abstract [en]

    In this work, we compared the effects of curcumin and cholesterol directly competing to insert into the DMPC lipid bilayer during bilayer formation from an initially non-ordered state. 2H and 14N nuclear magnetic resonance spectroscopy showed that curcumin is not embedded deep in the lipid bilayer and interacts mainly with the head group of the lipid. In a more complex system of DMPC/CHOL/CUR, curcumin amplifies the effect of cholesterol on the ordering of lipid acyl chains.

  • 15.
    Nazir, Uzma
    et al.
    Department of Chemistry, Quaid-i-Azam University, Islamabad, Pakistan.
    Akhter, Zareen
    Department of Chemistry, Quaid-i-Azam University, Islamabad, Pakistan.
    Naveed Zafar, Ali
    National Center for Physics, Quaid-i-Azam University Campus, Islamabad, Pakistan.
    Shah, Faiz Ullah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Experimental and theoretical insights into the corrosion inhibition activity of novel Schiff bases for aluminum alloy in acidic medium2019In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 9, no 62, p. 36455-36470Article in journal (Refereed)
    Abstract [en]

    Three novel Schiff bases, namely N-(4-((4-((phenylimino)methyl)phenoxy)methoxy)benzylidene)benzenamine (UA), N-(3-methoxy-4-((2-methoxy-4-((phenylimino)methyl)phenoxy)methoxy)benzylidene)benzenamine (UB), and N-(3-ethyl-4-((2-ethyl-4-((phenylimino)methyl)phenoxy)methoxy)benzylidene)benzenamine (UC), were synthesized and their structures were elucidated through diverse spectroscopic techniques such as FT-IR, GC-MS, 1H NMR and 13C NMR. The corrosion inhibition effect of these Schiff bases on aluminum alloy AA2219-T6 in acidic medium was explored using weight loss, Tafel polarization, and electrochemical impedance spectroscopy. Theoretical quantum chemical calculations using density functional theory were employed to determine the adsorption site. It was found that inhibition efficiencies increase with an increase in the inhibitor concentration. Tafel plots showed that these Schiff bases function as mixed inhibitors. Adsorption of the Schiff bases on aluminum followed the Langmuir adsorption isotherm and the value of  showed a dominant chemical mechanism. FT-IR and SEM techniques were used to investigate the surface morphology. The compounds showed a substantial corrosion inhibition for aluminum alloy in 0.1 M HCl at 298 K. UB and UC exhibited superior anticorrosion efficiency compared to UA originating from the electron-donating methoxy and ethoxy group substitutions, respectively. There was found to be good correlation between molecular structure and inhibition efficiencies.

  • 16.
    Barai, Manas
    et al.
    Department of Chemistry and Chemical Technology, Vidyasagar University, Midnapore, West Bengal, India.
    Mandal, Manas Kumar
    Department of Chemistry and Chemical Technology, Vidyasagar University, Midnapore, West Bengal, India.
    Karak, Atanu
    Department of Chemistry and Chemical Technology, Vidyasagar University, Midnapore, West Bengal, India.
    Bordes, Romain
    Chemistry and Chemical Engineering, Applied Surface Chemistry, Chalmers University of Technology, Gothenburg, Sweden.
    Patra, Anuttam
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Dalai, Sudipta
    Department of Chemistry and Chemical Technology, Vidyasagar University, Midnapore, West Bengal, India.
    Panda, Amiya Kumar
    Department of Chemistry and Chemical Technology, Vidyasagar University, Midnapore, West Bengal, India.
    Interfacial and Aggregation Behavior of Dicarboxylic Amino Acid-Based Surfactants in Combination with a Cationic Surfactant2019In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 35, no 47, p. 15306-15314Article in journal (Refereed)
    Abstract [en]

    The interfacial and micellization behavior of three dicarboxylic amino acid-based anionic surfactants, abbreviated as AAS (N-dodecyl derivative of -aminomalonate, -aspartate, and -glutamate) in combination with hexadecyltrimethylammonium bromide (HTAB) were investigated by surface tension, conductance, UV–vis absorption/emission spectroscopy, dynamic light scattering (DLS), and viscosity studies. Critical micelle concentration (CMC) values of the surfactant mixtures are significantly lower than the predicted values, indicating associative interaction between the components. Surface excess, limiting molecular area, surface pressure at the CMC, and Gibbs free energy indicate spontaneity of the micellization processes compared to the pure components. CMC values were also determined from the sigmoidal variation in the plot of micellar polarity and pyrene UV–vis absorption/emission intensities with surfactant concentration. The aggregation number, determined by static fluorescence quenching method, increases with decreasing mole fraction of the AAS (αAAS), where the micelles are mainly dominated by the HTAB molecules. The size of the micelle increases with decreasing αAAS, leading to the formation of larger and complex aggregates, as also supported by the viscosity studies. Micelles comprising 20–40 mol % AAS are highly viscous, in consonance with their sizes. Some of the mixed surfactant systems show unusual viscosity (shear thickening and increased viscosity with increasing temperature). Such mixed surfactant systems are considered to have potential in gel-based drug delivery and nanoparticle synthesis.

  • 17.
    Srivastava, Karnica
    et al.
    Physics Department, University of Lucknow, Lucknow, India.
    Shukla, Anuradha
    Physics Department, University of Lucknow, Lucknow, India.
    Karthick, T.
    Physics Department, University of Lucknow, Lucknow, India;Institute of Organic Chemistry and Biochemistry, Academy of Sciences, Prague, Czech Republic.
    Velaga, Sitaram
    Luleå University of Technology, Department of Health Sciences, Medical Science.
    Tandon, Poonam
    Physics Department, University of Lucknow, Lucknow, India.
    Sinha, Kirti
    Physics Department, University of Lucknow, Lucknow, India.
    Shimpi, Manishkumar R.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Molecular structure, spectroscopic signature and reactivity analyses of paracetamol hydrochloride monohydrate salt using density functional theory calculations2019In: CrystEngComm, ISSN 1466-8033, E-ISSN 1466-8033, Vol. 21, no 5, p. 857-865Article in journal (Refereed)
    Abstract [en]

    The aim of this study was to understand the role of the intermolecular hydrogen bond interactions present in paracetamol hydrochloride monohydrated salt. Paracetamol hydrochloride monohydrate salt (PRA-HCl) and paracetamol (form I) were investigated via vibrational (FT-IR and FT-Raman) spectroscopy and density functional theory (DFT) to gain insight into the hydrogen bond patterns present in these crystalline materials. Two different density functionals, wB97X-D and M062X, were used for the comparison of the results. The geometrical parameters of PRA-HCl and form I obtained using these functional were compared with the crystallographic data, which proved the existence of intra-molecular and intermolecular hydrogen bonds. The C10O2 group of form I forms an intramolecular hydrogen bond, while the O1–H18 group of PRA-HCl forms an intermolecular hydrogen bond with a chloride ion (Cl), resulting in the elongation of the bond length and shift to a lower wavenumber for the O1–H18 group. To examine the potency of hydrogen bonding, quantum theory of atoms in molecules (QTAIM) calculations were performed and the results suggested that O1–H18⋯Cl22 is a strong intermolecular hydrogen bond. The chemical reactivity parameters reveal that the PRA-HCl and PRA-OXA cocrystals are more reactive and softer (low HOMO–LUMO energy gap) in comparison to paracetamol (form I).

  • 18.
    Rohlmann, Patrick
    et al.
    KTH Royal Institute of Technology, Stockholm, Sweden.
    Munavirov, Bulat
    KTH Royal Institute of Technology, Stockholm, Sweden.
    Furó, István
    KTH Royal Institute of Technology, Stockholm, Sweden.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Rutland, Mark William
    KTH Royal Institute of Technology, Stockholm, Sweden. Surfaces, Processes and Formulation, RISE Research Institutes of Sweden, Stockholm, Sweden.
    Glavatskih, Sergei
    KTH Royal Institute of Technology, Stockholm, Sweden. Department of Electrical Energy, Metals, Mechanical Constructions and Systems, Ghent University, Ghent, Belgium.
    Non-halogenated Ionic Liquid Dramatically Enhances Tribological Performance of Biodegradable Oils2019In: Frontiers in Chemistry, E-ISSN 2296-2646, Vol. 7, article id 98Article in journal (Refereed)
    Abstract [en]

    It is demonstrated that a phosphonium orthoborate ionic liquid may serve as a wear reducing additive in biodegradable oils at steel-steel surfaces in the boundary lubrication regime. Tribological tests were performed in a ball-on-three plate configuration. A set of surface characterization techniques—SEM/EDS, FIB and white light interferometry were used to characterize surfaces following the tribotests and to observe the formation of any tribofilms. 11B NMR was used to follow changes in the composition of the ionic-liquid-oil blends and to identify boron-containing decomposition products after the tribotests. The ionic liquid reduces the wear of steel surfaces by up to 92% compared to the neat oil at 90°C; it is shown that the reduction in wear can be correlated with the formation of boron enriched patches in the boundary films.

  • 19.
    An, Rong
    et al.
    Herbert Gleiter Institute of Nanoscience, Department of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing, P.R. China. Center for Nanotechnology (CeNTech), Institute of Physics, Westfälische Wilhelms, Universität Münster, Münster, Germany .
    Wu, Muqiu
    Herbert Gleiter Institute of Nanoscience, Department of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing, P.R. China.
    Li, Jing
    State Key Laboratory of Materials Oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University, Nanjing, P.R. China.
    Qiu, Xiuhua
    Herbert Gleiter Institute of Nanoscience, Department of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing, P.R. China.
    Shah, Faiz Ullah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Li, Jianliang
    Department of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing, P.R. China.
    On the Ionic Liquid Film ‘Pinned’ by Core-Shell Structured Fe3O4@Carbon Nanoparticles and Their Tribological Properties2019In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 21, no 48, p. 26387-26398Article in journal (Refereed)
    Abstract [en]

    A strongly ‘pinned’ ionic liquid (IL, [BMIM][PF6]) film onto silicon (Si) surface via carbon capsuled Fe3O4 core-shell (Fe3O4@C) nanoparticles is achieved, revealing excellent friction-reducing ability at a high load. The adhesion force is measured as ~ 198 nN at the Fe3O4@C-Si interface by Fe3O4@C colloidal AFM tip, which is stronger than that at both Fe3O4@C-Fe3O4@C (~ 60 nN) and IL-Si (~ 10 nN) interfaces, indicating a strong ‘normal pin-force’ towards the Si substrate. The resulting strengthened force enables the formation of lateral IL networks via the dipole-dipole attractions among Fe3O4 cores. The observed blue shift of the characteristic band related to the IL anion in ATR-FTIR spectra confirmed the enhanced interaction. The N-Si, P-O chemical bonds formed as a result of the IL interactions with the Si substrate confirmed by XPS spectroscopy suggested that the IL lay on the Si plane. This orientation is favorable for Fe3O4@C nanoparticles to exert ‘normal pin-force’ and press the IL film strongly onto surfaces. The IL ios/clusters are thus anchored by these Fe3O4@C ‘pins’ onto the substrate to form a dense film, resulting in a smaller interaction size parameter, which is responsible for the reduced friction coefficient μ.

  • 20.
    Arkhipov, Victor P.
    et al.
    Department of Physics, Kazan National Research Technological University, Kazan, Russian Federation.
    Arkhipov, Ruslan V.
    Institute of Physics, Kazan Federal University, Kazan, Russian Federation.
    Kuzina, Natalia A.
    Department of Physics, Kazan National Research Technological University, Kazan, Russian Federation.
    Filippov, Andrei
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering. Kazan State Medical University, Kazan, Russian Federation.
    Oxyethylated Isononylphenols in Carbon Tetrachloride2019In: Applied Magnetic Resonance, ISSN 0937-9347, E-ISSN 1613-7507, Vol. 50, no 12, p. 1381-1389Article in journal (Refereed)
    Abstract [en]

    Translational diffusion coefficients of ethoxylated isononylphenol molecules C9H19C6H4O(C2H4O)nH in carbon tetrachloride were measured by nuclear magnetic resonance diffusometry. The hydrodynamic radii of the molecules were determined within the framework of the Stokes–Einstein relation. We showed that ethoxylated isononylphenols in carbon tetrachloride do not form micelles, and the dependence of the diffusion coefficients and, accordingly, the hydrodynamic radii of the nonionic surfactants on the number of oxyethylene groups have a kink in the region n = 6–8.

  • 21.
    Butakov, Anatoly
    et al.
    Radiophysics and Electronics, Chelyabinsk State University, Chelyabinsk, Russian Federation.
    Filippov, Andrei
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering. Institute of Physics, Kazan Federal University, Kazan, Russian Federation.
    Gimatdinov, Roustam
    Medical and Biological Physics, Kazan Medical University, Kazan, Russian Federation.
    Chernov, Vladimir
    Radiophysics and Electronics, Chelyabinsk State University, Chelyabinsk, Russian Federation.
    Peculiarities of NMR relaxation in micellar gels of Pluronic F-1272019In: Journal of Dispersion Science and Technology, ISSN 0193-2691, E-ISSN 1532-2351, Vol. 40, no 3, p. 403-407Article in journal (Refereed)
    Abstract [en]

    Based on the 1H relaxation of transverse nuclear magnetization of triblock-copolymer Pluronic F-127 in D2O, we proposed a model of the associated pluronic structure in which the polyethylene oxide of molecules in neighboring micelles are intertwined in regions of overlapping micellar coronas, while the polypropylene oxide cores of the micelles play a role of nodes in the 3D network. 

  • 22.
    Novikova, E. V.
    et al.
    Institute of Geology and Nature Management, Far East Branch, Russian Academy of Sciences, Blagoveshchensk, Russia.
    Ivanov, A. V.
    Institute of Geology and Nature Management, Far East Branch, Russian Academy of Sciences, Blagoveshchensk, Russia.
    Egorova, I. V.
    Blagoveshchensk State Pedagogical University, Blagoveshchensk, Russia.
    Troshina, R. S.
    Blagoveshchensk State Pedagogical University, Blagoveshchensk, Russia.
    Rodionova, N. A.
    Blagoveshchensk State Pedagogical University, Blagoveshchensk, Russia.
    Smolentsev, A. I.
    Nikolaev Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia. Novosibirsk State University, Novosibirsk, Russia.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering. University of Warwick, Coventry, United Kingdom.
    Principles of the Construction of Polymer Structures, Heteronuclear (13C, 15N) CP-MAS NMR, and Thermal Behavior of Heteroleptic Bismuth(III) Complexes of the General Composition [Bi(S2CNR2)2X] (X = NO3, Cl)2019In: Russian journal of coordination chemistry, ISSN 1070-3284, E-ISSN 1608-3318, Vol. 45, no 10, p. 695-705Article in journal (Refereed)
    Abstract [en]

    The crystalline heteroleptic bismuth(III) complexes, [Bi{S2CN(iso-C4H9)2}2(NO3)] (I) and [Bi{S2CN(C3H7)2}2Cl] (II), are isolated in preparative yields. Both compounds form 1D polymer structures and are characterized by X-ray diffraction analysis (CIF files CCDC nos. 1877115 (I) and 1876364 (II)) and (13C, 15N) CP-MAS NMR spectroscopy. The coordination mode of each of the dialkyldithiocarbamate ligands is S,S′-anisobidentately terminal. The inorganic anions performing the μ2-bridging function participate in the binding of the adjacent metallic atoms to form zigzag polymer chains. A new mode of bismuth(III) binding involving all oxygen atoms (O,O'-anisobidentate coordination to each adjacent bismuth atom) is found for the bridging nitrate groups in compound I. The bismuth atoms in the studied compounds are characterized by the eightfold [BiS4O4] (I) or sixfold [BiS4Cl2] (II) environment. The thermal behavior of the synthesized complexes is characterized by the data of simultaneous thermal analysis, using parallel recording of thermogravimetry and differential scanning calorimetry curves. In both cases, Bi2S3 is the only final product of the thermal transformations of compounds I and II.

  • 23.
    Khan, Zakir Zaman
    et al.
    Catalysis and Nanomaterials Lab 27, Department of Chemistry, Quaid-i-Azam University, Islamabad, Pakistan.
    Khan, Inayat Ali
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering. Catalysis and Nanomaterials Lab 27, Department of Chemistry, Quaid-i-Azam University, Islamabad, Pakistan.
    Khan, Ishtiaq
    Catalysis and Nanomaterials Lab 27, Department of Chemistry, Quaid-i-Azam University, Islamabad, Pakistan.
    Wattoo, Muhammad Hamid Sarwar
    Ishfaq Ahmad Research Laboratories Complex, R-Block, Pakistan Institute of Engineering and Applied Sciences (PIEAS), Islamabad, Pakistan.
    Badshah, Amin
    Catalysis and Nanomaterials Lab 27, Department of Chemistry, Quaid-i-Azam University, Islamabad, Pakistan.
    Pt and Co3O4 supported on ceria and zirconia for the catalytic reduction of N2O in the presence of CO2019In: Solid State Sciences, ISSN 1293-2558, E-ISSN 1873-3085, Vol. 98, article id 106035Article in journal (Refereed)
    Abstract [en]

    Ceria (CeO2) and zirconia (ZrO2) supported Pt and Co3O4-based nanocatalysts were synthesized and characterized by different instrumental techniques. The catalysts redox properties and active surface areas were evaluated using temperature-programmed reduction (TPR), temperature-programmed oxidation (TPO) and H2-pulse chemisorption, respectively. The catalysts were tested for the thermal oxidation of carbon monoxide (CO), reduction of nitrous oxide (N2O) and conversion of N2O/CO mixture (1:1 vol%) . In catalytic tests, Pt–Co3O4/CeO2 (10:10%) oxidized CO up to 100% at 25 °C and Co3O4/CeO2 (20%) reduced N2O up to 90% at 320 °C. Moreover, Pt–Co3O4/CeO2 (10:10%) converted N2O/CO mixture to N2/CO2 up to 90% at about 210 °C. The low-temperature catalytic activity of Pt–Co3O4/CeO2 (10:10%) for CO oxidation and N2O/CO mixture redox conversion were attributed to uniform particle size, metals and support proper combination and electron interaction.

  • 24.
    Filippov, Andrei
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering. Kazan State Medical University, Kazan, Russia.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering. Department of Physics, Warwick University, Coventry, UK.
    Shah, Faiz Ullah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Rapid carbene formation increasing ion diffusivity in an imidazolium acetate ionic liquid confined between polar glass plates2019In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 21, no 40, p. 22531-22538Article in journal (Refereed)
    Abstract [en]

    1-Ethyl-3-methyl-imidazolium acetate ([EMIM][OAc]) is one of the most widely used ionic liquids for various applications. This study is focussed on the chemical stability of [EMIM][OAc] on the surfaces of polar glass plates. 1H and 13C NMR spectroscopy and NMR diffusometry of [EMIM][OAc] IL confined between glass plates with a specific surface area 105–106 m−1 are thoroughly investigated. A rapid and spontaneous reaction took place on the surfaces of glass plates leading to the formation of neutral chemical moieties as evident by the appearance of new signals in the 1H NMR spectra. These new products are assigned as N-heterocyclic carbene (NHC) and acetic acid. These neutral chemical moieties have significantly increased the ion diffusivity by dissociation of the cation and the anion in [EMIM][OAc] IL. The yield and rate of formation of NHC and acetic acid are found to increase with the increasing surface area of polar glass plates and the time of contact between the IL and glass surfaces. Based on NMR spectroscopy, a dissociative reaction mechanism is proposed for the formation of free NHC in the neat [EMIM][OAc] IL.

  • 25.
    Filippov, Andrei
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering. Kazan State Medical University, Kazan, Russia.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering. Department of Physics, Warwick University, Coventry, UK.
    Shah, Faiz Ullah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Reactivity of CO2 with aqueous choline-based ionic liquids probed by solid-state NMR spectroscopy2019In: Journal of Molecular Liquids, ISSN 0167-7322, E-ISSN 1873-3166, Vol. 286, article id 110918Article in journal (Refereed)
    Abstract [en]

    CO2 absorption in a series of choline-based ionic liquids is investigated using solid-state 13C and 15N MAS NMR spectroscopy. Natural abundance and 13C enriched CO2 gas was purged through 50 wt% aqueous solutions of alkyldimethyl(2-hydroxyethyl)ammonium threonine, [N1,1,n,2OH][Threo], (alkyl = butyl, pentyl and hexyl) and pentyldimethyl(2-hydroxyethyl)ammonium taurine [N1,1,5,2OH][Tau]. The process of CO2 absorption results in precipitation of a solid sediment, which stays in equilibrium with the liquid phase. Upon degassing of the sample, the sediment is dissolved back into the IL-aqueous phase. Solid state 13C and 15N MAS NMR data suggest that the solid sediment is composed of neutral threonine (or taurine) in the zwitterionic forms and the liquid phase contained the products of reactions between the ionic liquids and CO2 molecules. A plausible mechanism for formation of the solid sediments and the reaction products in liquid phases is suggested.

  • 26.
    Patra, Anuttam
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Taner, Hasan Ali
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering. Department of Mining Engineering, Selcuk University Konya Turkey.
    Bordes, R.
    Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Göteborg.
    Holmberg, K.
    Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Göteborg.
    Larsson, Anna-Carin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Selective flotation of calcium minerals using double-headed collectors2019In: Journal of Dispersion Science and Technology, ISSN 0193-2691, E-ISSN 1532-2351, Vol. 40, no 8, p. 1205-1216Article in journal (Refereed)
    Abstract [en]

    A study was performed involving a series of double-headed carboxylate collectors with varying distance between the head groups (one, two or three carbon atoms). A collector with the same alkyl chain length but with only one carboxylate group was also included. All these were amino-acid based amphiphiles and the polar head group was connected to the hydrophobic tail via an amide linkage. Selective flotation recovery of different calcium minerals using these collectors was investigated. The double-headed collector with one carbon atom between the carboxylate groups was an apatite and fluorite specific reagent while the monocarboxylate surfactant showed high specificity for calcite. The flotation behavior of a simple conventional collector of the same alkyl chain length, a fatty acid salt, was also determined under identical flotation conditions in order to understand the effect of the amide group. Complementary experiments (ζ potential measurements, adsorption isotherm determinations) were also performed for these reagents. In order to shed light on the selectivity obtained with the dicarboxylate surfactants, the distances between the head groups were calculated and compared with the distances between neighboring calcium atoms on the surface of the minerals. It was found that the high degree of selectivity could be rationalized by perfect matching of these distances. To the best of our knowledge this is the first study where flotation selectivity in complex calcium mineral systems has been explained in terms of molecular recognition governing the interaction between the collector and the mineral surface.

  • 27.
    Filippov, Andrei
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering. Kazan State Medical University, Kazan, Russia.
    Gnezdilov, Oleg I.
    Kazan Federal University, Kazan, Russia. Zavoisky Physical-Technical Institute, FRC Kazan Scientific Center, Russian Academy of Sciences, Kazan, Russia.
    Luchkin, Alexander G.
    Kazan Federal University, Kazan, Russia.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Self-diffusion of ethylammonium nitrate ionic liquid confined between modified polar glasses2019In: Journal of Molecular Liquids, ISSN 0167-7322, E-ISSN 1873-3166, Vol. 284, p. 366-371Article in journal (Refereed)
    Abstract [en]

    Ethylammonium nitrate (EAN) ionic liquid confined between flat polar glass platesdemonstrates variable diffusivity that is sensitive to an external static magnetic field. Outside the magnetic field, diffusivity between the plates is higher than that in the bulk. However, after placing the system in a strong static magnetic field, the diffusivity gradually decreased. These processes occur during transformations between phases formed in EAN subjected to micrometer-size restrictions outside and within the magnetic field (Filippov et al., JMolLiq. [2018] 268, 49). In this study, we used samples of two types: (i) with roughened surface formed by treatment of the glass plates with aqueous solutions of hydrofluoric acid and (ii) with vacuum deposited TiO2 layers with a thickness of ca. 1 μm at glass-plate edges. Neither the surface modification of the glass plates, nor the TiO2 layers controlled thickness of EAN confined between glass-plates significantly changed the above-described effects, which have been observed in studies using untreated glass plates. Therefore, the range of systems with detected phase transformations in EAN and accompanying effects, such as accelerated diffusivity and change in diffusivity under the influence of a static magnetic field, was expanded to the systems with roughened surfaces and the systems with TiO2 layers controlled inter-plates distances. Results of experiments with roughened surfaces additionally suggested that the phase transformation of confined EAN in the external magnetic field is isotropic in nature rather than a phase transition from “layered to bulk” structures.

  • 28.
    Hafeez, Abdul
    et al.
    Department of Chemistry, Quaid-i-Azam University, Islamabad, Pakistan.
    Akhter, Zareen
    Department of Chemistry, Quaid-i-Azam University, Islamabad, Pakistan.
    Gallagher, John F.
    School of Chemical Sciences, Dublin City University, Glasnevin, Dublin, Ireland.
    Khan, Nawazish Ali
    Materials Science Laboratory, Department of Physics, Quaid-i-Azam University, Islamabad, Pakistan.
    Gul, Asghari
    Department of Chemistry, COMSATS University, Islamabad, Pakistan.
    Shah, Faiz Ullah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Synthesis, Crystal Structures, and Spectroscopic Characterization of Bis-aldehyde Monomers and Their Electrically Conductive Pristine Polyazomethines2019In: Polymers, ISSN 2073-4360, E-ISSN 2073-4360, Vol. 11, no 9, article id 1498Article in journal (Refereed)
    Abstract [en]

    Bis-aldehyde monomers 4-(4′-formyl-phenoxy)benzaldehyde (3a), 3-methoxy-4-(4′-formyl-phenoxy)benzaldehyde (3b), and 3-ethoxy-4-(4′-formyl-phenoxy)benzaldehyde (3c) were synthesized by etherification of 4-fluorobenzaldehyde (1) with 4-hydroxybenzaldehyde (2a), 3-methoxy-4-hydroxybenzaldehyde (2b), and 3-ethoxy-4-hydroxybenzaldehyde (2c), respectively. Each monomer was polymerized with p-phenylenediamine and 4,4′-diaminodiphenyl ether to yield six poly(azomethine)s. Single crystal X-ray diffraction structures of 3b and 3c were determined. The structural characterization of the monomers and poly(azomethine)s was performed by FT-IR and NMR spectroscopic techniques and elemental analysis. Physicochemical properties of polymers were investigated by powder X-ray diffraction, thermogravimetric analysis (TGA), viscometry, UV–vis, spectroscopy and photoluminescence. These polymers were subjected to electrical conductivity measurements by the four-probe method, and their conductivities were found to be in the range 4.0 × 10−5 to 6.4 × 10−5 Scm−1, which was significantly higher than the values reported so far.

  • 29.
    Loseva, O.V.
    et al.
    Institute of Geology and Nature Management, Far Eastern Branch of the Russian Academy of Sciences, Blagoveshchensk, Russian Federation.
    Rodina, T.A.
    Amur State University, Blagoveshchensk, Russian Federation.
    Ivanov, A.V.
    Institute of Geology and Nature Management, Far Eastern Branch of the Russian Academy of Sciences, Blagoveshchensk, Russian Federation.
    Smolentsev, A.I
    Nikolaev Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russian Federation. Novosibirsk State University, Novosibirsk, Russian Federation.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering. The University of Warwick, Coventry, UK.
    Tetranuclear heteroleptic mercury(ii) complexes of the composition [Hg4(S2CNPr2)6(NO3)2] and [Hg4(S2CNPr2)4Cl4]: structural organization, principles of construction of supramolecular polymeric chains, and thermal behavior2019In: Russian chemical bulletin, ISSN 1066-5285, E-ISSN 1573-9171, Vol. 68, no 4, p. 782-792Article in journal (Refereed)
    Abstract [en]

    New heteroleptic mercury(ii) complexes [Hg4(S2CNPr2)6(NO3)2] (1) and [Hg4(S2CNPr2)4Cl4] (2) were synthesized and characterized by single-crystal X-ray dif raction and 13C and 15N MAS NMR spectroscopy. In these complexes, the metal atoms are linked in pairs by bridging dipropyldithiocarbamate ligands (Pr2Dtc) to form tetranuclear cations and molecules. The further structural organization of compound 1 to the polymeric chains [Hg4(S2CNPr2)6(NO3)2]n occurs due to the linking of [Hg4(S2CNPr2)6]2+ cations by pairs of bridging nitrate groups. The formation of the supramolecular polymeric structure of 2 is determined by pairwise secondary Hg⋯Cl bonds between the cyclic [Hg4(S2CNPr2)4Cl4] molecules, in which the central eight-membered metallocycle [Hg4S4] adopts a distorted chair conformation. The thermal behavior of compounds 1 and 2 was studied by simultaneous thermal analysis.

  • 30.
    Mushtaq, Irrum
    et al.
    Department of Chemistry, Quaid-i-Azam University, Islamabad, Pakistan.
    Akhter, Zareen
    Department of Chemistry, Quaid-i-Azam University, Islamabad, Pakistan.
    Shah, Faiz Ullah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Tunable Self-Assembled Nanostructures of Electroactive PEGylated Tetra(Aniline) Based ABA Triblock Structures in Aqueous Medium2019In: Frontiers in Chemistry, E-ISSN 2296-2646, Vol. 7, p. 1-10, article id 518Article in journal (Refereed)
    Abstract [en]

    PEGylated tetra(aniline) ABA triblock structure PEG-TANI-PEG (2) consisting of tetra(aniline) (TANI) and polyethylene glycol (PEG) was synthesized by coupling the tosylated-PEG to boc-protected NH2/NH2 TANI (1) through a simple nucleophilic substitution reaction. Deprotection of 2 resulted in a leucoemeraldine base state of TANI (2-LEB), which was oxidized to stable emeraldine base (2-EB) state. 2-EB was doped with 1 M HCl to emeraldine salt (2-ES) state. FTIR, 1H and 13C NMR and UV-Vis-NIR spectroscopy, and MS (ESI) was used for structural characterization. The synthesized triblock structure exhibited good electroactivity as confirmed by CV and UV-Vis-NIR spectroscopy. Self-assembling of the triblock structure in aqueous medium was assessed by DLS, TEM, and SEM. Spherical aggregates were observed with variable sizes depicting the effect of concentration and oxidation of 2-LEB. Further, the aggregates showed acid/base sensitivity as evaluated by doping and dedoping of 2-EB with 1 M HCl and 1 M NH4OH, respectively. Future applications in drug delivery and sensors are envisaged for such tunable self-assembled nanostructures in aqueous media.

  • 31.
    Verma, Priya
    et al.
    Department of Physics, University of Lucknow, Lucknow, Uttar Pradesh, India.
    Srivastava, Anubha
    Department of Physics, University of Lucknow, Lucknow, Uttar Pradesh, India.
    Shukla, Anuradha
    Department of Physics, University of Lucknow, Lucknow, Uttar Pradesh, India.
    Tandon, Poonam
    Department of Physics, University of Lucknow, Lucknow, Uttar Pradesh, India.
    Shimpi, Manishkumar R.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Vibrational spectra, hydrogen bonding interactions and chemical reactivity analysis of nicotinamide–citric acid cocrystals by an experimental and theoretical approach2019In: New Journal of Chemistry, ISSN 1144-0546, E-ISSN 1369-9261, Vol. 43, no 40, p. 15956-15967Article in journal (Refereed)
    Abstract [en]

    Nicotinamide (NIC), also called vitamin B-3, is commonly known as a pellagra-preventive drug. Citric acid (CA) is a weak tribasic acid, generally used as a flavouring and chelating agent. Herein, a combined experimental and quantum chemical approach was adopted to study the structural properties and spectroscopic signatures of nicotinamide–citric acid (NIC–CA) cocrystals using monomer (2NIC + CA) and cluster (4NIC + CA) models. In the cluster model, two additional NIC molecules were attached to cover the nearest possible interactions to understand the complete molecular geometries and hydrogen bonding interactions present in the cocrystal. In addition to this, our strategy was to calculate and analyse the physicochemical properties of NIC and CA along with improved properties after NIC–CA cocrystal formation. The observed red shift in the stretching modes of CO and N–H of the NH2 groups of NIC and the CO and O–H groups of CA along with the elongation in bond lengths in the cluster model of NIC–CA indicated the presence of hydrogen bonding interactions as well as the formation of cocrystals. Moreover, natural bond orbital (NBO) analysis was performed to obtain information about the interactions that were responsible for the stability and formation of the NIC–CA cocrystal. The ‘quantum theory of atoms in molecules’ (QTAIM) calculations revealed that all the intra- and intermolecular hydrogen bonding interactions present in the NIC–CA (monomer) and NIC–CA (cluster) model were partially covalent in nature. The molecular electrostatic potential (MESP) map of NIC and CA shows that the carbonyl (CO) group and C–N of the pyridine ring in NIC are prone to electrophilic attack, and the hydroxyl (O–H) group of CA is prone to nucleophilic attack. The chemical reactivity parameters calculated using both models show that the NIC–CA cocrystal is more reactive and softer than NIC (API) and CA (co-former) since the band gap of the cocrystal is less than that of both NIC and CA.

  • 32.
    Loseva, O.V
    et al.
    Institute of Geology and Nature Management, Far-East Branch, Russian Academy of Sciences, Blagoveshchensk, Russia.
    Rodina, T.A
    Amur State University, Blagoveshchensk, Russia.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering. University of Warwick, Coventry, United Kingdom.
    Ivanov, A.V
    Institute of Geology and Nature Management, Far-East Branch, Russian Academy of Sciences, Blagoveshchensk, Russia.
    Chemisorption Activity of Mercury(II) Cyclopentamethylenedithiocarbamate: Synthesis, Structure, and Thermal Behavior of the [Hg2{S2CN(CH2)5}4] and [Au3{S2CN(CH2)5}6][Au{S2CN(CH2)5}2][Hg2Cl6]2 Complexes2018In: Russian journal of general chemistry, ISSN 1070-3632, E-ISSN 1608-3350, Vol. 88, no 12, p. 2540-2549Article in journal (Refereed)
    Abstract [en]

    The dinuclear complex mercury(II) cyclopentamethylenedithiocarbamate (piperidine-1-carbodithioate) [Hg2{S2CN(CH2)5}4] was synthesized and its chemisorption activity toward a solution of AuCl3 in 2 M HCl was studied. The chemisorption of gold from the solution forms an ionic gold(III)‒mercury(II) dithiocarbamato-chlorido complex comprising three isomeric gold cations and an unsymmetrical hexachlorodimercurate anion. The structural organization and thermal behavior of the resulting compounds was studied.

  • 33.
    Ivanov, Alexander V.
    et al.
    Institute of Geology and Nature Management, Far Eastern Branch of the Russian Academy of Sciences .
    Gerasimenko, A.V.
    Institute of Chemistry, Far Eastern Branch of the Russian Academy of Sciences.
    Egorova, I.V.
    Blagoveshchensk State Pedagogical University.
    Zaeva, A.S.
    Institute of Geology and Nature Management, Far East Branch, Russian Academy of Sciences.
    Novikova, E.V.
    Institute of Geology and Nature Management, Far East Branch, Russian Academy of Sciences.
    Rodionova, N.A.
    Blagoveshchensk State Pedagogical University.
    Gowda, V.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering. University of Oulu.
    Antzutkin, O.N.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering. Warwick University.
    Chemisorption Synthesis of the Ion-Polymeric Heteronuclear Gold(III)-Bismuth(III) Complex ([Au{S2CN(C3H7)2}2]3[Bi2Cl9])n Based on [Bi2{S2CN(C3H7)2}6]: 13C MAS NMR, Supramolecular Structure, and Thermal Behavior2018In: Russian journal of coordination chemistry, ISSN 1070-3284, E-ISSN 1608-3318, Vol. 44, no 8, p. 518-531Article in journal (Refereed)
    Abstract [en]

    Chemisorption synthesis on the basis of the binuclear compound [Bi2{S2CN(C3H7)2}6] (I) and preparative isolation of the ion-polymeric heteronuclear gold(III)-bismuth(III) complex ([Au{S2CN(C3H7)2}2]3[Bi2Cl9])n (II) are carried out. Compounds I and II are characterized in comparison by IR spectroscopy and 13C CP-MAS NMR. According to the X-ray diffraction analysis data (CIF file CCDC no. 1407705), the cationic moiety of compound II exhibits an unusually complicated supramolecular structure including six isomeric noncentrosymmetric complex cations [Au{S2CN(C3H7)2}2]+ (hereinafter A-F) and two binuclear anions [Bi2Cl9]3- as conformers. The isomeric gold(III) cations perform various structural functions. Owing to pair secondary interactions Au···S, cations B, C, E, and F form centrosymmetric ([E···E], [F···F]) and noncentrosymmetric ([B···C]) binuclear aggregates [Au2{S2CN(C3H7)2}4]2+, whereas cations A and D are not involved in dimerization. The strongest secondary Au···S bonds are formed between the binuclear and mononuclear cations, resulting in the formation of supramolecular cation-cationic polymer chains of two types: (⋅⋅⋅A⋅⋅⋅[B⋅⋅⋅C]⋅⋅⋅A⋅⋅⋅[B⋅⋅⋅C]⋅⋅⋅)n and (D⋅⋅⋅[E⋅⋅⋅E]⋅⋅⋅D⋅⋅⋅[F⋅⋅⋅F]⋅⋅⋅])n. In both chains, the gold atoms of the binuclear cations are characterized by a distorted octahedral coordination [S6], whereas in the mononuclear cations the gold atoms retain the square environment [S4]. The cation-anionic interactions are provided by secondary bonds Cl⋅⋅⋅S involving the terminal chlorine atoms of isomeric [Bi2Cl9]3- and the sulfur atoms of the binuclear cations [Au2{S2CN(C3H7)2}4]2+. The character of the thermal behavior of compounds I and II is studied by simultaneous thermal analysis with the identification of intermediate and final products of the thermal transformations. The thermolysis of compound I at 193-320°C is accompanied by the formation of Bi2S3 with an impurity of reduced metallic bismuth particles. The final products of the thermal transformations of compound II are reduced elemental gold and Bi2O3, and the thermal transformation intermediates are BiCl3 and Bi2S3.

  • 34.
    Trublet, Mylene
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Rusanova-Naydenova, Daniela
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Complete Column Trials for Water Refinement Using Titanium(IV) Phosphate Sorbents2018In: ACS Sustainable Chemistry & Engineering, E-ISSN 2168-0485, Vol. 6, no 5, p. 6157-6165Article in journal (Refereed)
    Abstract [en]

    A titanium phosphate sorbent with linked active units (LTP) is synthesized. XRD, 31P MAS NMR, and TGA techniques are used to disclose the relation between the ion-exchange units of −HPO4 (crystalline α-TiP) and of −H2PO4 (amorphous TiP1) type. The reported kinetics data of TiP1 sorbent in batch mode have been reprocessed according to the nonlinear approach in order to explore further the sorption mechanism. It was found that the data could be well described by the pseudo-second-order model in the case of Ni2+ ions. Consequently, fixed-bed column sorption experiments of Ni2+ ions on LTP were designed, and the effects of both the amount of nickel(II) ions in the feed solution and the flow rates on the sorption equilibrium were studied. The ion-exchange capacity is estimated to be 1.6 meq·g–1 during the first four cycles before decreasing to 1.2 meq·g–1 for cycles five and six. The experimental data were simulated following the Thomas model, and desorption experiments with HCl were performed. Observations show that regeneration and reutilization of the LTP ion-exchanger are possible through at least six cycles. It is revealed that the sorption performances in column conditions could be undoubtedly predicted from the corresponding batch sorption data.

  • 35.
    Trublet, Mylène
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Rusanova-Naydenova, Daniela
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Antzutkin, Oleg N
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering. Department of Physics, Warwick University, CV47AL, UK.
    Correction: Revisiting syntheses of Ti(IV)/H2PO4–HPO4functional ion-exchangers, properties and features2018In: New Journal of Chemistry, ISSN 1144-0546, E-ISSN 1369-9261, Vol. 42, no 2, p. 1521-Article in journal (Refereed)
    Abstract [en]

    Correction for ‘Revisiting syntheses of Ti(IV)/H2PO4–HPO4 functional ion-exchangers, properties and features’ by Mylène Trublet et al., New J. Chem., 2017, DOI: 10.1039/c7nj03065g.

  • 36.
    Dvoyashkin, Dvoyashkin
    et al.
    aculty of Oil and Gas, Almetyevsk State Oil Institute.
    Filippov, Andrei
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Diffusivity of crude oils contained in macroporous medium: 1H NMR study2018In: Mendeleev communications (Print), ISSN 0959-9436, E-ISSN 1364-551X, Vol. 2, p. 222-224Article in journal (Refereed)
    Abstract [en]

    Diffusivity of crude oils confined in pores of sand decreased with raising the fraction of oil at ordinary temperatures. This behaviour is suggested to be caused by adsorption of the high-molecular fractions of oils at the solid–liquid interface.

  • 37.
    Filippov, Andrei
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Azancheev, Nail
    Institute of Physics, Kazan Federal University, Kazan, Russia.
    Gibaydullin, Amal
    Institute of Physics, Kazan Federal University, Kazan, Russia.
    Bhattacharyya, Shubhankar
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Antzutkin, Oleg N.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Shah, Faiz Ullah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Dynamic Properties of Imidazolium Orthoborate Ionic Liquids Mixed with Polyethylene Glycol Studied by NMR Diffusometry and Impedance Spectroscopy2018In: Magnetic Resonance in Chemistry, ISSN 0749-1581, E-ISSN 1097-458X, Vol. 56, no 2, p. 113-119Article in journal (Refereed)
    Abstract [en]

    We used 1H pulsed field gradient (PFG) NMR to study the self-diffusion of polyethylene glycol (PEG) with average molecular mass of 200 and ions in mixtures of PEG with imidazolium bis(mandelato)borate (BMB) and imidazolium bis(oxalato)borate (BOB) ionic liquids (ILs). The ionic liquid was mixed with PEG in the concentration range of 0–100 wt%. Within the temperature range of 295 to 353 K, the diffusion coefficient of BMB is slower than that of the imidazolium cation. The diffusion coefficients of PEG, as well as the imidazolium cation and BMB anions, differ under all experimental conditions tested. This demonstrates that the IL in the mixture is present in at least a partially dissociated state. Generally, increasing the concentration of PEG leads to an increase in the diffusion coefficients of PEG and both the ions, and decreases their activation energy for diffusion. NMR chemical shift alteration analysis showed that the presence of PEG changes the chemical shifts of both ions but in different directions. Impedance spectroscopy was used to measure the ionic conductivity of the ionic liquids mixed with PEG.

  • 38.
    Filippov, Andrei
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering. Kazan State Medical University, Kazan, Russian Federation.
    Kurakin, S.
    Institute of Physics, Kazan Federal University, Kazan, Russian Federation.
    Gnezdilov, O.I.
    Institute of Physics, Kazan Federal University, Kazan, Russian Federation.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering. Department of Physics, Warwick University, Coventry, United Kingdom.
    Effect of magnetic field on diffusion of ethylammonium nitrate: water mixtures confined between polar glass plates2018In: Journal of Molecular Liquids, ISSN 0167-7322, E-ISSN 1873-3166, Vol. 4, p. 45-51Article in journal (Refereed)
    Abstract [en]

    We used 1H NMR diffusometry to study mixtures of ethylammonium nitrate (EAN) with water (3.1–12.4 mol% of added H2O) confined between polar glass plates and exposed to a static magnetic field of 9.4 T. The presence of such restrictions reverses the concentration dependence of the diffusivities of the EA (ethylammonium) cation and water typical for the bulk system. The presence of water weakens the effects of a static magnetic field on diffusion of the EA cation as well as on proton exchange of –NH3 groups. Surprisingly, the amplitude of the echo signal of water protons decreases during exposure to the magnetic field and finally disappears, a phenomenon that depends on the concentration of water in the system. Based on experimental data, we suggest that water in the system is present in two states with different dynamic properties. One type of water formed in confinement possesses NMR relaxation time typical for liquids; its diffusivity can be measured by 1H NMR. The second type of water is formed upon exposure of the sample of the first type to the magnetic field and eventually includes all the water in the system. This type of water possesses “solid-like” NMR relaxation features that makes it “invisible” to the NMR diffusometry technique. We suggest that this second type of water is adsorbed onto the glass plates. Correspondingly, EAN exists in two liquid phases: the first one contains an EAN-water mixture, while the second one contains neat EAN, and forms on the microscopic scale range under the influence of a static magnetic field.

  • 39.
    Khan, Amir Sada
    et al.
    Center of Research in Ionic Liquids, Department of Chemical Engineering, Universiti Teknologi PETRONAS .
    Man, Zakaria
    Center of Research in Ionic Liquids, Department of Chemical Engineering, Universiti Teknologi PETRONAS .
    Bustam, Mohamad Azmi
    Center of Research in Ionic Liquids, Department of Chemical Engineering, Universiti Teknologi PETRONAS .
    Nasrullah, Asma
    Fundamental and Applied Science Department, Universiti Teknologi PETRONAS .
    Ullah, Zahoor
    Department of Chemistry, Balochistan University of IT, Engineering and Management Sciences (BUITEMS).
    Sarwono, Ariyanti
    Center of Research in Ionic Liquids, Department of Chemical Engineering, Universiti Teknologi PETRONAS .
    Shah, Faiz Ullah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Muhammad, Nawshad
    Interdisciplinary Research Center in Biomedical Materials, COMSATS Institute of Information Technology, Lahore, Pakistan.
    Efficient Conversion of Lignocellulosic Biomass to Levulinic Acid Using Acidic Ionic Liquids2018In: Carbohydrate Polymers, ISSN 0144-8617, E-ISSN 1879-1344, Vol. 181, p. 208-214Article in journal (Refereed)
    Abstract [en]

    In the present research work, dicationic ionic liquids, containing 1,1-Bis(3-methylimidazolium-1-yl) butylene ([C4(Mim)2]) cation with counter anions [(2HSO4)(H2SO4)0], [(2HSO4)(H2SO4)2] and [(2HSO4)(H2SO4)4] were synthesised. ILs structures were confirmed using 1H NMR spectroscopy. Thermal stability, Hammett acidity, density and viscosity of ILs were determined. Various types of lignocellulosic biomass such as rubber wood, palm oil frond, bamboo and rice husk were converted into LA. Among the synthesized ionic liquids, [C4(Mim)2][(2HSO4)(H2SO4)4] showed higher % yield of LA up to 47.52 from bamboo biomass at 100 °C for 60 min, which is the better yield at low temperature and short time compared to previous reports. Surface morphology, surface functional groups and thermal stability of bamboo before and after conversion into LA were studied using SEM, FTIR and TGA analysis, respectively. This one-pot production of levulinic acid from agro-waste will open new opportunity for the conversion of sustainable biomass resources into valuable chemicals.

  • 40.
    Pilkington, Georgia A.
    et al.
    Surface and Corrosion Science, Department of Chemistry, KTH Royal Institute of Technology.
    Harris, Kathryn
    System and Component Design, Department of Machine Design, KTH Royal Institute of Technology.
    Bergendal, Erik
    Surface and Corrosion Science, Department of Chemistry, KTH Royal Institute of Technology.
    Reddy, Akepati Bhaskar
    System and Component Design, Department of Machine Design, KTH Royal Institute of Technology.
    Pålsson, Gunnar K.
    Department of Physics and Astronomy, Division of Materials Physics, Uppsala University.
    Vorobiev, Alexei
    Department of Physics and Astronomy, Division of Materials Physics, Uppsala University.
    Antzutkin, Oleg N.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Glavatskih, Sergei
    System and Component Design, Department of Machine Design, KTH Royal Institute of Technology.
    Rutland, Mark W.
    Surface and Corrosion Science, Department of Chemistry, KTH Royal Institute of Technology.
    Electro-responsivity of ionic liquid boundary layers in a polar solvent revealed by neutron reflectance2018In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 148, article id 193806Article in journal (Refereed)
    Abstract [en]

    Using neutron reflectivity, the electro-responsive structuring of the non-halogenated ionic liquid (IL) trihexyl(tetradecyl)phosphonium-bis(mandelato)borate, [P6,6,6,14][BMB], has been studied at a gold electrode surface in a polar solvent. For a 20% w/w IL mixture, contrast matched to the gold surface, distinct Kiessig fringes were observed for all potentials studied, indicative of a boundary layer of different composition to that of the bulk IL-solvent mixture. With applied potential, the amplitudes of the fringes from the gold-boundary layer interface varied systematically. These changes are attributable to the differing ratios of cations and anions in the boundary layer, leading to a greater or diminished contrast with the gold electrode, depending on the individual ion scattering length densities. Such electro-responsive changes were also evident in the reflectivities measured for the pure IL and a less concentrated (5% w/w) IL-solvent mixture at the same applied potentials, but gave rise to less pronounced changes. These measurements, therefore, demonstrate the enhanced sensitivity achieved by contrast matching the bulk solution and that the structure of the IL boundary layers formed in mixtures is strongly influenced by the bulk concentration. Together these results represent an important step in characterising IL boundary layers in IL-solvent mixtures and provide clear evidence of electro-responsive structuring of IL ions in their solutions with applied potential.

  • 41.
    An, Rong
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering. Herbert Gleiter Institute of Nanoscience, Nanjing University of Science and Technology, Nanjing.
    Zhou, Guobing
    School of Chemical Biological and Materials Engineering, University of Oklahoma.
    Zhu, Yudan
    State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University.
    Zhu, Wei
    State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University.
    Huang, Liangliang
    School of Chemical Biological and Materials Engineering, University of Oklahoma.
    Shah, Faiz Ullah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Friction of Ionic Liquid–Glycol Ether Mixtures at Titanium Interfaces: Negative Load Dependence2018In: Advanced Materials Interfaces, ISSN 2196-7350, Vol. 5, no 14, article id 1800266Article in journal (Refereed)
    Abstract [en]

    Structural reorientation of alkyl chains in the phosphonium cation of orthoborate ionic liquid mixed with glycol ether occurs with increasing normal load of the AFM tip. The flat reoriented structure, similar to the ‘blooming lotus leaf’, produces a new sliding interface that is responsible for the observed lower friction at higher loads. This work is reported by Rong An, Liangliang Huang, Faiz Ullah Shah and co‐workers in article number 1800263.

  • 42.
    An, Rong
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering. Herbert Gleiter Institute of Nanoscience, Nanjing University of Science and Technology, Nanjing.
    Zhou, Guobing
    School of Chemical Biological and Materials Engineering, University of Oklahoma.
    Zhu, Yudan
    State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University.
    Zhu, Wei
    State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University.
    Huang, Liangliang
    School of Chemical Biological and Materials Engineering, University of Oklahoma.
    Shah, Faiz Ullah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Friction of Ionic Liquid–Glycol Ether Mixtures at Titanium Interfaces: Negative Load Dependence2018In: Advanced Materials Interfaces, ISSN 2196-7350, Vol. 5, no 14, article id 1800263Article in journal (Refereed)
    Abstract [en]

    The atomic force microscopy experiments and nonequilibrium molecular dynamics (NEMD) simulations demonstrate a negative friction–load dependence to ionic liquid–glycol ether mixtures, that is, the friction decreases as the normal load increases. NEMD simulations reveal a structural reorientation of the studied ionic liquid (IL): as the normal load increases, the cation alkyl chains of ILs change the orientation to preferentially parallel to the tip scanning path. The flat‐oriented IL structures, similar to the “blooming lotus leaf,” produce a new sliding interface and reduce the friction. A further molecular dynamics simulation is carried out by adopting slit‐pore models to mimic the tip approaching process to confirm the dynamics of ILs. A faster diffusion of ILs in the smaller slit pore is observed. The faster diffusion of ILs in the more confined slit pore facilitates the structural reorientation of ILs. The resulted new sliding surface is responsible for the observed smaller friction at higher loads, also known as the negative friction–load dependence. These findings provide a fundamental explanation to the role of ILs in interfacial lubrications. They help to understand liquid flow properties under confinement, with implications for the development of better nanofluidic devices.

  • 43.
    Shah, Faiz Ullah
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Holmgren, Allan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Rutland, Mark W.
    Surface and Corrosion Science, Department of Chemistry, KTH Royal Institute of Technology.
    Glavatskih, Sergei
    System and Component Design, KTH Royal Institute of Technology.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering. Department of Physics, University of Warwick.
    Interfacial Behavior of Orthoborate Ionic Liquids at Inorganic Oxide Surfaces Probed by NMR, IR and Raman Spectroscopy2018In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 122, no 34, p. 19687-19698Article in journal (Refereed)
    Abstract [en]

    Absorption modes and reactivity of non-halogenated ionic liquids (ILs) at inorganic oxide surfaces of γ-Al2O3, MgO and SiO2 particles were characterized using multinuclear (11B, 31P and 29Si) solid-state magic-angle-spinning NMR, FTIR and Raman spectroscopy. ILs are composed of the trihexyl(tetradecyl)phosphonium cation, [P6,6,6,14]+, and bis(mandelato)borate, [BMB]-, or bis(salicylato)borate, [BScB]-, anions. Spectroscopic measurements were performed on room temperature (298 K) samples and samples exposed to 15 hours of heating at 373 K. The single pulse 11B NMR data of heated [P6,6,6,14][BMB] mixed with the inorganic oxides showed a significant change in spectra of the anion for all three oxides. In contrast, no such spectral changes were detected for heated [P6,6,6,14][BScB] mixed with the inorganic oxides. 31P MAS NMR data for the IL/metal oxide systems revealed interactions between [P6,6,6,14]+ and the surfaces of oxides. A significant intensity of 31P CP-MAS NMR signals indicated a low mobility of cations in these systems. The existence of strongly adhered surface layers of ILs on SiO2 particles was also confirmed by 1H-29Si CP-MAS NMR spectroscopy. FTIR and Raman spectroscopic data revealed strong interactions between the anions and the inorganic surfaces and there is strong correlation with the data obtained from NMR spectroscopy. Although their chemical structures are rather similar, the [BScB]- anion is more stable than the [BMB]- anion at the inorganic oxide surface.

  • 44.
    Filippov, Andrei
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering. Institute of Physics, Kazan Federal University, Kazan, Russia .
    Antzutkin, Oleg N.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering. Department of Physics, Warwick University, Coventry, United Kingdom .
    Magnetic field effects dynamics of ethylammonium nitrate ionic liquid confined between glass plates2018In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 20, no 9, p. 6316-6320Article in journal (Refereed)
    Abstract [en]

    Self-diffusion and NMR relaxation of the ethylammonium (EA) cation were studied in the protic ionic liquid, ethylammonium nitrate (EAN), confined between polar glass plates separated by a few μm distance and exposed to an external magnetic field of 9.4 T. The diffusion coefficient of EA (D) and the transverse NMR relaxation rate (1/T2) of –NH3 protons were increased immediately after placing the sample in the magnetic field by factors of ∼2 and ∼22, respectively, in comparison with those of bulk EAN. Further exposure of the sample to the magnetic field led to gradual changes in D, T1 and T2 towards their bulk values with a time constant of ∼70 min. Complete “recovery” of the sample to the “accelerated” D and “shortened” T2 values occurred at longer than 24 hours after the removal of the EAN sample from the magnet. Because the observed characteristic times of the change far exceed the times of molecular processes in EAN, we suggested that this phenomenon is related to reversible phase transformations occurring in confined EAN.

  • 45.
    Rodiouchkina, Maria
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Berglund, Kim
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Mouzon, Johanne
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Forsberg, Fredrik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    Shah, Faiz Ullah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Rodushkin, Ilia
    ALS Laboratory Group, ALS Scandinavia AB.
    Larsson, Roland
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Material Characterization and Influence of Sliding Speed and Pressure on Friction and Wear Behavior of Self-Lubricating Bearing Materials for Hydropower Applications2018In: Lubricants, ISSN 2075-4442, Vol. 6, no 2, article id 39Article in journal (Refereed)
    Abstract [en]

    Nowadays, hydropower plants are forced to have more frequent power control and the self-lubricated bearings used in the applications are one of the most critical components affected by the continuously changing operating conditions. In this study, microstructure and composition of two commercially available bearing materials (Orkot TXM Marine and Thordon ThorPlas) used in hydropower turbines were studied. In addition, the influence of sliding speed and applied pressure on the friction and wear behavior of the materials was investigated systematically for dry sliding conditions. The bearing materials were characterized using X-ray microtomography, Nuclear Magnetic Resonance (NMR) spectroscopy and Inductively Coupled Plasma–Sector Field Mass Spectrometry (ICP-SFMS) techniques. Friction and wear tests were carried out with a polymer pin sliding against a stainless steel (SS2333) plate with a linear reciprocating motion. Test conditions were: room temperature, 9–28 MPa pressure and 10–40 mm/s sliding speed ranges. Surface analysis of the polymer pins and the wear tracks were performed by optical profilometry, Scanning Electron Microscope (SEM) and Energy Dispersive Spectroscopy (EDS) techniques. Test results show that, for both materials, the coefficient of friction (COF) is decreasing at higher pressures. Surface analysis reveals higher concentrations of solid lubricants in the transfer layers formed at higher pressures, explaining the decrease in COF. Furthermore, the specific wear rate coefficients are increasing at higher sliding speeds, especially at lower pressures. Results of this study demonstrate that, under dry sliding conditions, changes in sliding speed and pressure have a significant influence on the tribological behavior of these bearing materials.

  • 46.
    Srivastava, K.
    et al.
    Physics Department, University of Lucknow, Lucknow, India.
    Khan, E.
    Physics Department, University of Lucknow, Lucknow, India.
    Shimpi, Manishkumar
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Tandon, P.
    Physics Department, University of Lucknow, Lucknow, India.
    Sinha, K.
    Physics Department, University of Lucknow, Lucknow, India.
    Velaga, Sitaram
    Luleå University of Technology, Department of Health Sciences, Medical Science.
    Molecular structure and hydrogen bond interactions of a paracetamol-4,4′-bipyridine cocrystal studied using a vibrational spectroscopic and quantum chemical approach2018In: CrystEngComm, ISSN 1466-8033, E-ISSN 1466-8033, Vol. 20, no 2, p. 213-222Article in journal (Refereed)
    Abstract [en]

    The purpose of the current study is to perform the structural and spectroscopic characterization of paracetamol-4,4′-bipyridine (PRA-BPY) cocrystal using infrared, Raman spectroscopy and density functional theory (DFT) calculations. To reveal the interactions between PRA and BPY, two models (monomer and dimer + PRA) of a cocrystal are designed and optimized using DFT with a 6-311G (d, p) basis set. An atoms in molecule study shows that the non-covalent interactions in particular hydrogen bonds involved in forming the cocrystal are moderate in nature. Natural bond orbital analysis of the second order perturbation theory of the Fock matrix suggests that interactions LP (1) N13 → π∗(C15-O16) and LP (1) N56 → σ∗(N13-H14) are responsible for the stabilization of the molecule. 

  • 47.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Polymorphism of Alzheimer’s Aβ Amyloid Fibrils and Oligomers2018In: Modern Magnetic Resonance / [ed] Graham A. Webb, Cham: Springer, 2018, p. 333-347Chapter in book (Refereed)
    Abstract [en]

    An overview of the strategy and experimental solid-state NMR, TEM, STEM, and AFM methods useful for obtaining atomic-level-resolution structural models of Alzheimer’s amyloid-β peptide fibrils and oligomers is presented. Polymorphism of amyloid fibrils and oligomers and the relevance to neurotoxicity is discussed.

  • 48.
    Shimpi, Manishkumar
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Giri, Lopamudra
    Indian Institute of Technology Bhubaneswar, Toshali Bhavan, Bhubaneswar.
    Rao Pedireddi, Venkateswara
    Indian Institute of Technology Bhubaneswar, Toshali Bhavan, Bhubaneswar.
    Preparation and Structure Analysis of Three New Copper Complexes of Mellitic Acid With 4,4′-Bipyridine and 1,3-bis(4-pyridyl)Propane2018In: ChemistrySelect, ISSN 2365-6549, Vol. 3, no 3, p. 855-858Article in journal (Refereed)
    Abstract [en]

    Coordination complexes, [Cu-2(H2L)(bpy)(2)].2H(2)O, (1a), [Cu(H3L)(2) (H2O)(4)].(H(2)bpypa)(2).6H(2)O, (2a) and [Cu(H3L)(4)] [Cu(H2O)(6)].(H(2)bpypa)(4).20H(2)O, (2b), of mellitic acid, H6L, with 4,4'-bipyrdine, (bpy), and 1,3-bis(4-pyridyl) propane, (bpypa), have been prepared and the three-dimensional structures are established by single crystal X-ray diffraction unequivocally. The complex 1a was prepared following hydrothermal method, while the complexes 2a and 2b were obtained concomitantly from an aqueous solution at room temperature. In the crystals of 1a, both acid and the aza-donors form coordination bonds with metal ions, while in 2a and 2b coordination bonding prevails between metal and acid molecules only, with azadonor molecules remain intact without coordinating to metal species. Further, 1a and 2b are noted to be yielding a hostguest network, whereas 2a forms planar sheets that are stacked in three-dimensional arrangemen

  • 49.
    Dinesha,
    et al.