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  • 251.
    Ivanov, Alexander V.
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Konfederatov, V.A.
    Institute of Geology and Nature Management, Far East Branch, Russian Academy of Sciences, Blagoveshchensk.
    Gerasimenko, A.V.
    Institute of Chemistry, Far Eastern Branch of the Russian Academy of Sciences, 690022, Vladivostok.
    Larsson, Anna-Carin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Polymeric thallium(I) O,O′-diisopropyl dithiophosphate [Tl{S2P(O-iso-C3H7)2}]n: synthesis, structure, and 13C and 31P CP/MAS2009In: Russian journal of coordination chemistry, ISSN 1070-3284, E-ISSN 1608-3318, Vol. 35, no 11, p. 857-863Article in journal (Refereed)
    Abstract [en]

    The crystalline polymeric thallium(I) O,O′-diisopropyl dithiophosphate [Tl{S2P(O-iso-C3H7)2}] n (I) was obtained and examined by solid-state 13C and 31P CP/MAS NMR spectroscopy. Diagrams of the χ2 statistic were constructed from the complete 31P MAS NMR spectra and used to calculate the 31P chemical shift anisotropy (δaniso = (δ zz - δiso)) and the asymmetry parameter (η = (δ yy - δ xx )/(δ zz - δiso)). The 31P chemical shift tensor has a nearly axial symmetry (η = 0.22, δ zz < δ yy ≈ δ xx ). The MAS NMR spectral patterns correspond to the negative sign of δaniso (δ zz < δ yy < δ xx ), which indicates bridging or chelating-bridging coordination of the dithiophosphate ligands (Dtph). X-ray diffraction analysis revealed a polymeric structure of compound I. The polymer chain consists of alternating mononuclear [Tl{S2P(O-iso-C3H7)2}] molecules with opposite spatial orientations. The Dtph ligands are coordinated in a mixed, chelating-μ3-bridging fashion. The shape of the 31P NMR signal was interpreted in terms of the 31P-203,205Tl coupling pattern proposed from crystallographic data.

  • 252.
    Ivanov, Alexander V.
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Korneeva, E. V.
    Amur Institute of Integrated Research, Far East Division, Russian Academy of Sciences.
    Gerasimenko, A. V.
    Institute of Chemistry, Far East Division, Russian Academy of Sciences.
    Forsling, Willis
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Structural organization of nickel(II), zinc(II), and copper(II) complexes with diisobutyldithiocarbamate: EPR, 13C and 15N CP/MAS NMR, and X-ray diffraction studies2005In: Russian journal of coordination chemistry, ISSN 1070-3284, E-ISSN 1608-3318, Vol. 31, no 10, p. 695-707Article in journal (Refereed)
    Abstract [en]

    The structures and spectroscopic properties of nickel(II), zinc(II), and copper(II) complexes with dibutyl- and diisobutyldithiocarbamate were studied by EPR and 13C and 15N CP/MAS NMR spectroscopy and X-ray diffraction analysis. According to the EPR data, copper(II) forms mononuclear [63/65Cu{S2CNR2}2] and heterobinuclear complexes [63/65CuZn{S2CNR2}4] under magnetic dilution conditions. The isomeric forms of nickel(II) and zinc(II) diisobutyldithiocarbamates were detected by 13C and 15N NMR spectroscopy. The crystalline zinc(II) diisobutyldithiocarbamate was found to have a unique structural organization with alternating mononuclear [Zn{S2CN(i-C4H9)2}2] and binuclear molecular forms [Zn2{ S2CN(i-C4H9)2}4] in the 1 : 1 ratio.

  • 253.
    Ivanov, Alexander V.
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Kritikos, M.
    Arrhenius Laboratory, University of Stockholm.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Forsling, Willis
    Lund, A.
    University of Linköping.
    Lutsenko, A.I.
    Amur Institute of Integrated Research, Far East Division, Russian Academy of Sciences.
    Bis(diethyldithiocarbamato)pyridinezinc(II) and -copper(II) clathrates M(Edtc)2Py·nL (L = CH2Cl2 and CHCl3; n = 1 and 0.5): Molecular and crystal structures and EPR and high-resolution solid-state (13C, 15N) NMR spectra1999In: Russian journal of coordination chemistry, ISSN 1070-3284, E-ISSN 1608-3318, Vol. 25, no 8, p. 543-555Article in journal (Refereed)
    Abstract [en]

    X-ray diffraction analysis, EPR, and high-resolution solid-state (13C, 15N) NMR spectroscopy were used to examine structural organization and spectral properties of six bis(diethyldithiocarbamato)pyridine-zinc(II) and copper(II) solvates with dichloromethane and chloroform, M(Edtc)2Py·nL (n = 1 and 0.5). Typical of the clathrate-type structures, the compounds are penetrated by the ordered molecular channels filled with chemically nonbonded chlorohydrocarbon molecules. At the molecular level, the geometry of coordination polyhedra of complexing atoms is intermediate between trigonal bipyramidal and square pyramidal (the contribution of the square-pyramidal component is quantitatively estimated for the zinc clathrate). Accordingly, the ground state of the unpaired electron in the copper(II) compounds is a combination of the dx2-y2 and dz2 orbitals. It is shown that the nonequivalence of the Edtc- ligands in zinc(II) clathrates manifests itself both magnetically and structurally. The chlorine atoms of the solvate dichloromethane molecules, unlike chloroform molecules, are disordered over the two structural positions with different multiplicities. The 13C and 15N NMR signals are assigned to the atomic positions in the resolved molecular structures

  • 254.
    Ivanov, Alexander V.
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Kritikos, M.
    Arrhenius Laboratory, University of Stockholm.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Lund, A.
    University of Linköping.
    Structure, EPR, and 13C and 15N NMR of Clathrates of Bis(diethyldithiocarbamato)pyridinezinc(II) and Bis(diethyldithiocarbamato)pyridinecopper(II) with 1,2-Dichloroethane1999In: Russian Journal of Inorganic Chemistry, ISSN 0036-0236, E-ISSN 1531-8613, Vol. 44, no 10, p. 1605-1614Article in journal (Refereed)
    Abstract [en]

    The structural organization of the clathrates of bis(diethyldithiocarbamato)pyridinezinc(II) and -copper(II) with 1,2-dichloroethane, M(Edtc)2Py · L, was studied by EPR, high-resolution solid-state 13C and 15N NMR, and X-ray crystallography. The clathrates contain typical molecular channels and cavities, which accommodate chemically unbound dichloroethane molecules. At the molecular level, the geometry of the zinc and copper coordination polyhedra is intermediate between a trigonal bipyramid and a square pyramid. The ground state of the unpaired electron of copper(II) is a result of mixing the dx2-y2 and dz2 orbitals. The Edtc ligands incorporated in the zinc(II) clathrate are somewhat nonequivalent, both magnetically and structurally. The chlorine atoms of the 1,2-dichloroethane molecule are disordered over two structural positions with different occupancies, which may point to the occurrence of several conformations. The 13C and 15N NMR signals were assigned based on combined analysis of available structural and NMR data

  • 255.
    Ivanov, Alexander V.
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Kritikos, M.
    Stockholm University.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Lund, A.
    University of Linköping.
    Mitrofanova, V.I.
    Amur Institute of Integrated Research, Far East Division, Russian Academy of Sciences.
    Bis(diethyldithiocarbamato)pyridinezinc(II) and copper(II) clathrates with pyridine: Molecular structure and EPR and high-resolution solid-state (13C, 15N) NMR spectra1998In: Russian journal of coordination chemistry, ISSN 1070-3284, E-ISSN 1608-3318, Vol. 24, no 9, p. 645-654Article in journal (Refereed)
    Abstract [en]

    EPR, high-resolution solid-state (13C, 15N) NMR, and X-ray diffraction methods were used to study bis(diethyldithiocarbamato)pyridinezinc(II) and copper(II) clathrates with pyridine, M(EdIc)2Py · Py. The structural functionalities of the Py molecules in these clathrates were found to be different: one of them is coordinated to the complexing atom, while the other (solvate) is hydrogen-bonded to the sulfur atom of one of the ligands. The heterocycle of the uncoordinated Py molecule was found to be geometrically distorted. The structures of the copper and zinc coordination polyhedra are close to trigonal-bipyramidal: two sulfur atoms and the nitrogen atom of pyridine form the equatorial plane; another two sulfur atoms occupy axial positions at larger distances. EPR spectra of the magnetically diluted copper(II) clathrate exhibit well-resolved SHFS from the nitrogen atom of Py, owing to the contribution of the dz2 orbital to the ground-state wave function of the unpaired electron. The NMR data suggest that the nitrogen atoms of the Edtc- ligands are magnetically inequivalent and that the 15N chemical shift of the uncoordinated Py molecule changes in an unusual fashion. Signal assignment was carried out for the experimental 13C and 15N NMR spectra

  • 256.
    Ivanov, Alexander V.
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Kritikos, M.
    Arrhenius Laboratory, University of Stockholm.
    Lund, A.
    University of Linköping.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Rodina, T.A.
    Amur Institute of Integrated Research, Far East Division, Russian Academy of Sciences.
    Clathrate Formation of Bis(diethyldithiocarbamato)pyridinezinc(II) and Bis(diethyldithiocarbamato)pyridinecopper(II) with Benzene by EPR, High-Resolution Solid-State 13C and 15N NMR, and X-ray Crystallography1998In: Russian Journal of Inorganic Chemistry, ISSN 0036-0236, E-ISSN 1531-8613, Vol. 43, no 9, p. 1368-1376Article in journal (Refereed)
    Abstract [en]

    The structures of the clathrates of bis(diethyldithiocarbamato)pyridinezinc(H) and-copper(II) with benzene were studied by EPR, high-resolution solid-state 13C and 15N NMR, and X-ray crystallography. The geometry of the coordination polyhedra in the clathrates M(EDtc)2· Py · C6H6is close to trigonal-bipyramidal. Two short M-S bonds and the M-N bond form the equatorial plane, and two long M-S bonds point toward the axial positions. For the magnetically diluted copper(II) clathrate, the hyperfine structure can be observed at low temperatures due to the nitrogen atom of pyridine, which is associated with the contribution of the dz2orbital to the ground-state wave function of the unpaired electron. The 13C and 15N NMR signals were assigned.

  • 257.
    Ivanov, Alexander V.
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Kritikos, Mikael
    Stockholm University.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Forsling, Willis
    The structural reorganisation of bis(diethyldithiocarbamato)morpholine-zinc(II) and -copper(II) in the course of solid-state solvation with morpholine and benzene molecules studied by ESR, solid-state 13C and 15N CP/MAS NMR spectroscopy and single-crystal X-ray diffraction2001In: Inorganica Chimica Acta, ISSN 0020-1693, E-ISSN 1873-3255, Vol. 321, no 1-2, p. 63-64Article in journal (Refereed)
    Abstract [en]

    Six forms of both non-solvated and solvated adducts of bis(diethyldithiocarbamato)–zinc(II) and –copper(II) with morpholine, of general formulas [M{O(CH2)4NH}{S2CN(C2H5)2}2] and [M{O(CH2)4NH}{S2CN(C2H5)2}2]·L (M=Zn(II) (1): L=O(CH2)4NH (2), C6H6 (3); M=Cu(II) (4): L=O(CH2)4NH (5), C6H6 (6)), have been prepared and studied by means of ESR, solid-state natural abundance 13C and 15N CP/MAS NMR spectroscopy and single crystal X-ray diffraction data. The existence of two conformers, which are correlated as rotation isomers, was unambiguously established for both zinc(II) and copper(II) non-solvated adducts 1 and 4. These two isomeric forms are characterised by different modes of spatial orientation of the non-planar morpholine ring relative to the two four-membered metallochelate rings. The geometry of the adduct molecules is close to square pyramidal, C4v, and therefore the ground state of the unpaired copper(II) electron corresponds to the 3dx2−y2 atomic orbital (AO). Solvation of the studied adducts in the solid state leads to their significant structural reorganisation at the molecular level, i.e. their structural unification yielding qualitatively new structural states with: (i) different lengths of the Zn---N bond; (ii) reoriented heterocyclic ring of the coordinated morpholine molecule; and (iii) an enhanced contribution of trigonal-bipyramidal character to the geometry of the coordination polyhedra of the central atom (from 7.5 and 22.7% in original adducts to 75% in solvated forms). The type of geometry of the coordination polyhedrons in the solvated forms of the adducts (intermediate between trigonal bipyramid D3h and square pyramid C4v) correlates with the fact that the ground state of the unpaired copper(II) electron is a mixture of 3dz2 and 3dx2−y2 AOs. All observed ESR and NMR resonances have been assigned and are in agreement with the structures obtained from X-ray diffraction data.

  • 258.
    Ivanov, Alexander V.
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Larsson, Anna-Carin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Rodionova, N. A.
    Blagoveshchensk State Pedagogical University.
    Gerasimenko, A. V.
    Institute of Chemistry, Far East Division, Russian Academy of Sciences.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Forsling, Willis
    Structural organization of nickel(II) and copper(II) O,O'-dialkyl phosphorodithioate complexes as probed by X-ray diffraction, EPR, and CP/MAS 13C and 31P NMR2004In: Russian Journal of Inorganic Chemistry, ISSN 0036-0236, E-ISSN 1531-8613, Vol. 49, no 3, p. 373-385Article in journal (Refereed)
    Abstract [en]

    The nickel(II) and copper(II) complexes [M{S2P(OR)(2)}(2)] (M = Ni, Cu-63, Cu-65; R = C2H5, C3H7, i-C3H7, C4H9, i-C4H9, s-C4H9, i-C5H11, c-C6H11) with eight symmetric O,O'-dialkyl phosphorodithioates were synthesized, and their structures and spectral properties were studied by EPR and CP/MAS C-13 and P-31 NMR. As determined by EPR, the [CuS4] chromophores in the lattice of nickel(II) complexes have predominantly a square-planar structure. The chromophores in complexes with phosphorodithioate ligands incorporating bulky alkyl substituents have somewhat distorted geometries. NMR shows that the Dtph groups in most nickel(II) complexes are structurally equivalent. An exception is [Ni{S2P(OC3H7)(2)}(2)], which gives rise to two (1 : 1) P-31 NMR signals. For [Ni(S2P(O-i-C4H9)(2))(2)], the alpha and beta modifications were obtained. In the alpha modification, the phosphorodithioate groups are nonequivalent, whereas the P modification has structurally equivalent ligands. The broadening of the P-31 NMR signal of the [Ni{S2P(O-s-C4H9)(2)}(2)] complex is rationalized by the existence of six optical isomers (due to two chiral centers in each of the ligands). For the Dtph groups acting as bidentate terminal ligands in the nickel(II) complexes, the P-31 chemical shift anisotropy delta(aniso) and asymmetry parameter eta were calculated from experimental NMR spectra. Single-crystal X-ray diffraction shows that bis(O,O'-dipropyl phosphorodithioato)nickel(II) exists in the form of two centrosymmetric molecules. In the structure of alpha-bis(O,O'-dipropyl phosphorodithioato)nickel(II), the Dtph ligands in the molecule are nonequivalent. The experimental P-31 NMR signals in the spectra of [Ni{S2P(OC3H7)(2)}(2)] and alpha-[Ni{S2P(O-i-C4H9)(2)}(2)] are assigned to the structural positions of phosphorus atoms in the corresponding molecular structures determined by X-ray diffraction.

  • 259.
    Ivanov, Alexander V.
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Leskova, S. A.
    Russian Adademy of Sciences.
    Mel'nikova, M. A.
    Rodina, T. A.
    Russian Adademy of Sciences.
    Lund, A.
    Linköping University.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Forsling, Willis
    Adducts of zinc and copper(II) morpholinedithiocarbamate complexes with morpholine of the composition [M(Mf)(MfDtC)(2)] and [M(Mf)(MfDtC)(2)]center dot Mf: Synthesis, thermal analysis, EPR, and CP/MAS C-13 NMR2003In: Russian Journal of Inorganic Chemistry, ISSN 0036-0236, E-ISSN 1531-8613, Vol. 48, no 3, p. 415-421Article in journal (Refereed)
    Abstract [en]

    The zinc and copper(II) morpholineditiohcarbamate complexes [M-2(MfDtc)(4)] and their adducts with morpholine [M(Mf)(MfDtc)(2)], including the solvated forms [M(Mf)(MfDtc)(2)] . Mf (M = Zn, Cu-63, Cu-65), have been synthesized and characterized by thermal analysis, EPR, and CP/MAS C-13 NMR data. Upon thermal destruction, the initial complexes, their adducts, and solvated forms lose weight in one, two, and three steps, respectively. The ultimate products of the thermal destruction of these complexes are zinc and copper sulfides. The range of the thermal destruction of the "dithiocarbamate part" is progressively shifted to lower temperatures in going from the initial binuclear complexes to their adducts and solvated forms. EPR shows that the geometry of the [CuS4N] chromophore in the [Cu(Mf)(MfDtc)(2)] adduct is close to square-pyramidal, the unpaired electron being predominantly localized in the metal 3d(x2-y2) AO. The outer-sphere solvation of the adduct is accompanied by structural reorganization at the molecular level. This reorganization involves a distortion of the [CuS4] base of the square-pyramidal polyhedron [CuS4N] toward a trigonal bipyramid. C-13 NMR shows that all of the zinc complexes under consideration are characterized by intramolecular nonequivalence of dithiocarbamate ligands. The N-15 NMR spectra adequately reflect the difference in the structural functions of pairs of dithiocarbamate ligands in [Zn-2(MfDtc)(4)].

  • 260.
    Ivanov, Alexander V.
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Leskova, S.A.
    Amur State University, Blagoveshchensk, Russian Federation.
    Kritikos, M.
    Arrhenius Laboratory, University of Stockholm.
    Forsling, Willis
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Adduct formation of the zinc morpholinedithiocarbamate complex with morpholine as studied by CP/MAS 15N NMR and single-crystal X-ray diffraction2004In: Russian Journal of Inorganic Chemistry, ISSN 0036-0236, E-ISSN 1531-8613, Vol. 49, no 12, p. 1863-1870Article in journal (Refereed)
    Abstract [en]

    The adduct of the zinc morpholineditiohcarbamate complex with morpholine [Zn(Mf)(MfDtc)2] and its solvated form [Zn(Mf)(MfDtc) 2]·Mf were studied by CP/MAS 15N NMR and single-crystal X-ray diffraction. These complexes are molecular, and the dithiocarbamate ligands therein are structurally nonequivalent. Solvation of the adduct aggravates this nonequivalence. The molecular and crystal structure of [Zn(Mf)(MfDtc)2]·Mf was determined by X-ray crystallography. The crystal structure of this compound has a system of ordered channels accommodating the outer-sphere morpholine molecules of solvation, which points to the formation of clathrate structures. The zinc coordination polyhedron [ZnS4N] is a somewhat distorted square pyramid with the four sulfur atoms at the base and the nitrogen atom at the apex. The square-pyramidal (SP) (97%) and trigonal-bipyramidal (TBP) (3%) contributions to the geometry of the zinc polyhedron were calculated. The 15N NMR signals were assigned to the structural positions of the nitrogen atoms in the molecular structure determined

  • 261.
    Ivanov, Alexander V.
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Loseva, O.V.
    Russian Academy of Sciences, Institute of Geology and Nature Management, Far East Division, Vladivostok.
    Ivanov, M.A.
    Russian Academy of Sciences, Institute of Geology and Nature Management, Far East Division, Vladivostok.
    Konfederatov, V.A.
    Russian Academy of Sciences, Institute of Geology and Nature Management, Far East Division, Vladivostok.
    Gerasimenko, A.V.
    Russian Academy of Sciences, Institute of Geology and Nature Management, Far East Division, Vladivostok.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Forsling, Willis
    Crystalline cadmium dialkyl phosphorodithioate complexes: synthesis and structural organization as probed by multinuclear C-13, P-31, and Cd-113 CP/MAS NMR and single-crystal X-ray diffraction2007In: Russian Journal of Inorganic Chemistry, ISSN 0036-0236, E-ISSN 1531-8613, Vol. 52, no 10, p. 1595-1602Article in journal (Refereed)
    Abstract [en]

    The cadmium O,O'-dethyl (I) and O,O'-di-sec-butyl phosphorodithioate (II) complexes have been synthesized and characterized in detail by(13)C, P-31, and Cd-113 CP/MAS NMR. X-ray crystallography shows that complex II has a binuclear molecular structure [Cd-2{S2P(O-s-C4H9)(2)}(4)]. For P-31 and Cd-113 NMR signals, the chemical shift anisotropy delta(aniso) and the asymmetry parameter eta have been calculated. The P-31 NMR signals are assigned to the terminal and bridging ligands in the complexes.

  • 262.
    Ivanov, Alexander V.
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Lutsenko, I. A.
    Russian Adademy of Sciences.
    Forsling, Willis
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Bis(dimethyldithiocarbamato)(pyridine)zinc and -copper(II) and Their Benzene Solvates: EPR and Solid-State Natural Abundance (13C, 15N) CP/MAS NMR2002In: Russian journal of coordination chemistry, ISSN 1070-3284, E-ISSN 1608-3318, Vol. 28, no 1, p. 57-63Article in journal (Refereed)
    Abstract [en]

    Adducts of bis(dimethyldithiocarbamato)zinc and -copper(II) complexes with pyridine, [M(Py)(Mdtc)2], and their benzene solvates [M(Py)(Mdtc)2] · 0.5C6H6 were synthesized. The electron paramagnetic resonance method and solid-state 13C and 15N CP/MAS NMR spectroscopy were used to perform a comparative study of the compounds obtained. The EPR data showed that the geometry of Cu(II) coordination polyhedra both in the adduct itself [Cu(Py)(Mdtc)2], and in its solvate, [Cu(Py)(Mdtc)2] · 0.5C6H6 is intermediate between a square pyramid (SP) and a trigonal bipyramid (TBP), the contribution from the latter being dominant (75%) in [Cu(Py)(Mdtc)2]. In the solvated adduct [Cu(Py)(Mdtc)2] · 0.5C6H6, the copper(II) polyhedron is distorted to form an SP-enriched structure (the contribution from TBP is reduced to 55%). It was found NMR data that [Zn(Py)(Mdtc)2] exists in a single high-symmetry molecular form. Coordinated pyridine molecule shows molecular motion about the Zn-N bond. The solvation of the adduct results in structural nonequivalence of the Mdtc-ligands in [Zn(Py)(Mdtc)2] · 0.5C6H6. Signals in the 15N NMR spectra were assigned to the structural positions of the atoms in the previously described molecular structure of a solvated adduct. It was found that the heterogeneous reaction of adduct formation during the absorption of pyridine from the gas phase by polycrystalline [Zn2(Mdtc)4] species is accompanied by the dissociation of binuclear molecules.

  • 263.
    Ivanov, Alexander V.
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Lutsenko, I. A.
    Russian Adademy of Sciences.
    Ivanov, M. A.
    Russian Adademy of Sciences.
    Gerasimenko, A. V.
    Russian Adademy of Sciences.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Synthesis, structural and multinuclear natural abundance (C-13, P-31, Pt-195) CP/MAS NMR studies of crystalline O,O '-dialkyldithiophosphate platinum(II) complexes2008In: Russian journal of coordination chemistry, ISSN 1070-3284, E-ISSN 1608-3318, Vol. 34, no 8, p. 584-593Article in journal (Refereed)
    Abstract [en]

    Platinum(II) O,O'-dicyclohexyl dithiophosphate [Pt{S2P(O-cyclo-C6H11)(2)}(2)] (I) and platinum(II) O,O'-diisopropyl dithiophosphate [Pt{S2P(O-iso-C3H7)(2)}(2)] (II) complexes were obtained and studied by solidstate C-13, P-31, and Pt-195 CP/MAS NMR spectroscopy. The dithiophosphate (Dtph) ligands in molecular structure I were found to be coordinated by platinum in S,S'-bidentate fashion to form the planar chromophore [PtS4] (single-crystal X-ray diffraction data). For complex II, a new alpha-form (alpha-II) was obtained and identified by P-31 MAS NMR spectroscopy. The P-31 chemical shift anisotropy delta(aniso) and the asymmetry parameter eta of the P-31 chemical shift tensor were calculated from the whole MAS spectra.

  • 264.
    Ivanov, Alexander V.
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Lutsenko, I.A.
    Institute of Geology and Nature Management, Far East Branch, Russian Academy of Sciences, Blagoveshchensk.
    Komeeva, E.V.
    Institute of Geology and Nature Management, Far East Branch, Russian Academy of Sciences, Blagoveshchensk.
    Gerasimenko, A.V.
    Institute of Chemistry, Far Eastern Branch of the Russian Academy of Sciences, 690022, Vladivostok.
    Ogil'ko, G.V.
    Blagoveshchensk State Pedagogical University.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Larsson, Anna-Carin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Binding of Au3+ from solutions by nickel(II) and cadmium diisopropyl dithiophosphates: MAS P-31 NMR, structure and thermal behavior of the polynuclear complex [Au-2{S2P(O-iso-C3H7)(2)}(2)] (n)2012In: Russian journal of coordination chemistry, ISSN 1070-3284, E-ISSN 1608-3318, Vol. 38, no 6, p. 430-439Article in journal (Refereed)
    Abstract [en]

    The paper deals with reactions of freshly precipitated diisopropyl dithiophosphate (Dtph) complexes of nickel(II), [Ni{S2P(O-iso-C3H7)(2)}(2)] and cadmium, [Cd-2{S2P(O-iso-C3H7)(2)}(4)], with the [AuCl4](-) in 2M HCl, resulting in gold transition from the solution to the precipitate as polymeric gold(I) diisopropyl dithiophosphate. The reduction of gold(III) to gold(I) noted in both cases is due to oxidation of the relevant part of the Dtph group to bis(O,O'-di-(iso)-propoxythiophosphoryl) disulfide, (iso-C3H7O)(2)P(S)S-S(S)P(O-iso-C3H7)(2). The polynuclear gold(I) complex [Au-2{S2P(O-iso-C3H7)(2)}(2)] (n) (I) was isolated on a preparative scale from the chemisorption system and studied by MAS P-31 NMR and X-ray diffraction. The key structural unit of I is the non-centrosymmetric binuclear molecule [Au-2{S2P(O-iso-C3H7)(2)}(2)] in which the gold atoms are connected by two bridging Dtph groups. The structure contains two types of non-equivalent binuclear molecules related as conformational isomers. Owing to the relatively weak Au-Au contacts, the neighboring binuclear [Au-2{S2P(O-iso-C3H7)(2)}(2)] molecules are involved in an infinite polymeric chain with conformer alternation along the chain. To elucidate the conditions for the recovery of bound gold(I), the precipitates formed in the sorption systems were studied by simultaneous thermal analysis under argon. As the final product, thermolysis gives reduced metallic gold. The ability of dithiophosphate complexes to bind gold from a solution is much lower than that of dithiocarbamate complexes, which is due to oxidation of some Dtph groups to disulfide.

  • 265.
    Ivanov, Alexander V.
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Mitrofanova, Valentina I.
    Russian Adademy of Sciences.
    Kritikos, Mikael
    Stockholm University.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Rotation isomers of bis(diethyldithiocarbamato)zinc(II) adduct with pyridine, Zn(EDtc)(2)center dot Py: ESR, C-13 and N-15 CP/MAS NMR and single-crystal X-ray diffraction studies1999In: Polyhedron, ISSN 0277-5387, E-ISSN 1873-3719, Vol. 18, no 15, p. 2069-2078Article in journal (Refereed)
    Abstract [en]

    The adduct of bis(diethyldithiocarbamato)zinc(II) with pyridine, Zn(EDtc)2·Py, was prepared and studied by means of ESR (63Cu2+ and 65Cu2+ were used as spin labels), solid-state natural abundance 13C and 15N CP/MAS NMR spectroscopy and single-crystal X-ray diffraction data analysis. Two rotation isomers of the adduct were unambiguously determined by these three independent methods. It was found that these two isomers have different orientations of the pyridine ring about the N(Py)-Zn axis. The acute angles of the plane of the pyridine molecules relative to the most weak Zn-S bond are equal to 45.6 and 52.7° in the different isomers. Adduct molecules adopt a geometry which is intermediate between the square pyramidal (C4v) and the trigonal bipyramidal (D3h). All ESR and NMR resonances of Zn(EDtc)2·Py were assigned

  • 266.
    Ivanov, Alexander V.
    et al.
    Russian Adademy of Sciences.
    Novikova, E. V.
    Russian Adademy of Sciences.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Forsling, Willis
    Solvation isomers of solvated adducts of copper and zinc diethyldithiocarbamate complexes in the M(II)-EDtc-Py-Mf systems: synthesis, EPR, and solid-state C-13 and N-15 CP/MAS NMR2001In: Russian Journal of Inorganic Chemistry, ISSN 0036-0236, E-ISSN 1531-8613, Vol. 46, no 12, p. 1832-1838Article in journal (Refereed)
    Abstract [en]

    The crystalline adducts [M(B)(EDtc)(2)] (M = Zn, Cu; B = Py, Mf) quantitatively absorb bases to produce their solvated forms incorporating outer-sphere molecules of N-donor bases: [M(Mf)(EDtc)(2)] . Mf, [M(Mf)(EDtc)(2)] . Py, and [M(Py)(EDtc)(2)] . Mf. The adducts of the last two types ire solvate isomers, which differ in the distribution of different bases between the outer and inner coordination spheres, Computer simulation points to the individual character of the EPR spectra of the isomers [Cu(Mf)(EDtc)(2)] . Py and [Cu(Py)(EDtc)(2)] . Mf and the lack of redistribution of base molecules between two coordination spheres. The copper coordination polyhedra in these compounds are close to a trigonal bipyramid (the TBP contribution is about 80%); the ground state of the unpaired electron is dominated by the 3d(z2) copper(II) AO. Combined analysis of C-13 and N-15 NMR data permitted the identification of the signals that arise from the coordinated and outer-sphere pyridine molecules in the solvate isomers [Zn(Mf)(EDtc)(2)] . Py and [Zn(Py)(EDtc)(2)] . Mf.

  • 267.
    Ivanov, Alexander V.
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Novikova, E.V.
    Blagoveshchensk State Pedagogical University.
    Leskova, S.A.
    Amur State University, Blagoveshchensk, Russian Federation.
    Forsling, Willis
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Adducts of zinc and copper(II) dialkyldithiocarbamate complexes with hexamethyleneimine: synthesis, EPR and CP/MAS 13C and 15N NMR2004In: Russian Journal of Inorganic Chemistry, ISSN 0036-0236, E-ISSN 1531-8613, Vol. 49, no 1, p. 95-101Article in journal (Refereed)
    Abstract [en]

    Powders of the zinc and copper(II) dimethyl- (MDtc), diethyl- (EDtc), and morpholinedilhiocarbamate (MfDtc) complexes quantitatively absorb hexamethyleneimine (Hmi) to produce the adducts [M{NH(CH2) 6}(S2CNR2)2] (M = Zn, Cu; R = CH3, C2H5; R2 = (CH 2)4O). The heterogeneous reaction of adduct formation is accompanied by dissociation of the binuclear molecules [M2(DtC) 4] of the initial dithiocarbamate complexes. Computer-aided simulation of EPR spectra for the copper(II) adducts shows that they are individual. The coordination polyhedron of copper in these compounds is intermediate between a trigonal bipyramid (TBP) and a square pyramid (SP). Based on EPR data, the TBP contribution is quantitatively estimated. 13C and 15N NMR shows that the MDtc and EDtc ligands in the adducts are structurally nonequivalent, whereas the MfDtc ligands are structurally equivalent. The 15N isotropic chemical shifts of the dithiocarbamate groups depend on alkyl substituents at the nitrogen atom.

  • 268.
    Ivanov, Alexander V.
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Pakusina, A. P.
    Blagoveshchensk State Pedagogical University.
    Ivanov, M. A.
    Russian Adademy of Sciences.
    Sharutin, V. V.
    Blagoveshchensk State Pedagogical University.
    Gerasimenko, A. V.
    Russian Adademy of Sciences.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Gröbner, G.
    Umeå university.
    Forsling, Willis
    Synthesis and single-crystal X-ray diffraction and CP/MAS 13C and 15N NMR study of tetraphenylantimony N,N-dialkyldithiocarbamate complexes: a manifestation of conformational isomerism2005In: Doklady. Physical chemistry, ISSN 0012-5016, E-ISSN 1608-3121, Vol. 401, no 4-6, p. 44-48Article in journal (Refereed)
  • 269.
    Ivanov, Alexander V.
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Palazhchenko, V. I.
    Russian Adademy of Sciences.
    Strikha, V.E.
    Russian Adademy of Sciences.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Forsling, Willis
    Structural features and NMR195Pt Spectroscopy of cooperite monocrystals (Natural PtS)2006In: Doklady Earth Sciences, ISSN 1028-334X, E-ISSN 1531-8354, Vol. 410, no 7, p. 1141-1144Article in journal (Refereed)
  • 270.
    Ivanov, Alexander V.
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Rody, Tatyana
    Amur State University, Blagoveshchensk, Russian Federation.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Structural organisation of [Ni(II)--Me(II)--Dtc] (Me = Zn, Cd, Hg) Dithiocarbamate complexes: ESR, 13C and 15N CP/MAS NMR studies1998In: Polyhedron, ISSN 0277-5387, E-ISSN 1873-3719, Vol. 17, no 18, p. 3101-3109Article in journal (Refereed)
    Abstract [en]

    Magnetically diluted systems of dithiocarbamate complexes of the type 63,65Cu/[Ni(II)--Me(II)--Dtc] (Me = Zn, Cd, Hg; Dtc = MDtc (dimethyl-) or EDtc (diethyldithiocarbamate)), which model the structural heterogeneity on the local, molecular and supramolecular levels, have been prepared and studied by means of ESR and solid state 13C and 15N CP/MAS NMR spectroscopy.

  • 271.
    Ivanov, Alexander V.
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Zaeva, A. S.
    Blagoveshchensk State Pedagogical University.
    Novikova, E. V.
    Institute of Geology and Nature Management, Blagoveshchensk.
    Rodina, T. A.
    Amur State University, Blagoveshchensk, Russian Federation.
    Forsling, Willis
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Adducts of zinc and copper(II) dialkyldithiocarbamate complexes with dialkylamines: synthesis, EPR, and C-13 and N-15 CP/MAS NMR2007In: Russian Journal of Inorganic Chemistry, ISSN 0036-0236, E-ISSN 1531-8613, Vol. 52, no 5, p. 691-697Article in journal (Refereed)
    Abstract [en]

    Crystalline adducts of zinc and copper(II) dithiocarbamate (Dtc) complexes with dialkylamines [M(NHR′2)(S2CNR2)2] (M = Zn, 63Cu, 65Cu; R = CH3, C2H5, or R2 = (CH2)4O; R′ = C2H5, C3H7) have been preparatively isolated. The structures and spectral properties of the adducts have been studied by EPR and 13C and 15N MAS NMR. Chemisorption of bases on powders of dinuclear dithiocarbamates leads to their dissociation into monomeric adducts. Computer simulation demonstrates that the experimental EPR spectra of isotope-substituted copper(II) adducts have an individual character. The geometry of the copper polyhedra is intermediate between a trigonal bipyramid (TBP) and a tetragonal pyramid (TP). The TBP and TP contributions have been quantified based on EPR data. 13C and 15N MAS NMR data show that the Dtc ligands incorporated into the zinc adduct molecule are structurally nonequivalent. The dependence of the isotropic 15N chemical shifts of the Dtc groups on the alkyl substituents at the nitrogen atom is interpreted based on the concept of joint manifestation of the (+)inductive effect of the alkyl substituents and the mesomeric effect of the Dtc groups

  • 272.
    Ivanov, Alexander V.
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Zaeva, A.S.
    Blagoveshchensk State Pedagogical University.
    Gerasimenko, A.V.
    Institute of Chemistry, Far East Division, Russian Academy of Sciences.
    Forsling, Willis
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Synthesis and single-crystal X-ray diffraction and CP/MAS 13C and 15N NMR study of zinc diethyldithiocarbamate adducts with dialkylamines: manifestation of conformational isomerism2005In: Doklady. Physical chemistry, ISSN 0012-5016, E-ISSN 1608-3121, Vol. 404, no 4-6, p. 205-209Article in journal (Refereed)
  • 273.
    Ivanov, Alexander V.
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Zinkin, S. A.
    Russian Adademy of Sciences.
    Forsling, Willis
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Kritikos, M.
    Stockholm University.
    Structural organization of symmetrical dialkylthiuram disulfides and their cyclic analogs: X-Ray diffraction and CP/MAS (13C, 15N) NMR studies2003In: Russian journal of coordination chemistry, ISSN 1070-3284, E-ISSN 1608-3318, Vol. 29, no 2, p. 142-150Article in journal (Refereed)
    Abstract [en]

    High-resolution 13C and 15N solid-state NMR spectra were recorded for seven crystalline tetraalkyl-thiuram disulfides and their cyclic analogs of the general formula [R2NC(S)S]2 (where R = CH3, C2H5, C3H7, and i-C3H7 or R2 = (CH2)5, (CH2)6, and (CH2)4O). The 15N and 13C NMR resonances were assigned to the particular atoms in the compounds studied. Different isotropic 15N chemical shifts for both dialkyldithiocarbamato groups were interpreted while considering the inductive effects of the alkyl substituents combined with the mesomeric effect of the dithiocarbamato group. X-ray diffraction data were used to refine the molecular structure of bis(cyclohexamethylene)thiuram disulfide and to quantitatively characterize the conformations of the seven-membered N(CH2)6 heterocycles.

  • 274.
    Ivanov, Alexander V.
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Zinkin, S. A.
    Russian Adademy of Sciences.
    Gerasimenko, A. V.
    Russian Adademy of Sciences.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Forsling, Willis
    Structural organization of silver(I) complexes with O,O′-dialkyl dithiophosphates: Solid-state 13C and 31P CP/MAS NMR and single-crystal X-ray diffraction studies2007In: Russian journal of coordination chemistry, ISSN 1070-3284, E-ISSN 1608-3318, Vol. 33, no 1, p. 20-31Article in journal (Refereed)
    Abstract [en]

    Silver(I) complexes with four symmetrically substituted O,O′-dialkyl derivatives of dithiophosphoric acid of the general formula [Ag{S2P(OR)2}] n (R = C2H5, i-C3H7, C4H9, and s-C4H9) were obtained. Their structures and spectroscopic characteristics were studied by solid-state 13C and 31P CP/MAS NMR spectroscopy and X-ray diffraction analysis. The parameters of the anisotropy of the 31P chemical shift 31P-δ aniso and η (δ aniso is the chemical shift anisotropy and η is the asymmetry parameter) calculated from the diagrams of the x 2-statistic revealed that the (RO)2PS2 groups act as bridging ligands in all the silver(I) complexes obtained. The hexanuclear complex [Ag6{S2P(O-i-C3H7)2}6] was found to form two modifications α and β. According to the X-ray diffraction data, the silver(I) complex with O,O′-di-s-butyl dithiophosphate exists as discrete hexanuclear molecules [Ag6{S2P(O-s-C4H9)2}6]. In the clear molecules β-[Ag6{S2P(O-i-C3H7)2}6], the signals for the phosphorus atoms were assigned to their positions determined from the X-ray diffraction data.

  • 275.
    Ivanov, Alexander V.
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Zinkin, S.A.
    Amur Institute of Integrated Research, Far East Division, Russian Academy of Sciences.
    Konzelko, A.A
    Amur Institute of Integrated Research, Far East Division, Russian Academy of Sciences.
    Forsling, Willis
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    CP/MAS C-13 and N-15 NMR study of polynuclear silver(I) N, N-diakyldithiocarbamate complexes (R=CH3, C2H5, C3H7, iso-C3H7)2004In: Russian Journal of Inorganic Chemistry, ISSN 0036-0236, E-ISSN 1531-8613, Vol. 49, p. 593-598Article in journal (Refereed)
    Abstract [en]

    Polynuclear silver(I) dialkyldithiocarbamate complexes (R = CH3, C2H5, C3H7, iso-C3H 7) were synthesized and studied by CP/MAS 13C and 15N NMR. The experimental 15N NMR signals were assigned to the positions of nitrogen atoms in the known molecular structures. Differences in the 15N isotropic chemical shifts of the dialkyldithiocarbamate ligands are explained in the framework of the joint manifestation of the mesomeric effect of dithiocarbamate groups and the (+)inductive effect of alkyl substituents

  • 276.
    Ivanov, A.V.
    et al.
    Institute of Geology and Nature Management, Far East Branch, Russian Academy of Sciences, Blagoveshchensk.
    Egorova, I.V.
    Blagoveshchensk State Pedagogical University.
    Ivanov, M.A.
    Institute of Geology and Nature Management, Far East Branch, Russian Academy of Sciences, Blagoveshchensk.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Tsvykh, R.S.
    University of Warwick, Coventry.
    Structure of crystalline bismuth(III) N,N-dipropyldithiocarbamate [Bi{S2CN(C3H7)2}3] according to 13C and 15N MAS NMR and X-ray diffraction analysis: Supramolecular self-organization and conformational isomerism2014In: Doklady. Physical chemistry, ISSN 0012-5016, E-ISSN 1608-3121, Vol. 454, no 1, p. 16-20Article in journal (Refereed)
  • 277.
    Ivanov, M.A.
    et al.
    Institute of Geology and Nature Management, Far East Branch, Russian Academy of Sciences, Blagoveshchensk.
    Gerasimenko, A.V.
    Institute of Chemistry, Far Eastern Branch of the Russian Academy of Sciences, 690022, Vladivostok.
    Ivanov, A.V.
    Institute of Geology and Nature Management, Far East Branch, Russian Academy of Sciences, Blagoveshchensk.
    Solozhenkin, P.M.
    Institute of Comprehensive Exploitation of Mineral Resources, Russian Academy of Sciences, Kryukovsky Tupik 4, Moscow.
    Sharutin, V.V.
    Southern Ural State University, Chelyabinsk.
    Larsson, Anna-Carin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Pushilin, M.A
    Institute of Chemistry, Far Eastern Branch of the Russian Academy of Sciences, 690022, Vladivostok.
    The diethyl dithiophosphate complex of tetraphenylantimony(V) and its solvated form, [Sb(C6H5)(4){S2P(OC2H5)(2)}] center dot 1/2 C6H6: Synthesis, crystal structure, and C-13, P-31 CP/MAS NMR study: an example of monodentate coordination of dithio ligands2013In: Russian Journal of Inorganic Chemistry, ISSN 0036-0236, E-ISSN 1531-8613, Vol. 58, no 2, p. 197-205Article in journal (Refereed)
    Abstract [en]

    The O,O'-diethyl dithiophosphate complex of tetraphenylantimony(V) [Sb(C6H5)(4){S2P(OC2H5)(2)}] (I) and its benzene-solvated form I center dot 1/2C(6)H(6) (II) were synthesized and studied by high-resolution solid-state C-13 and P-31 NMR (MAS NMR). The diethyl dithiophosphate (Dtph) groups in I and II were quantitatively characterized by the P-31 chemical shift anisotropy (delta(aniso)), the asymmetry parameter (eta), and the principal values of chemical shift tensors (delta (xx) , delta (yy) , delta (zz) ). The calculation of the anisotropy parameters included construction of chi(2) statistic diagrams from full P-31 MAS NMR spectra. In both complexes, the Dtph groups were found to have mainly axially symmetric P-31 chemical shift tensors (for delta (zz) < delta (xx) a parts per thousand delta (yy) ) with similar anisotropy parameters (delta(aniso) and eta), which is due to their identical S-monodentate function. According to X-ray diffraction data, II has a trigonal bipyramidal (TBP) molecular structure with Smonodentate coordination of Dtph in the TBP axial position and outer-sphere position of the benzene molecule. The desorption of the outer-sphere benzene solvent molecules from structure II, which was noted in MAS NMR experiment, passes through the formation of three intermediate solvated forms with benzene content n < 1/2.

  • 278.
    Ivanov, M.A.
    et al.
    Russian Academy of Sciences, Institute of Geology and Nature Management, Far East Division, Blagoveshchensk.
    Sharutin, V.V.
    Blagoveshchensk State Pedagogical University.
    Ivanov, Alexander
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Gerasimenko, A.V.
    Russian Academy of Sciences, Institute of Geology and Nature Management, Far East Division, Vladivostok.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Synthesis, structure, and 13C and 31P CP/MAS NMR of the tetraphenylantimony(V) di-iso-propyl phosphorodithioate complex [Sb(C6H5)4{S2P(O-iso-C3H7)2}] and its solvated form [Sb(C6H5)4{S2P(O-iso-C3H7)2}] · 1/2C6H6: an example of the monodentate coordination of dithio ligands2009In: Russian Journal of Inorganic Chemistry, ISSN 0036-0236, E-ISSN 1531-8613, Vol. 54, no 5, p. 708-716Article in journal (Refereed)
    Abstract [en]

    The crystalline tetraphenylantimony(V) O,O′-di-iso-propyl phosphorodithioate complex [Sb(C6H5)4{S2P(O-i-C3H7)2}](I) and its solvated form [Sb(C6H5)4{S2P(O-i-C3H7)2}] · 1/2C6H6(II) were synthesized. Solid compounds I and II were studied by MAS NMR (13C, 31P). The 31P NMR chemical shift anisotropy 31P δaniso = (δ zz - δiso) and asymmetry parameter η = (δ yy - δ xx )/(δ zz - δiso) were calculated using χ 2 plots constructed on the basis of the 31P MAS NMR data. The O,O′-di-iso-propyl phosphorodithioate ligands in both complexes are characterized by predominantly the axially symmetric 31P chemical shift tensor (for the case δ zz < δ xx ≈ δ yy ) with close values of anisotropy parameters (δaniso and η), which reflects their identical S-monodentate structural function. X-ray crystallography showed that II has a trigonal-bipyramidal molecular structure with the uncommon monodentate coordination of the Dtph ligands through an S atom in an axial position of the trigonal bipyramid and the benzene molecule in the outer sphere.

  • 279.
    Ivanov, M.A.
    et al.
    Institute of Geology and Nature Management, Far East Branch, Russian Academy of Sciences, Blagoveshchensk.
    Sharutin, V.V.
    Blagoveshchensk State Pedagogical University.
    Ivanov, Alexander V.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Gerasimenko, A.V.
    Institute of Chemistry, Far Eastern Branch of the Russian Academy of Sciences, 690022, Vladivostok.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Tetraphenylantimony(V) O,O″-dialkyl dithiophosphates [Sb(C 6H5)4{S2P(OR)2}] (R = s-C4H9, c-C6H11): synthesis, structures, and 13C and 31P CP/MAS NMR spectra2008In: Russian journal of coordination chemistry, ISSN 1070-3284, E-ISSN 1608-3318, Vol. 34, no 7, p. 527-535Article in journal (Refereed)
    Abstract [en]

    Tetraphenylantimony(V) O,O′-di-sec-butyl dithiophosphate (I) and tetraphenylantimony(V) O,O′-dicyclohexyl dithiophosphate (II) [Sb(C 6H5)4{S2P(OR)2}] (R = sec-C4H9 or cyclo-C6H11) were obtained. Their structures and spectroscopic properties were studied by X-ray diffraction analysis and 13C and 31P CP/MAS NMR spectroscopy. The dithiophosphate (Dtph) ligands in complexes I and II were found to be coordinated in S-monodentate and S,S′-bidentate fashions, respectively (MAS NMR data). According to X-ray diffraction data, the coordination polyhedron of antimony in molecular structure I is a trigonal bipyramid with unusual monodentate coordination of the Dtph group in the axial position.

  • 280.
    Ivanov, Maxim A.
    et al.
    Institute of Geology and Nature Management, Far East Branch, Russian Academy of Sciences, Blagoveshchensk.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Sharutin, Vladimir V.
    Blagoveshchensk State Pedagogical University.
    Ivanov, Alexander V.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Pakusina, Antonya P.
    Blagoveshchensk State Pedagogical University.
    Pushilin, Mikhail A.
    Institute of Chemistry, Far Eastern Branch of the Russian Academy of Sciences.
    Forsling, Willis
    Preparation and structural organisation of heteroleptic tetraphenylantimony(V) complexes comprising unidentately and bidentately coordinated O,O'-dialkyldithiophosphate groups: multinuclear (C-13 P-31) CP/MAS NMR and single-crystal X-ray diffraction studies2007In: Inorganica Chimica Acta, ISSN 0020-1693, E-ISSN 1873-3255, Vol. 360, no 9, p. 2897-2904Article in journal (Refereed)
    Abstract [en]

    O,O′-dipropyldithiophosphate and O,O′-di-iso-butyldithiophosphate (Dtph) tetraphenylantimony(V) complexes of the general formula [Sb(C6H5)4{S2P(OR)2}] (R = C3H7, i-C4H9) were prepared and studied by means of 13C, 31P CP/MAS NMR spectroscopy and single-crystal X-ray diffraction. Distorted octahedral and trigonal bipyramidal molecular structures have been established for prepared complexes. These unexpected structural distinctions between chemically related compounds are defined by the principally different coordination modes of O,O′-dipropyldithiophosphate and O,O′-di-iso-butyldithiophosphate ligands in their molecular structures (i.e., S,S′-bidentate chelating and S-unidentately coordinated, respectively). To characterise quantitatively phosphorus sites in both species of dithiophosphate ligands, 31P chemical shift anisotropy parameters (δaniso and η) were calculated from spinning sideband manifolds in MAS NMR spectra. The 31P chemical shift tensors for the bidentate chelating and unidentately coordinated dithiophosphate ligands display a profoundly rhombic and nearly axially symmetric characters, respectively.

  • 281.
    Ivanov, Maxim A.
    et al.
    Institute of Geology and Nature Management, Far Eastern Branch of the Russian Academy of Sciences.
    Larsson, Anna-Carin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Ivanov, Alexander V.
    Institute of Geology and Nature Management, Far Eastern Branch of the Russian Academy of Sciences .
    Gerasimenko, Andrey V.
    Institute of Chemistry, Far Eastern Branch of the Russian Academy of Sciences.
    Merkulov, Eugene B.
    Institute of Chemistry, Far Eastern Branch of the Russian Academy of Sciences.
    An example of S,S′-bidentate coordination mode of the dithiophosphate group in the heteroleptic tetraphenylantimony(V) complex, [Sb(C6H5)4{S2P(O-cyclo-C6H11)2}]: multinuclear (13C, 31P) CP MAS NMR, single-crystal X-ray diffraction studies and thermal behaviour2017In: Polyhedron, ISSN 0277-5387, E-ISSN 1873-3719Article in journal (Refereed)
    Abstract [en]

    Crystalline O,O′-di-cyclo-hexyl dithiophosphate (Dtph) tetraphenylantimony(V) complex, [Sb(C6H5)4{S2P(O-cyclo-C6H11)2}] (1) was prepared and studied by means of heteronuclear (31C, 31P) CP MAS NMR spectroscopy, single-crystal X-ray diffraction and thermal analysis. To characterise quantitatively the phosphorous site in complex 1, 31P chemical shift anisotropy parameters (δaniso and η) were successfully defined from spinning sideband manifolds in experimental MAS NMR spectra. The positive sign of the calculated δaniso unambiguously reveals the terminal S,S′-chelating structural function of di-cyclo-hexyl Dtph groups; whereas, the minimal δ22 value among all presently known tetraphenylantimony(V) dialkyl Dtphs points out to extremely low value of the S–P–S angle. Distorted octahedral molecular structure comprising Dtph ligand with S,S′-bidentate chelating coordination mode has been established for the prepared complex. Therefore, in comparison with tetraphenylantimony(V) Dtph complexes containing S-unidentately coordinated Dtph groups, terminally chelating di-cyclo-hexyl Dtph ligand of crystalline complex 1 expectedly exhibits the smallest S–P–S angle of 113.49°. The thermal behaviour of this compound was studied by means of thermal analysis technique as a combination of TG and DSC. The thermal decomposition involves the organic and inorganic parts of 1, yielding almost equal quantities of Sb2S3 and SbPO4, which were identified using powder XRD.

  • 282.
    Jain, Achint K.
    et al.
    Department of Pharmaceutics, Indian Institute of Technology, Banaras Hindu University.
    Mishra, Sandeep Kumar
    Department of Pharmaceutics, Indian Institute of Technology (Banaras Hindu University), Varanasi.
    Rao Vuddanda, Parameswara
    Department of Pharmaceutics, Indian Institute of Technology (Banaras Hindu University), Varanasi.
    Singh, Sanjay Kumar
    Department of Pharmaceutics, Indian Institute of Technology, Banaras Hindu University, Varanasi, Uttar Pradesh.
    Singh, Royana S.
    Department of Anatomy, Institute of Medical Sciences, Banaras Hindu University, Varanasi.
    Singh, Sanjay
    Department of Pharmaceutics, Indian Institute of Technology, Banaras Hindu University, Varanasi, Uttar Pradesh.
    Targeting of diacerein loaded lipid nanoparticles to intra-articular cartilage using chondroitin sulfate as homing carrier for treatment of osteoarthritis in rats2014In: Nanomedicine: Nanotechnology, Biology and Medicine, ISSN 1549-9634, E-ISSN 1549-9642, Vol. 10, no 5, p. 1031-1040Article in journal (Refereed)
    Abstract [en]

    Targeted delivery of antiosteoarthritic drug diacerein to articular tissue could be a major achievement and soluble polysaccharide chondroitin sulfate (ChS) may be a suitable agent for this. Therefore, diacerein loaded solid lipid nanoparticles modified with ChS (ChS-DC-SLN) were prepared for synergistic effect of these agents to combat multidimensional pathology of osteoarthritis (OA). Prepared formulation were of size range 396. ±. 2.7. nm, showed extended release up to 16. h and increased bioavailability of diacerein by 2.8 times. ChS-DC-SLN were evaluated for their effect on histopathology of femoro-tibial joint of rat knee and amount of ChS and rhein (an active metabolite of diacerein) at targeted site. Concentration of rhein was significantly higher in case of ChS-DC-SLN (7.8. ±. 1.23. μg/ml) than that of drug dispersion (2.9. ±. 0.45. μg/ml). It can be stated that ChS served as homing to articular cartilage for targeting of drug. Thus, ChS-DC-SLN have great potential to enhance the overall efficacy of treatment for OA. From the Clinical Editor: This study demonstrates the feasibility of targeted delivery of diacerein to articular tissue using soluble polysaccharide chondroitin sulfate as the targeting vector. This approach has the potential to significantly increase anti-arthritic drug concentration in joints without leading to systemic toxicity

  • 283.
    Jarlbring, Mathias
    Luleå tekniska universitet.
    Characterisation and surface reactions of iron oxides and fluorapatite in aqueous suspensions2004Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    The final objective of this study is to produce chemical models of flotation- like systems, including oxidation products of magnetite (maghemite and hematite) together with apatite. This is started by investigating the acid base properties, surface complexation and surface characteristics of the systems hematite-H+ and maghemite-H+ (paper I), fluorapatite-OH- (paper II) and a mixed system of maghemite-fluorapatite-OH- (paper III). Synthetic minerals were prepared and characterised with BET, SEM, XRD, FT-IR and FT- Raman. The acid base properties were investigated using high precision emf potentiometric titrations and z-potential measurements. Titration data were interpreted using models based on the theory of surface complexation, assuming the formation of surface complexes with charge dependent formation constants. The constant capacitance model was applied to interpret titration data for all three systems. The obtained models will contribute to a better understanding of the reactions during the apatite/magnetite separation by flotation. The surface site density Ns (sites/nm2) for maghemite was found to be very low compared to other iron oxides. The mixed system of maghemite and fluorapatite was interpreted with two different models. FT-Raman together with the Ns (sites/nm2) value reveals that interactions occurred between the fluorapatite and maghemite particles in the system. These interactions have to be chemical or sterical, because both surfaces are negatively charged in the actual pH-range.

  • 284.
    Jarlbring, Mathias
    Luleå tekniska universitet.
    Surface reactions in aqueous suspensions of fluorapatite and iron oxides2006Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The main objectives have been to study and model surface reactions of aqueous suspen-sions of minerals with relevance to the dephosphorization of iron oxides by reverse froth flotation. Synthetic hematite, maghemite and fluorapatite in colloidal forms were prepared and thoroughly characterized using XRD, SEM, BET, FT-IR and FT-Raman. The protolytic surface reactions were studied by means of high precision potentiometric titrations at two different ionic strengths. The æ-potentials were measured as a function of pH for maghemite and fluorapatite in aqueous suspensions at 0.10 mol dm-3 ionic strength. Surface complex equilibria according to the constant capacitance model (CCM) were established for aqueous single minerals as well as for a mixed mineral suspension of fluorapatite-maghemite. Two different models were adopted for the mixed system. It was found that a model based on the results from the subsystems of fluorapatite and maghemite interpreted titration data extremely well and information about the interac-tions between the two minerals was obtained by this model as well. These interactions were confirmed by SEM/X-ray mapping and FT-Raman spectroscopy. Solid state nu-clear magnetic resonance (NMR) spectroscopy was used to achieve information about the surface reactions of fluorapatite on the molecular level and merge this knowledge with the results from the surface complex model calculations. By means of 1H and 31P MAS NMR the phosphorus and calcium hydroxyl surface sites of fluorapatite were as- signed and their composition and mutual ratio were studied as a function of pH. The adsorption of maghemite and Fe2+-ions as well as the adsorption of the flotation re-agent ATRAC on the fluorapatite surface were studied using 1H and 31P MAS NMR. Maghemite particles and Fe2+-ions were found to be adsorbed in a close vicinity of the 31P nuclei. This was indicated by an increasing broad spinning side band manifold with increasing iron adsorption in the 31P MAS NMR spectra, caused by the influence on the chemical shift anisotropy (CSA) of the 31P nuclei due to the paramagnetic properties of the adsorbed iron species. The adsorption of ATRAC was found to be depending on both pH and concentration. The results from FT-IR and NIR-Raman spectroscopy of ATRAC in ethanol solutions including added calcium nitrate displayed that ATRAC contains four carbonyl functions which are clearly affected by the presence of Ca2+-ions, which indicate their importance on the adsorption of ATRAC at the fluorapatite surface.

  • 285.
    Jarlbring, Mathias
    et al.
    Luleå tekniska universitet.
    Gunneriusson, Lars
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Forsling, Willis
    Characterisation of the protolytic properties of synthetic carbonate free fluorapatite2005In: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 285, no 1, p. 206-211Article in journal (Refereed)
    Abstract [en]

    The acid/base surface properties of carbonate free fluorapatite (Ca 5(PO4)3F) have been characterised using high precision potentiometric titrations and surface complex modelling. Synthetic carbonate free fluorapatite was prepared and characterised by SEM, XRD, FT-IR and FT-Raman. The specific surface area was determined to be 17.7±1.2 m2g-1 with BET (N2 adsorption). The titrations were performed at 25±0.2°C, within the pH range 5.7-10.8, in 0.10 and 0.50 mol dm -3 NaNO3 ionic media. Experimental data were interpreted using the constant capacitance model and the software FITEQL 4.0. The surface equilibria: S1OH ⇄ S1O- + H+ lgβ-110s (int), S2OH ⇄ S2O- + H+ lgβ-101s (int) well describes the surface characteristics of synthetic fluorapatite. The equilibrium constants obtained were: lgβ-110s(int)=-6.33±0.05 and lgβ-101s(int)=-8.82±0.06 at I=0.10 moldm-3. At the ionic strength 0.50 mol dm-3, the equilibrium constants were slightly shifted to: lgβ-110s(int)=-6.43±0.05 and lgβ-101s(int)=-8.93±0.06. The number of active surface sites, Ns, was calculated from titration data and was found to be 2.95 and 2.34 sites nm-2 for the ionic strengths 0.10 and 0.50 mol dm-3, respectively. pHPZC or the IEP was found to be 5.7 from Z-potential measurements

  • 286.
    Jarlbring, Mathias
    et al.
    Luleå tekniska universitet.
    Gunneriusson, Lars
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Forsling, Willis
    Protolytic surface reactions of a fluorapatite-maghemite mixture in aqueous suspension2005In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 21, no 17, p. 7717-7721Article in journal (Refereed)
    Abstract [en]

    Synthetically prepared maghemite and fluorapatite, characterized with BET, SEM, XRD, FT-IR, and FT-Raman, are used to investigate the protolytic properties and surface characteristics in a mixed system of maghemite and fluorapatite by means of potentiometric titrations and surface complex modeling. Titrations were performed in the pH range of 7.3-10.5 at 25 ± 0.2 C in ionic media of 0.10 mol dm-3 NaNO3 with 0.0100 mol dm-3 HNO3 and 0.0100 mol dm-3 NaOH used as titrants. The constant capacitance model (CCM) was applied to interpret the titration data. Two models with different surface equilibria were tested. In the first model, the mixed system was treated as a one-component system with a total surface area of 40.04 ± 5.2 m2 g-1 without any consideration to the subsystems. The surface equilibria, XOH + H + XOH2+, lg (int) = 6.74 ± 0.07; XOH XO- + H +, lg (int) = -7.75 ± 0.07, were found to represent an accurate model for the system, and the specific capacitance was optimized to 2.0 F m-2. The number of active surface sites Ns was found to be 1.2 sites nm-2. This model has, however, no relation to the subsystems of maghemite and fluorapatite. The second model is related to the subsystems and displays the surface equilibria, S2OH S2O- + H +, lg (int) = -9.12 ± 0.01; FeOH + H + FeOH2+, lg (int) = 6.80 ± 0.01; FeOH FeO- + H +, lg (int) = -7.77 ± 0.01, where S2OH is related to fluorapatite and FeOH is representing maghemite. Fluorapatite corresponds to the dominating active surface in the system. The specific capacitance was optimized to 18 F m-2. The Ns values were found to be 2.27 sites nm-2 for fluorapatite and 0.80 sites nm-2 for maghemite. The Ns values together with evidence from the FT-Raman and SEM investigations reveal that interactions between maghemite and fluorapatite surfaces occur during the titration. The acid-base properties and surface characteristics of the subsystems maghemite-H+ and fluorapatite-OH- using the CCM have been published earlier.

  • 287.
    Jarlbring, Mathias
    et al.
    Luleå tekniska universitet.
    Gunneriusson, Lars
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Hussmann, Björn
    Technische Universität Hamburg-Harburg.
    Forsling, Willis
    Surface complex characteristics of synthetic maghemite and hematite in aqueous suspensions2005In: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 285, no 1, p. 212-217Article in journal (Refereed)
    Abstract [en]

    The acid-base properties of the maghemite (γ-Fe2O3)/water and hematite (α-Fe2O3)/water interfaces have been studied by means of high precision potentiometric titrations and the experimental results are evaluated as surface complexation reactions. Synthetic maghemite and hematite were prepared and characterized using a combination of SEM, FT-IR and XRD. The specific surface area of the minerals was determined by the BET method. The titrations were performed at 25.0± 0.2°C within the range 2.8 < pH < 8.5 NaNO3 ionic medium giving total ionic strengths of 0.10 and 0.50 mol dm-3 in both systems. Experimental data were evaluated using the constant capacitance model. The total proton exchange capacities of the solids were determined by saturation of the surfaces with excess acid. The number of protonated surface sites per nm2 was found to be 0.81 ± 0.05 and 1.03 ± 0.04 for maghemite, at I = 0.10 and 0.50 mol dm-3, respectively. The IEP for maghemite was determined from the ζ-potential using a Zetasizer 4 instrument.

  • 288.
    Jarlbring, Mathias
    et al.
    Luleå tekniska universitet.
    Sandström, Dan
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Forsling, Willis
    Characterization of active phosphorus surface sites at synthetic carbonate-free fluorapatite using single-pulse 1H, 31P, and 31P CP MAS NMR2006In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 22, no 10, p. 4787-4792Article in journal (Refereed)
    Abstract [en]

    The chemically active phosphorus surface sites defined as POx, POxH, and POxH2, where x = 1, 2, or 3, and the bulk phosphorus groups of PO43- at synthetic carbonate-free fluorapatite (Ca5(PO4)3F) have been studied by means of single-pulse 1H,31P, and 31P CP MAS NMR. The changes in composition and relative amounts of each surface species are evaluated as a function of pH. By combining spectra from single-pulse 1H and 31P MAS NMR and data from 31P CP MAS NMR experiments at varying contact times in the range 0.2-3.0 ms, it has been possible to distinguish between resonance lines in the NMR spectra originating from active surface sites and bulk phosphorus groups and also to assign the peaks in the NMR spectra to the specific phosphorus species. In the 31P CP MAS NMR experiments, the spinning frequency was set to 4.2 kHz; in the single-pulse 1H MAS NMR experiments, the spinning frequency was 10 kHz. The 31P CP MAS NMR spectrum of fluorapatite at pH 5.9 showed one dominating resonance line at 2.9 ppm assigned to originate from PO43- groups and two weaker shoulder peaks at 5.4 and 0.8 ppm which were assigned to the unprotonated POx (PO, PO2-, and PO32-) and protonated POxH (PO2H and PO3H-) surface sites. At pH 12.7, the intensity of the peak representing unprotonated POx surface sites has increased 1.7% relative to the bulk peak, while the intensity of the peaks of the protonated species POxH have decreased 1.4% relative to the bulk peak. At pH 3.5, a resonance peak at -4.5 ppm has appeared in the 31P CP MAS NMR spectrum assigned to the surface species POxH2 (PO3H2). The results from the 1H MAS and 31P CP MAS NMR measurements indicated that H+, OH-, and physisorbed H2O at the surface were released during the drying process at 200 °C.

  • 289.
    Javed, Muhammad Asadullah
    et al.
    NMR Research Unit, University of Oulu.
    Ahola, Susanna
    NMR Research Unit, University of Oulu.
    Håkansson, Pär
    NMR Research Unit, University of Oulu.
    Mankinen, Otto
    NMR Research Unit, University of Oulu.
    Aslam, Muhammad Kamran
    NMR Research Unit, University of Oulu.
    Filippov, Andrei
    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.
    Glavatskih, Sergei
    System and Component Design, Department of Machine Design, KTH Royal Institute of Technology.
    Antzutkin, Oleg N.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Telkki, Ville-Veikko
    NMR Research Unit, University of Oulu.
    Y Structure and dynamics elucidation of ionic liquids using multidimensional Laplace NMR2017In: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, Vol. 53, no 80, p. 11056-11059Article in journal (Refereed)
    Abstract [en]

    We demonstrate the ability of multidimensional Laplace NMR (LNMR), comprising relaxation and diffusion experiments, to reveal essential information about microscopic phase structures and dynamics of ionic liquids that is not observable using conventional NMR spectroscopy or other techniques.

  • 290.
    Johansson, Karin
    Luleå tekniska universitet.
    Solid state 29Si and 27Al magic angle spinning NMR studies of mechanochemically modified cement2001Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Solid state 29Si and 27Al magic angle spinning (MAS) NMR spectroscopy has been used to investigate how mechanochemical modification affects the hydration kinetics, as well as the structural and chemical properties, in cement blends. The modification comprises intensive treatment of rapid hardening Portland cement with condensed silica fume additive in a vibrating grinding mill. 29Si MAS NMR was utilised to follow the hydration reactions of calcium silicates at five different ages and with two different water/binder ratios. The hydration rate was higher in the cement pastes formed by the treated blends, especially at an early age, and more pronounced at high water/binder ratios. Variations in relative intensities of 29Si resonances suggest different structures of calcium silicate hydrate nets in the pastes. This can be correlated with enhanced compressive strength in cement pastes produced by modified blends. 27Al MAS NMR was used to characterise the coordination state of aluminium in anhydrous and hydrous aluminate and ferrite phases. The hydrated cement blends showed 27Al resonances characteristic of four-, five-, and six-coordinated aluminium. 1H-27Al CPMAS experiments revealed that only the octahedral phases are located in a proton-rich environment. The signal in the Al(IV) range is due to incorporation of aluminium in the hydrated silicate phases, and is most likely an intermediate formed prior to the octahedral hydration products. A higher Al(IV)/Al(VI) ratio in cement pastes formed by mechanochemically treated blends may contribute to increased early strength development.

  • 291. Johansson, Karin
    et al.
    Larsson, C.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Forsling, Willis
    Kota, Hanumantha Rao
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Ronin, Vladimir
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Reply to the discussion by Knut O. Kjellsen of the paper "Kinetics of the hydration reactions in the cement paste with mechanochemically modified cement: 29Si magic-angle-spinning NMR study"2000In: Cement and Concrete Research, ISSN 0008-8846, E-ISSN 1873-3948, Vol. 30, no 8, p. 1325-1328Article in journal (Refereed)
  • 292.
    Johansson, Karin
    et al.
    Luleå tekniska universitet.
    Larsson, Cecilia
    Luleå tekniska universitet.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Forsling, Willis
    Rao, K. Hanumantha
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Ronin, Vladimir
    Kinetics of the hydration reactions in the cement paste with mechanochemically modified cement 29Si magic-angle-spinning NMR study1999In: Cement and Concrete Research, ISSN 0008-8846, E-ISSN 1873-3948, Vol. 29, no 10, p. 1575-1581Article in journal (Refereed)
    Abstract [en]

    A comparative 29Si solid state NMR study of kinetics of the hydration reactions in cement pastes based on rapid-hardening ordinary Portland cement (SH) and on the mechanochemically modified cement (MSH) is presented. The mechanical activation of a cement/silica fume blend in a vibrating mill accelerates the hydration reactions by 15-20%, especially during the initial period of hardening. Variations in relative intensities of 29Si resonances assigned to the hydration products in SH/MSH blends suggest different structures of hydrated SH nets. This can be correlated with a pronounced increase of the MSH-cement binding capacity reported earlier.

  • 293.
    Johansson, U.
    et al.
    Luleå University of Technology.
    Holmgren, Allan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Forsling, Willis
    Frost, R.L.
    Queensland University of Technology, Centre for Instrumental and Developmental Chemistry.
    Adsorption of silane coupling agents onto kaolinite surfaces1999In: Clay minerals, ISSN 0009-8558, E-ISSN 1471-8030, Vol. 34, no 2, p. 239-246Article in journal (Refereed)
    Abstract [en]

    The adsorption of the silane coupling agents N-(2-amino-ethyl)-3-aminopropyltrimethoxysilane (Z-6020), N-(2-(vinylbenzyl-amino)-ethyl)-3-amino-propyl-trimethoxysilane (Z-6032) and 3-glycidoxy-propyl-trimethoxysilane (Z-6040) onto the surface of kaolinite has been studied using the solvents water and ethanol. The adsorbed silanes were analysed using diffuse reflectance Fourier transform infrared (DRIFT) spectroscopy and FT-Raman spectroscopy. When the silane coupling agents are dissolved in water, silanol groups are formed. Raman spectra of aqueous solutions of the silanes show that condensation of the silanols into oligomers occurred. The peak at 1000 cm(-1) assigned to Si-O-Si vibrations indicates that polymerization has occurred. A similar behaviour is observed when the silanes are dissolved in ethanol. The DRIFT spect-ra show that the silane coupling agents adsorb onto the surface of kaolinite, It is proposed that the oligomers are bonded to the kaolinite surface only by hydrogen bondings with no covalent bonds formed.

  • 294.
    Johansson, Ursula
    Luleå tekniska universitet.
    Spectroscopic studies of kaolinite surfaces1998Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    In this thesis, specific surface reactions on kaolinite have been investigated. The methods used are diffuse reflectance Fourier transform (DRIFT), FT-Raman and micro Raman spectroscopy. The deuterium exchange of the hydroxyl protons of kaolinite has been studied. Results show that long reaction time and increased temperature are needed for the deuteration to occur. A change in pH does not seem to influence the isotopic exchange. The adsorption of three silane coupling agents, starch and dextrin onto the kaolinite surface has been investigated. It is suggested that the adsorption occurs through hydrogen bonding. Studies of the hydroxyl vibrations of kaolinite in near-IR, mid-IR and Raman spectra were performed. Raman spectra were recorded at 298K and at 77K. Difference, combination and summation bands appear in near- and mid-IR spectra. Shifts of the hydroxyl bands, are observed in Raman spectra when kaolinite is cooled to 77K.

  • 295.
    Johansson, Ursula
    Luleå tekniska universitet.
    Surface reactions on Kaolinite studied by FT-spectroscopy1997Licentiate thesis, comprehensive summary (Other academic)
  • 296.
    Johansson, Ursula
    et al.
    Luleå tekniska universitet.
    Frost, Ray L.
    Queensland University of Technology.
    Forsling, Willis
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Kloprogge, Theo
    Queensland University of Technology.
    Raman spectroscopy of the kaolinite hydroxyls at 77 K1998In: Applied Spectroscopy, ISSN 0003-7028, E-ISSN 1943-3530, Vol. 52, no 10, p. 1277-1282Article in journal (Refereed)
    Abstract [en]

    Raman spectroscopy of two types of kaolinites has been obtained at liquid nitrogen temperature (77 K) with the use of a Raman microprobe and a thermal stage. The Raman spectrum is characterized by the combination of the frequencies of the inner hydroxyl and the inner surface hydroxyl groups. The inner hydroxyl frequency is reduced, and the outer hydroxyl frequencies move to higher frequencies upon cooling to 77 K. The inner hydroxyl frequency shifts from 3620 cm-1 at 298 K to 3615 cm-1 at 77 K. The two in-phase inner surface hydroxyl frequencies move from 3684 and 3689 cm-1 at 298 K to 3690 and 3699 cm-1 at 77 K. The two out-of-phase vibrations shift from 3650 and 3668 cm-1 to 3656 and 3675 cm-1. The bandwidth of the inner hydroxyl frequency decreases from 3.7 to 2.1 cm-1 at 77 K. The bandwidth of the inner surface hydroxyl frequency (upsilon 1) increases upon cooling from 17.4 to 19.2 cm-1. It is proposed that the increased resolution at low temperature enabled an additional inner surface hydroxyl frequency to be observed.

  • 297.
    Johansson, Ursula
    et al.
    Luleå tekniska universitet.
    Holmgren, Allan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Forsling, Willis
    Frost, Ray L.
    Queensland University of Technology.
    Isotopic exchange of kaolinite hydroxyl protons: a diffuse reflectance infrared Fourier transform spectroscopy study1998In: The Analyst, ISSN 0003-2654, E-ISSN 1364-5528, Vol. 123, no 4, p. 641-645Article in journal (Refereed)
    Abstract [en]

    Specific surface reactions on kaolinite were investigated by deuterium exchange of the hydroxyl protons of kaolinite, The kaolinite samples were reacted with deuterium oxide for 48 h and 2.5 and 5 weeks, at various pH values (3, natural and 8) and at different temperatures (ambient, and 30, 60 and 100 degrees C), Analyses were performed using diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy. The spectral results show that it is very difficult at room temperature to exchange the hydroxyl protons isotopically with deuterons at the surface of kaolinite, The temperature and the reaction time must be increased for successful exchange. It was found that the most suitable temperature for isotopic exchange was 60 degrees C. The pH did not significantly influence the deuteration, Only at high pH were changes of the OD bands in the DRIFT spectra observed, This study shows that it is possible to deuterate kaolinite without using intercalation. All three types of hydroxyl protons from the inner, inner surface and edge were exchanged.

  • 298.
    Johnson, Bruce B.
    et al.
    La Trobe University.
    Ivanov, Alexander V.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Forsling, Willis
    31P nuclear magnetic resonance study of the adsorption of phosphate and phenyl phosphates on γ-Al2O32002In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 18, no 4, p. 1104-1111Article in journal (Refereed)
    Abstract [en]

    Adsorption of diphenyl-, phenyl- and orthophosphate on γ-Al2O3 was studied with a combination of macroscopic and 31P solid-state NMR measurements. Results for adsorption suggest that diphenyl phosphate was bound largely as an outer-sphere complex, while phenyl phosphate was held largely as inner-sphere surface complexes with an outer-sphere complex present only at higher pH values. Both the adsorption edge and the cross polarization magic angle spinning NMR spectra were consistent with the interaction between the surface and phenyl phosphate being driven by electrostatic forces. Adsorption of orthophosphate was more complex, with evidence of outer- and inner-sphere complexes and surface precipitation. Increasing the orthophosphate concentration and equilibration time tended to increase the fraction bound as a surface precipitate.

  • 299.
    Jolsterå, Rickard
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Reactions at the water-mineral interface of olivine and silicate modified maghemite2010Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    The main objectives for this licentiate thesis have been to study and model the reactions at the water-mineral interface of two subsystems: maghemite-H+-silicate and olivine-H+. An increased knowledge of these systems will make it possible to further extend the complexity of the aqueous phase in future experiments. This will make it possible to further approach a composition that resembles the flotation and agglomeration process water in the production of iron ore pellets. To be able to characterise and predict the influence of different species from the process water on the different mineral particle surfaces, is an important step towards optimisation of the pellet production process and increased recirculation of the process water. Both synthetic and natural minerals were used in the experiments, in which the protolytic surface exchange reactions of the subsystems were analysed by high precision potentiometric titrations. The minerals and their surfaces were characterised using XRD, XPS, SEM-EDS and BET, both before and after the experiments. The zeta potential of olivine and silicate modified maghemite particles were also determined as a function of pH. Surface complexation models were derived to describe the reactions in the systems. The Constant Capacitance Model (CCM) was used to model the experimental results.The evaluation of the potentiometric data from the studies of the maghemite-H+-silicate system indicates that soluble silicates will mainly adsorb to maghemite as monodentate surface species at the defined experimental conditions. Models including polymerisation of adsorbed silicates and/or bidentate silicate ligands were tested, but could not well be fitted to titration data. The adsorption maximum of silicates was found to be within the range pH 9.0 to 9.5. At the experimental conditions used, approximately 82 % of the added silicate was adsorbed. At higher pH, the silicate started to desorb from the maghemite surface and at pH 11.1 only 60 % was still adsorbed. Olivine ((Mg,Fe)2SiO4), one of the major rock forming silicate minerals in nature, is added in the agglomeration process to improve the performance of the iron ore pellets in the blast furnace. The results from the studies of the olivine - H+ system shows that the dissolution of olivine is essentially incongruent, with an excess of magnesium ions released in to the aqueous suspension. Studies of olivine samples equilibrated in electrolytes with magnesium ions added using XPS, SEM and zeta potential measurements have also shown that the magnesium ion release and adsorption at the surface layers is reversible, no support for surface precipitation of new phases as Mg(OH)2 could be found. Experimental potentiometric data of olivine-H+ at alkaline conditions was successfully fitted to a two pKa electrostatically corrected model. The importance of steady state conditions when acquiring titration data was illustrated by comparing the amount of active surface sites detected by steady state titrations and considerably faster titrations.

  • 300.
    Jolsterå, Rickard
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Surface reactions of magnetite and maghemite with dissolved and added ions in process water2012Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Reactions between mineral surfaces and dissolved species in process water, both inorganic and organic play an important role in mineral processing. Reverse flotation of finely comminuted iron ore is sometimes employed in order to remove the phosphorous mineral apatite. An anionic collector, designed to specifically adsorb at the calcium specific surface sites of apatite is added, rendering the apatite particles hydrophobic properties. However, some of the collector adsorbs also at the magnetite surfaces, thereby introducing undesired characteristics to the upgraded iron ore concentrate.Of this reason, magnetite and maghemite surfaces and their interactions with the most abundant and important ions in the process water during flotation, and their potential influence on collector adsorption at magnetite was studied. Maghemite was included in the experiments, since previous work had shown that oxidation of the magnetite surface into maghemite may occur during the processing of the iron ore concentrate. The complex system that the dissolved ions in the process water and the iron oxide particles constitute at flotation and agglomeration was divided into smaller subsystems.The protolytic characteristics for the magnetite-H+ and maghemite-H+ systems proved to be similar when their modelled intrinsic surface complexation constants were compared. However, the surface site density of magnetite was found to be 50 % greater than for maghemite. Both potentiometric titrations and ATR-FTIR spectroscopy were used to study and characterize the adsorption of silicate. The results from the surface complexation modelling suggested that the silicate adsorbed as monodentate surface complexes at the maghemite surfaces. The results showed a silicate adsorption maximum at pH 8.5 to 9.5 for both iron oxides. Within this range pH, the surface complex ΞFeOSiO(OH)2 - was proposed as the dominating surface specie in the maghemite-silicate system.The iron ore pellet additive olivine proved to release substantial amounts of Mg2+ when immersed in water, indicating that olivine probably is the main source of Mg2+ to the process water. Thus, the surface characteristic of olivine particles in water suspensions was studied. Since olivine proved to be a significant source of magnesium ions, adsorption of Mg2+ at maghemite and magnetite was studied and modelled. The results suggested that magnesium ions adsorbed as a mix of mono- and bidentate surface complexes when the number of surface sites was in excess. Increased amounts of Mg2+ i.e., ≥1 Mg2+ site-1, resulted in a model including only monodentate surface complexes.Experiments involving competitive adsorption of carbonate and silicate showed that added silicate replaced adsorbed carbonate. Other competitive experiments, with Mg2+ and Ca2+, showed that Mg2+ had a stronger affinity for the magnetite surface than Ca2+. The preferential adsorption of Mg2+ at the iron oxide surface may then have protective properties, by preventing adsorption of the calcium specific collector. Results from both in-situ ATR-FTIR spectroscopy and contact angle measurements indicated also that added Mg2+ reduced the adsorption of collector and thereby increased the wettability of the magnetite surfaces.

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