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Shimpi, Manishkumar R.ORCID iD iconorcid.org/0000-0001-7469-4197
Alternative names
Publications (10 of 17) Show all publications
Srivastava, K., Shukla, A., Karthick, T., Velaga, S., Tandon, P., Sinha, K. & Shimpi, M. R. (2019). Molecular structure, spectroscopic signature and reactivity analyses of paracetamol hydrochloride monohydrate salt using density functional theory calculations. CrystEngComm, 21(5), 857-865
Open this publication in new window or tab >>Molecular structure, spectroscopic signature and reactivity analyses of paracetamol hydrochloride monohydrate salt using density functional theory calculations
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2019 (English)In: CrystEngComm, ISSN 1466-8033, E-ISSN 1466-8033, Vol. 21, no 5, p. 857-865Article in journal (Refereed) Published
Abstract [en]

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

Place, publisher, year, edition, pages
Royal Society of Medicine Press, 2019
National Category
Physical Chemistry Other Health Sciences
Research subject
Chemistry of Interfaces; Health Science
Identifiers
urn:nbn:se:ltu:diva-72732 (URN)10.1039/C8CE01761A (DOI)000458828500009 ()
Note

Validerad;2019;Nivå 2;2019-01-31 (johcin)

Available from: 2019-01-30 Created: 2019-01-30 Last updated: 2019-03-11Bibliographically approved
Verma, P., Srivastava, A., Shukla, A., Tandon, P. & Shimpi, M. R. (2019). Vibrational spectra, hydrogen bonding interactions and chemical reactivity analysis of nicotinamide–citric acid cocrystals by an experimental and theoretical approach. New Journal of Chemistry, 43(40), 15956-15967
Open this publication in new window or tab >>Vibrational spectra, hydrogen bonding interactions and chemical reactivity analysis of nicotinamide–citric acid cocrystals by an experimental and theoretical approach
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2019 (English)In: New Journal of Chemistry, ISSN 1144-0546, E-ISSN 1369-9261, Vol. 43, no 40, p. 15956-15967Article in journal (Refereed) Published
Abstract [en]

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

Place, publisher, year, edition, pages
Royal Society of Chemistry, 2019
National Category
Physical Chemistry
Research subject
Chemistry of Interfaces
Identifiers
urn:nbn:se:ltu:diva-76508 (URN)10.1039/C9NJ03085A (DOI)2-s2.0-85073613645 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-10-25 (johcin)

Available from: 2019-10-25 Created: 2019-10-25 Last updated: 2019-11-04Bibliographically approved
Shimpi, M. R., Al-Hayali, A., Cavanagh, K. L., Rodríguez- Hornedo, N. & Velaga, S. P. (2018). Tadalafil-malonic acid cocrystal: Physicochemical characterization, pH-solubility and supersaturation studies. Crystal Growth & Design, 18(8), 4378-4387
Open this publication in new window or tab >>Tadalafil-malonic acid cocrystal: Physicochemical characterization, pH-solubility and supersaturation studies
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2018 (English)In: Crystal Growth & Design, ISSN 1528-7483, E-ISSN 1528-7505, Vol. 18, no 8, p. 4378-4387Article in journal (Refereed) Published
Abstract [en]

The purpose of this study was to enhance the solubility and dissolution of a poorly water-soluble drug, tadalafil (TDF), by cocrystal formation with malonic acid (MOA), to characterize the cocrystal structure, and to quantify the cocrystal solution behavior. The crystal structure revealed a 1:1 stoichiometry wherein the TDF molecules form a double layered structure through N–H…O=C interactions linked to a catemeric chain of MOA molecules via O-H…O hydrogen bonds. Cocrystal solubility advantage (SA defined as Scocrystal/Sdrug) or supersaturation index was determined from eutectic point measurements to be 102 to 129 in the pH range of 1 to 3. Cocrystal dissolution generated supersaturation levels (Cmax/Sdrug) of 30 in buffer and 120 in the presence of a nucleation inhibitor, HPMC. The amorphous form of TDF generated supersaturation 3 times lower than cocrystal in buffer, and not significantly different from cocrystal in the presence of HPMC. Thus, supersaturation index is a valuable metric for assessing the risk of cocrystal conversion during kinetic studies and for predicting conditions when the usage of a precipitation inhibitor may significantly increase cocrystal exposure levels.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2018
National Category
Other Health Sciences Physical Chemistry
Research subject
Health Science; Chemistry of Interfaces
Identifiers
urn:nbn:se:ltu:diva-69663 (URN)10.1021/acs.cgd.8b00362 (DOI)000440956100024 ()
Note

Validerad;2018;Nivå 2;2018-08-02 (rokbeg)

Available from: 2018-06-19 Created: 2018-06-19 Last updated: 2019-09-23Bibliographically approved
Shimpi, M., Velaga, S., Shah, F. U. & Antzutkin, O. (2017). Pharmaceutical Crystal Engineering Using Ionic Liquid Anion–Solute Interactions. Crystal Growth & Design, 17(4), 1729-1734
Open this publication in new window or tab >>Pharmaceutical Crystal Engineering Using Ionic Liquid Anion–Solute Interactions
2017 (English)In: Crystal Growth & Design, ISSN 1528-7483, E-ISSN 1528-7505, Vol. 17, no 4, p. 1729-1734Article in journal (Refereed) Published
Abstract [en]

The main purpose of this work was to investigate the potential of ionic liquids (ILs) in crystal engineering. We have employed ILs with different combinations of cations and anions to study their role in directing crystal structure formation of a nicotinamide (NIC) and oxalic acid (OXA) system. A new crystal form of NIC–OXA salt (2:1) was identified and characterized using standard solid state tools such as powder X-ray diffraction, differential scanning calorimetry, thermogravimetric analysis, and Raman and infrared spectroscopy. The crystal structure of the 2:1 salt was elucidated using single-crystal X-ray diffraction. The NIC–OXA 2:1 salt form revealed a two-dimensional layered structure, while the known 1:1 salt had a perpendicular “tape-like” structure. The 2:1 salt form could only be crystallized from the ILs possessing hydrogen bond acceptor functionality. We demonstrated that specific ILs could be selected as solvents for altering the solid-state structure of organic and inorganic materials.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2017
National Category
Physical Chemistry Other Health Sciences
Research subject
Chemistry of Interfaces; Health Science
Identifiers
urn:nbn:se:ltu:diva-62372 (URN)10.1021/acs.cgd.6b01698 (DOI)000398884400035 ()2-s2.0-85017106217 (Scopus ID)
Note

Validerad; 2017; Nivå 2; 2017-04-06 (rokbeg)

Available from: 2017-03-09 Created: 2017-03-09 Last updated: 2018-12-14Bibliographically approved
Ahmed, H., Shimpi, M. R. & Velaga, S. P. (2017). Relationship between mechanical properties and crystal structure in cocrystals and salt of paracetamol (ed.). Drug Development and Industrial Pharmacy, 43(1), 89-97
Open this publication in new window or tab >>Relationship between mechanical properties and crystal structure in cocrystals and salt of paracetamol
2017 (English)In: Drug Development and Industrial Pharmacy, ISSN 0363-9045, E-ISSN 1520-5762, Vol. 43, no 1, p. 89-97Article in journal (Refereed) Published
Abstract [en]

Objectives were to study mechanical properties of various solid forms of paracetamol and relate to their crystal structures. Paracetamol Form I (PRA), its cocrystals with oxalic acid (PRA-OXA) and 4,4-bipyridine (PRA-BPY) and hydrochloride salt (PRA-HCL) were selected. Cocrystals and salt were scaled-up using rational crystallization methods. The resulting materials were subjected to differential scanning solid-state characterization. The powders were sieved and 90-360 µm sieve fraction was considered. These powders were examined by scanning electron microscopy (SEM) and densities were determined. Tablets were made at applied pressures of 35-180 MPa under controlled conditions and the tablet height, diameter and hardness were measured. Tensile strength and porosity of the tablets were estimated using well known models. Crystal structures of these systems were visualized and slips planed were identified. Cocrystal and salt of PRA were physically pure. Sieved powders had comparable morphologies and particle size. The apparent and theoretical densities of powders were similar but no clear trends were observed. The tensile strengths of these compacts were increased with increasing pressure whereas tabletability decreased in the order oxalic acid > PRA-HCL ≈ PRA-OXA > BPY > PRA-BPY. Tablet tensile strength decreases exponentially with increasing porosity with the exception of PRY-BPY and BPY. Slip plane prediction based on attachment energies may not be independently considered. However, it was possible to explain the improved mechanical properties of powders based on the crystal structure. Cocrystallization and salt formation have introduced structural features that are responsible for improved tableting properties of PRA.

Place, publisher, year, edition, pages
Taylor & Francis, 2017
National Category
Other Health Sciences Physical Chemistry
Research subject
Health Science; Chemistry of Interfaces
Identifiers
urn:nbn:se:ltu:diva-14404 (URN)10.1080/03639045.2016.1220568 (DOI)000394022300010 ()27486671 (PubMedID)2-s2.0-84983364665 (Scopus ID)dc140b53-84da-46de-b395-b9ad22a9730d (Local ID)dc140b53-84da-46de-b395-b9ad22a9730d (Archive number)dc140b53-84da-46de-b395-b9ad22a9730d (OAI)
Note

Validerad; 2017; Nivå 2; 2017-01-23 (rokbeg)

Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-11-15Bibliographically approved
Wang, Y., Shimpi, M., Sarman, S. S., Antzutkin, O., Glavatskih, S., Kloo, L. & Laaksonen, A. (2016). Atomistic insight into tetraalkylphosphonium-bis(oxalato)borate ionic liquid/water mixtures: 2. Volumetric and Dynamic Properties (ed.). Journal of Physical Chemistry B, 120(30), 7446-7455
Open this publication in new window or tab >>Atomistic insight into tetraalkylphosphonium-bis(oxalato)borate ionic liquid/water mixtures: 2. Volumetric and Dynamic Properties
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2016 (English)In: Journal of Physical Chemistry B, ISSN 1520-6106, E-ISSN 1520-5207, Vol. 120, no 30, p. 7446-7455Article in journal (Refereed) Published
Abstract [en]

Atomistic simulations have been performed to investigate the microscopic structural organization of aqueous solutions of trihexyltetradecylphosphonium bis(oxalato)borate ([P6,6,6,14][BOB]) ionic liquid (IL). The evolution of the microscopic liquid structure and the local ionic organization of IL/water mixtures as a function of the water concentration is visualized and systematically analyzed via radial and spatial distribution functions, coordination numbers, hydrogen bond network, and water clustering analysis. The microscopic liquid structure in neat IL is characterized by a connected apolar network composed of the alkyl chains of [P6,6,6,14] cations and isolated polar domains consisting of the central segments of [P6,6,6,14] cations and [BOB] anions, and the corresponding local ionic environment is described by direct contact ion pairs. In IL/water mixtures with lower water mole fractions, the added water molecules are dispersed and embedded in cavities between neighboring ionic species and the local ionic structure is characterized by solvent-shared ion pairs through cation-water-anion triple complexes. With a gradual increase in the water concentration in IL/water mixtures, the added water molecules tend to aggregate and form small clusters, intermediate chain-like structures, large aggregates, and eventually a water network in water concentrated simulation systems. A further progressive dilution of IL/water mixtures leads to the formation of self-organized micelle-like aggregates characterized by a hydrophobic core and hydrophilic shell consisting of the central polar segments in [P6,6,6,14] cations and [BOB] anions in a highly branched water network. The striking structural evolution of the [P6,6,6,14][BOB] IL/water mixtures is rationalized by the competition between favorable hydrogen bonded interactions and strong electrostatic interactions between the polar segments in ionic species and the dispersion interactions between the hydrophobic alkyl chains in [P6,6,6,14] cations

National Category
Physical Chemistry
Research subject
Chemistry of Interfaces
Identifiers
urn:nbn:se:ltu:diva-15193 (URN)10.1021/acs.jpcb.6b02921 (DOI)000381235800015 ()27387981 (PubMedID)2-s2.0-84982854550 (Scopus ID)eafce11a-b303-45be-8852-7dd6bf732ea7 (Local ID)eafce11a-b303-45be-8852-7dd6bf732ea7 (Archive number)eafce11a-b303-45be-8852-7dd6bf732ea7 (OAI)
Note

Validerad; 2016; Nivå 2; 20160817 (andbra)

Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Prajapati, P., Pandey, J., Shimpi, M., Srivastava, A., Tandon, P., Velaga, S. & Sinha, K. (2016). Combined spectroscopic and quantum chemical studies of ezetimibe (ed.). Journal of Molecular Structure, 1125, 193-203
Open this publication in new window or tab >>Combined spectroscopic and quantum chemical studies of ezetimibe
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2016 (English)In: Journal of Molecular Structure, ISSN 0022-2860, E-ISSN 1872-8014, Vol. 1125, p. 193-203Article in journal (Refereed) Published
Abstract [en]

Ezetimibe (EZT) is a hypocholesterolemic agent used for the treatment of elevated blood cholesterol levels as it lowers the blood cholesterol by blocking the absorption of cholesterol in intestine. Study aims to combine experimental and computational methods to provide insights into the structural and vibrational spectroscopic properties of EZT which is important for explaining drug substance physical and biological properties. Computational study on molecular properties of ezetimibe is presented using density functional theory (DFT) with B3LYP functional and 6-311++G(d,p) basis set. A detailed vibrational assignment has been done for the observed IR and Raman spectra of EZT. In addition to the conformational study, hydrogen bonding and molecular docking studies have been also performed. For conformational studies, the double well potential energy curves have been plotted for the rotation around the six flexible bonds of the molecule. UV absorption spectrum was examined in methanol solvent and compared with calculated one in solvent environment (IEF-PCM) using TD-DFT/6-31G basis set. HOMO-LUMO energy gap of both the conformers have also been calculated in order to predict its chemical reactivity and stability. The stability of the molecule was also examined by means of natural bond analysis (NBO) analysis. To account for the chemical reactivity and site selectivity of the molecules, molecular electrostatic potential (MEPS) map has been plotted. The combination of experimental and calculated results provide an insight into the structural and vibrational spectroscopic properties of EZT. In order to give an insight for the biological activity of EZT, molecular docking of EZT with protein NPC1L1 has been done.

National Category
Physical Chemistry Other Health Sciences
Research subject
Health Science
Identifiers
urn:nbn:se:ltu:diva-11371 (URN)10.1016/j.molstruc.2016.06.070 (DOI)000384785100020 ()2-s2.0-84977267315 (Scopus ID)a5232fd0-c67e-4e39-8bef-97b581b12e77 (Local ID)a5232fd0-c67e-4e39-8bef-97b581b12e77 (Archive number)a5232fd0-c67e-4e39-8bef-97b581b12e77 (OAI)
Note

Validerad; 2016; Nivå 2; 20160630 (andbra)

Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Pandey, J., Prajapati, P., Shimpi, M., Tandon, P., Velaga, S., Srivastava, A. & Sinha, K. (2016). Studies of molecular structure, hydrogen bonding and chemical activity of a nitrofurantoin-L-proline cocrystal: a combined spectroscopic and quantum chemical approach (ed.). RSC Advances, 6(78), 74135-74154
Open this publication in new window or tab >>Studies of molecular structure, hydrogen bonding and chemical activity of a nitrofurantoin-L-proline cocrystal: a combined spectroscopic and quantum chemical approach
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2016 (English)In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 6, no 78, p. 74135-74154Article in journal (Refereed) Published
Abstract [en]

Nitrofurantoin (NTF) has been used as an antibacterial drug to treat bacterial infections of the urinary tract. The purpose of this work is to predict the hydrogen bonds (potential synthons) present in the cocrystal of nitrofurantoin-L-proline (NTF-LP) through a computational approach (DFT calculations) and validate using vibrational spectroscopic studies. The present study illustrates the formation and characterization of the cocrystal of NTF-LP. The molecular structure of the NTF-LP cocrystal has been predicted by forming several models on the basis of the hydrogen bonding patterns observed in other NTF cocrystals. A conformational study and potential energy surface scan have been plotted around three flexible bonds of the cocrystal molecule and two stable conformers have been obtained. NBO analysis of the second order perturbation theory of the Fock matrix suggests that interaction n1O(39) → σ*(N13–H21) is responsible for the stabilization of the molecule. Quantum theory of atoms in molecules (QTAIM) explains that all interactions are medium and partially covalent in nature as ∇2ρBCP > 0, HBCP < 0. The molecular electrostatic potential surface (MEPS) of the cocrystal has been visualized for its most electropositive potential in the region of the NH2+ group and most electronegative potential in the vicinity of the COO− group. The HOMO and LUMO energies and electronic charge transfer (ECT) confirms that charge flows from the co-former (LP) to NTF (API). Local reactivity descriptor parameters have been used to predict the reactive sites of the cocrystal and global reactivity descriptor parameters suggest that the cocrystal is softer thus more reactive in comparison to NTF. The experimental and theoretical results support the formation of the cocrystal through the strong hydrogen bond present between the NH group of NTF and carboxylate COO− group of LP and shows that LP is present in the zwitterionic form.

National Category
Physical Chemistry Other Health Sciences
Research subject
Health Science
Identifiers
urn:nbn:se:ltu:diva-11629 (URN)10.1039/C6RA13035F (DOI)000381513600022 ()2-s2.0-84982082527 (Scopus ID)aa59f798-6822-4bd4-b877-c9bf01e3d91c (Local ID)aa59f798-6822-4bd4-b877-c9bf01e3d91c (Archive number)aa59f798-6822-4bd4-b877-c9bf01e3d91c (OAI)
Note

Validerad; 2016; Nivå 2; 2016-08-17 (andbra)

Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Shimpi, M., Biswas, S. N., Sarkar, S. & Pedireddi, V. (2016). Synthesis and Structural Evaluation of Five Coordination Complexes of Benzenepentacarboxylic Acid with Aza-donor Ligands (ed.). Paper presented at . Journal of Molecular Structure, 1114, 38-47
Open this publication in new window or tab >>Synthesis and Structural Evaluation of Five Coordination Complexes of Benzenepentacarboxylic Acid with Aza-donor Ligands
2016 (English)In: Journal of Molecular Structure, ISSN 0022-2860, E-ISSN 1872-8014, Vol. 1114, p. 38-47Article in journal (Refereed) Published
Abstract [en]

Synthesis and structural features of five new coordination assemblies, [Co(bpyH)(H2O)5](BPCH)·(bpyH2)0.5·(H2O) (1a), [{Cu(H2O)3}·{Cu0.5(bpy)0.5(H2O)0.5}2(μ-BPCH)] (1b), [{Cd0.5(BPCH)}2·{Cd0.5(bpy)(H2O)2}2]·6(H2O) (1c), [Cu(BPCH2)(bpyeaH)].2(H2O) (1d) and [Cd2 (bpyea)0.5(oxalate)0.5(μ-BPC)(H2O)]·(bpyeaH2)·2(H2O) (1e), have been reported. All the assemblies were prepared by co-crystallization of benzenepentacarboxylic acid (BPCH5) either with 4,4′-bipyridine (bpy) or 1,2-bis(4-pyridyl)ethane (bpyea) in the presence of a transition metal ion (either Co(II), Cu(II) or Cd(II)) as the case may be. All the five compounds were synthesized by hydrothermal method and structures were determined by single crystal X-ray diffraction. All the obtained compounds, 1a-1e, exhibit distinct 3-D polymeric architectures either in the form of stacked layers or host-guest networks in which water molecules play a pivotal role providing additional stabilization by coordinate bonds as well as hydrogen bonds. Other non-covalent interactions such as C–H…π and π…π stacking also participate in the formation of exotic 3-D structures of these complexes.

National Category
Physical Chemistry
Research subject
Chemistry of Interfaces
Identifiers
urn:nbn:se:ltu:diva-12136 (URN)10.1016/j.molstruc.2016.02.010 (DOI)000374073800006 ()2-s2.0-84977672684 (Scopus ID)b368f282-a5e8-478e-9d88-dcf3c8c96a27 (Local ID)b368f282-a5e8-478e-9d88-dcf3c8c96a27 (Archive number)b368f282-a5e8-478e-9d88-dcf3c8c96a27 (OAI)
Note
Validerad; 2016; Nivå 2; 20160212 (andbra)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Golets, M., Shimpi, M., Wang, Y.-L., Antzutkin, O., Glavatskih, S. & Laaksonen, A. (2016). Understanding the thermal decomposition mechanism of a halogen-free chelated orthoborate-based ionic liquid: a combined computational and experimental study (ed.). Physical Chemistry, Chemical Physics - PCCP, 18, 22458-22466
Open this publication in new window or tab >>Understanding the thermal decomposition mechanism of a halogen-free chelated orthoborate-based ionic liquid: a combined computational and experimental study
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2016 (English)In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 18, p. 22458-22466Article in journal (Refereed) Published
Abstract [en]

In the last few decades, ionic liquids (ILs) have gained significant attention as lubricants and lubricant additives due to their polar nature, low vapour pressure and tunable physicochemical properties. In this work, quantum chemistry calculations and atomistic Molecular Dynamics (MD) simulations were employed to predict thermal degradation mechanisms of a potential lubricating agent - the tributyloctylphosphonium bis(oxalato)borate ([P4,4,4,8][BOB]) IL. It was found that the onset of decomposition of the studied IL coincides with a cleavage of the B-O bonds in the [BOB](-) anion. Consequently, a series of chemical reactions of the [P4,4,4,8](+) cation with the [BOB](-) anion was triggered yielding alkylboranes, alkenes, trialkylphosphines, CO and CO2. Another ionic system, consisting of [P4,4,4,8][Cl], was also tested for a comparison. Thermogravimetric measurements have shown a higher thermal stability of [P4,4,4,8][BOB] compared to that of [P4,4,4,8][Cl] at least at the initial stage of decomposition, in accord with the presented calculations. Quantum chemical frequency calculations also agreed with the experimental Fourier Transform Infrared (FTIR) spectroscopy results.

National Category
Physical Chemistry
Research subject
Chemistry of Interfaces
Identifiers
urn:nbn:se:ltu:diva-11366 (URN)10.1039/c6cp03191a (DOI)000381436500049 ()27465515 (PubMedID)2-s2.0-84981517816 (Scopus ID)a51708b5-24be-459b-bfa7-90d98ec83162 (Local ID)a51708b5-24be-459b-bfa7-90d98ec83162 (Archive number)a51708b5-24be-459b-bfa7-90d98ec83162 (OAI)
Note

Validerad; 2016; Nivå 2; 20160816 (andbra)

Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
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ORCID iD: ORCID iD iconorcid.org/0000-0001-7469-4197

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