Molecular dynamics (MD) simulations for crystalline benzene (C(6)H(6)), pyridinium iodide [C(5)NH(6)](+)I(-), and pyridinium nitrate [C(5)NH(6)](+)NO(3)(-) have been performed as a function of temperature and pressure. Despite the similar shape of the benzene molecule and the pyridinium cation, the experimental and simulated data have showed clear differences in their dynamics. Therefore, the rotational dynamics have been explored in detail by comparing thoroughly the existing experimental results together with new quasielastic neutron scattering (QENS) data obtained for (PyH)NO(3) and molecular dynamics simulations. The correlation times, activation energy, geometry of motion of benzene molecule and pyridinium cation, isothermal compressibility, and activation volume obtained from the simulations are compared with the experimental results obtained by nuclear magnetic resonance and QENS methods. MD simulations have also revealed that reorientation of the pyridinium cation in pyridinium nitrate between two inequivalent positions is strongly affected by the hydrogen bond N-H···O between the cation and the anion and the influence of temperature on strength of the hydrogen bond is much more important than that of the pressure.
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http://dx.doi.org/10.1063/1.4774096 | DOI Listing |
J Environ Manage
June 2024
School of Environment and Ecology, Jiangnan University, Wuxi, 214122, China. Electronic address:
The carbonization of lignocellulosic biomass with ionic liquids (ILs) are considered as an advantageous approach for the preparation of carbonaceous materials. The commonly used imidazolium and pyridinium based ILs have drawbacks such as toxicity, resistance to biodegradation, high cost and viscosity. These issues can be mitigated by diluting ILs with water, although excessive water content above 1 wt% can reduce the solubility of biomass.
View Article and Find Full Text PDFPyridinium cesium cobalt nitrate, (PyH)CsCo(NO), obtained from a nitric acid solution crystallizes in the orthorhombic space group with unit cell parameters = 8.6905(14) Å, = 11.9599(18) Å, = 18.
View Article and Find Full Text PDFMolecules
February 2023
Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1 bld. 3, Moscow 119991, Russia.
The reaction of pyridine with cyanuric chloride was studied under microwave activation as well as in the presence of silver nitrate. The product of hydrolysis containing two pyridinium rings and chloride anion was isolated. The structures of these anion exchanger salts with chloride, nitrate and perrhenate anions are discussed.
View Article and Find Full Text PDFJ Fluoresc
July 2023
School of Chemistry and Materials Engineering, Fuyang Normal University, Anhui, 236037, Fuyang, People's Republic of China.
A novel D-π-A type fluorescent probe L(NO) for Cu (II) sensing was designed and fully characterized. The probe consists of a styryl-pyridine cation fluorescent group and a di-(2-picolyl)amine (DPA) receptor unit, which are linked by a phenyl group to form an electron donor-π-acceptor (D-π-A) conjugate system, especially the introduction of a nitrate counter anion for significantly enhanced water solubility of the probe. Fluorescence titration studies of the probe L(NO) showed a higher selectivity for Cu than other metal ions, and the emission spectrum was strongly quenched upon binding.
View Article and Find Full Text PDFJ Mol Graph Model
January 2023
Department of Chemistry, Faculty of Sciences, University of Guilan, P.O. Box 41335-1914, Rasht, Iran.
Physicochemical properties of the three series of task-specific ILs formed from methyl pyridinium [MPy], phenyl diazenyl methyl pyridinium [DMPy] and functionalized diazenyl methyl pyridinium [X-DMPy] (X: NH, OH, OCH, CH, CH, H, F, CHO, CN and NO) cations and benzoate ([Y1]), benzenesulfonate ([Y2]), nitrate ([Y3]) and tetra fluoroborate ([Y4]) anions were investigated using density functional theory (DFT) calculations at M06-2X/AUG-cc-pVDZ level of theory. For the introduced task-specific ILs the structural parameters, energetic, electronic and topological characteristics were calculated and discussed using electrostatic maps and indexes of NBO, QTAIM, ECW and NCI. The effect of the type of anions, functional group, variation of the substituents on the functional group at cationic part on the interaction energy as well as some of their physical, chemical and optical properties are taking into account.
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