Department of Physical Chemistry
The Department of physical chemistry is a leading center for education and research in physical chemistry. With expert faculty, modern facilities, and a strong focus on innovation, we prepare students for successful careers and academic excellence. Join us and be part of a dynamic learning community shaping the future.
Welcome to the Department of physical chemistry, one of the leading academic and research centers in the field of physical chemistry. With distinguished faculty members, advanced educational facilities, and a dynamic research environment, our faculty provides an excellent platform for the development of knowledge and specialized skills.
Our goal at the Department of physical chemistry is to nurture competent, creative, and dedicated graduates who can play a significant role in scientific, industrial, and social fields. Our academic programs emphasize the latest scientific resources, applied research, and continuous interaction with the industry, preparing students for both professional careers and further academic pursuits.
Articles
International Journal of Thermophysics (15729567)18(5)pp. 1197-1216
A general equation of state, originally proposed for compressed solids by Parsafar and Mason, has been successfully applied to dense fluids. The equation was tested with experimental data for 13 fluids, including polar, nonpolar, saturated and unsaturated hydrocarbons, strongly hydrogen bonded, and quantum fluids. This equation works well for densities larger than the Boyle density ρB [1/ρB = TB dB2(TB)/dT, where B2(TB) is the second virial coefficient at the Boyle temperature, at which B2 = 0] and for a wide temperature range, specifically from the triple point to the highest temperature for which the experimental measurements have been reported. The equation is used to predict some important known regularities for dense fluids, like the common bulk modulus and the common compression points, and the Tait-Murnaghan equation. Regarding the common points, the equation of state predicts that such common points are only a low-temperature characteristic of dense fluids, as verified experimentally. It is also found that the temperature dependence of the parameters of the equation of state differs from those given for the compressed solids. Specifically they are given by Ai(T) = ai + biT + ciT2 - diT ln(T).
Journal of Physical Chemistry B (15205207)101(42)pp. 8578-8583
In the present work the existence of a common compression factor point for binary mixtures has been investigated, both experimentally and theoretically. We found that the linear isotherm regularity (LIR) is able to predict the common compression factor point and the common bulk modulus point for binary mixtures, as well as pure dense fluids. An important conclusion deduced from this work is that a physical interpretation for such points may be given using LIR. The LIR along with the mean geometric approximation (MGA) have been used to relate the density at the common points of a mixture to those of its pure components. The numerical investigation shows that such a relation may be represented by a quadratic function in terms of the system composition for most mixtures. However, we have found that such a quadratic relation is generally valid for all investigated mixtures. An important result obtained from this work is that we may get information about the magnitude of interactions between unlike molecules, compared to those of like interactions. Such a result can be used to predict the deviation of a solution from ideality without having any vapor pressure data.
Journal of Chemical Physics (10897690)108(6)pp. 2361-2374
A combined experimental and theoretical study of the NMR spin-lattice relaxation times for the deteron of D2 in D2-Ar mixtures is presented A gas-handling system and a sample cell have been designed and successfully emploved in the experimental part of this study. Spin-lattice relaxation times for the deuteron of D2 in D2-Ar mixtures have been measured over the temperature range 180-420 K at several densities and mole fractions, and extrapolation to infinite dilution has been carried out. The quality of the results has been tested by analysis of the one-dimensional spectra. Theoretical values of the spin-lattice relaxation times associated with the D2-Ar interaction have been calculated using the XC(fit) potential energy surface obtained by Bissonnette et al. [J. Chem. Phys. 105, 2639 (1996)]. Two reliable methods have been proposed to compare the theoretical and experimental NMR spin-lattice relaxation times obtained for the equilibrium mixture of the two parity isomers of the D2-Ar system under conditions in which separate measurement of their deuteron relaxation times is not possible. The agreement between experimental and theoretical results is found to be relatively good only for higher temperatures. These results indicate that the anisotropies of the XC(fit) potential energy surface need refinement. © 1998 American Institute of Physics.
Journal of Chemical Physics (10897690)108(15)pp. 6170-6184
A combined experimental and theoretical study of the nuclear magnetic resonance (NMR) spin-lattice relaxation times for the proton and deuteron of HD in HD-Ar mixtures is presented. Spin-lattice relaxation times for the proton and deuteron of HD in HD-Ar mixtures have been measured over the temperature range 180-420 K at several densities and mole fractions, and extrapolation to infinite dilution has been carried out. Theoretical values of the spin-lattice relaxation times associated with the HD-Ar interaction have been calculated using the XC(fit) potential energy surface obtained by Bissonnette et al. [J. Chem. Phys. 105, 2639 (1996)], transformed to allow displacement of the center-of-mass of the HD molecule from its center-of-force. Both experimental and theoretical results show that the density-dependence of the deuteron relaxation times lies in the linear regime, while that of the proton lies in the non-linear regime. The experimental and theoretical results for the relaxation times of the proton are in excellent agreement. The corresponding results for the deuteron are in good agreement (within a few percent); the agreement is, however, not as good as it is for the proton. These results indicate that the transformed XC(fit) potential energy surface represents the anisotropic part of the HD-Ar interaction rather accurately. It is argued that the improved quality of the XC(fit) potential energy surface for the heteronuclear HD-Ar interaction is due to the large contribution that the isotropic part of the homonuclear potential surface makes to the anisotropic part of the heteronuclear potential surface. © 1998 American Institute of Physics.
Journal of Physical Chemistry A (15205215)107(33)pp. 6476-6482
Electronic, structural, and spectroscopic properties of the ground-state neutral and singly ionized mono-, di-, tri-, and tetrafluoropyrroles are studied using ab initio and density functional theory quantum mechanical methods. The effects of the number and position of the substituents on the electrochemical properties of the pyrrole ring have been studied. Using the optimized structures obtained for these molecules and their cations, IR and NMR spectra have been calculated and analyzed. The results of this study, including charge- and spin-density distribution analyses, show that among all of these compounds 3-fluoropyrrole and 3,4-difluoropyrrole have the most suitable conditions for electropolymerization.
JOURNAL OF MOLECULAR STRUCTURE-THEOCHEM (01661280)626(1-3)pp. 143-158
Structural, thermochemical stability, electrical and molecular orbital properties of (CO)n cyclic oligomers of CO (oxocarbons) have been calculated using RHF and DFT-B3LYP levels of theory with 6-31G*basis set. Contributions of these compounds in the macroscopic properties of solid CO have been investigated. Atoms in molecule (AIM) and NBO analyses have been carried out to study in detail the nature of the C-C bonds in these molecules. Population analysis has been used to search for any possible aromaticity in the rings of these cyclic oxocarbons. AIM and population analysis showed that ring bonds in the (CO)3 molecule have an aromatic character significantly more than those in other molecules do. The results of this study showed that (CO)n cyclic oligomers do not contribute significantly to the physicochemical properties of CO in the solid phase due to being thermodynamically instable at standard pressure and temperature. © 2003 Elsevier Science B.V. All rights reserved.
JOURNAL OF MOLECULAR STRUCTURE-THEOCHEM (01661280)663(1-3)pp. 149-157
Molecular structure and bonding, thermochemical stability, and vibrational and NMR spectra of (NPF2)n; n = 2, 3, 4 and (NPX 2)3; X = H, Cl, Br cyclic phosphazenes have been studied employing quantum computational ab initio RHF and density functional B3LYP and B3PW91 methods using 6-31G, 6-31G* and 6-31 + G* basis sets. This study showed that these compounds have planar structure and, except for (NPH2)3, all are thermodynamically stable in the gas phase. Fluorophosphazenes (NPF2)n are found to be more stable than other phosphazenes. Furthermore, the identical values obtained for all P-N bond lengths in (NPX2)3, with X = H, F, Cl and Br, phosphazenes suggests that the π-bond system of the ring in this series of compounds has aromatic character. This is approved by high values of cross electron density between indirectly bonded atoms of the ring obtained in a population analysis carried out on these systems. © 2003 Elsevier B.V. All rights reserved.
JOURNAL OF MOLECULAR STRUCTURE-THEOCHEM (01661280)636(1-3)pp. 185-193
Intermolecular potential energy surface (IPS) for F2-F 2 system has been examined using RHF, MP2 and DFT-B3LYP methods. A number of basis sets from the double-zeta and triple-zeta family were used in order to evaluate the basis set effects. These effects vary with the level of theory used. Counterpoise (CP) correction has been used to show the extent of the basis set superposition error (BSSE) on the potential energy curves obtained for F2-F2 system. CP corrections revealed that B3LYP and RHF levels of theory predict a totally repulsive interaction between the two monomers of F2-F2 system. The deepest BSSE-corrected potential well have been obtained at MP2 level of theory with 6-31G* basis set. At RHF and B3LYP levels of theory the least repulsive BSSE-corrected potential have been obtained with 6-31G* basis set. Effects of basis set on the characteristics of the calculated IPS have also been analyzed based on the position of the potential minimum and its well depth as well as its corresponding hard sphere collision diameter. © 2003 Elsevier B.V. All rights reserved.
Journal of Physics B: Atomic, Molecular and Optical Physics (09534075)37(20)pp. 4143-4157
Ionization of the hydrogen molecular ion under linearly polarized intense laser fields is simulated by direct solution of the fixed-nuclei time-dependent Schrödinger equation for X = 790 nm and 1 = 1 × 1014 W cm-2. Different adaptive grids used in this study produced very similar results. The results are in agreement with, and thus support, the results of recent calculations carried out by other researchers. Detailed structure of the ionization rates is presented which has not been reported so far in the literature. The use of the virtual detector method resulted in more details of the ionization rates of the hydrogen ion molecule and hydrogen atom. This method especially allowed a simultaneous detection of the parallel and perpendicular components of the ionization rates.
Khosravi-darani, K.,
Sabzyan, H.,
Zeini-isfahani, A.,
Parsafar, G. Iranian Journal Of Chemistry And Chemical Engineering (10219986)23(2)pp. 45-53
In this work, a more accurate prediction of liquid evaporation flux has been achieved. The statistical rate theory approach, which is recently introduced by Ward and Fang and exact estimation of vapor pressure in the layer adjacent to the liquid-vapor interface have been used for prediction of this flux. Firstly, the existence of an equilibrium layer adjacent to the liquid-vapor interface is considered and the vapor pressure in this layer and its thickness calculated. Subsequently, by using the Fick's second law, an appropriate vapor pressure expression for the pressure of equilibrium layer is derived and by this expression and the statistical rate theory approach, evaporation flux is predicted more accurately than the previous work. Finally, some novel steady state evaporations are simulated and the effects of both liquid and vapor temperature and the effect of the length of the evaporation chamber on the evaporation flux are investigated.
View all 310 Research output
