Journal of Physical and Theoretical Chemistry
Volume:10 Issue: 3, Autumn 2013

In this paper, the structural properties of C20 and C12B8 fullerene interacting with glycine based onthree active sites of glycine and one C atom or one B atom in C12B8 were analyzed through thedensity functional theory. It was found out that the binding of glycine to C12B8 generated a complex.Our results were extremely relevant in order to identify the potential applications of functionalizedC12B8 as drug delivery systems. Glycine prefered to interact with the C12B8 cage via its carbonyloxygen (B=O) active site. B atoms were relatively favored in energy over the C atoms in the C12B8 –glycine while the stable ordering of three active sites on glycine molecule was =O site> –O site> –Nsite.

Using the Gaussian 2003 software and MP2 /6 – 311+ G method for the C2H4 : O2, CO:Cl2 andCO2:CO2 pairs and MP2/6-311++G** method for the CO2:H2O pair and B3lyp/6-31G methodfor the O2:O2 pair the optimized interaction energies between two considered pair molecules ofstudied gases(C2H4:O2, CO:Cl2, CO2:H2O, O2:O2 and CO2:CO2 pairs) as a function of thedistances between the centers of two considered molecules were evaluated and the results wereinterpreted according to the Lennard – Jones equation. In addition, the second virial coefficientof each pair gas was calculated upon the appropriate equations of statistical thermodynamics.The resultant coefficients were almost comparable with those are available in the literature.

The structures and stability of 531 novel boron nitride substituted isomers of 12-crown-4 etherverified theoretically. For a collection of 23 selected BN isomers, structural geometry, vibrationalstability, energy gaps, natural bond population analysis, and nonlinear optical responses investigatedtheoretically. The changes of standard enthalpies for ionization reactions and electron affinityreactions studied as well. The presence of double bonds in BN isomers of 12c4 might develop theirhost-guest chemistry. Moreover, the results of ionization potentials and electron affinities calculatedby single point calculations showed good correlation with those of thermochemistry ones. Theobserved correlations clearly suggest a lower cost of computations for the mentioned physicalproperties. The polarizability and hyperpolarizability results introduced some BN substituted crownethers as efficient candidates for construction of practical devices for optical harmonic generation andsignal processing.

At the present study, different properties of Sarin with the formula [(CH3)2CHO]CH3POF was studiedin gas phase. Geometrical optimizations of Sarin, single point calculation, NMR and Electricalparameters were carried out in gas phase with the Hartee -Fock method coupled to 6-31g* basis setsfor all atoms. The results obtained from a comparison between tables and charts came up fordiscussion and analysis.

The interaction of Fe2+ ion with Pyrazole was theoretically studied by Gussian 03, software at HF/(LanL2DZ+6-31G) and HF/ (LanL2DZ+6-31G (d)) levels in gas phase and solution. In this study acompartion between optimized structures of Pyrazole molecule in aspect of thermodynamicparameters such as enthalpy (H°), Gibbs free energy (G°) and entropy (S°) in presence of metallic ion(Fe2+), was performed. Thermodynamically analysis indicate that the relative enthalpy (H°) and Gibbsfree energy (G°) are negative values but entropy (S°) is positive value for Pyrazole-Fe2+ complex,suggesting thermodynamic favorability for covalent attachment of Pyrazole into Fe2+ ion. Also, theresults show with increasing dielectric constant of solvent the stability of Pyrazole –Fe2+ complexincreases

Using the Computational methods, the interaction effect of Tyrosine Amino acid on Graphene wasinvestigated. For this purpose, the Density Functional Theory (DFT) in the ground state of 6-31Gwas used, and the interaction effects of Tyrosine on Graphene was investigated through attachmentto three different base positions. Different parameters such as energy levels, the amount ofChemical Shift in different atoms, the amount of HOMO/LUMO was determined and relatedparameters like Electrophilicity scale, chemical hardness, Chemical potential, and the maximumamount of electronic charge transferred. The Graphene oxide has the capability to act as adrugnano carrier and also as a mixture with special electrical properties. The results of thisinvestigation also show that the attachment of Tyrosine Amino acid, as an organic compound, tothe chemical structure of Graphene can change these capabilities to a great extent and also increasethe role that this mixture already plays in medical, Pharmaceutical, and electronic industries.