Electrical Conductance And Theoretical Study Of Glutamic Acid In Different Solvents at 310.16k

Abstract

The electrical conductivities of glutamic acid in the water, methanol, and ethanol are measured at 310.16 K and the conductivity parameters: Association constant (KA), equivalent conductance at infinite dilution (Λo) and the distance parameter (R). (Λo, KA, and R) are calculated. Values of Λo are found to be in the order: water > methanol > ethanol, but the order is reversed for the amount of KA and R. This indicates the increase of ion-solvent interaction and formation of solvent separated ion-pair in the above order. The main interest is to find an accurate yet efficient solvation model for semiempirical quantum-mechanical and Density Function Theory (DFT) methods applicable to amino acids (glutamic acid) in the context of computer-aided conductivity studying. It was reparametrization of the Conductor like Screening Model (COSMO) and Conductor-like Polarizable Continuum Model (CPCM) CPCM solvent model for Parameterization method three (PM3), Hartree-Fock (HF) & DFT calculation in Gaussian interface, version 16.0 which used to calculate many descriptors of the glutamic molecule and study the relationship between these descriptors and the association constant (KA). Molecular volume (MV), Connolly parameters, and the entropy were showed the same result corresponding with the experimental parameters.

دراسة توصيلية وحسابية للكلورامفينيكول في مذيبات ودرجات حرارية مختلفة

“…After completing the minimization energy of the molecule ,the description in the water and methanol must be calculated initially using the PM3 method, and then using the 6-311G(d) base established by HF. The best conformer with the least energy was therefore taken into account as the actual sample representing the molecule for measurement, and this sample was utilized as a starting model for other calculations 17 .…”