the thermodynamic functions such as enthalpy (h), gibbs free energy (g) and entropy (s) of serineand threonine amino acids were theoretically studied at different condition (solvents andtemperatures) by using gussian o3, software. first, the structural optimization of isolated serine andthreonine were done in the gas phase by using the hartree-fock (hf) level of theory with 3-21g, 6-31g and 6-3...

in this paper,the molecular geometry for three tautomers of uracil and four tautomers of cytosine has been analyzed. vibrational ir spectra of the tautomers were   investigated at hf and b3lyp level using the ab initio 6-31g* and lanl2dz basis sets from the program package gaussian 98 (a.7 public domain version). the physico-chemical and biochemical properties of uracil and cytosine are one of...

glycine, alanine and valine are taken as amino acids with an equal polar head and with thedifference in the length of hydrocarbon chains. the structural optimizations show the results of theisolated glycine, alanine and valine in the gases phase, at the hartree-fock level by means ofsto-3g,3-21g, 6-31g and 6-31+g basis sets. the calculations were performed for the ten (1-10)solvents using pcm m...

the potential energy surface of gaseous glycine determined years ago in the ab initio b3lyp/6-311++g** calculations is composed of thirteen stable conformers. we performed the ab initiomolecular orbital calculations as the starting point to carry out a force field and normal coordinatecalculation on the most stable conformer of non-zwitterionic glycine [conformer (i)]. thecalculations were carr...

compound (n,n-bis (salicylidene) 1,2-diaminophenylene) was prepared by condensation of ethanolsolution of 2-hydroxybanzaldehyde and 1,2-diaminophenylene. the compound was characterized by1h nmr, infrared spectroscopy (ft-ir) data and analytical data. the geometrical parameters andenergies have been obtained from density functional theory (dft) b3lyp method and hartree-fock (hf) method with 3-21...

we have studied the adsorption processes of h2 on the v (100) surface of vanadium using self consistent field theory.dissociative adsorptions of h2 are significantly favored compared to molecular adsorptions. there is a significant charge transfer from the first layer of the vanadium surface to the hydrogen atoms. three possible adsorption sites, top, bridge and center site, were considered in ...

more recently medical chemistry research has been focused on proteins that drive and controlcell cycle progression. among them, the cyclin dependent kinases (cdk’s) are a group ofserine/threonine kinases, which rule the transition between successive stages of the cell cycle. theactivity of cdk’s is regulated by multiple mechanisms, including binding to cyclins, which is a broadclass of positive...

In this paper, the quantum chemistry calculations related to the structural parameter of the three anions and the resulting complexes with glycine and alanine have been performed. The calculations were carried out using the HF and DFT method and in the base series 6-31G *. Natural Transplantation Orbital (NBO), hybrid capacity for bindings and is obtained. The ratio of the internal electrons, V...