Investigations study of structural Chemical properties for Some Thiazol Derivatives using Quantum calculations methods

DFT Ab-Intio quantum mechanical method within Gaussian 09 ( RB3LYP/6-311G) for calculating the geometry optimization of some Thiazol derivatives[C13H6BrN5O5S)A), C13H8N6O5S(B), C15H11N5O5S(C)]. The geometry parameter (bond length and bond angles ), physical properties and thermodynamic functions. As a result showed that the compound C15H11N5O5S(C) has high value of thermodynamic functions ( E0 ,A0, S0,H0,G0, CV, Cp ) .The results found Heat formation ( in KJ / mol) by using PM3 model in MOPAC program, the compound C15H11N5O5S(C) has less value which means high stability than other ’s and has high value in all thermodynamic functions.Calculations’ results showed the compound C13H8N6O5S (B) has less value in energy gap ( ΔE=2.616) that means this compound more activity than other ’s.