Electronic Structure, Thermodynamics functions and Physical properties for oxazolo[4,5-b]pyridine Derivatives by Ab Initio calculation (RHF Method)

Abstract

This study involved the adoption of the program (Gaussian 03) to use the method of calculation the total (Ab initio of method) according to the Hartree - Fock method (RHF), for the purpose of the expense of dimensional geometric (lengths and angles bond) when the geometry of a balanced, functions thermodynamic, some physical properties, charges.Also, For (R-Cl, R-F, R-CH3, R-NH2, R-NO2) molecules the calculated some physical properties (ΔHf (in kcal/mole), μ (in Debye) ,orbital energies (EHOMO, ELUMO, in eV), IP (in eV) and measurement stability Δ ) by using (semi-empirical method, MINDO/3 model). Have shown calculation results that the compound (R-F) has the lowest value entropy (S0) and heat capacity (Cv, Cp), as well as the lower value of the heat of formation (the more Stability) and the highest value (Δ), as shown by the results of the account that the compound (R-Cl) has the lowest value (EHOMO, Δ) and the highest value for the ionization energy (IP) as well as to the heat of formation , which means that the compound (R-Cl) is less stability and easier ionization compared to other compound. The results showed that both nitrogen atoms (N3, N7) Had the highest value when the compound (R-NH2),which makes it a strong legend when Linked to metal and the formation of the complex.