Estimation of thermodynamic properties of some organic molecules

Experimental measurements of some thermodynamic parameters involve experimental difficulties and the corresponding methods possess real drawbacks. Consequently, it is necessary to resort to a theoretical calculation of these parameters. Literature reveals that the first order valence connectivity (1?v ) van der waals volume (vW), electrotopological state index ( E ) and refractotopological state index (R ),the important structural ,size and electronic parameters have been found to be one of the most fundamental characteristics of the physical properties of organic molecules.In the present study, the thermodynamic properties, e.g., standard specific heat capacities (Cpo), standard entropy (So), change of standard Gibb’s free energy (?Gfo), change of enthalpy of formation (?Hf 0), enthalpy of vaporization (?Hv), enthalpy of sublimation (?Hs ) and enthalpy of melting (?Hm ) have been found to be significantly correlated with the size, structural and electronic parameters,with the above structural ,size and electronic parametersTherefore, these structural, size and electronic parameters can be used for the theoretically estimation of the above thermodynamic properties.