The optimized geometry, molecular stability, mulliken atomic charges and natural bond orbital analysis of the title compounds were obtained at DFT level for theory with complete relaxation in the potential energy surface using 6-311G** basis set. The global minimum energy obtained for the titled compounds was observed to be -722.1339 a.u. and -722.1333 a.u. respectively. The influence of substitution on the geometry of the molecule have been thoroughly investigated. The bonding capability of a molecule depends on the electronic charge on the chelating atoms. The reason for the stability of the molecules under investigation arising from intermolecular charge transfer that occurs within the molecule from bond pairs and lone pairs was also investigated from natural bond orbital analysis. The atomic charge values were obtained by mulliken population analysis for the titled compounds.