Role of heteropolar bonds in OCM-2 oligocarbonatemethacrylate

The OCM-2 oligocarbonatemethacrylate was investigated using a HYPERCHEM 4.0 molecular computer package. We have optimized the geometry of the OCM-2 molecule receiving a non-linear structure. Non-uniformly distributed electron charge densities and multipole moments were obtained from nb initio calculations. The heteropolar C=O double chemical bonds are transversal with respect to a bent central chain and play an important role in the formation of the optical and non-linear optical features. We have calculated different HOMO-LUMO energy gaps using semiempirical PM3 and ab initio methods for singlet and triplet states and the best agreement with the optical absorption data was observed for the PM3 triplet states. One can expect that the OCM-2 electronic structure properties have strong influence on the solid mixturies, which are formed on basis of the OCM-2 polymer and analogous compounds. (C) 1997 Elsevier Science Ltd.