Computational study of dimethyl- and trimethyl-tin(IV) complexes of porphyrin derivatives

The molecular geometry, energetics and electronic charge distribution of di organo- and triorgano-tin(IV) complexes of [protoporphyrin-IX] and [meso-te tra(4-carboxyphenyl)porphine] derivatives were determined at semi-empirical and ab initio levels. To study the molecular details of the complexes, sim pler molecule models were calculated by the ab initio pseudo-potential meth od. The molecular properties of these complexes are essentially independent of the presence of the peripheral tin atoms. Agreement was always found am ong the results of the different computational approaches, as well as betwe en the theoretical and the experimental findings on the molecular geometry of the hypothesized complexes. Interaction modes between water and the orga no-tin systems considered were affected strongly by the presence of periphe ral tin atoms. Copyright (C) 2001 John Wiley & Sons, Ltd.