Theoretical study of the relative stability of isomeric forms of platinum carboxamide complexes

The relative stability of the trans- and cis-isomers of both N-iminol and O-carboxamide forms of the carboxamide chloro-complexes of Pt(II) and Pt(IV) has been theoretically studied at HF//HF, MP2//HF and B3PW91 levels of theory. For the two latter approaches, the trans-N-iminol forms appear to be the most stable ones for both the Pt(II) and Pt(IV) series of complexes. The difference between the total energies of the most stable N-iminol and O-amide forms is only slightly higher for the Pt(II) than for the Pt(IV) species despite the significant variation of the hardness of the metal center.