Organometallic platinum(II) complexes of methyl-substituted phenanthrolines

摘要

A series of dimestiylplatinum(II) complexes of symmetrically substituted dimethyl-1,10-phenanthrolines (dmphen) was prepared and examined in view of their electronic structure. Electrochemical data of the parent complexes nd spectroscopic data of parent and one-electron reduced species reveal the variable electronic infuence of the methyl substituents in different positions of the heteroaromatic system. From multi-frquency S, X, K and Q-band EPR measurements of the corresponding radical anions and of analogous species with 1,10-phenanthrooline, 3,4,7,8-tetramethy-1,10-phenanthroline and 2,2'-bipyridine ligands hyperfine coupling constants and g vlues were obtained and used for an estimation of the contributions from platinum orbitals to the singly occupied molecular orbital. X-Ray crystal structures are reported for [(2,9-dmphen)PtMes_2] and [(2,9-dmphen)PtPh_2], allowng us to probe the steric interactions between the methyl substituents of the phenanthroline and the mesityl ligands.