Electrochemical behavior and uv spectra of the complexes triangulo-(Ph3P)(L)PtFe2(CO)8

1. The heterometallic complexes (Ph3P)(L)PtFe2(CO)8, like the homometallic compounds M3(CO)12 (M=Fe or Os), successively add two electrons under the conditions of electrochemical reduction in MeCN, being converted into radical anions and dianions, respectively. The reduction process is controlled by diffusion, and the value of the formation potential of the radical anion depends on the nature of L, decreasing along the series L=CO=PhsAs≅Ph3Sb≅Ph3P>(PhO)3P > (EtO)3P. 2. The electronic absorption spectra of the complexes (Ph3P)(L)PtFe2(CO)8 display bands which correspond to σ → σ* transitions between levels which are responsible for the formation of the metal-metal bonds, and it has been discovered that their position is influenced by the charge of the ligands attached to the Pt atom.