Metal-Dithiolenes of Disubstituted Imidazolidine-2,4,5-trithione Monoanion. An Electrochemical and EPR Study

EMANUELA GRIGIOTTI;FRANCO LASCHI;PIERO ZANELLO;ARCA, MASSIMILIANO;CARLA DENOTTI;FRANCESCO A. DEVILLANOVA

2004-01-01

---

Abstract

The electrochemical properties of a series of [M(R,R’timdt)2] dithiolenes (M = Ni, Pd, Pt; R,R’timdt = monoanion of disubstituted imidazolidine-2,4,5-trithione) have been studied by cyclic voltammetry, controlled potential coulometry, and EPR spectroscopy. All the compounds undergo two separate one-electron reductions and one two-electron oxidation, which proceed through a single step in the case of nickel complexes, and through two separate steps in the case of palladium and platinum complexes. Inductive effects played by the R and R’ substituents influence the formal electrode potentials of the electron transfer processes. EPR spectroscopy has proved that the unpaired electron in monoanions [M(R,R’timdt)2]− is located on a SOMO, which, even if mainly ligand centred, is significantly contributed by the metal.