Carbon monoxide substitutions by trimethyl phosphite in diiron dithiolate complex: Fe-Fe bond cleavage, selectivity of the substitutions, crystal structures and electrochemical studies

Abstract

The reaction of substitution of carbon monoxide by P(OMe)3 in the complex (μ-η2PhC(S) = C(S)Ph)Fe2(CO)61 under thermal activation afforded two colored compounds: a binuclear disubstituted complex (μ-PhC(S) = C(S)Ph)Fe2(CO)4 [P(OMe)3]22 and a mononuclear iron disubstituted complex (η2PhC(S) = C(S)Ph)Fe(CO)[P(OMe)3]23. Mass spectrometry, 1H NMR, IR and electrochemical studies established that two (CO) have been substituted by P(OMe)3 in complexes 2 and 3. The X-ray studies show that the two P(OMe)3 ligands are in apical positions in trans of the iron – iron bound of complex 2 and in equatorial positions in complex 3. However, the substitution reaction of (CO) by P(OMe)3 in complex 1 under electron transfer catalysis (ETC) led to the monosubstituted compound (μ-PhC(S) = C(S)Ph)Fe2(CO)5 [P(OMe)3] 4.