Novel Approach to Mixed Group 15/16 Element Ligands—Formation of Unusual Trichalcogenophosphonato Ligands in Mixed Fe/Cr Clusters

Trithiophosphonato and triselenophosphonato ligands containing mixed Fe/Cr clusters have been synthesized from the reaction of [Fe3(CO)9(μ3-Y)2] (Y=S or Se) with [CpCr(CO)2(η3-P3] in the presence of trimethylamine oxide. This novel approach leads to new clusters containing the first examples of P(S)S2 and P(Se)Se2 ligands in complexed forms (see picture).