Homonuclear half-sandwich iridium and rhodium complexes containing dichalcogenolato-functionalized o-carboranyl ligands

Dichalcogenolato-functionalized nido-carborane ((NMe4)[7,8-(HS)2-7,8-C2B9H10]) L was developed for the formation of reactive 16-electron Ir and Rh complexes. The mono-nuclear 16-electron complex (NMe4)[Cp*Ir(7,8-(S)2-7,8-C2B9H10)] (1) and bi-nuclear 16-electron neutral metallacarborane (Cp*Ir)[1,2-(S)2-3-(η5-Cp*)-3,1,2-IrC2B9H9] (2) were synthesized step by step from the reactions of L with half-sandwich metal compounds. In the presence of NaH, the reaction of L with [Cp*RhCl2]2 afforded bi-nuclear complex (Cp*Rh)2(μ-H)[7,8-(S)2-7,8-C2B9H10] (3) in good yield. Additionally, [1-S-2-O-1,2-C2B10H10]2− was employed in the construction of M–M bonds, and the bi-nuclear complex (Cp*Ir)2[1-S-2-O-1,2-C2B10H9] (4) was synthesized through the reaction of [1-S-2-O-1,2-C2B10H10]2− with [Cp*IrCl2]2. All complexes were characterized by spectroscopic and crystallographic analysis.

Graphical abstractDichalcogenolato-functionalized nido-carborane ((NMe4)[7,8-(HS)2-7,8-C2B9H10]) ligand was investigated for the formation of reactive 16-electron Ir and Rh complexes and the construction of metal– metal bonds.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Novel bi-nuclear half-sandwich complexes based on nido-carborane ligand. ► Construction of metal–metal bond in the bi-nuclear complex. ► Structures of these complexes were confirmed by X-ray crystallography.