Cobalt(III)-mediated intramolecular coupling of B(3)/B(6) in CpCoS₂C₂B₁₀H₁₀ with Cp ligand

Half-sandwich 16e complex CpCoS₂C₂B₁₀H₁₀ (Cp: cyclopentadienyl) (1) reacted with HCCCO_-2Me in the presence of 2-methylpropanedithioic acid to generate compounds {(C₅H₄CoS₂C₂B₉H₉)(CH=CHCO₂Me)(Me₂C = CS₂H)} (2) and (Me₂C=CS₂H)₃Co (3). In 2’ one S-Co bond of 1 was broken’ and the S atom linked with the terminal acetylenyl carbon atom of the HCCCO_-2Me. Meanwhile’ the Co atom in 1 linked to the S atom in 2- methylpropanedithioic acid with covalent bond while linked to the SH unit with coordinative bond. One carbon atom of Cp ring linked to the B(3)/B(6) cite of the carborane cage. The H atom of the B(3)/B(6) cite migrated to the internal acetylenyl carbon atom to form a trans-ethylenic bond. The Co atom of 1 linked to three S atoms of three 2-methylpropanedithioic acid molecules with covalent bond’ while linked to the other three SH units with coordinative bond. As a result’ product 3 formed. Complexes 2 and 3 have been characterized by IR’ NMR, elemental analysis’ mass spectrum and single-crystal X-ray diffraction analysis.