Substitution, cage functionalization, and oxidation of the charge-compensated triruthenium monocarbollide cluster complex [1-SMe2-2,2-(CO)2-7,11-(μ-H)2-2,7,11-{Ru2(CO)6}-closo-2,1-RuCB10H8]

Abstract

The compound [1-SMe₂-2,2-(CO)₂-7,11-(μ-H)₂-2,7,11-{Ru₂(CO)₆}-closo-2,1-RuCB₁₀H₈] 1a reacts with PMe₃ or PCy₃ (Cy = cyclo-C₆H₁₁) to give the structurally different species [1-SMe₂-2,2-(CO)₂-7,11-(μ-H)₂-2,7,11-{Ru₂(CO)₅(PMe₃)}-closo-2,1-RuCB₁₀H₈] 4 and [1-SMe₂-2,2-(CO)₂-11-(μ-H)-2,7,11-{Ru₂(μ-H)(CO)₅(PCy₃)}-closo-2,1-RuCB₁₀H₈] 5, respectively. A symmetrically disubstituted product [1-SMe₂-2,2-(CO)₂-7,11-(μ-H)₂-2,7,11-{Ru₂(CO)₄(PMe₃)₂}-closo-2,1-RuCB₁₀H₈] 6 is obtained using an excess of PMe₃. In contrast, the chelating diphosphines 1,1′-(PPh₂)₂-Fe(η-C₅H₄)₂ and 1,2-(PPh₂)₂-closo-1,2-C₂B₁₀H₁₀ react with 1a to yield oxidative-insertion species [1-SMe₂-2,2-(CO)₂-11-(μ-H)-2,7,11-{Ru₂(μ-H)(μ-[1′,1″-(PPh₂)₂-Fe(η-C₅H₄)₂])(CO)₄}-closo-2,1-RuCB₁₀H₈] 7 and [1-SMe₂-2,2-(CO)₂-11-(μ-H)-2,7,11-{Ru₂(μ-H)(CO)₄(1′,2′-(PPh₂)₂-closo-1′,2′-C₂B₁₀H₁₀)}-closo-2,1-RuCB₁₀H₈] 8, respectively. In toluene at reflux temperatures, 1a with Bu^tSSBu^t gives [1-SMe₂-2,2-(CO)₂-7-(μ-SBu^t)-11-(μ-H)-2,7,11-{Ru₂(μ-H)(μ-SBu^t)(CO)₄}-closo-2,1-RuCB₁₀H₈] 9, and with Bu^tCCH gives [1-SMe₂-2,2-(CO)₂-7-{μ:η²-(E)–CHC(H)Bu^t}-11-{μ:η²-(E)–CHC(H)Bu^t}-2,7,11-{Ru₂(CO)₅}-closo-2,1-RuCB₁₀H₈] 10. In the latter, two alkyne groups have inserted into cage B–H groups, with one of the resulting B-vinyl moieties involved in a C–H⋯Ru agostic bond. Oxidation of 1a with I₂ or HgCl₂ affords the mononuclear ruthenium complex [1-SMe₂-2,2,2-(CO)₃-closo-2,1-RuCB₁₀H₁₀] 11.