Ten-Vertex closo- and hyper-closo-Phosphinometallocarborane Complexes Derived from Sodium Dodecahydro-1,3-dicarba-arachno-nonaborate(1-)

Article abstract of DOI:10.1021/ja00394a013

Reactions of Na(1,3-C2B7H12) with 2 or (R = Ph, p-tolyl) and of Na(1,3-R'2-1,3-C2B7H10) (R'= H, CH3) with afforded the complexes (Ia-d).Complex Ia (M = Rh, R'= H, R = Ph) is a catalyst precurssor for the homogeneous hydrogenation of vinyltrimethylsilane under mild conditions.Reactions of Na(1-r¹-3-r²-1,3-C2B7H10) (R¹ = R² = H, CH3; R¹ = H, R² = Ph) with yielded the unsaturated complexes 1-3-R²-6,6-(PPh3)2-6,2,3-RuC2B7H7> (IIa-c).Complex IIa (R¹ = R² = H) is the most effective ruthenacarborane catalyst yet studied for the homogeneous hydrogenation of terminal alkenes, and it reacts with carbon monoxide to form (III).The addition of excess triethylphosphine to a dichloromethane solution of IIa results in a thermochromic solution which exhibits a remarkyble equilibrium between 2-6,2,3-RuC2B7H9> (IV) and 3-6,2,3-RuC2B7H9> (V), the polyhedral structures of which are significantly different, as evidenced by multinuclear dynamic FT NMR.Complex IV reacts with carbon monoxide to form 2-6-CO-6,2,3-RuC2B7H9> (VI).Possible modes of formation of these species are discussed.