Model intermediates for rhodacarborane catalysis: Isolation of a disubstituted closo-bis(triphenylphosphine)hydridorhodacarborane

Article abstract of DOI:10.1021/om00120a004

Reaction of a carbon-disubstituted [nido-7-(R)-9-(R′)-7,9-C₂B₉H₁₀] ^- (R = CH₃; R′ = C₆H₅) (V) ion with [(PPh₃)₃RhCl] in ethanol at the reflux temperature for 24 h yielded [closo-2,2-(PPh₃)₂-2-H-1-(CH₃)-7-(C ₆H₅)-2,1-7-RhC₂B₉H₉] (VI) rather than the corresponding exo-nido tautomer expected. In addition to spectroscopic characterization (IR, NMR), the molecular structure of VI was determined crystallographically for [C₄₅H₄₉B₉P₂Rh·C ₄H₈O·C₂H₅OH]: M_r = 970.215; monoclinic; space group P2₁/n; a = 24.694 (6) A?, b = 18.714 (6) A?, c = 12.117 (2) A?, β= 112.33 (2)°, V = 5180 (2) A?³, and Z = 4. The structure was refined to R = 0.067 and R_w = 0.081 using 3421 reflections (of 6396 reflections measured) with 2θ < 43.0° (Mo Kα radiation).