Hybrid diborolyl/carbaboranyl triple-decker compounds: [(eta(5)-pentamethylcyclopentdienyl)ruthenium(mu,eta(5)-1,3-diborolyl)rhodiumcarbaboranyl] complexes

Reaction of the violet sandwich [(eta (5)-C5Me5)Ru{eta (5)-(CMe)(2)(BMe)(2) (CMe)}] with [(C2H4)(2)RhCl](2) generates the tetranuclear complex [(eta (5 )-C5Me5)Ru{mu,eta (5)-(CMe)(2)(BMe)(2)(CMe)}RhCl](2) (7). Treatment of 7 wi th the nido-2,3-Et2C2B4H51- anion leads to the violet air-sensitive triple- decker complex [(eta (5)-C5Me5)Ru{mu,eta (5)-(CMe)(2)(BMe)(2)(CMe)}Rh(eta ( 5)-2,3-Et2C2B4H5) (8), i, which the neutral carborane functions as a 5e don or. Its structure is derived from H-1-, B-11-,C-13-NMR and mass spectral da ta. The green paramagnetic triple decker [(eta (5)-C5Me5)Ru(mu,eta (5)-(CMe )(2)(BMe)(2)(CMe)}Rh(C2B9H11)] (9) is obtained from the nido-7,8-C2B9H121- carboranyl anion and 7. Reaction of 7 with the nido-6-Me-5,6,9-C3B7H91- ani on yields the green, air-stable triple-decker complexes [(eta (5)-C5Me5)Ru{ mu,eta (5)-(CMe)(2)(BMe)(2)(CMe)}Rh(2-Me-2,3,4-C3B7H9)] (10a) and [(eta (5) -C5Me5)Ru{mu,eta (5)(CMe)(2)(BMe)(2)(CMe)}Rh(4-Me-2,3,4-C3B7H9)] (10b) havi ng 30 valence electrons. An X-ray structure analysis of 10a confirms the ex pected octadecahedral geometry for the closo-RhC3B7 cluster framework. (C) 2000 Elsevier Science B.V. All rights reserved.