[4-{(p-cym)Ru}-5-{(Ph_3P)_2(CO)Os}B_4H_8]: the first nido-heterobimetallahexaborane cluster

摘要

The cluster nido-[4-{(p-cym)Ru}-5-{(Ph_3P)_2(CO)Os}B_4H_8] (1), where p-cym = [1-Me-4-~iPrC_6H_4], has been prepared as a pale yellow, air-sensitive solid from the reaction of [(p-cym)RuCl_2]_2 with Li[(PPh_3)_2(CO)OsB_5H_8]. The species was characterized by multinuclear NMR spectroscopy and high resolution mass spectrometry. The spectral data suggest a structure in which the two metal moieties are adjacent to each other in the basal region of a nido-hexaborane cluster. The pentagonal open face, B_3RuOs, contains four bridging H atoms comprising two B-H-B and two metal-H-B bridge bonds. Attempts to prepare the related Os_2B_4 and Ru_2B_4 clusters are also described as are observations on the degradation of these bimetallahexaboranes compared to their single metal-containing congeners, the osma- and ruthenahexaboranes.