Comparative metallaborane chemistry: preparation and nuclear magnetic resonance studies of some nido-5-metalladecaboranes of rhodium, iridium, ruthenium, and osmium

Abstract

The isolation, and characterisation by n.m.r. spectroscopy, of the new ten-vertex nido-metalladecaboranes [5-(η⁵-C₅Me₅)-nido-5-RhB₉H₁₃], [5-(η⁵-C₅Me₅)-nido-5-IrB₉H₁₃], [6-(η⁵-C₅Me₅)-nido-6-IrB₉H₁₃], [5-(η⁶-C₆Me₆)-nido-5-RuB₉H₁₃], and [5-(η⁶-C₆Me₆)-nido-5-OsB₉H₁₃] are described. The n.m.r. data of the nido-5-metalladecaboranes, together with those of the previously reported first-row transition element compounds [5-(η⁵-C₅Me₅)-nido-5-CoB₉H₁₃] and [5-(η⁶-C₆H₃Me₃-1,3,5)-nido-FeB₉H₁₃] permit an examination of n.m.r. shielding trends for this compound type across two columns and down three rows of the periodic Table. Similarities within the periods are more marked than those within the groups. [6-(OH)-5-(η⁶-C₆Me₆)-nido-5-OsB₉H₁₂] was also tentatively identified during this work.