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.