| Pentaborane(9), B(,5)H(,9), is reduced by two equivalents of alkali metal napthalides (M = Na, K, Rb, Cs) in THF or glyme to form a new, thermally stable nonahydropentaborate(2-) dianion, B(,5)H(,9) ('2-). The dianion has been characterized by boron-11 NMR spectroscopy, IR spectroscopy, physical methods, and reactivity studies. Protonation of B(,5)H(,9) ('2-) with HCl or HBr has provided a high yield route from B(,5)H(,9) to B(,5)H(,11). The reactions of the dianion with B(,5)H(,9) and B(,2)H(,6) were also investigated.;The preparation of the tetradecayhydrononaborate(1-) anion, B(,9)H(,14) ('-), from deprotonation reactions of pentaborane(9) using sodium or potassium hydride was studied using low temperature boron-11 NMR spectroscopy to elucidate the reaction pathways. The main pathway for the production of B(,9)H(,14) ('-) is the reaction of B(,5)H(,8) ('-) with B(,5)H(,9), which is thought to initially form a B(,10)H(,17) ('-) intermediate and then decompose thermally to B(,9)H(,14) ('-) and BH(,3). At room temperature the side products are the result of B(,6)H(,11) ('-) decomposition. Detailed studies of some of the impurities in this synthesis are also reported.;The boroxine supported triosmium cluster ((mu)-H)(,3)(CO)(,9)Os(,3)((mu)(,3)-CO) (,3)(B(,3)O(,3)) was a good starting material for the preparation of triosmium carbonyl methylidyne derivatives of pentaborane(9), decaborane(14), and o-carborane using Friedel-Crafts reactions. Pentaborane(9), was substituted in the apical position to form ((mu)-H)(,3)(CO)(,9)Os(,3)((mu)(,3)-C-1-B(,5)H(,8)) which was isolated and characterized by mass spectroscopy, boron-11 and proton NMR spectroscopy, IR spectroscopy, and reactivity studies. Substituted decaborane(14) and o-carborane clusters were also prepared and characterized. The formation of these species implies the formation of the non-planar carbocation " ((mu)-H)(,3)(CO)(,9)Os(,3)((mu)(,3)-C) ('+)" as an intermediate in the synthesis. |
