| Summary: | The work described in this thesis was carried out to explore the chemistry of carbanonaborane(14), CB8H14. Incorporation of metal atoms into the molecular framework was of particular interest. An n.m.r. investigation of the monocarbaboranes CB8H14 and [CB8H13] indicated the presence of unsymmetrical bridging hydrogen atoms in both carbaboranes. More significantly, the endo-hydrogen attached to the carbon atom is involved in exchange with all the three bridging hydrogen atoms in the anion, whereas no such exchange is observed in the neutral precursor. The reaction of [MCl(CO)(H) (PPh3)3) (M = Ru, Os) with Li[CB8H13J yields the nido-metallacarbaboranes [ (CO) (PPh3) 2MCB8H10 (PPh3) ]. Both compounds have a decaborane(14) like cage structure with the 6- and 9- positions occupied by CH and [M(PPh3)2(CO) ] fragments. Minor products of these reactions have been isolated and characterised as two isomeric chlorinated nldo ruthenacarbaboranes and two isomeric closo ruthena- and auracarbaboranes. A similar reaction with [Ru(Cl) (η-C5H5) (PPh3)2] yields the arachno species [ (η-C5H5) (H) (PPh3)RuCB8H12] (3). In this case the cage arrangement is similar to that in [B10H14]2- with the 6- and 9- positions substituted by CH2 and (RuH(η-C5H5)(PPh3)] fragments. The metalla derivatives isolated from reaction of Li(CB8H13] with gold reagents, Au(PR3)Cl, were all found to have arachno structures. These auracarbaboranes all have a triple cluster structure consisting of a carbaborane-gold-carbaborane sandwich. The central gold cluster unit consists of either one, two, or seven gold atoms. The heptanuclear gold cluster is the most novel of these auracarbaboranes and displays a different geometry of the central gold cluster to that of the only other known heptanuclear gold cluster.
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