Synthesis and characterization of the hypoelectronic ruthenaborane {(eta(5)-C5Me5)Ru}(2){eta(6)-C6H6)Ru}B7H7}

The thermal conversion ofcommo-{1-(Cp*Ru)(mu -H)B4H9}(2)Ru, 1, into {(eta ( 5)-C5Me5)Ru}(2){eta (6)-C6H6)Ru}B7H7}, 2, is described. Compound 2 is a sin gle cage, hypoelectronic triruthenaborane in which the C6H6 ligand is deriv ed from the reaction solvent. As an (n -1) skeletal electron pair (sep) clo sed, deltahedral cluster, 2 constitutes a structural link between 10 fragme nt metallaboranes with (n + 1) and (n) sep as well as with one with (n - 2) sep. This series establishes a connection between decreasing average coord ination number of the cluster boron atoms with decreasing sep thereby provi ding a useful B-11 NMR chemical shift correlation.