SYNTHESIS AND CHARACTERIZATION OF GALLIUM-CONTAINING SILSESQUIOXANES

The reaction of [(c-C6H11)(7)Si7O9(OH)(3)] (1a) with GaX3 (X = Cl or I ) in the presence of Proton Sponge (C14H18N2) affords [(c-C6H11)(7)Si7 O12GaX](-) [C14H18N2 . H](+) (2a, R = Cl; 2b, R = I). A single-crystal X-ray diffraction study of 2a reveals discrete ions with no significa nt interactions. Upon thermolysis both 2a and 2b liberate an equivalen t of [C14H18N2 . H]X-+(-) to produce quantitative yields of [(c-C6H11) (7)O12Ga](2) (3), a siloxy-bridged dimer which is isomorphous with pre viously characterized dimers containing Ti3+ and V3+. The reaction of 3 with Ph3PO affords [(c-C6H11)(7)Si7O12Ga(OPPh3)] (5), which was char acterized by single-crystal X-ray diffraction study, The reaction of t risilanol 1a with Ga(CH2SiMe3)(3) affords 6, an interesting cluster de rived from the reaction of two molecules of 1a with six molecules of G a(CH2SiMe3)(3) and six molecules of water.