SYNTHESIS OF A METALLABORANE COMPLEX CONTAINING PD(III) AND THE FIRSTDOUBLY CHARGE COMPENSATED OLLIDE ION - X-RAY CRYSTAL-STRUCTURE OF 1,4-BR-2-1,2,5-(PME2PH)(3)-CLOSO-1-PDB11H8

The reaction of [Me3NH][nido-B11H14] with 4 equiv of lithium alkyl in THF at 5 degrees C generated the putative ollide ion, Li-4[B11H11], wh ich was not isolated. This was treated in situ with (PMe2Ph)(2)PdBr2 t o yield the metallaborane 1,4-Br-2-1,2,5-(PMe2Ph)(3)-closo-1-PdB11H8. This metallaborane contains the first doubly charge compensated ollide ion. It was isolated in low yield from the reaction mixture by chroma tography. Characterization of this air-stable palladium ollide complex by magnetic susceptibility, EPR, and CV confirmed that it contains Pd (III) and is paramagnetic. It was also characterized by an X-ray diffr action study of a single crystal. The sample consisted of rust-colored crystals of monoclinic space soup P2(1)/c, with a = 9.749(13) Angstro m, b = 16.30(2) Angstrom, c = 21.65(3) Angstrom, beta = 97.21(4)degree s, and Z = 4. The structure was determined by conventional heavy-atom methods and refined to a final value of R = 0.0730 (5172 reflections), R-w = 0.0620.