Polyhedral palladaborane chemistry: isolation and structural characterization of ten-vertex [(PMe2Ph)(2)PdB9H12(PMe2Ph)] and eleven-vertex [(PMe2Ph)(2)PdB10H12]

Ten-vertex [6,6-(PMe2Ph)(2)-arachno-6-PdB9H12-9-(PMe2Ph) 1a and eleven-vert ex [7,7(PMe2Ph)(2)-nido-7-PdB10H12] 2a have been isolated as occasional by- products from an extension to palladaborane chemistry of the one-pot route for the preparation of the nine-vertex platinaborane [(PMe2Ph)(2)PtB8H12] 3 b from [PtCl2(PMe2Ph)(2)] and B10H14, but using [PdCl2(PMe2Ph)(2)] instead of [PtCl2(PMe2Ph)(2)] to generate [4,4-(PMe2Ph)(2)-arachno-4-PdB8H12] 3a in yields of upto 75%. The two by-products la and 2a are each characterized b y single-crystal X-ray diffraction analysis. Space group and cell parameter s are as follows: for 1a, triclinic, P (1) over bar, a = 10.1139(2) Angstro m, b = 10.3955(2) Angstrom, c = 31.5086(7) Angstrom, alpha = 94.4720(12)deg rees, beta = 91.6420(10)degrees, and gamma = 105.3790(11)degrees; for 2a, m onoclinic, P2(1)/n, a = 14.6059(3) Angstrom, b = 10.9988(2) Angstrom, c = 1 5.1516(3) Angstrom, and B = 93.0000(14)degrees. Whereas 1a and 1b are isomo rphous, Compounds 2a and 2b are not, and show significant differences in in tramolecular conformation.