SYNTHESIS AND CHEMISTRY OF ICOSAHEDRAL BIS(PHOSPHINE)METALLADIARSABORANES AND BIS(PHOSPHINE)DISTIBABORANES CONTAINING NICKEL AND PALLADIUM - CRYSTAL AND MOLECULAR-STRUCTURES OF CLOSO-1,1-(ME2PPH)2-1,2,3-PDAS2B9H9, LOSO-1,6-CL2-1,5-(ME2PPH)2-1,2,3-PDAS2B9H7.CH2CL2, AND CLOSO-1,1-(ME2PPH)2-1,2,3-PDSB2B9H9

The reaction of (Me2PPh)2MCl2 species (M = Ni or Pd) with the nido-7,8 -As2B9H92- ion and (Me2PPh)2PdCl2 with the nido-7,8-Sb2B9H92- ion at r oom temperature led to the formation of icosahedral bis(phosphine)meta lladiheteroboranes in low to moderate yields for M = Ni(1 for As) or M = Pd (3 for As and 5 for Sb). In addition, closo-1-Cl-1,5-(Me2PPh)2-1 ,2,3-NiAs2B9H8(2) was isolated and fully characterized. In the palladi um-containing reaction, the corresponding 6-chloro-substituted closo-1 ,6-Cl2-1,5-(Me2PPh)2-1,2,3-PdAs2B9H7 (4) was isolated. These complexes were formed by interchange of phosphine and hydrido ligands on the pa rent complex, followed by chlorine for hydrogen interchange. Compound 3 was characterized by an X-ray diffraction study. Purple crystals wer e monoclinic space group P2(1)/n, with a = 12.874(3) angstrom, b = 10. 421(3) angstrom, c = 19.555(6) angstrom, beta = 104.08(1)-degrees, and Z = 4. The structure was determined by conventional heavy-atom method s and refined to a final value of R = 0.0506 (3799 reflections), R(w) = 0.0494. Compound 4 was characterized by an X-ray diffraction study. Green crystals were monoclinic space group C2/c, with a = 37.011(13) a ngstrom, b = 10.267(3) angstrom, c = 17.465(6) angstrom, beta = 116.65 (1)-degrees, and Z = 8. The structure was determined by conventional h eavy-atom methods and refined to a final value of R = 0.0780 (6080 ref lections), R(w) = 0.0731. Compound 5 was characterized by an X-ray dif fraction study. Purple crystals were monoclinic space group P2(1)/n, w ith a = 12.958(3) angstrom, b = 10.619(2) angstrom, c = 19.587(6) angs trom, beta = 103.98(1)-degrees, and Z = 4. The structure was determine d by conventional heavy-atom methods and refined to a final value of R = 0.0301 (10158 reflections), R(w) = 0.0338.