138826-99-0Relevant academic research and scientific papers
Synthesis and chemistry of icosahedral bis(phosphine)metalladiarsaboranes and -distibaboranes containing nickel and palladium. Crystal and molecular structures of closo-1,1-(Me2PPh)2-1,2,3-PdAs2B 9H9, closo-1,6-Cl2-1,5-(Me2PPh)2-1,2,3-PdAs 2B9H ...
Jasper Jr., Steve A.,Roach, Steve,Stipp, John N.,Huffman,Todd, Lee J.
, p. 3072 - 3080 (2008/10/08)
Full title: Synthesis and chemistry of icosahedral bis(phosphine)metalladiarsaboranes and -distibaboranes containing nickel and palladium. Crystal and molecular structures of closo-1,1-(Me2PPh)2-1,2,3-PdAs2B 9H9, closo-1,6-Cl2-1,5-(Me2PPh)2-1,2,3-PdAs 2B9H7·CH2Cl2, and closo-1,1-(Me2PPh)2-1,2,3-PdSb2B 9H9. 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 room temperature led to the formation of icosahedral bis(phosphine)metalladiheteroboranes 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-NiAs2B 9H8 (2) was isolated and fully characterized. In the palladium-containing reaction, the corresponding 6-chloro-substituted closo-1,6-Cl2-1,5-(Me2PPh)2-1,2,3-PdAs 2B9H7 (4) was isolated. These complexes were formed by interchange of phosphine and hydrido ligands on the parent complex, followed by chlorine for hydrogen interchange. Compound 3 was characterized by an X-ray diffraction study. Purple crystals were monoclinic space group P21/n, with a = 12.874(3) A?, b = 10.421(3) A?, c = 19.555(6) A?, β = 104.08(1)°, and Z = 4. The structure was determined by conventional heavy-atom methods and refined to a final value of R = 0.0506 (3799 reflections), Rw = 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?, b = 10.267(3) A?, c = 17.465(6) A?, β = 116.65(1)°, and Z = 8. The structure was determined by conventional heavy-atom methods and refined to a final value of R = 0.0780 (6080 reflections), Rw = 0.0731. Compound 5 was characterized by an X-ray diffraction study. Purple crystals were monoclinic space group P21/n, with a = 12.958(3) A?, b = 10.619(2) A?, c = 19.587(6) A?, β = 103.98(1)°, and Z = 4. The structure was determined by conventional heavy-atom methods and refined to a final value of R = 0.0301 (10158 reflections), Rw = 0.0338.
Metallaheteroborane Chemistry. Part 9. Syntheses and Spectroscopy of Platinum and Palladium Phosphine Complexes containing η5--based Cluster Ligands. Crystal Structures of (L = PPh3 or PMe2Ph) and
McGrath, Marguerite,Spalding, Trevor R.,Fontaine, Xavier L. R.,Kennedy, John D.,Thornton-Pett, Mark
, p. 3223 - 3234 (2007/10/02)
The reaction between and closo-1,2-As2B10H10 in ethanol gives 1 in low yield (9percent).Reaction of - and in tetrahydrofuran (thf) in the presence of a ten-fold excess of NEt3 affords (M = Pt, R3 = Me2Ph 2; M = Pd, R3 = Ph3 3 or Me2Ph 4) and (R3 = Ph3 5; or R3 = Me2Ph, 6) in low-to-moderate (20-45percent) yields.X-Ray diffraction analyses of 1, 2 and 5 confirm the closo icosahedral MAs2B9 cage structures and the presence of a MAs2 triangulated face in each of these molecules.Both compounds 1 and 2 crystallise in the monoclinic space group P21/n with Z = 4.Cell dimensions: 1, a = 1230.0(2), b = 1736.5(4), c = 1881.0(3) pm and β = 91.44(2) deg; 2, a = 1308.6(3), b = 1058.0(2), c = 1934.7(3) pm and β = 104.45(2) deg.The structure of 1 was refined to a final R of 0.0574 (R' 0.0532) for the 4160 reflections with I >= 2.0?(I).One of the As atoms is disordered over two sites.Calculated Pt-As distances are 259.1(5), 255.7(5) and 264.0(6) pm, As-As 251.5(6) and 243.5(5) pm.Structure 2 had a final R of 0.0384 (R' 0.0376) for 3778 reflections with I >= 2.0?(I).The Pt-As distances are 265.5(4) and 254.5(4) pm and As-As is 249.7(3) pm.Compound 5 crystallises in the triclinic space group P1/ with Z = 2, a = 1037.8(2), b = 1321.9(3), c = 1712.9(3) pm, α = 103.67(1), β = 93.19(1) and γ = 110.86(1) deg; final R = 0.392 (R' 0.0408) for 4688 reflections with I >= 2.0?(I).The Pd-As distances are 256.3(4) and 253.9(4) pm and As-As is 247.7(3) pm.Compounds 1-6 were characterised by multielement NMR spectroscopy.Variable-temperature 1H studies of 2, 4 and 6 show the metal to As2B9 ligand bonding is fluxional at room temperature with ΔG(excit.)298 -1 for 2 and 4 and possibly slightly higher for 6 at ca. 32 kJ mol-1.An analysis of the frontier molecular orbitals of the model ligand P2B9H9 and their possible interactions with a Pt(PH3)2 group shows no clear preference between the two possible conformations that the PtP2 unit could adopt above the P2B3 face to which it bonds.
