Donna L. Staley

Pentafluorophenylarsines. The crystal and molecular structures of tetrakis(pentafluorophenyl)diarsine, (C6F5)2AsAs(C6F5)2, tetrakis(pentafluorophenyl)diarsenic(III) oxide, (C6F5)2AsOAs(C6F5)2, and tris(pentafluorophenyl)arsine

Abstract Crystalline materials from a high-boiling fraction obtained as by-products in the preparation of C6F5AsCl2, or from subsequent reaction with elemental mercury, have been crystallographically identified as consisting primarily of secondary and tertiary substituted pentafluorophenylarsenic compounds. The crystal and molecular structures of three of these products are reported: (C6F5)2AsAs(C6F5)2 (1), (C6F5)2AsOAs(C6F5)2 (2), and (C6F5)3As (3). 1: C24F20As2, tetragonal, P 4 21c, a 13.253(3), c 42.584(10) A, V 7479 A3, Z = 12 (three independent half-molecules), R(F) 6.54%. 2: C24F20As2O, monoclinic, C2/c, a 16.676(5), b 7.755(2), c 22.266(6) A, β 117.13(2)°, V 2563 A3, Z = 4 (one half-molecule), R(F) 4.85%. 3: C18F15As, triclinic, P 1 , a 8.902(2), b 10.888(2), c 11.185(2) A, α 109.59(2), β 103.12(2), γ 106.95° V 911.3(4) A3, R(F) 4.50%. 1 is twisted 16.5° from a trans conformation and contains the longest AsAs bond reported for any organoarsenic compound, 2.479(4) A. However, non-bonded F…F contact distances fail to support steric reasons for these distortions. 2 has an AsOAs angle fo 116.2(3)° determined primarily by lattice packing effects. 3 is pyramidal with AsC distances and CAsC angles typical of triarylarsines.

Synthesis and molecular structure of a dinuclear phosphorus ylide complex: μ-dichlorobis[chloro(benzoylmethylenetri-n-butylphosphorane)palladium(II)]

Abstract The synthesis and molecular structure of μ-dichlorobis[chloro(benzoylmethylenetri-n-butylphosphorane)palladium(II)] is reported. The characterization of the dinuclear ylide species, wherein the ylide is not ortho-metalated, but solely coordinated through the ylide-methine carbon, is discussed. The role of the title compound in the overall formation of an ortho-metalated dinuclear species is also discussed. X-ray crystal data for C40H66O2P2Pd2Cl4: P21/n, monoclinic, a 12.928(4), b 13.318(4), c 15.948(5) A; β 110.16(2)°, V 2504(1) A3, Z = 2, Rf 5.98%, wRf 6.24%, for 3776 observed reflections with F0 > 5σ(F0).