A fluxional high-nuclearity gold-platinum cluster: structure of [Au6Pt(CC-tert-butyl)(PPh3)7]+[Au(CC-tert-butyl)2]-

Abstract

cf. 1 and 2) for the planar form, whereas a B-P bond length of 1.91 Á is predicted for the most stable ground state, which has a pyramidal phosphorus, a 0°twist angle, and a dihedral angle of 124°. The HPH angle was calculated to be 103.4°. The corresponding angles and distances in the title compound show it to be somewhat nearer the planar form than the ground state of BH2PH2. However further variations of an R'2BPR2 molecule may show a range of these parameters. It is also interesting to note that when calculations were carried out on the orthogonal form (i.e. twist angle = 90°) of BH2PH2, a much longer BP distance of 1.98 Á was calculated.11In summary the structure of Mes2BPPh2 further supports the largely double B-P bond assignment in compounds 1 and 2. The pyramidal phosphorus should still be capable of ligand behavior. Complexes involving the title compound as a ligand and other variations involving its arsenic and antimony analogues are under investigation.Note Added in Proof. Professor Noth has informed us that the structure of [|B(PEt2)3|2], a dimer, has been solved. This also has pyramidal phosphorus centers in the terminal positions. Supplementary Material Available: A table summarizing the data collection and refinement and tables of atom coordinates, bond distances, angles, anisotropic thermal parameters, and hydrogen coordinates and thermal parameters (7 pages); a table of structure factors (19 pages). Ordering information is given on any masthead page.

Crystallographic and aluminum-27 NMR study on premelting phenomena in crystals of sodium tetrachloroaluminate

“…111. 8 (1) 111.7(1) 111.7(1) C1( 2)-A1-C1(3A) 110.7 (1) 111.0 (1) 110.8 (1) C1( 2)-A1-C(4B) 109.3 (1) 109.3 (1) 109.2 (1) C1(3A)-A1-C! (4B) 105.6 (1) 105.4 (1) 105.…”

Complexes with platinum-gold and -silver bonds: catalysis by silver(I) of alkyl exchange reactions between platinum centers

“…(-70 °C), 1.13 [d, 6 H, V(PtH) = 75, V(AgH) = 2 Hz, PtMe]; 31P (-80 °C), -0.5 [d X 2, V(107AgP) = 606, V(109AgP) = 676 Hz];…”

“…(-80 °C) 0.86 [d, 6 H, V(PtH) = 65, V(AgH) = 4 Hz, MePt], 7.6-8.6 (m, 8 H, bpy); 195Pt (-80 °C), 439 (s, v br, Pt).…”

“…There has been much recent interest in complexes with PtAg and PtAu bonds. Most such compounds are clusters, with PtAug,1 2 PtjAug,3 Pt3Au,4 PtgAu2,5 PtAug,6 and PtAu77 clusters all having been prepared since 1984. Several unusual PtAg bonded complexes have been characterized also,8"11 including one complex [(C6F5)3-(SC4H8)PtAgPPh3] with a covalent PtAg bond and no supporting bridging ligands.9 No analogous binuclear PtAu bonded complexes are well characterized, although there is an early claim for the complex [(Ph3P)2ClPtAuPPh3] , 12 The chemistry of gold-metal bonded complexes has been reviewed.…”

Gold–Heterometal Interactions and Bonds

“…The cation of [{(Ph 3 P)Au} 6 Pt(m-C:C t Bu)(PPh 3 )][Au(C:C t Bu) 2 ] 407 exhibits a central core resulting from two PtAu 4 square pyramids fused about a common PtAu 2 triangular face [553]. Alternatively, it might be described as derived from a distorted Pt-centered Au 8 cube with two missing vertices.…”