88056-72-8Relevant academic research and scientific papers
Intermediates in the formation of gold clusters. Preparation and X-ray analysis of [Au7(PPh3)7 ]+ and synthesis and characterization of [Au8(PPh3)6I]PF6
Van Der Velden,Beurskens,Bour,Bosman,Noordik,Kolenbrander,Buskes
, p. 146 - 151 (2008/10/08)
The evaporation of metallic gold into a toluene solution containing PPh3 (L) leads to the formation of a number of compounds from which the heptanuclear [Au7L7]+ (C126H105Au7P7+) can be isolated as the major constituent. An X-ray analysis has been performed on a single crystal, space group P1, with cell dimensions a = 34.94 (1) ?, b = 44.25 (2) ?, c = 15.45 (1) ?, α = 99.98 (3)°, β = 102.66 (3)°, γ = 88.11 (3)°, V = 22953.5 ?3, and Z = 8. The final R value is 0.099. The gold atoms in the [Au7L7]+ cation form a slightly distorted pentagonal bipyramid, which is a novel feature for heptanuclear metal clusters. The axial Au-Au distance (average 2.584 ± 0.001 ?) is the shortest distance ever found in gold clusters. The axial-equatorial and equatorial-equatorial Au-Au distances have mean values of 2.82 ± 0.08 and 2.95 ± 0.06 ?, respectively. All P-Au vectors point approximately to the center of the cluster with normal P-Au distances (2.27 ± 0.09 ?). Physical data including 197Au M?ssbauer and (solid-state) 31P{1H} NMR are reported. [Au7L7]+ can also be observed during the reaction of L with the novel compound [Au8L6I]PF6. The latter cluster could be prepared from the reaction of [Au9L8]3+ with Bu4NI. The intermediacy of the title compounds in the formation and reactivity of gold cluster compounds will be discussed.
