124605-53-4Relevant academic research and scientific papers
Phosphole complexes of gold(I) halides: Comparison of solution and solid-state structures by a combination of solution and CP/MAS 31P NMR spectroscopy and X-ray crystallography
Attar, Saeed,Bearden, William H.,Alcock, Nathaniel W.,Alyea, Elmer C.,Nelson, John H.
, p. 425 - 433 (2008/10/08)
A series of complexes of 1-phenyldibenzophosphole (DBP), 1-phenyl-3,4-dimethylphosphole (DMPP), and triphenylphosphine of the type LnAuX (n = 1, L = DBP, DMPP, Ph3P, X = Cl, Br, I; n = 3, L = DBP, X = Cl, Br, I; n = 3, L = Ph3P, X = Cl; n = 4, L = DBP, DMPP, X = PF6) have been prepared and characterized. The structures of (DBP)AuCl (1), (DBP)3AuCl (2), and (DMPP)AuCl (3) have been determined from three-dimensional X-ray data collected by counter methods. Compound 1 crystallized in space group P1 with a = 10.257 (1) ?, b = 10.992 (2) ?, c = 17.131 (3) ?, α = 83.04 (1)°, β = 81.62 (1)°, γ = 66.96 (1)°, and Z = 4. Compound 2 crystallized in space group P1 with a = 11.152 (2) ?, b = 10.729 (2) ?, c = 19.168 (5) ?, α = 84.92 (2)°, β = 87.22 (2)°, γ = 76.08 (2)°, and Z = 2. Compound 3 crystallized in space group C2/c with a = 10.281 (2) ?, b = 14.812 (4) ?, c = 16.867 (4) ?, α = 89.96 (2)°, β = 91.71 (2)°, γ = 90.00 (2)°, and Z = 8. The three structures were refined by least-squares methods with RF = 0.0286 for 1, RF = 0.0364 for 2, and RF = 0.0265 for 3 for 4715, 6086, and 1787 unique reflections with I/σ(I) ≥ 3.0 for 1-3 respectively. A moderately strong relativistic interaction occurs between the two independent molecules of 1 with an Au-Au distance of 3.116 (2) ?. One of these molecules is nearly linearly coordinated (〈PAuCl = 178.8 (1)°) while the other is slightly bent (〈PAuCl = 172.4 (1)°). The CP/MAS 31P{1H} NMR spectrum of this complex shows two resonances in a 1:1 intensity ratio. Complex 3 is nearly linear in the solid state (〈PAuCl = 176.1 (1)°), and its CP/MAS 31P{1H} NMR spectrum shows three resonances in a 1:1:1 intensity ratio for reasons that are not yet understood. Complex 2 is a distorted tetrahedral molecule that exhibits an attractive interaction between two adjacent dibenzophosphole planes. Though the three phospholes are crystallographically inequivalent (d(AuP) = 2.359 (1), 2.382 (1), and 2.374 (2) ?) the molecule has effective Cs symmetry as evidenced by the observation of two 31P resonances in a 2:1 intensity ratio in its CP/MAS 31P{1H} NMR spectrum. Variable-temperature 31P{1H} NMR spectra obtained on solutions of LAuCl + L in various ratios were analyzed to determine the nature of the species present in solution and to gain information regarding their relative stabilities as a function of the nature of the phosphine.
