Terminal Gold-Oxo Complexes
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- 作者：Rui Cao ; Travis M. Anderson ; Paula M. B. Piccoli ; Arthur J. Schultz ; Thomas F. Koetzle ; Yurii V. Geletii ; Elena Slonkina ; Britt Hedman ; Keith O. Hodgson ; Kenneth I. Hardcastle ; Xikui Fang ; Martin L. K
- 刊名：Journal of the American Chemical Society
- 出版年：2007
- 出版时间：September 12, 2007
- 年：2007
- 卷：129
- 期：36
- 页码：11118 - 11133
- 全文大小：541K
- 年卷期：v.129,no.36(September 12, 2007)
- ISSN：1520-5126
文摘
In contradiction to current bonding paradigms, two terminal Au-oxo molecular complexes havebeen synthesized by reaction of AuCl3 with metal oxide-cluster ligands that model redox-active metal oxidesurfaces. Use of K10[
2-P2W17O61]·20H2O and K2WO4 (forming the [A-PW9O34]9- ligand in situ) producesK15H2[Au(O)(OH2)P2W18O68]·25H2O (1); use of K10[P2W20O70(OH2)2]·22H2O (3) produces K7H2[Au(O)(OH2)P2W20O70(OH2)2]·27H2O (2). Complex 1 crystallizes in orthorhombic Fddd, with a = 28.594(4) Å, b =31.866(4) Å, c = 38.241(5) Å, V = 34844(7) Å3, Z = 16 (final R = 0.0540), and complex 2 crystallizes inhexagonal P6(3)/mmc, with a = 16.1730(9) Å, b = 16.1730(9) Å, c = 19.7659(15) Å, V = 4477.4(5) Å3, Z= 2 (final R = 0.0634). The polyanion unit in 1 is disorder-free. Very short (~1.76 Å) Au-oxo distances areestablished by both X-ray and 30 K neutron diffraction studies, and the latter confirms oxo and trans aqua(H2O) ligands on Au. Seven findings clarify that Au and not W is present in the Au-oxo position in 1 and 2.Five lines of evidence are consistent with the presence of d8 Au(III) centers that are stabilized by the flankingpolytungstate ligands in both 1 and 2: redox titrations, electrochemical measurements, 17 K optical spectra,Au L2 edge X-ray absorption spectroscopy, and Au-oxo bond distances. Variable-temperature magneticsusceptibility data for crystalline 1 and 2 establish that both solids are diamagnetic, and 31P and 17O NMRspectroscopy confirm that both remain diamagnetic in solution. Both complexes have been furthercharacterized by FT-IR, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), andother techniques.
2-P2W17O61]·20H2O and K2WO4 (forming the [A-PW9O34]9- ligand in situ) producesK15H2[Au(O)(OH2)P2W18O68]·25H2O (1); use of K10[P2W20O70(OH2)2]·22H2O (3) produces K7H2[Au(O)(OH2)P2W20O70(OH2)2]·27H2O (2). Complex 1 crystallizes in orthorhombic Fddd, with a = 28.594(4) Å, b =31.866(4) Å, c = 38.241(5) Å, V = 34844(7) Å3, Z = 16 (final R = 0.0540), and complex 2 crystallizes inhexagonal P6(3)/mmc, with a = 16.1730(9) Å, b = 16.1730(9) Å, c = 19.7659(15) Å, V = 4477.4(5) Å3, Z= 2 (final R = 0.0634). The polyanion unit in 1 is disorder-free. Very short (~1.76 Å) Au-oxo distances areestablished by both X-ray and 30 K neutron diffraction studies, and the latter confirms oxo and trans aqua(H2O) ligands on Au. Seven findings clarify that Au and not W is present in the Au-oxo position in 1 and 2.Five lines of evidence are consistent with the presence of d8 Au(III) centers that are stabilized by the flankingpolytungstate ligands in both 1 and 2: redox titrations, electrochemical measurements, 17 K optical spectra,Au L2 edge X-ray absorption spectroscopy, and Au-oxo bond distances. Variable-temperature magneticsusceptibility data for crystalline 1 and 2 establish that both solids are diamagnetic, and 31P and 17O NMRspectroscopy confirm that both remain diamagnetic in solution. Both complexes have been furthercharacterized by FT-IR, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), andother techniques.