A. Sasane, Takayo Matuo, D. Nakamura
Apr 1, 1971
Citations
0
Influential Citations
22
Citations
Journal
Journal of Magnetic Resonance
Abstract
Abstract The nuclear quadrupole resonance of halogens in a variety of anhydrous and hydrated tetrahaloaurates(III) was observed between 77 and 400°K. From the number of resonance lines, the number of different kinds of crystallographically nonequivalent halogen atoms was determined. The ionic character of AuCl and AuBr bonds is estimated as 41% and 34%, respectively. The central gold atom in the tetracoordinated complex ion carries a fraction of protonic charge (0.64ϵ in [AuCI 4 ] − and 0.36ϵ in [AuBr 4 ] − , respectively). The positive temperature coefficient of resonance frequencies observed for some tetrahaloaurates(III) is attributable to hydrogen bond formation. The anomalous temperature dependence of bromine resonance frequency of cesium tetrabromoaurate(III) is presumed to be due to the torsional oscillation of tetrabromoaurate(III) ions in crystals involving a considerable anharmonicity.