Vibrational spectra and normal coordinate analyses of the gold halides AuX (X = Cl, Br and I)

Abstract

Complete vibrational spectra of the gold(I) halides AuX (X = Cl, Br and I) were measured. On the basis of the crystal structures symmetry analyses for both isolated chains and unit cells of the compounds were performed. Normal coordinate calculations for the chain molecules were carried out, and the most important force constants discussed. The valence force constants f d (Au-X) decrease in the series X = Cl, Br and I (1.75 × 10 2, 1.63 × 10 2 and 1.22 × 10 2 N m −1, respectively) and are lower throughout than the f d values for the corresponding AuX 2 − anions. Correlations between valence force constants and bond lengths in both AuX and AuX 2 − are pointed out.