The crystal structure of anhydrous nitrates and their complexes. Part V. Potassium tetranitratoaurate(III)

Abstract

A three-dimensional X-ray crystal structure analysis of potassium tetranitratoaurate(III) has shown it to consist of discrete K⁺ and [Au(NO₃)₄]^– ions. Z= 2 in a monoclinic unit cell of dimensions a= 9·21 ± 0·02 Å, b= 7·14 ± 0·02 Å, c= 10·04 ± 0·02 Å, β= 128·6 ± 0·3° and space group P2₁/c. In the anions, the gold atom is co-ordinated in a square planar manner by four equivalent unidentate nitrato groups, mean Au–O being 2·00 ± 0·02 Å. The dimensions of the nitrato-groups differ from those of a typical nitrate ion, having three different N–O bonds of average length 1·37 ± 0·03, 1·23 ± 0·03, and 1·17 ± 0·03 Å. The effects of unidentate co-ordination upon the dimensions of nitrato groups are discussed.