Mössbauer study of the dynamic behaviour of gold in molecular crystals

Measurements are reported of the temperature dependence of the Mossbauer fraction of a number of AuI and AuIII complexes. A simple model is described with which this temperature dependence of the Mossbauer fraction was analysed in terms of intra- and Inter-molecular vibrations. The observed difference between Mossbauer fractions of AuI and AuIII complexes has to be attributed mainly to the larger mass of the latter, rather than to the difference in co-ordination number.