A golden future for hydrogen bonding

21 Mar 2017

Written by Kirsty Muirhead for Chemistry World

Source: © Royal Society of Chemistry Two-dimensional contour plot of [Me2Au]− adduct with HCN. Red areas identify the stabilising interactions and blue destabilising interactions

Gold has surprised chemists by showing that a formally positively charged Au(I) ion can be a hydrogen bond acceptor.¹ This discovery challenges the traditional view that hydrogen bond acceptors are negatively charged.

Catharine Esterhuysen and her colleagues at the University of Stellenbosch, South Africa, used theoretical calculations to study how dimethylaurate interacted with six hydrogen bond donors including HF, HCN and NH_3.This study expands their previous work showing that Au(I) can be a hydrogen bond acceptor for water.² Strong or moderate hydrogen bonds were found for five of the pairs. As expected, the Au(I)···H–X bonds were weaker than those formed with the negative auride ion, but surprisingly the bonds with HF and HCN were more stabilising than their analogues with [(CO)₄Co]^–, which contains a negatively charged Co^– centre.