Strong interactions through the X•••Au-Y bridge:: the Au bond?

The interaction between AuOH and the lone-pair donors (HF, H2O) is shown to result in well-bound complexes whose structure resembles that of the corresponding H-bonded systems with the gold atom replacing hydrogen. The dissociation energies are estimated to be 10.7 and 27.4 kcal/mol for HF...Au-OH and H2O...Au-OH, respectively. However, the interaction between AuOH and the lone pair donors is found to involve significant charge transfer. Furthermore, the Au-O stretching frequency increases upon the complex formation. It is concluded that, in spite of certain similarity to the H-bonded species, the Au-bonded complexes should be considered as Lewis acid-base pairs. (C) 2003 Elsevier Science B.V. All rights reserved.