Reactions of Au+ and Au- with benzene and fluorine-substituted benzenes

Reactions of gold anions and cations generated by laser desorption/ionizati on were studied in the FTICR spectrometer. Au- associated with C6F6 to give the novel Au-(C6F6) complex, whose binding energy was estimated to be 24 /- 4 kcal mol(-1) from analysis of the radiative association (RA) kinetics. Au+ associated with C6F5H to give Au+(C6F5H), with binding energy estimate d to be 31 kcal mol(-1). Au+ reacted with C6H6 to form the well known Au+(C 6H5) and Au+(C6H5), complexes. The observation of rapid charge transfer fro m Au+(C6H6) to C6H6 was interpreted as showing that benzene binds more stro ngly to neutral Au than to Au+. The neutral Au-C6H6 bond is accordingly con cluded to be stronger than about 70 kcal mol(-1). (C) 1999 Elsevier Science B.V.