Terminal Au-N and Au-O Units in Organometallic Frames.

Since gold is located well beyond the oxo wall, chemical species with terminal Au-N and Au-O units are extremely rare and limited to low coordination numbers. We report here that these unusual units can be trapped within a suitable organometallic frame. Thus, the terminal auronitrene and auroxyl derivatives [(CF ) AuN] and [(CF ) AuO] were identified as local minima by calculation. These open-shell, high-energy ions were experimentally detected by tandem mass spectrometry (MS ): They respectively arise by N or NO dissociation from the corresponding precursor species [(CF ) Au(N )] and [(CF ) Au(ONO )] in the gas phase. Together with the known fluoride derivative [(CF ) AuF] , they form an interesting series of isoleptic and alloelectronic complexes of the highly acidic organogold(iii) moiety (CF ) Au with singly charged anions X of the most electronegative elements (X=F, O, N). Ligand-field inversion in all these [(CF ) AuX] species results in the localization of unpaired electrons at the N and O atoms.