Dinuclear gold® complexes

A related dinuclear species 77, recently described, constitutes the first dinuclear gold(I) complex with heterobridged phosphor-1,1 -dithiolato moieties and bis(ylide) bridging ligands [ 102]. It is obtained by reaction between [ AuS2PPh2] and the diylide gold complex 74 (R=Me). No intermolecular Au-Au interaction is observed in 77 but the oxidative addition of chlorine to the product leads to a new complex 78 in which a single bond is formed between the two Au(II) centers (Scheme 26). 

Figure 1.2 Amidine ligands used in the synthesis of terta-, tri-, and dinuclear gold complexes.

Bardaji, M., Laguna, A., Perez, M.R. and Jones, P.G. (2002) Unexpected ring-opening reaction to a new cyanamide-fhiolate ligand stabilized as a dinuclear gold complex. Organometallics, 21, 1877. 

The treatment of 2-amino-4,5-dihydrothiazole with [Au(ACAC)(PPh3)] evolves to an unprecedented ring-opening reaction to give the new ligand (2-cyanamide)ethylthiolate, stabilized as the dinuclear gold complex (Equation (42)).2315... 

Figure 6. Orbital diagram for dinuclear gold complexes.

Figure 7. Organometallic reactions of dinuclear gold complexes.

The first descriptions of heteronuclear luminescent supramolecular complexes were given by Fackler et al. in 1988 and 1989. In these studies, one gold-thallium and one gold-lead complex were reported. As in the case of the gold-silver dinuclear systems, the extended systems appeared as a result of the unidirectional polymerization of dinuclear or trinuclear units through metal-metal interactions. These were prepared by reaction of the gold precursor [PPN][Au(MTP)2] (PPN = N(PPh3)2 ... 

Dinuclear gold(I) and gold(II) complexes of pyridine-2-thiolate, 27, 28a and 28b, were studied by cyclic voltammetry at a Pt working electrode in CH2CI234. The dinuclear gold complex, 27, has an irreversible, extended oxidation process at +0.53 V vs SCE. No reduction wave was observed out to —1.8 V. The cyclic voltammograms for the dinuclear gold(II) complexes show irreversible reduction waves at —0.44 V (28a) and —0.43 V (28b). After reduction, the return oxidation scan shows an irreversible oxidation process at +0.55 V, indicative of the presence of 27. 

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