Gold complexes halogen-donors

In this section I will comment on some examples of gold complexes that display supramolecular entities in the solid state, although in these cases the metal atom is not directly involved in the van der Waals interactions. As in the previous section, the electron density donor can be a non-metal different from hydrogen, which can be a halogen or a chalcogen a hydrogen atom of a covalent NM — H bond or a doud of n electron density. 

Bibenzyl is formed in a yield of 22% when a degassed solution in acetonitrile of benzyl chloride, an electron donor such as triethylamine and a catalytic amount of the gold complex 88, is irradiated. The gold complex (88) is described as a potent new photocatalyst for such systems and performs better than existing catalysts. The mechanism of the process has been shown to involve direct halogen transfer as shown in equation 9. The resultant alkyl radicals then yield the final product. A similar reaction operates with 1-bromopentane when it is irradiated under the same conditions This yields -decane178. 

Homoleptic complexes with bidentate C C donor ylide derivatives are well known. Oxidative addition of some gold(I) [Au2 (CH2)2PR2 2] species by addition of halogen, pseudo-halogen, or alkyl halide affords dinuclear Au(II) complexes which... 

In these complexes, the gold-metal bonds are apparently weak and polar and, in man cases, the metal carbonyl anion can be displaced by donor ligands (equation go)716 726>732,733 a well as by halogens and similar reagents.721... 

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