Synthesis of dinuclear N-heterocyclic dicarbene Au(III)/Au(III) and Au(II)/Au(II) complexes via oxidative addition of chlorine or bromine to Au(I)/Au(I) species

摘要

Oxidative addition of chlorine to dinuclear N-heterocyclic dicarbene gold(I) complexes of formula [Au 2(RIm-Y-ImR) _2](PF _6) _2 (R = Me, Y = (CH _2) _(1-4); R = Cy, Y = CH _2) affords in high yield stable Au(III)/Au(III) and Au(II)/Au(II) complexes. The nature of the products depends on the bridge between the two carbene moieties. With Y = methylene, ethylene and butylene, Au(III)/Au(III) dinuclear dicarbene complexes are formed. Only in the case of the propylene bridge the main product is an Au(II)/Au(II) complex. The same reaction output is now proposed also in the oxidative addition of bromine, as fully supported by the X-ray structure of complex [Au _2Br _2(MeIm-(CH _2) _3-ImMe) 2](PF _6) _2.