cis-[7,8-Bis(diphenylphosphino)-7,8-dicarba-nido-undecaborato-P,P']dichlorogold(III) Chloroform Solvate

Ligand-enabled oxidation of gold(i) complexes with o-quinones

Chelating P^P and hemilabile P^N ligands were found to trigger the oxidation of Au(i) complexes by o-benzoquinones. The ensuing Au(iii) catecholate complexes have been characterized by NMR spectroscopy, single crystal X-ray diffraction and X-ray absorption spectroscopy. They adopt tetracoordinate square-planar structures. Reactivity studies substantiate the reversibility of the transformation. In particular, the addition of competing ligands such as chloride and alkenes gives back Au(i) complexes with concomitant release of the o-quinone. DFT calculations provide insight about the structure and relative stability of the Au(i) o-quinone and Au(iii) catecholate forms, and shed light on the 2-electron transfer from gold to the o-quinone.

Chelating P^P and hemilabile P^N ligands were found to trigger the oxidation of Au(i) complexes by o-benzoquinones.

Crystal structure of 1-butyl-2,3-di-methyl-imidazolium dicarba-7,8-nido-undeca-borate

In the title mol-ecular salt, C9H17N2 (+)·C2H12B9 (-), the carborane cage has a bridging B-H-B bond on the open B3C2 face. The butyl side chain of the cation adopts an extended conformation [C-C-C-C = 179.6 (1)°]. In the crystal, the imidazolium ring is almost coplanar with the open face of the carborane anion. The cations stack in the [010] direction and the dihedral angle between the imidazolium rings of adjacent cations is 68.45 (6)°. The butyl chains extend into the space between carborane anions.