Synthesis, structural studies and computational evaluation of cyclophanes incorporating imidazole-2-selones.

We report new cyclophanes containing imidazole-2-selone groups linked by xylylene rings. A set of imidazole-2-selone cyclophanes is synthesized by reaction corresponding to imidazolium cyclophanes with selenium in the presence of KCO. The structural behavior of the new imidazole-2-selone cyclophanes was determined by H and C NMR spectra and X-ray diffraction studies.

Stable Au complexes with four N-heterocyclic carbene groups can be prepared in high yield directly from KAuCl.

Gold(iii) N-heterocyclic carbene (NHC) complexes of form [Au(NHC)Cl]Cl were synthesized by reaction of KAuCl with bis- and tetrakis(imidazolium) salts in the presence of a mild base. Treatment of these complexes with KPF afforded four-coordinate Au complexes of form [Au(NHC)](PF). X-Ray crystallography showed the [Au(NHC)] cations in the hexafluorophosphate salts to have a square planar Au(NHC) moiety [AuC 2.