Organoplatinum(ii) complexes containing chelating or bridging bis(N-heterocyclic carbene) ligands: formation of a platinum(ii) carbonate complex by aerial CO2 fixation

Abstract

The preparation of two new bis(N-heterocyclic carbene) platinum(II) complexes, in which NHC rings are joined by a CH₂ linker group, is described. While, the chelate complex [PtMe₂(bis-NHC1)], 1, was formed with large tert-butyl wingtips, the iso-propylN-substituent analogue favors formation of the cluster complex [Pt₂Me₄(μ-SMe₂)(μ-bis-NHC2)]₂(μ-Ag₂Br₂), 2, in which two binuclear platinum(II) complexes are linked together by an Ag₂Br₂ unit. The chelating platinum complex 1 undergoes aerial CO₂ fixation and forms platinum(II) carbonate complex [Pt(CO₃)(bis-NHC1)], 3.