Template Synthesis of a Coordinated Tetracarbene Ligand with Crown Ether Topology

A template-controlled reaction cascade starting from [Pt(PMe3)4](CF3SO3)2 and 2-azidophenyl isocyanide yields the tetracarbene complex [1](CF3SO3)2. The four NH,NH-stabilized carbene ligands in [1]2+ can be bridged at the metal template by reaction with N,N-dimethylformamide (DMF) and diphosgene to give the coordinated cyclic tetracarbene ligand with crown ether topology in complex [2](Cl)2.