A homoleptic tris(diphosphacyclobutadiene) tripledecker sandwich complex.

The synthesis and characterisation of [Co 2 (η 4 -P 2 C 2 t Bu 2 ) 2 (μ:η 4 :η 4 -P 2 C 2 t Bu 2 )] (1) is described, featuring two cobalt atoms and three diphosphacyclobutadiene ligands. This compound is the first triple-decker sandwich complex which exclusively contains cyclobutadiene ligands.