η4-Phosphole tricarbonylmanganates: a new type of chelating ligands for transition metals

3,4-Dimethylphosphacymantrene (1) reacts with tert-butyllithium to give the corresponding (η4-3,4-dimethyl-1-tert-butylphosphole)tricarbonylmanganate (2) which can act as a chelating ligand (L) toward a Pd2Cl2 dimeric core. The X-ray crystal structure of L2Pd2Cl2 (3) shows a bite angle of 60.5°.