Synthesis of two novel Re7 carbido-carbonyl complexes. X-ray crystal structure of the anion [Re7C(CO)22]

Oxidation of the carbido cluster trianion [Re7C(CO)21]3- with C7H7BF4 gives the unstable paramagnetic species [Re7C(CO)21]2-, which, under an atmosphere of CO undergoes further oxidation to the monoanion [Re7C(CO)22]-. This anion, which was characterized by an X-ray study, has the unusual feature of a CO ligand bridging a Re-Re edge. © 1987.