The action of methyltriphenylphosphonium or methyltriphenylarsonium iodide upon octacarbonyldiiododirhenium, Re2(CO)8I2, - depending on the stoichiometry of the reactants - resulted in the anions [Re2(CO)7I3]−, [Re(CO)4I2]−and [Re(CO)3I3]2-. These were isolated and characterized as the corresponding methyltriphenylphosphonium as well as methyltriphenylarsonium salts.