Oxotrichlorobis(triphenylphosphine)rhenium(V) reacts with monobenzoylhydrazine and dibenzoylhydrazine in benzene-ethanol in the presence of hydrochloric acid to give [N-benzoylhydrazido(3-)-O,N′] dichlorobis(triphenylphosphine)rhenium(V). The chelate ring is opened by a number of nucleophiles to give rhenium(III) benzoylazo-complexes. Certain tertiary and ditertiary phosphines react further in alcoholic solvents to yield rhenium(I) dinitrogen complexes. In the presence of a ketone [ReOCl 3(PPh3)2] reacts with monobenzoylhydrazine to give a chelate complex derived from the ketone hydrazone.
