A series of rhenium (II1)-oxo-alkoxide-bis (acety1ene) complexes of the form Re (0)(OR)(R'Cd! R') z have been prepared by reaction of the iodide derivatives R~(O) I (R'CECR')~ with thallium alkoxides. An X-ray crystal structure of the phenoxide complex 7a shows the pseudotetrahedral coordination geometry typical of Re (0) X (RC= CR) z compounds, with a short rhenium-oxo bond of 1.712 (13) A and a longer Re-OPh distance ...