189. Quinquevalent compounds of uranium. Part III. Uranium penta-alkoxides

New uranium penta-alkoxides were prepared from uranium penta-ethoxide by alcohol exchange. Volatilities were measured under reduced pressure, and molecular weights ebullioscopically in benzene. The compounds were compared with penta-alkoxides of niobium and tantalum. Steric effects in binuclear octahedral complexes M/sub 2/(OR)/sub 10/ are discussed. (auth)