DEHYDROGENATION OF ORGANOLANTHANIDE ALKOXIDES AND X-RAY CRYSTAL-STRUCTURE OF REACTION-PRODUCT [(C5H-5)2YB(MU-OCH=C=CH2)]2

[Cp3Yb] reacts with HOR (Cp = C5H5; R = CH2CH=CH2, CH2CH2Me) in thf (thf = tetrahydrofuran)at room temperature to give complexes [{Cp2Yb(mu-OR)}2], which are dehydrogenated to yield the new complex [{Cp2Yb(mu-OCH=C=CH2)}2] in refluxing thf solution; the X-ray crystal structure shows that the new complex is dimeric with oxygen atoms as bridging groups.