PHOTOCHEMICAL DEHYDROGENATION OF [C5H5(CO)FE]2(MU-CO)(MU-CHCH2CH2CH2CH3) TO FE](MU-CO)(MU-ETA(1),ETA(3)-CHCH=CHCH2CH3)[FEC5H5]

Photolysis of [C5H5(CO)Fe]2(mu-CO)(mu-CHCH2CH2CH2CH3) (2) in an unsucc essful effort to cleave the mu-alkylidene ligand led to expulsion of C O and H-2 and to formation of [C5H5Fe(CO)](mu-CO)(mu-eta1,eta3-CHCH= C HCH2CH3)[FeC5H5] (3). The Contrast between the facile photochemical cl eavage reactions of the mu-alkenylidene complex [C5H5(CO)Fe]2(mu-CO)(m u-C=CHCH2CH2CH3) (1) and the slow photochemical dehydrogenation of mu- alkylidene complex 2 is discussed.