REACTIVITY OF HYDROGEN HALIDE ADDUCTS OF TRIOSMIUM CLUSTERS .2. SYNTHESIS OF MU-ETA(1)-PHENYL AND MU-ETA(1) ETA(6)-PHENYL CLUSTERS/

The reaction of Os-3(CO)(9)(mu-H)(2)(mu-eta(2)-C=N(CH2)(3))Br (2) with diphenyl mercury yields the mu-eta(1)-phenyl derivative s-3(CO)(10)(m u-eta(2)-C=N(CH2)(3))(mu-eta(1)-C6H5) (3) Compound 3 converts to the n ovel mu-eta(1):eta(6)-phenyl derivative O)(8)(mu-eta(2)-C=N(CH2)(3))(m u-eta(1):eta(6)-C6H5 (4) On thermolysis in octane. The solid-state str ucture of 4 is reported. In order to clear up ambiguities in the locat ion of the hydrides for the previously reported 2, we report the solid -state structure and solution dynamics of Os-3(CO)(9)(mu-H)(2)(mu-eta( 2)-C=NCH(CH3)CH2CH2)Br (6), where carbon-nitrogen disordering is obvia ted by the presence of the 2-methyl group, The further reaction of 2 w ith excess HBr results in degradation of the cluster and the isolation of Os-2(CO)(6)(mu-H)(mu-eta(2)-CHNH(CH)(3))Br-2 (7). This compound re presents an unusual example of acid-promoted hydrogenation of a carbon -nitrogen double bond and is an essential reversal of the dehydrogenat ion associated with the formation of the mu-imidoyl ligands in the tit le complexes.