POLY-CARBON LIGAND CHEMISTRY - NOVEL BEHAVIOR OF MU-ETA(1),ETA(2)ALPHA,BETA-BUTADIYNYLS TOWARDS METAL FRAGMENT ADDITIONS

Reaction of mu-PPh(2))(mu-eta(1),eta(alpha,beta)(2)-C=C-C=CR)] (R = Bu (t) 1a, Ph 1b) with the labile complexes [Pt(PPh(3))(2)(eta-C2H4], [Pt (dppb)(eta-C2H4)] and [Ni(cod)(2)] or [Ni(CO)(4)] leads to the heteron uclear derivatives )(mu(3)-eta(1),eta(1),eta(1)-C=C-C=CR)(mu-PPh(2))] 2a,b, (3)-eta(1),eta(1),eta(1)-C=C-C=CBu(t))(mu-PPh(2))] 2c and )-eta( 1),eta(1),eta(2),eta(4)-Bu(t)C=CC4C=CBu(t))] 3 resulting from addition of a PtL(2) fragment and Ni-assisted stoichiometric coupling of two m olecules of 1a respectively; the X-ray crystal structures of 2a and 3 are described.