A(5)-CYCLOPENTADIENYL)ZIRKONIUM(2-N-BUTYL)ACETYLID DIMER

The crystal structure of tetrakis[1,1,2,2(eta(5))-cydopentadienyl] [mu -1 kappa C:2(eta(2))-1-hexynyl][mu-2 kappa C:1(eta(2))-1-hexynyl]dizir conium, [(eta(5)-C5H5)(2)Zr-C=C-(n)Bu](2), was determined by X-ray dif fraction. The compound forms centrosymmetric dimers, in which the Zr a toms are linked through side-on coordination of the C=C function, corr esponding to a two-electron donor bond. At 171.0 degrees, the Zr-C=C a xis in the monomer is almost linear; the Zr-C distance of the sigma bo nd is 2.206 Angstrom, and the side-on Zr C distances are 2.437 and 2.4 13 Angstrom, respectively.