Reactions of a ditungsten-capped tetrayne with cobalt carbonyls: molecularstructures of {W(CO)3Cp}(2){mu-C-8[Co-2(mu-dppm)(m)(CO)(6-2m)](n)} (m = 0,1; n = 1, 2)

The carbon-rich complex {W(CO)(3)Cp}(2)(mu-C-8) reacts with Co-2(mu-dppm)(m )(CO)(8-2m) (m = 0, 1) to give several complexes formed by addition of Co-2 (mu-dppm)(m)(CO)(6-2m) moieties to one or two C=C triple bonds. X-Ray struc ture determinations on {W(CO)(3)Cp}(2){mu-C-8[Co-2(mu-dppm)(m)(CO)(6-2m]n}) [m = 0, n = 1, 2; m = 1, n = 1, 2 (two isomers)] confirm the presence of t he C-8 chain linking the two W(CO)(3)Cp groups.