New binding modes for CSe: coinage metal coordination to a tungsten selenocarbonyl complex.

The new tungsten selenocarbonylate [NEt][W([triple bond, length as m-dash]CSe)(CO)(Tp*)] (Tp* = hydrotris(dimethylpyrazolyl)borate) reacts with group 11 reagents to provide σ-π or isoselenocarbonyl complexes of the form [WM(μ-CSe)(CO)(PR)(Tp*)] (M = Cu, Ag, Au; R = Ph, Cy; n = 1,3) depending on the phosphine stoichiometry or steric bulk. With [Cu(NCMe)]PF and 1,4,7-trithiacyclononane ([9]aneS) however, the tetrametallic species [WCu(μ-CSe)(CO)([9]aneS)(Tp*)](PF) is obtained in which one Cu coordinates to the W[triple bond, length as m-dash]C triple bond and two coordinate to the Se atom.