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

The new tungsten selenocarbonylate [NEt4][W([triple bond, length as m-dash]CSe)(CO)2(Tp*)] (Tp* = hydrotris(dimethylpyrazolyl)borate) reacts with group 11 reagents to provide σ-π or isoselenocarbonyl complexes of the form [WM(μ-CSe)(CO)2(PR3)n(Tp*)] (M = Cu, Ag, Au; R = Ph, Cy; n = 1,3) depending on the phosphine stoichiometry or steric bulk. With [Cu(NCMe)4]PF6 and 1,4,7-trithiacyclononane ([9]aneS3) however, the tetrametallic species [WCu3(μ-CSe)(CO)2([9]aneS3)3(Tp*)](PF6)2 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.