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

The new tungsten selenocarbonylate [NE 4 ][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 (PR 3 ) n (Tp*)] (M = Cu, Ag, Au; R = Ph, Cy; n = 1,3) depending on the phosphine stoichiometry or steric bulk. With [Cu(NCMe) 4 ]PF 6 and 1,4,7-trithiacyclononane ([9]aneS 3 ) however, the tetrametallic species [WCu 3 (μ-CSe)(CO) 2 ([9]aneS 3 ) 3 (Tp*)](PF 6 ) 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.