Alkynylselenolatoalkylidynes (LnM C-Se-C CR) as building blocks for mixed metal/main-group extended frameworks

Abstract

The reactions of [W([triple bond, length as m-dash]CBr)(CO)2(Tp*)] (Tp* = hydrotris(3,5-dimethylpyrazol-1-yl)borate) with lithium alkynylselenolates LiSeC[triple bond, length as m-dash]CR (R = SiMe3, SiiPr3, nBu, tBu, Ph, p-tolyl) afford the alkynylselenolatoalkylidyne complexes [W([triple bond, length as m-dash]CSeC[triple bond, length as m-dash]CR)(CO)2(Tp*)]. Desilylation of the SiMe3 complex furnishes the parent [W([triple bond, length as m-dash]CSeC[triple bond, length as m-dash]CH)(CO)2(Tp*)], which may be further derivatised by deprotonation and treatment with triphenylcarbenium or triphenylmetal chlorides to give mixed-heteroatom products [W([triple bond, length as m-dash]CSeC[triple bond, length as m-dash]CEPh3)(CO)2(Tp*)] (E = C, Si, Ge, Sn, Pb). This procedure extends to dichlorosilanes, whereby the unusual bimetallic complexes [(Tp*)(CO)2W[triple bond, length as m-dash]CSeC[triple bond, length as m-dash]CSiRR′C[triple bond, length as m-dash]CSeC[triple bond, length as m-dash]W(CO)2(Tp*)] (R, R′ = Ph, CH3) are obtained, bridged by unsaturated units interrupted by two different main-group heteroatoms. Finally, the trimetallic analogues, [{(Tp*)(CO)2W([triple bond, length as m-dash]CSeC[triple bond, length as m-dash]C)}3SiR] (R = Ph, Et), may be prepared in the same manner from appropriate organotrichlorosilanes.