Synthesis and structures of mono- and tetra-nuclear silver complexes of styrene-containing N-heterocyclic carbene

Abstract

Two tetra-nuclear Ag(I) complexes with styrene-functionalized N-heterocyclic carbene [AgL 2] 2[Ag 2X 4] (L = 1-methyl-3-(4-vinylbenzyl)imidazol-2-ylidene, X = Cl, 2a; X = I, 2b) were prepared by the reactions between the corresponding imidazolium salts with Ag 2O. The reaction mixture was further treated with AgBF 4 to give a mononuclear ion-pair complex [AgL 2][BF 4] ( 3). The molecular structures of these new Ag(I) complexes have been determined by X-ray diffraction analyses. 2a and 2b consist of two [Ag(L) 2] + fragments with the central [Ag 2X 4] 2− anion held together by the close Ag(I)–Ag(I) interactions. Complex 3 is a mononuclear ion-pair complex with a linear bi-coordinate Ag fragment.