Mercury(ii), copper(ii) and silver(i) complexes with ether or diether functionalized bis-NHC ligands: synthesis and structural studies

Abstract

The oligoether-linked dibenzimidazolium (or diimidazolium) salts, bis[2-(3-ethylbenzimidazolium-1-yl)ethyl]ether diiodide (1), bis[2-(3-ⁿbutylbenzimidazolium-1-yl)ethyl]ether diiodide (2), 1,1′-[1,2-ethanediyl-bis(oxy-1,2-ethanediyl)]-bis(3-benzylbenzimidazolium-1-yl) diiodide (3), 1,1′-[1,2-ethanediyl-bis(oxy-1,2-ethanediyl)]-bis(3-ethylbenzimidazolium-1-yl) di-hexafluorophosphate (4), 1,1′-[1,2-ethanediyl-bis(oxy-1,2-ethanediyl)]-bis(3-benzylimidazolium-1-yl) diiodide (5), and their five mercury(II), copper(II) and silver(I) complexes with ether or diether linkers mercury-{C,C′-bis[2-(3-ethylimidazolin-2-yliden-1-yl)ethyl]ether} tetraiodomercurate (7), copper-{C,C′-bis[2-(3-ⁿbutylimidazolin-2-yliden-1-yl)ethyl]ether} tetraiodomercurate (8), mercury-{C,C′-1,1′-[1,2-ethanediylbis(oxy-1,2-ethanediyl)]-bis(3-benzylbenzimidazolin-2-yliden-1-yl)} triiodomercurate acetate (9), silver-{C,C′-1,1′-[1,2-ethanediylbis(oxy-1,2-ethanediyl)]-bis(3-ethylbenzimidazolin-2-yliden-1-yl)} hexafluorophosphate (10) and mercury-{C,C′-1,1′-[1,2-ethanediylbis(oxy-1,2-ethanediyl)]-bis(3-benzylimidazolin-2-yliden-1-yl)} tetraiodomercurate (11), as well as one anionic complex bis[2-(3-ⁿbutylbenzimidazolium-1-yl)ethyl]ether di-μ-iodo-bis(diiodomercurate) (6) were prepared and characterized. Each of N-heterocyclic carbene metal complexes 7–11 possesses a macrometallocycle, respectively, formed by one metal atom and one bidentate chelate carbene ligand. In the crystal packing of complexes 6–11, 2D supramolecular layers are formed via intermolecular weak interactions, including π–π interactions, hydrogen bonds, C–H⋯π contacts and weak Hg⋯I bonds.