New mercury(II) and silver(I) complexes containing NHC metallacrown ethers with the π–π stacking interactions

The oligoether-linked bis-benzimidazolium salt 1,1′-[1,2-ethanediylbis(oxy-1,2-ethanediyl)]bis[(3-secbutyl)benzimidazolium-1-yl]iodide (H2L1 · I2), 1,1′-[1,2-ethanediylbis(oxy-1,2-ethanediyl)]bis[(3-ethyl)benzimidazolium-1-yl]iodide (H2L2 · I2) and 1,1′-[1,2-ethanediylbis(oxy-1,2-ethanediyl)]bis[(3-secbutyl)benzimidazolium-1-yl]hexafluorophosphate (H2L1 · (PF6)2) and their three new mercury(II) and silver(I) complexes containing NHC metallacrown ethers, HgL1 · (Hg2 · I6) (1), HgL2 · I2 (2) and AgL1 · PF6 (3) were prepared and characterized. In the packing diagrams of H2L2 · I2, 1, 2 and 3 benzimidazole ring head-to-tail π–π stacking interactions are observed.