Hg(II), Ag(I) and Au(I) complexes with aniline or pyridine-functionalized N-heterocyclic carbene

[Hg(La)2](PF6)2 (1), [Hg(Lb)2](PF6)2 (2), [Hg(Lc)2](PF6)2 (3), [Ag(La)2]I (4) and Au(La)Cl (5) (La, Lb, and Lc are aniline or pyridine N-functionalized imidazol-2-ylidene) have been synthesized and characterized. Single crystals of 1·MeOH, 3 and 5 are obtained and their crystal structures are determined by X-ray diffraction analysis. The molecular structure of 1·MeOH shows that Hg(II) center is coordinated to two carbene ligands, one nitrogen atom from aniline group and one oxygen atom from methanol. The anions are embedded between two cations layers and linked the cations through the intermolecular hydrogen bonding. The Hg(II) center of 3 is coordinated to two carbene ligands and two nitrogen atoms from pyridine group. The PF6− anions of 3 hold two adjacent cations through Hg⋯F interactions and H⋯F hydrogen bonding and the crystal packing consists of alternating anion and cation layers. The Au atom of 5 is linearly coordinated with a carbenoic carbon and a chloro ligand, and the molecules are neatly arranged to a one-dimensional hole through weak hydrogen bonding interactions. For 1·MeOH and 5, the –NH2 group of aniline plays an important role in stabilizing the crystal structure through intramolecular and intermolecular hydrogen bonding interactions.

The crystal structures of [Hg(La)2MeOH](PF6)2, [Hg(Lc)2](PF6)2 and Au(La)Cl (La/Lb is aniline/pyridine N-functionalized imidazol-2-ylidene) are determined. The –NH2 group of aniline in [Hg(La)2MeOH](PF6)2 and Au(La)Cl, and the PF6 anions in [Hg(La)2MeOH](PF6)2 and [Hg(Lc)2](PF6)2 play important roles in stabilizing the crystal structure through intramolecular and intermolecular hydrogen bonding interactions.Figure optionsDownload as PowerPoint slide