A double salt with remarkable supramolecular channels: Synthesis and crystal structure of bis[1,3-dimesitylimidazolium]tetrachloronickelate(II)–[1,3-dimesitylimidazolium]chloride, which contains substituted imidazolium cations, and both tetrachloronickela

The reaction of nickel(II) acetylacetonate trimer with 1,3-bis(2,4,6-trimethylphenyl)imidazolium chloride, [IMesH]Cl, leads to the formation of the remarkable double salt [IMesH]2[NiCl4]·[IMesH]Cl 2, (or alternatively [IMesH]3[NiCl4]Cl). The solid-state structure of this species was determined by a single X-ray diffraction study. The molecular parameters of the ions are unremarkable, but this double salt crystallizes in the chiral space group P63 despite the achiral nature of all the ions: the chirality arises from the helical arrangement of the imidazolium mesityl groups. Additionally, the crystal contains hydrophobic channels of ca. 4.5 Å diameter, and there are extensive H-bonding interactions in the crystal. The double salt reacts with potassium tert-butoxide to give the known bis-N-heterocyclic carbene complex trans-[Ni(IMes)2Cl2], 3.

Graphical abstractNickel(II) acetylacetonate reacts with 1,3-bis(2,4,6-trimethylphenyl)imidazolium chloride, [IMesH]Cl, and the double salt [IMesH]2[NiCl4]·[IMesH]Cl can be isolated. This salt exhibit supramolecular channels, and H-bonded interactions that generate a helical chiral arrangement of the IMesH cations, despite the achiral nature of all the ions.Figure optionsDownload full-size imageDownload as PowerPoint slide