Zinc(II)-included hemicryptophane: coordination of an acetonitrile guest within the cavity

Abstract

A zinc(II)-included hemicryptophane, which has a zinc(II) centre embedded in the cavity, was synthesised in high yield and characterised by fast atom bombardment mass spectrometry, 1H NMR spectroscopy and X-ray crystal structure analysis. The X-ray crystal structure shows that zinc(II)-included hemicryptophane has a preorganised cavity, formed by the cyclotriveratrylene and tris(aminoethyl)amine (tren) moieties. The zinc(II) centre is coordinated to the N4 core of the tren cap and to the nitrogen atom in acetonitrile. The acetonitrile guest is stabilised through CH–π interactions. The absolute configuration of the nitrogen atom in the amino group was assigned by anomalous X-ray scattering; the results indicated that a chiral zinc(II)-included hemicryptophane was obtained by spontaneous asymmetric crystallisation.