Induction of Λ -helicity in a zinc complex with an alanine-appended aminopyridine ligand

The crystal structure of tris[dimethyl 5-({1-[(pyridin-2-yl- κ N)carbamoyl- κ O]ethyl}carbamoyl)benzene-1,3-dicarboxylate]zinc(II) dinitrate acetonitrile trisolvate, [Zn(C19H19N3O6)3](NO3)2 · 3CH3CN or [Zn(L)3](NO3)2 · 3CH3CN, (1), has been determined by single-crystal X-ray diffraction. The neutral ligand L coordinates to the Zn2+ cation in a bidentate fashion via the pyridine N atom and an amide O atom, forming a six-membered chelate ring. The Λ -helical chirality of the Zn2+ coordination sphere is induced by pendant l-alanine residues through stacking interactions between the arene groups of two coordinated ligands, assisted by a hydrogen bond between amide groups bonded to the stacked arene rings. The third ligand is coordinated to the Zn2+ cation by the same six-membered chelate ring, but in the opposite direction with respect to the analogous chelate rings of the first two coordinated ligands. Besides ionic interactions between [ZnL3]2+ complexes and NO3 − anions, several types of hydrogen bonds and intermolecular stacking interactions contribute to the stability of the solid-state phase.

Source: Acta Crystallographica Section C - July 5, 2021 Category: Chemistry Authors: Peri ć , B. Kokan, Z. Kirin, S.I. Tags: alanine aminopyridine supramolecular chirality zinc complex crystal structure amino acid research papers Source Type: research