engleski

2D Solid state aggregation of chiral zinc acylaminopyridine complexes by aromatic π•••π stacking interactions

Recently we have shown that non-covalent assemblies of chiral acylamino-pyridine ligand L exhibit supramolecular chirality in the solid state and in solution, L = (MeO2C)2Ph-CO-Ala-NH-Py. As revealed by CD spectroscopy, in solution the supramolecular chirality is completely inverted if the ligand L is complexed to zinc cation. In this communication we report the crystal structure of [ZnL3]2+ complexes that crystallize with NO3– counter-anions and acetonitrile solvent molecules into solid state compound [ZnL3][NO3]2•3CH3CN [P21, a=10.5897(2), b=22.8595(5), c=14.3102(3) Å ; β=92.524(2)o]. Significant interactions controlling aggregation of the [ZnL3]2+ complexes are electrostatic interactions, hydrogen bonding and aromatic π•••π stacking. The stacking motif, which extrudes in direction of the axis a, originates in part from two ligands within the same complex exhibiting a well known secondary structural motif, the "van Staveren conformation". The title compound forms 2D aggregates in solid state.

aromatic π•••π stacking ; van Staveren conformation

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