Stereochemical Features of the Crystallization of Eight-Membered 1,5-Diazaheterocycles with Chiral Aminoindanole Fragments at Nitrogen Atoms

Abstract

© 2020, Pleiades Publishing, Ltd. The work juxtaposes crystal structures of two hydrochlorides of eight-membered 1,5-diazaheterocycles with chiral aminoindanole fragments located at the nitrogen atoms and having similar configurations. In spite of chemical and stereochemical identity of a half of diazaheterocycle molecules, in crystals these compound are realized in the general position rather than the special position on the twofold axis of rotation. The following reasons are considered to be responsible for the asymmetrization of the molecules in the crystal: conformation of the eight-membered heterocycle, selective protonation of only one of two nitrogen atoms, positions of the counter-ion and the solvent molecule within the unit cell, and a nonequivalent system of hydrogen bonds.