Ionic disparity of identical molecules in polymorphs
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Updated: Sep 26, 2026

From Molecules to Materials: Engineering New Ionic Liquid Crystals Through Halogen Bonding
Published on: March 24, 2018
Andrzej Katrusiak1, Anna Katrusiak
1Faculty of Chemistry, Adam Mickiewicz University, Grunwaldzka 6, 60-780 Poznań, Poland. katran@amu.edu.pl
Abstract:
[structure: see text] Formation of ionic pairs of identical molecules, extremely common in Nature but exceptional for diffractometric observations in the crystalline state, has been found in one of two polymorphs of a nucleobase analogue, 4,6-pyrimidinedione (1). The occurrence of the neutral and ionic polymorphs of 1 in many respects resembles neutral-ionic transitions of electon-donor/acceptor complexes. The ionization affects the reactivity of 1 and illustrates general properties of H-tautomers with low-disproportionation energy.
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