Armand Budzianowski, Mariana Derzsi, Piotr J. Leszczynski, Michał K. Cyrański and Wojciech Grochala
Acta Crystallographica Section B
Volume 66, Part 4 (August 2010)
Acta Cryst. (2010). B66, 451-457 [doi:10.1107/S0108768110019580]
Authorised by IUCr electronic reprint of the article
This work is dedicated to Professor Andrzej Katrusiak to celebrate 30 years of his involvement in research, and in recognition of his contributions to the field of hydrogen-bonded systems (Katrusiak, 1992, 1993).
Two polymorphs (, ) of pyrazinium hydrogen sulfate (pyzH+HSO, abbreviated as PHS) with distinctly different hydrogen-bond types and topologies but close electronic energies have been synthesized and characterized for the first time. The -polymorph (P212121) forms distinct blocks in which the pyzH+ and HSO ions are interconnected through a network of NHO and OHO hydrogen bonds. The -form () consists of infinite chains of alternating pyzH+ and HSO ions connected by NHO and OHN hydrogen bonds. Density functional theory (DFT) calculations indicate the possible existence of a hypothetical polar P1 form of the -polymorph with an unusually high dipole moment.