Salts of amino acids with polar symmetry exhibiting a dimeric cation of the [A(1)⁺⋅⋅⋅A(2)] type. New type of polymorphism

Author(s)

G.S. Tonoyan, Gerald Giester, M. Szafrański, A.M. Petrosyan

Abstract

A new class of amino acids salts containing different amino acids has recently been discovered: the present paper reports on synthesis and crystal structures of thirteen salts with a dimeric cation of the [A(1)+⋅⋅⋅A(2)] type. All have polar symmetry, thus being potential pyroelectrics or ferroelectrics: (L-ProH⋅⋅⋅Sar)BF4 (I), (L-ProH⋅⋅⋅Sar)ClO4 (II), (L-ProH⋅⋅⋅Sar)NO3 (III), (L-ProH⋅⋅⋅Sar)Br (IV), (L-ProH⋅⋅⋅Sar)I (V), (all with space group C2), (β-AlaH⋅⋅⋅DMG)I (VI), (β-AlaH⋅⋅⋅DMG)BF4 (VII), (β-AlaH⋅⋅⋅DMG)NH2SO3 (VIII) and (DMGH⋅⋅⋅Sar)ClO4 (XIII) (all with space group Pna21), (β-AlaH⋅⋅⋅Bet)Br (IX), (β-AlaH⋅⋅⋅Bet)I (X) (both with space group Cc), as well as (SarH⋅⋅⋅DMG)BF4 (XI) and (SarH⋅⋅⋅DMG)ClO4 (XII) (both with space group Pc). These compounds except (XIII) are formed by slow evaporation at room temperature from aqueous solutions containing stoichiometric ratios of components. Protonation in a pair of amino acids may depend on the anion, as in the cases of (SarH⋅⋅⋅Bet)ClO4 and (BetH⋅⋅⋅Sar) NH2SO3⋅0.5H2O, (DMGH⋅⋅⋅Bet)ClO4⋅H2O and (BetH⋅⋅⋅DMG)I⋅H2O or, for the same anion, on the conditions of crystallization, as in the case of (SarH⋅⋅⋅DMG)ClO4 (obtained from aqueous solution) and (DMGH⋅⋅⋅Sar)ClO4 (crystallized from acetic acid). The phases (SarH⋅⋅⋅DMG)(ClO4) (s.g. Pc) and (DMGH⋅⋅⋅Sar)(ClO4), (s.g. Pna21) represent a peculiar type of polymorphism, where the difference is evident in the position of the proton in the dimeric cation, too.

Organisation(s)

Department of Mineralogy and Crystallography

External organisation(s)

National Academy of Sciences of the Republic of Armenia, Adam Mickiewicz University

Journal

Journal of Crystal Growth

Volume

626

Pages

1-11

No. of pages

11

ISSN

0022-0248

DOI

https://doi.org/10.1016/j.jcrysgro.2023.127472

Publication date

2024

Peer reviewed

Yes

Austrian Fields of Science 2012

105116 Mineralogy, 105113 Crystallography

Keywords

ASJC Scopus subject areas

Condensed Matter Physics, Materials Chemistry, Inorganic Chemistry

Portal url

https://ucrisportal.univie.ac.at/en/publications/b9f630fc-2e22-4ed1-9f72-4ce4fc0b8519