L-CYSTEINE OXALATES WITH DIMERIC AND TRIMERIC CATIONS

Author(s)
V. V. Ghazaryan, Gerald Giester, V.S. Minkov, E. V. Boldyrevab, A.M. Petrosyan
Abstract

Single crystals of two new compounds, (L-CysH⋯L-Cys)(HC2O4) (I) and (L-CysH⋯L-Cys⋯L-CysH)(HC2O4)2·0.5H2O (II), were obtained. Crystal structures were solved and refined using single-crystal X-ray diffraction, and compared with the previously known orthorhombic and monoclinic modifications of the simple salt (L-CysH)(HC2O4). Compound I crystallizes in the triclinic crystal system (space group P1, Z = 2) and contains (L-CysH⋯L-Cys) dimeric cations with very short O⋯O interatomic distance of 2.434(2) Å. Hydrogen oxalate anions form head-to-tail type chains with very short hydrogen bonds, characterized by O⋯O distances of 2.422(2) Å and 2.417(3) Å. The crystal lattice of II is monoclinic with the space group C2, Z = 4. It contains a new type of cation, that has never been observed before for cysteine salts, i.e. trimeric (L-CysH⋯L-Cys⋯L-CysH) cation. Protonated L-cysteinium cations are connected to the zwitterionic L-cysteine moiety through the same oxygen atom of the carboxylate group via hydrogen bonds, with O···O distances of 2.6410(18) Å and 2.4888(19) Å. Similar to the structure I, the hydrogen oxalate anions form head-to-tail type chains linked by short hydrogen bonds with O⋯O distances of 2.4369(17) Å and 2.4330(17) Å, respectively. The crystals were characterized by IR and Raman spectroscopy. The batches obtained on crystallization were also characterized by X-ray powder diffraction, in order to check the phase purity of all the sample.

Organisation(s)
Department of Mineralogy and Crystallography
External organisation(s)
Max-Planck-Institut für Chemie (Otto-Hahn-Institut), National Academy of Sciences of the Republic of Armenia, Novosibirsk State University (NSU)
Journal
Journal of Structural Chemistry
Volume
65
Pages
2088-2100
No. of pages
13
ISSN
0022-4766
DOI
https://doi.org/10.1134/S0022476624100172
Publication date
2024
Peer reviewed
Yes
Austrian Fields of Science 2012
105116 Mineralogy, 105113 Crystallography
Keywords
Portal url
https://ucrisportal.univie.ac.at/en/publications/11d29338-dd95-4153-afbe-44c45b5ef943