Small molecule crystallography
In collaboration with research groups in the fields of organic and organometallic chemistry we carry out crystallographic studies of various compounds. (CCDC reference codes: 1525622, 1525638, 1525646, 1825313, 1890659, 1890661, 1990174, 244367, 244368, 244369, 244370, 1525638, 1525622, 1525646).
Configuration of chirality centers, as well as ring conformation and puckering of amine nitrogens of a novel partly saturated beta-carboline was confirmed by the crystal structure of its solvate with DMSO. Both DMSO molecules are disordered in the structure with preferred orientation more favorable for hydrogen bonding (Collaboration: Prof. Csámpai ‘s group Institute of Chemistry, Eötvös Loránd University).
Configuration was confirmed for two 1,3-diazaspiro[bicyclo[3.1.0]hexane]oxindole derivatives synthetized in one-pot reaction of isatins, α-amino acids and 2H-azirines. The partial merohedral twinning of the compound was rationalized by the formation of pseudo-symmetric linear associates of the molecules within the crystal structure, which are connected in a cog-like superstructure. (Collaboration: AVIDIN Ltd., Department of Organic Chemistry, University of Szeged).
We are involved in a structural study on calcium D-isosaccharinate and calcium D-gluconate, two main products decomposition of cellulose in alkaline environments (coordination polymers). Unusually, the calcium coordination number is nine for calcium-gluconate, while it is eight for calcium isosaccharinate as now established (Collaboration: Crystallography Laboratory, Biological Research Center, HAS; Departments of Organic and Inorganic and Analytical Chemistry, University of Szeged;University of Sydney).
The structure of the antiproliferative compound 4,5-dihydrobenzoferroceno[1,2-d][1,2,3]selenadiazole contains four crystallographically independent molecules. A small tilt of one of the molecules cause C2/c -like pseudo-symmetry and perfect pseudo-merohedral twinning. (Collaboration: research groups of Prof. Pasinszki and Prof. Csámpai, Institute of Chemistry, Eötvös Loránd University).
The comparative alcoholysis study of N-silylated heterocyclic carboxamides (lactams, imides, ureas) was carried out along with QM calculations and crystallographic analysis aiming to explore the relationship between the molecular structure and the respective silyl transfer ability. The structural constraints imposed on the accessibility of the carbonyl oxygen for the silicon center play a decisive role in the ease of desilylation. The new model proved to be useful to predict the relative rates of silyl transfer reactions for a wider range of substrates. (Collaboration: Dr. Szalay Department of Inorganic Chemistry, Institute of Chemistry, Eötvös Loránd University). In the crystal structures of N-trimethylsilylated cyclic ureas, the bond lengths and angles around the Si atom vary significantly, supporting that the silylating power depends on the pseudo-pentacoordinate character of the tetracoordinate silicon. A simple structure-based number measuring the pseudo-pentacoordinate character of the silicon can be used for predicting reactivity.
Tibor Pasinszki , Dániel Dzsotján , Győző György Lajgut , Veronika Harmat , Antal Csámpai , Andrea Bor , István Zupkó
Synthesis, spectral- and theoretical study, x-ray analysis, and antiproliferative activity of 4,5-dihydrobenzoferroceno[1,2-d][1,2,3]selenadiazole and its benzo-fused analogue
Journal of Organometallic Chemistry 863:70-76. | DOI: 10.1016/j.jorganchem.2018.03.031 (2018) Kivonat
Roland Szalay , Veronika Harmat , János Eőri , Gábor Pongor
Strong influence of intramolecular Si⋯O proximity on reactivity: Systematic molecular structure, solvolysis, and mechanistic study of cyclic N-trimethylsilyl carboxamide derivatives
Tetrahedron Letters 58(23):2186-2192. | DOI: 10.1016/j.tetlet.2017.04.057 (2017) Kivonat
V. Bugris , Cs. Dudás , B. Kutus , V. Harmat , K. Csankó , S. Brockhauser , I. Pálinkó , Peter Turner , P. Sipos
Crystal and solution structures of calcium complexes relevant to problematic waste disposal: calcium gluconate and calcium isosaccharinate
Acta Crystallographica Section B 598-609 | doi.org/10.1107/S2052520618013720 (2018) Kivonat
Anikó Angyal , András Demjén , Veronika Harmat , János Wölfling , László G. Puskás , Iván Kanizsai
1,3-Dipolar Cycloaddition of Isatin-Derived Azomethine Ylides with 2H‐Azirines: Stereoselective Synthesis of 1,3- Diazaspiro[bicyclo[3.1.0]hexane]oxindoles
The Journal of Organic Chemistry 4273-4281 DOI: 10.1021/acs.joc.9b00242 (2019) Kivonat
Kinga Judit Fodor , Dániel Hutai , Tamás Jernei , Angéla Takács , Zsófia Szász , Máté Sulyok-Eiler , Veronika Harmat , Rita Oláh Szabó , Gitta Schlosser , Ferenc Hudecz , László Kőhidai , Antal Csámpai
Novel Polycondensed Partly Saturated β-Carbolines Including Ferrocene Derivatives: Synthesis, DFT-Supported Structural Analysis, Mechanism of Some Diastereoselective Transformations and a Preliminary Study of their In Vitro Antiproliferative Effects
Molecules 25(7), 1599 | doi: 10.3390/molecules25071599 (2020) Kivonat