Crystal Structure Studies on Some of Benzamide Ring Substituted Isoselenazolones and Symmetric Diaryl Monoselenides Derived from Benzamides

Autor: Jerry P. Jasinski, Sangit Kumar, Shah Jaimin Balkrishna, Rahul Shukla
Rok vydání: 2014
Předmět:
Zdroj: Proceedings of the National Academy of Sciences, India Section A: Physical Sciences. 84:165-177
ISSN: 2250-1762
0369-8203
DOI: 10.1007/s40010-014-0129-5
Popis: In the present work, crystal structures of four benzamide ring substituted isoselenazolones and also crystal structures of thiophenamide and ortho-methoxy benzamide derived symmetric diaryl selenides studied. Diaryl selenides were obtained as unexpected product in the copper catalyzed Se-N bond forming reaction. Isos- elenazolones were synthesized by copper catalyzed reac- tion and have been reported earlier. Ebselen derivatives studied in this work were obtained from 2-halo-N-aryl- benzamides, selenium powder, potassium carbonate base in the presence of catalytic amount of copper iodide and 1, 10-phenanthroline. When 2-chloro-thiophenyl amide was subjected under identical reaction conditions, instead of Se-N bond formation, symmetrical monoselenide was obtained in excellent yield. Symmetric aryl selenides were characterized by multi-nuclear ( 1 H, 13 C and 77 Se) NMR spectroscopy, mass spectrometry and single crystal X-ray diffraction techniques. Crystal structure studies on diaryl selenides revealed interesting intramolecular Se_N/O interactions in which one nitrogen out of two and one oxygen out of two interacted with one selenium atom. Intramolecular non-bonding interaction of selenium with methoxy oxygen is observed in isoselenazolone bearing methoxy group ortho to selenium center while intermo- lecular Se_O interaction between two isoselenazolone molecules is present in fluoro group containing isos- elenazolones and therefore they exist as dimer in asym- metric unit.
Databáze: OpenAIRE
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