Alkyl-substituted dipyrrylmethenes and their oxa- and thia-analogs: “structure—solvation properties-correlations

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• 作者：A. S. Semeik ; M. B. Berez ; O. M. Chernova ; E. V. Antina ; S. A. Syrbu ; T. V. Lyubimova and A. M. Kutepov
• 关键词：pyrroles ; dipyrrylmethenes ; solutions ; spectrophotometry ; calorimetry ; thermogravimetry ; synthesis
• 刊名：Russian Chemical Bulletin
• 出版年：2003
• 出版时间：August 2003
• 年：2003
• 卷：52
• 期：8
• 页码：1807-1813
• 全文大小：324 KB
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Chemistry
  Chemistry
  Organic Chemistry
  Inorganic Chemistry
  Russian Library of Science
  
• 出版者：Springer New York
• ISSN：1573-9171

文摘

New data on the spectral properties and solution enthalpies of unsymmetrically substituted 2-(alkyl-2-pyrrolylmethylidene)methylpyrrolium bromides (or ,-dipyrrylmethene hydrobromides), their ,-, ,-isomers, as well as their oxa and thia analogs, that is, 2-(2-furylmethylidene)- and 2-(2-thienylmethylidene)-3,4,5-trimethyl-1H-pyrrolium bromides, in solutions of organic solvents of different nature are presented. A decrease in the number of substituents, as well as replacement of the heteroatom (N) in one five-membered ring of the dipyrrylmetnehe by oxygen or sulfur atoms cause a monotonic hypsochromic shift of absorption bands in the electronic absorption spectrum and weakening of the chromophore properties of the compounds. The chromophore properties of isomers are weakened from the ,- to ,- and ,-dipyrrylmethenes. Main trends in the influence of structural factors on the specific features of thermooxidative destruction of the above-mentioned compounds were analyzed.