Dyes and Pigments

New unsymmetrical squaraine dyes derived from imidazo [1, 5-a] pyridine

Y Prostota, OD Kachkovsky, LV Reis, PF Santos

Index: Prostota, Yaroslav; Kachkovsky, Oleksiy D.; Reis, Lucinda V.; Santos, Paulo F. Dyes and Pigments, 2013 , vol. 96, # 2 p. 554 - 562

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Citation Number: 18

Abstract

The reaction of squaric acid with excess 3-methylimidazo [1, 5-a] pyridine afforded almost exclusively the corresponding semisquaraine. The later underwent condensation with several heterocyclic compounds possessing active methyl groups, forming a novel class of unsymmetrical squaraines. The spectral properties of the obtained dyes were investigated and quantum-chemical calculations were performed to examine the dependence of the ...