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论文类型：期刊论文

发表时间：2009-09-01

发表刊物：DYES AND PIGMENTS

收录刊物：SCIE、EI、Scopus

卷号：82

期号：3

页面范围：396-400

ISSN号：0143-7208

关键字：Synthesis; Squaric acid; Cyanine dye; Squarylium dye; Photostability; Water-solubility

摘要：Novel, water-soluble, squarylium indocyanine dyes with various N-substituents on 3H-indolenine were synthesized. The maxima of absorption and emission wavelengths of the dyes in different solvents were in the range 628-670 nm and exhibited negative solvatochromism with increasing solvent polarity in protic solvents. Dyes with N-benzyl rings (such as N-benzyl, N-carboxylbenzyl and N-fluorobenzyl) displayed greater photostability than dyes containing N-alkyl groups (such as N-ethyl and N-carboxylpentanyl) in aqueous solution. The electron-withdrawing group (such as carboxyl and fluoro group) on the N-benzyl group of cyanine dyes improved photostability compared to dyes that contained an electron-donating group (such as methyl). The fading constant k of the N-carboxylbenzyl dye was considerably lower than that of the N-carboxylpentanyl dye. (C) 2009 Elsevier Ltd. All rights reserved.