Synthesis of Novel Quinaldine-Based Squaraine Dyes: Effect of Substituents and Role of Electronic Factors
摘要:
[GRAPHICS]Condensation of squaric acid with quinaldinium salts containing electron-donating substituents gave only the semisquaraines. However, with salts possessing electronegative and electron-withdrawing groups, the squaraine dyes were isolated in quantitative yields. The semisquaraines formed undergo condensation with highly nucleophilic salts yielding the unsymmetrical squaraine dyes. These results demonstrate the role of electronic factors and provide valuable information for the design of efficient squaraine-based sensitizers that can have potential applications in photodynamic therapy.
Synthesis of Novel Quinaldine-Based Squaraine Dyes: Effect of Substituents and Role of Electronic Factors
摘要:
[GRAPHICS]Condensation of squaric acid with quinaldinium salts containing electron-donating substituents gave only the semisquaraines. However, with salts possessing electronegative and electron-withdrawing groups, the squaraine dyes were isolated in quantitative yields. The semisquaraines formed undergo condensation with highly nucleophilic salts yielding the unsymmetrical squaraine dyes. These results demonstrate the role of electronic factors and provide valuable information for the design of efficient squaraine-based sensitizers that can have potential applications in photodynamic therapy.
Novel semisquaraine regioisomers: isolation, divergent chemical reactivity and photophysical properties
作者:Rekha R. Avirah、Kuthanapillil Jyothish、Cherumuttathu H. Suresh、Eringathodi Suresh、Danaboyina Ramaiah
DOI:10.1039/c1cc15261k
日期:——
A zwitterionic semisquaraine 1,3-regioisomer which exhibits distinct photophysical properties and chemical reactivity was isolated. Uniquely, this isomer has been identified as the reactive intermediate in the squaraine dye formation reaction rather than the neutral 1,2-isomer and opens up new avenues for the synthesis of novel dyes for optoelectronic applications.
Synthesis of New Cholesterol- and Sugar-Anchored Squaraine Dyes: Further Evidence of How Electronic Factors Influence Dye Formation
作者:Kuthanapillil Jyothish、Rekha R. Avirah、Danaboyina Ramaiah
DOI:10.1021/ol052639j
日期:2006.1.1
Synthesis of new quinaldine-based squaraine dyes linked to cellular recognition elements that exhibit near-infrared absorption (> 740 nm) are described. Both product analysis and theoretical calculations substantiate the interesting electronic effects of various substituents in the dye formation reaction. These results are useful in the synthesis of symmetrical and unsymmetrical squaraine dyes that can have potential biological and photodynamic therapeutical applications.
Synthesis of Novel Quinaldine-Based Squaraine Dyes: Effect of Substituents and Role of Electronic Factors
作者:Kuthanapillil Jyothish、Kalliat T. Arun、Danaboyina Ramaiah
DOI:10.1021/ol048411y
日期:2004.10.1
[GRAPHICS]Condensation of squaric acid with quinaldinium salts containing electron-donating substituents gave only the semisquaraines. However, with salts possessing electronegative and electron-withdrawing groups, the squaraine dyes were isolated in quantitative yields. The semisquaraines formed undergo condensation with highly nucleophilic salts yielding the unsymmetrical squaraine dyes. These results demonstrate the role of electronic factors and provide valuable information for the design of efficient squaraine-based sensitizers that can have potential applications in photodynamic therapy.