Synthesis and photochromism of isomeric unsymmetrical diarylethenes bearing both naphthalene and thiophene moieties
摘要:
Three new isomeric unsymmetrical diarylethenes bearing both naphthalene and thiophene moieties were synthesized. Their photochromism, fluorescence and electrochemistry properties were investigated in detail. Each of the diarylethene derivatives showed notable photochromism and functioned as an effective fluorescent switch both in solution and in PMMA films. The cyclization quantum yield and the molar absorption coefficients of both the open- and closed-ring isomers were found to decrease based on the position of the chloro substituent attached to the terminal benzene ring as follows: para- > meta- > the ortho-position. Consequently, the cycloreversion quantum yield would increase para- to meta- to ortho-chloro substitution. When compared with the unsubstituted parent compound, the presence of the chloro substituent on the terminal benzene ring of these diarylethenes, regardless of the substitution position, would considerably lower the band gaps of the open- and closed-ring isomers. Our results indicated that the chlorine atom and its substitution position have significant influence on the optical and electrochemical properties of the diarylethenes bearing a naphthalene moiety. (C) 2012 Elsevier B.V. All rights reserved.
New photochromic diarylethenes bearing a condensed aromatics moiety
摘要:
A new class of diarylethenes based on a hybrid structure of naphthalene and thiophene have been developed and their properties including photochromism, fatigue resistance, and fluorescence have been investigated. The condensed aromatic naphthalene was connected directly to the central cyclopentene ring as an aryl moiety and available to participate in the photoinduced cyclization reaction. All of these compounds have exhibited good photochromism, notable fatigue resistance, and obvious fluorescence photo-switches in both solution and polymer matrix. Nevertheless, significantly different properties have been observed among these diarylethenes, which may be attributed to the effect of different substituent groups. Compared with the analogs bearing other six-membered aryl unit, the naphthalene moiety is more conducive, which leads to higher molar absorption coefficient and blue shift of the absorption maximum. (C) 2011 Elsevier Ltd. All rights reserved.
A new class of diarylethenes based on a hybrid structure of naphthalene and thiophene have been developed and their properties including photochromism, fatigue resistance, and fluorescence have been investigated. The condensed aromatic naphthalene was connected directly to the central cyclopentene ring as an aryl moiety and available to participate in the photoinduced cyclization reaction. All of these compounds have exhibited good photochromism, notable fatigue resistance, and obvious fluorescence photo-switches in both solution and polymer matrix. Nevertheless, significantly different properties have been observed among these diarylethenes, which may be attributed to the effect of different substituent groups. Compared with the analogs bearing other six-membered aryl unit, the naphthalene moiety is more conducive, which leads to higher molar absorption coefficient and blue shift of the absorption maximum. (C) 2011 Elsevier Ltd. All rights reserved.
Synthesis and photochromism of isomeric unsymmetrical diarylethenes bearing both naphthalene and thiophene moieties
作者:Renjie Wang、Shouzhi Pu、Gang Liu、Shiqiang Cui、Weijun Liu
DOI:10.1016/j.jphotochem.2012.06.003
日期:2012.9
Three new isomeric unsymmetrical diarylethenes bearing both naphthalene and thiophene moieties were synthesized. Their photochromism, fluorescence and electrochemistry properties were investigated in detail. Each of the diarylethene derivatives showed notable photochromism and functioned as an effective fluorescent switch both in solution and in PMMA films. The cyclization quantum yield and the molar absorption coefficients of both the open- and closed-ring isomers were found to decrease based on the position of the chloro substituent attached to the terminal benzene ring as follows: para- > meta- > the ortho-position. Consequently, the cycloreversion quantum yield would increase para- to meta- to ortho-chloro substitution. When compared with the unsubstituted parent compound, the presence of the chloro substituent on the terminal benzene ring of these diarylethenes, regardless of the substitution position, would considerably lower the band gaps of the open- and closed-ring isomers. Our results indicated that the chlorine atom and its substitution position have significant influence on the optical and electrochemical properties of the diarylethenes bearing a naphthalene moiety. (C) 2012 Elsevier B.V. All rights reserved.