کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1409748 1501799 2012 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Synthesis and characterization of photoactive azobenzene-based chromophores containing a bulky cholesteryl moiety
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آلی
پیش نمایش صفحه اول مقاله
Synthesis and characterization of photoactive azobenzene-based chromophores containing a bulky cholesteryl moiety
چکیده انگلیسی

This study describes the synthesis of a series of azobenzene-based chromophores bearing pendent bulky cholesteryl groups, using esterification reactions. The chromophores were composed of liquid crystalline mesophases with six or eleven methylene segments as spacers, and with electron-donating (OCH3) and electron-withdrawing (NO2) terminal groups. The target compounds were characterized by nuclear magnetic resonance spectroscopy, differential scanning calorimetry, polarizing optical microscopy, absorption, and photoluminescence spectroscopies. All the azobenzene derivatives with six or eleven methylene segments revealed chiral nematic phases. We investigated the effects of these photochromic compounds’ structures on E/Z photoisomerization under UV irradiation. Chromophores containing the electron-withdrawing nitro-group (NO2) underwent a faster rate of Z to E isomerization in darkness than the electron-donating (OCH3) groups did; the isomerization process proceeded via a rotation mechanism. Self-assembled aggregates of C6 solution exhibited enhanced fluorescence in THF/water mixtures at 10% water fraction.


► We synthesized a series of azobenzene derivatives.
► They have been spectrally characterized.
► We studied the E/Z isomerization using UV–vis spectroscopy.
► The influence of terminal groups and spacer length on photoreactivity and mesomorphic properties.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Molecular Structure - Volume 1015, 16 May 2012, Pages 129–137
نویسندگان
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