کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
175519 458912 2016 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
1,3-Bis(phenylamino)squaraine – Photophysical and photochemical properties
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی مهندسی شیمی (عمومی)
پیش نمایش صفحه اول مقاله
1,3-Bis(phenylamino)squaraine – Photophysical and photochemical properties
چکیده انگلیسی


• Spectroscopic properties of 1,3-bis(phenylamino)squaraine depend on solvent.
• In polar protic solvents, rate of radiative process does not depend on viscosity.
• In polar protic solvents, rate of non-radiative process does not depend on viscosity.
• 1,3-Bis(phenylamino)squaraine undergoes bimolecular quenching process.
• Fluorescence quenching rate depends on the structure of quencher and diffusion.

A novel squarylium dye possessing donor–π–acceptor structure that features a fixed imine phenyl ring as an electron donor and 3,4-dihydroxycyclobut-3-ene-1,2-dione moiety as an electron acceptor was synthesized. The structure of the dye was elucidated by means of NMR and IR spectroscopy and elemental analysis. The compound was studied using steady-state absorption and emission spectroscopy, as well as the time-resolved spectroscopy. The measurements were carried out in solvents of different polarity. The dye absorbs in the visible light region about 400 nm and emits light with low fluorescence quantum yield, below 1 × 10−3 M. An increases polarity of solvent results in a blue-shift of absorption band and red-shift of emission band, respectively.The rate constants of radiative and non-radiative deactivation of excited state depend on the viscosity of solvent used. The bimolecular quenching of excited singlet state of squaraine depends on the rate of diffusion process.

1,3-Bis(phenylamino)squarine shows the negative solvatochromism in the absorption spectra and bathochromic shifts of fluorescence spectra with increasing the polarity of solvents. On the other hand, dye shows a blue shift in the absorption band and the lowest emission in the protic solvent, water, with its excited state decaying non-radiatively, involving the hydrogen bond interactions. The strong hydrogen bonding solvent forms hydrogen bonds with the oxygen lone pair or/and nitrogen lone pair of dye molecule, which reduces the magnitude of the intramolecular charge transfer within dye molecule. 1,3-Bis(phenylamino)squaraine in its excited singlet state undergoes bimolecular quenching process. The quenching rate of constants depends on the structure of quencher and achieved values higher than that for diffusion-controlled reactions.Figure optionsDownload as PowerPoint slide

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Dyes and Pigments - Volume 127, April 2016, Pages 179–186
نویسندگان
, , , , ,