scholarly journals Substantial Intramolecular Charge Transfer Induces Long Emission Wavelengths and Mega Stokes Shifts in 6-Aminocoumarins

2017 ◽  
Vol 121 (24) ◽  
pp. 13274-13279 ◽  
Author(s):  
Xiaogang Liu ◽  
Jacqueline M. Cole ◽  
Zhaochao Xu
Keyword(s):  
Charge Transfer ◽  
Intramolecular Charge Transfer ◽  
Stokes Shifts

Design and synthesis of BODIPY-clickate based Hg2+ sensors: the effect of triazole binding mode with Hg2+ on signal transduction

2016 ◽  
Vol 45 (6) ◽  
pp. 2700-2708 ◽  
Author(s):  
Mani Vedamalai ◽  
Dhaval Kedaria ◽  
Rajesh Vasita ◽  
Shigeki Mori ◽  
Iti Gupta
Keyword(s):  
Signal Transduction ◽  
Charge Transfer ◽  
Intramolecular Charge Transfer ◽  
Binding Mode ◽  
Mercury Ion ◽  
Ion Binding ◽  
Design And Synthesis ◽  
Transfer Processes ◽  
Stokes Shifts ◽  
Mercury Sensing

Highly selective BODIPY-clickates for mercury sensing are reported. These BODIPY clickates exhibits emission in red region with unprecedented large Stokes shifts (116 and 154 nm) upon mercury ion binding due to the intramolecular charge transfer processes.

Photophysical, electrochemical, and spectroelectrochemical investigation of electronic push–pull benzothiadiazole fluorophores

2015 ◽  
Vol 87 (7) ◽  
pp. 649-661 ◽  
Author(s):  
Monika Wałęsa-Chorab ◽  
Marie-Hélène Tremblay ◽  
Mohamed Ettaoussi ◽  
William G. Skene
Keyword(s):  
Thin Films ◽  
Charge Transfer ◽  
Intramolecular Charge Transfer ◽  
Charge Transfer Band ◽  
Aprotic Solvents ◽  
Neutral Form ◽  
Electron Withdrawing Group ◽  
Fluorescence Wavelength ◽  
Stokes Shifts ◽  
Spectroelectrochemical Properties

AbstractTwo electronic push–pull fluorophores consisting of a benzothiadiazole core and a terminal N,N-dimethylamino electron donating group were prepared. The effect of the terminal electron withdrawing group (–NO2 and –CN) on the spectroscopic, electrochemical, and spectroelectrochemical properties were examined. The fluorophores were solvatochromic with Stokes shifts upward of 9000 cm−1 being observed in aprotic solvents of varying polarity. It was found that the fluorophores fluoresced appreciably (86 % > Φfl > 18 %) in hexane, toluene, diethyl ether, dichloromethane, ethyl acetate, and THF. The fluorescence was quenched in acetonitrile, acetone, and DMSO. The fluorophores also fluoresced appreciably in thin films when embedded in poly(methyl methacrylate) and poly(dimethylsiloxane) matrices. Protonating the terminal amine with trifluoroacetic acid quenched the intramolecular charge transfer band, although the fluorophores remained fluorescent. The fluorophores could also be reversibly oxidized electrochemically. The resulting oxidized state was visually different than the neutral form. Electrochemical oxidation also led to reversible changes in both the fluorescence wavelength and intensity.

scholarly journals Donor-acceptor substituted phenylethynyltriphenylenes – excited state intramolecular charge transfer, solvatochromic absorption and fluorescence emission

2010 ◽  
Vol 6 ◽  
pp. 992-1001 ◽  
Author(s):  
Ritesh Nandy ◽  
Sethuraman Sankararaman
Keyword(s):  
Excited State ◽  
Charge Transfer ◽  
Linear Correlation ◽  
Intramolecular Charge Transfer ◽  
Stokes Shift ◽  
Fluorescence Emission ◽  
Solvent Polarity ◽  
Donor And Acceptor ◽  
Electron Donor And Acceptor ◽  
Stokes Shifts

Several 2-(phenylethynyl)triphenylene derivatives bearing electron donor and acceptor substituents on the phenyl rings have been synthesized. The absorption and fluorescence emission properties of these molecules have been studied in solvents of different polarity. For a given derivative, solvent polarity had minimal effect on the absorption maxima. However, for a given solvent the absorption maxima red shifted with increasing conjugation of the substituent. The fluorescence emission of these derivatives was very sensitive to solvent polarity. In the presence of strongly electron withdrawing (–CN) and strongly electron donating (–NMe2) substituents large Stokes shifts (up to 130 nm, 7828 cm−1) were observed in DMSO. In the presence of carbonyl substituents (–COMe and –COPh), the largest Stokes shift (140 nm, 8163 cm−1) was observed in ethanol. Linear correlation was observed for the Stokes shifts in a Lippert–Mataga plot. Linear correlation of Stokes shift was also observed with E T(30) scale for protic and aprotic solvents but with different slopes. These results indicate that the fluorescence emission arises from excited state intramolecular charge transfer in these molecules where the triphenylene chromophore acts either as a donor or as an acceptor depending upon the nature of the substituent on the phenyl ring. HOMO–LUMO energy gaps have been estimated from the electrochemical and spectral data for these derivatives. The HOMO and LUMO surfaces were obtained from DFT calculations.

Intramolecular charge transfer-induced solvatochromism and large stokes shifts of furocoumarins

2021 ◽  
pp. 125406
Author(s):  
Nadia Nabihah Mohd Yusof Chan ◽  
Azila Idris ◽  
Zul Hazrin Zainal Abidin ◽  
Hairul Anuar Tajuddin ◽  
Zanariah Abdullah
Keyword(s):  
Charge Transfer ◽  
Intramolecular Charge Transfer ◽  
Stokes Shifts

Synthesis structural and spectroscopic properties of quinoxaline-bridged bisBODIPYs

2018 ◽  
Vol 22 (09n10) ◽  
pp. 899-907
Author(s):  
Changjiang Yu ◽  
Tingting Li ◽  
Qinghua Wu ◽  
Wenbo Hu ◽  
Erhong Hao ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Intramolecular Charge Transfer ◽  
Spectroscopic Properties ◽  
Knoevenagel Reaction ◽  
X Ray Diffraction ◽  
Absorption Bands ◽  
Polar Solvents ◽  
Broad Absorption ◽  
X Ray ◽  
Stokes Shifts

Two novel quinoxaline-bridged bisBODIPYs have been synthesized by the condensation of 2,3-bis(5-formylpyrrol-2-yl)quinoxaline with 3-ethyl-2,4-dimethylpyrrole followed by a modification using a Knoevenagel reaction. They were well characterized by X-ray diffraction, NMR, HRMS UV-vis and fluorescence spectroscopy. These two quinoxaline-bridged bisBODIPYs have unusual broad absorption bands, which are different from those of typical BODIPYs They exhibit broad red-shifted emission bands centered at around 610 nm and 730 nm respectively with larger Stokes shifts at the range of 1421–2136 cm[Formula: see text] Both bisBODIPYs show different extent solvent-dependent fluorescence and exhibit fluorescence quenching in polar solvents due to the existence of possible intramolecular charge transfer.

Dynamic adjustment of emission from both singlets and triplets: the role of excited state conformation relaxation and charge transfer in phenothiazine derivates

2021 ◽  
Author(s):  
Weidong Qiu ◽  
Xinyi Cai ◽  
Mengke Li ◽  
Liangying Wang ◽  
Yanmei He ◽  
...  
Keyword(s):  
Excited State ◽  
Charge Transfer ◽  
Intramolecular Charge Transfer ◽  
Dynamic Adjustment ◽  
Twisted Intramolecular Charge Transfer

Dynamic adjustment of emission behaviours by controlling the extent of twisted intramolecular charge transfer character in excited state.

Steric Effects on Intramolecular Charge Transfer Fluorescence of Benzo[b]thiophene-1,1-dioxide Bridged Macrocages

2021 ◽  
Author(s):  
Keita Nobuhara ◽  
Yusuke Inagaki ◽  
Wataru Setaka
Keyword(s):  
Charge Transfer ◽  
Intramolecular Charge Transfer ◽  
Fluorescence Properties ◽  
Steric Effects ◽  
Sensor Molecules

Intramolecular charge transfer (ICT) fluorescence has been widely investigated and exploited in sensor molecules. However, steric effects on the ICT fluorescence properties have rarely been reported so far, although research...

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