Heptamethine Cyanine Dyes with a Large Stokes Shift and Strong Fluorescence:  A Paradigm for Excited-State Intramolecular Charge Transfer

2005 ◽  
Vol 127 (12) ◽  
pp. 4170-4171 ◽  
Author(s):  
Xiaojun Peng ◽  
Fengling Song ◽  
Erhu Lu ◽  
Yanan Wang ◽  
Wei Zhou ◽  
...  
Keyword(s):  
Excited State ◽  
Charge Transfer ◽  
Intramolecular Charge Transfer ◽  
Stokes Shift ◽  
Cyanine Dyes ◽  
Strong Fluorescence ◽  
Large Stokes Shift

Remarkable Solvatofluorochromism of a [2.2]Paracyclophane-Containing Organoboron Complex: A Large Stokes Shift Promoted by Excited State Intramolecular Charge Transfer

ChemPhotoChem ◽  
2017 ◽  
Vol 1 (5) ◽  
pp. 188-197 ◽  
Author(s):  
Mirai Tanaka ◽  
Shunsuke Muraoka ◽  
Yasunori Matsui ◽  
Eisuke Ohta ◽  
Atsushi Sakai ◽  
...  
Keyword(s):  
Excited State ◽  
Charge Transfer ◽  
Intramolecular Charge Transfer ◽  
Stokes Shift ◽  
Large Stokes Shift

Remarkable Solvatofluorochromism of a [2.2]Paracyclophane-Containing Organoboron Complex: A Large Stokes Shift Promoted by Excited State Intramolecular Charge Transfer

ChemPhotoChem ◽  
2017 ◽  
Vol 1 (5) ◽  
pp. 135-135
Author(s):  
Mirai Tanaka ◽  
Shunsuke Muraoka ◽  
Yasunori Matsui ◽  
Eisuke Ohta ◽  
Atsushi Sakai ◽  
...  
Keyword(s):  
Excited State ◽  
Charge Transfer ◽  
Intramolecular Charge Transfer ◽  
Stokes Shift ◽  
Large Stokes Shift

Spectroscopic Studies of Dimethylamino Derivatives of Fluorene

2000 ◽  
Vol 55 (11-12) ◽  
pp. 902-908 ◽  
Author(s):  
J. Heldt ◽  
J. R. Heldt ◽  
T. Redzimski ◽  
H. Diehl ◽  
P. Schultz
Keyword(s):  
Dipole Moment ◽  
Excited State ◽  
Charge Transfer ◽  
Fluorescence Spectra ◽  
Intramolecular Charge Transfer ◽  
Stokes Shift ◽  
Spectroscopic Studies ◽  
Polar Solvents ◽  
Derivatives Of ◽  
Transfer State

Abstract 2-dimethylamino-9-fluorenol and 2-dimethylamino-9(4'dimethylamino)phenyl-9-fiuorenol in polar solvents in the excited state undergo conformation changes in which two fluorescent isomers are created. The isomers (in the local excited (LE) and charge transfer (CT) configuration) possess separate fluorescence bands, one appearing from the S1 (LE) state and the second from the intramolecular charge transfer state S1 (CT) of the neutral, aromatic molecule. Both bands show a solvatochromic effect. Using the method of the solvent induced Stokes shift of the absorption and fluorescence spectra the permanent dipole moment of the excited state of fluorene and its two derivatives have been determined. The dipole moment of the ground state and the Onsager cavity radius of the studied molecules were calculated with the Auestion Model 1 (AM1) program.

Intramolecular fluorescence quenching in aminocoumarines. Identification of an excited state with full charge separation

1985 ◽  
Vol 63 (7) ◽  
pp. 1649-1653 ◽  
Author(s):  
Wolfgang Rettig ◽  
André Klock
Keyword(s):  
Dipole Moment ◽  
Excited State ◽  
Charge Transfer ◽  
Fluorescence Quenching ◽  
Charge Separation ◽  
Intramolecular Charge Transfer ◽  
Stokes Shift ◽  
Twisted Intramolecular Charge Transfer ◽  
Full Charge

The fluorescence of 6-aminocoumarine (A6C) is very weak and anomalously redshifted as compared to its 7-substituted analogues 4-methyl-7-aminocoumarine (A7C) and 4-methyl-7-diethylaminocoumarine (DEA7C). The solvatochromic redshift in homologous alcohols is much stronger for A6C, pointing to an increased dipole moment of the emitting state. A twisted intramolecular charge transfer (TICT) state with full charge separation is made responsible for this emission. This is rationalized by molecules-in-molecules calculations. The strong Stokes shift in n-hexane and in ethanol glass at 77 K suggests that A6C emits from a TICT state even under these conditions.

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.

scholarly journals About the origin of the large Stokes shift in aminoalkyl substituted heptamethine cyanine dyes

2020 ◽  
Vol 22 (1) ◽  
pp. 129-135 ◽  
Author(s):  
Cristina Sissa ◽  
Anna Painelli ◽  
Francesca Terenziani ◽  
Massimo Trotta ◽  
Roberta Ragni
Keyword(s):  
Excited State ◽  
Ground State ◽  
Stokes Shift ◽  
Cyanine Dyes ◽  
Ground State Structure ◽  
State Structure ◽  
Large Stokes Shift

Aminoalkyl substituted heptamethine cyanines show a large Stokes shift, ascribed to the geometry relaxation upon photoexcitation that drives the molecule from a distorted ground state structure to a planar and cyanine-like excited state.

A Colorific and Fluorescent Dual Signal Probe for DNA

2012 ◽  
Vol 441 ◽  
pp. 398-402
Author(s):  
Tong Wu ◽  
Xiao Jun Peng
Keyword(s):  
Charge Transfer ◽  
Rational Design ◽  
Fluorescence Enhancement ◽  
Intramolecular Charge Transfer ◽  
Stokes Shift ◽  
Red Shift ◽  
Large Stokes Shift ◽  
Signal Probe ◽  
High Fluorescence

The synthesis and characteristics of a new styryl colorific and fluorescent dual signal probe for DNA are described. Sty-HPy shows a high fluorescence enhancement (> 35-fold) in conjunction with a visible colorific change (45 nm red-shift) when bound to dsDNA. The large Stokes shift (140 nm) and sensitive colorific response to DNA are both attributed to the rational design of intramolecular charge transfer (ICT) intra Sty-HPy.

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.

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