Can Twisted Internal Charge-Transfer(TICT)State be Formed in Rigid Polymers?

1995 ◽  
Vol 50 (10) ◽  
pp. 949-952 ◽  
Author(s):  
A. Kawski ◽  
G. Piszczek ◽  
B. Kukliński
Keyword(s):  
Charge Transfer ◽  
Polyvinyl Alcohol ◽  
Emission Band ◽  
Room Temperature ◽  
Intramolecular Charge Transfer ◽  
Rotational Relaxation ◽  
Emission Anisotropy ◽  
Internal Charge Transfer ◽  
Anisotropy Spectra ◽  
Internal Charge

Abstract Absorption, emission and emission anisotropy spectra of 4-cyano-N,N-dimethylaniline (CDMA) and 4-cyano-2,6,N,N-tetramethylaniline (CTMA) were investigated in polyvinyl alcohol) (PVA) films. It was found that the CDMA and CTMA molecules in PVA films at room temperature display phosphorescence, the emission band of which overlaps with the longwave fluorescence band a. The low value of the emission anisotropy shows that in the rigid PVA matrix there are microscopic defects in the form of empty spaces in which a certain fraction of the CDMA or CTMA molecules can attain twisted intramolecular charge-transfer states (TICT) due to rotational relaxation. The emission anisotropies in the shortwave, b, and longwave, a, fluorescence bands of CDMA in propylene glycol were found to be distinctly different, this indicating that the directions of the transition moments are not parallel.

Solvatochromic study of internal charge transfer in 7,7-disubstituted quinone methides

1983 ◽  
Vol 48 (8) ◽  
pp. 2376-2385 ◽  
Author(s):  
Libuše Pavlíčková ◽  
Bohumír Koutek ◽  
Václav Jehlička ◽  
Milan Souček
Keyword(s):  
Charge Transfer ◽  
Absorption Band ◽  
Transition Energy ◽  
Intramolecular Charge Transfer ◽  
Quinone Methides ◽  
Long Wavelength ◽  
Wavelength Absorption ◽  
Internal Charge Transfer ◽  
Long Wavelength Absorption Band ◽  
Internal Charge

Electronic spectra of 7,7-disubstituted quinone methides I-III with substituents of various electronegativities were measured in thirteen solvents. Character of the long-wavelength transition was investigated by correlation between transition energy and ionization potential of the donor part of the molecule as well as by comparison of transition moment with Δμ. The long wavelength absorption band of Ia-Id, IIa and IV does not correspond to a pure (π-π*) transition, but it is perturbed by intramolecular charge transfer.

scholarly journals Ultrafast synthesis of near-zero-cost S-doped Ni(OH)2 on C3N5 under ambient conditions with enhanced photocatalytic activity

RSC Advances ◽  
2021 ◽  
Vol 11 (57) ◽  
pp. 36166-36173
Author(s):  
Lixiao Han ◽  
Cong Peng ◽  
Jinming Huang ◽  
Shengyao Wang ◽  
Xiaohu Zhang ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Photocatalytic Activity ◽  
Charge Transfer ◽  
Room Temperature ◽  
Transfer Efficiency ◽  
Ambient Conditions ◽  
Highly Efficient ◽  
Internal Charge Transfer ◽  
Internal Charge

2D S–Ni(OH)2 is facially planted on 2D C3N5 at room temperature in 30 minutes via a reaction between Ni(NO3)2 and Na2S in aqueous solution. Due to quick internal charge transfer efficiency, the hybrid is highly efficient for photocatalytic H2 production.

scholarly journals An internal charge transfer-dependent solvent effect in V-shaped azacyanines

2015 ◽  
Vol 13 (48) ◽  
pp. 11714-11720 ◽  
Author(s):  
Mariusz Tasior ◽  
Ilko Bald ◽  
Irena Deperasińska ◽  
Piotr J. Cywiński ◽  
Daniel T. Gryko
Keyword(s):  
Optical Properties ◽  
Charge Transfer ◽  
Solvent Effect ◽  
Intramolecular Charge Transfer ◽  
Non Linear ◽  
Linear Optical Properties ◽  
Linear Optical ◽  
Internal Charge Transfer ◽  
Internal Charge

Intramolecular charge transfer dictates linear and non-linear optical properties of D–π-A+–π-D compounds.

A benzothiazole-based fluorescence turn-on sensor for copper(II)

2021 ◽  
Author(s):  
Gyeongjin Kim ◽  
Donghwan Choi ◽  
Cheal Kim
Keyword(s):  
Charge Transfer ◽  
Limit Of Detection ◽  
Theoretical Calculations ◽  
Enhanced Fluorescence ◽  
Turn On ◽  
Fluorescent Response ◽  
Chelation Enhanced Fluorescence ◽  
Fluorescence Turn On ◽  
Internal Charge Transfer ◽  
Internal Charge

Abstract A new benzothiazole-based chemosensor BTN (1-((Z)-(((E)-3-methylbenzo[d]thiazol-2(3H)-ylidene)hydrazono)methyl)naphthalen-2-ol) was synthesized for the detection of Cu2+. BTN could detect Cu2+ with “off-on” fluorescent response from colorless to yellow irrespective of presence of other cations. Limit of detection for Cu2+ was determined to be 3.3 µM. Binding ratio of BTN and Cu2+ turned out to be a 1:1 with the analysis of Job plot and ESI-MS. Sensing feature of Cu2+ by BTN was explained with theoretical calculations, which might be owing to internal charge transfer and chelation-enhanced fluorescence processes.

Absorption, Fluorescence and Emission Anisotropy Spectra of 4-Cyano-N,N-dimethylaniline in Different Media and at Different Temperatures

1997 ◽  
Vol 52 (5) ◽  
pp. 409-414
Author(s):  
A. Kawski ◽  
G. Piszczek
Keyword(s):  
Emission Band ◽  
Effect Of Temperature ◽  
Broad Emission Band ◽  
Fixed Temperature ◽  
Emission Anisotropy ◽  
Paraffin Oil ◽  
Broad Emission ◽  
Negative Emission ◽  
Different Temperatures ◽  
Anisotropy Spectra

Abstract The effect of temperature on fluorescence and emission anisotropy spectra of 4-cyano-N,N-dimethylaniline (CDMA) was investigated in viscous (glycerol and paraffin oil) and rigid (polyvinyl alcohol) PVA and polyvinyl chloride) PVC) media. A strong effect of temperature on the intensity of a and b emission bands was observed. It was also found that the emission anisotropy, r, does not vary in the longwave emission band a at a fixed temperature but decreases in the emission band b together with the decreasing wavelength. The latter effect is due to the fact that the transition moment in this band is perpendicular to the long axis of the CDMA molecule. For CDMA in paraffin oil, a normal b band with negative emission anisotropy only occurs. In all other media used, the emission anisotropy has lower values, approaching zero, which results from the considerable covering of band b with a broad emission band a.

A molecular tailoring approach – a new guide to quantify the energy of push–pull effects: a case study on (E)-3-(1H-pyrrol-2-yl)prop-2-enones

2020 ◽  
Vol 22 (39) ◽  
pp. 22190-22194
Author(s):  
Andrei V. Afonin ◽  
Danuta Rusinska-Roszak
Keyword(s):  
Charge Transfer ◽  
New Approach ◽  
Internal Charge Transfer ◽  
Internal Charge ◽  
Molecular Tailoring

We report a new approach to quantify the push–pull effect in molecules with internal charge transfer.

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