The Nature of the Intramolecular Charge Transfer Excited State inp-Pyrrolocyanobenzene (PBN) and Other Derivatives of Benzene Substituted by Electron Donor and Acceptor Groups

2002 ◽  
Vol 106 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Shmuel Zilberg ◽  
Yehuda Haas
Keyword(s):  
Excited State ◽  
Charge Transfer ◽  
Electron Donor ◽  
Intramolecular Charge Transfer ◽  
Donor And Acceptor ◽  
Electron Donor And Acceptor ◽  
Derivatives Of

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.

Structural Requirements for Intramolecular Charge-Transfer in Excited State of 4-(9-Anthryl)-N,N-dimethylaniline

1982 ◽  
Vol 37 (6) ◽  
pp. 598-606 ◽  
Author(s):  
Aleksander Siemiarczuk ◽  
Jacek Koput ◽  
Andrzej Pohorille
Keyword(s):  
Excited State ◽  
Charge Transfer ◽  
Intramolecular Charge Transfer ◽  
Dipole Moments ◽  
Atomic Charge ◽  
Transfer Model ◽  
Charge Densities ◽  
Singlet States ◽  
Donor And Acceptor ◽  
Electron Donor And Acceptor

Abstract Excited state kinetics and other photophysical features of 4-(9-anthryl)-N,N-dimethylaniline and two model compounds have been thoroughly examined in order to establish the structural conditions for highly polar excited state formation.Also quantum chemical calculations by means of INDO/S CI and PCILO methods have been performed to obtain potential energy curves, dipole moments and atomic charge densities for the ground and lowest excited singlet states as a function of the angle of twist between anthryl and dimethylaniline subunits.Both the experimental and theoretical results confirm the previously proposed TICT (Twisted Intramolecular Charge-Transfer) model predicting the perpendicularity between electron donor and acceptor moieties as a condition for nearly full charge-separation in excited states for some classes of aromatic compounds.

Charge-Transfer Crystal with Segregated Packing Structure Constructed with Hexaarylbenzene and Tetracyanoquinodimethane

CrystEngComm ◽  
2021 ◽  
Author(s):  
Rempei Ando ◽  
Mingoo Jin ◽  
Hajime Ito
Keyword(s):  
Charge Transfer ◽  
Solid State ◽  
Electron Donor ◽  
Packing Structure ◽  
Donor And Acceptor ◽  
Solid State Materials ◽  
Electron Donor And Acceptor ◽  
Acceptor Molecules

Charge-transfer (CT) crystals bearing segregated domains between the electron donor and acceptor molecules are a promising platform for developing new organic functional solid-state materials. However, there is limited diversity in...

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.

Temperature dependent spectroscopic and excited state dynamics of 3-hydroxychromones with electron donor and acceptor substituents

2017 ◽  
Vol 5 (2) ◽  
pp. 024011 ◽  
Author(s):  
Alan Szalai ◽  
Luciana Giordano ◽  
Verónica M Sánchez ◽  
Teresa D Z Atvars ◽  
Marcelo Faleiros ◽  
...  
Keyword(s):  
Excited State ◽  
Electron Donor ◽  
Temperature Dependent ◽  
Excited State Dynamics ◽  
Donor And Acceptor ◽  
Electron Donor And Acceptor

Influence of electron donor and acceptor substituents on the excited state properties of rhenium(I) tetracarbonyl chelate complexes

1998 ◽  
pp. 2893-2900 ◽  
Author(s):  
Frederik W. M. Vanhelmont ◽  
Melath V. Rajasekharan ◽  
Hans U. Güdel ◽  
Silvia C. Capelli ◽  
Jürg Hauser ◽  
...  
Keyword(s):  
Excited State ◽  
Electron Donor ◽  
Chelate Complexes ◽  
Donor And Acceptor ◽  
Electron Donor And Acceptor
Sign in / Sign up

Export Citation Format

Share Document