scholarly journals Dipole Moment and Polarizability of Tunable Intramolecular Charge Transfer States in Heterocyclic π-Conjugated Molecular Dyads Determined by Computational and Stark Spectroscopic Study

2018 ◽  
Vol 122 (17) ◽  
pp. 9346-9355 ◽  
Author(s):  
Egmont J. Rohwer ◽  
Maryam Akbarimoosavi ◽  
Steven E. Meckel ◽  
Xunshan Liu ◽  
Yan Geng ◽  
...  
Keyword(s):  
Dipole Moment ◽  
Charge Transfer ◽  
Spectroscopic Study ◽  
Intramolecular Charge Transfer ◽  
Molecular Dyads

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.

Photoinduced intramolecular charge transfer process of betaine pyridinium: A theoretical spectroscopic study

2011 ◽  
Vol 515 (1-3) ◽  
pp. 42-48 ◽  
Author(s):  
Aurélie Perrier ◽  
Stéphane Aloïse ◽  
Zuzanna Pawlowska ◽  
Michel Sliwa ◽  
François Maurel ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Spectroscopic Study ◽  
Transfer Process ◽  
Intramolecular Charge Transfer ◽  
Charge Transfer Process

Two-photon absorption of styryl-quinolinium, -pyridinium, and -barbituric acid derivatives, and intramolecular charge transfer

2001 ◽  
Vol 79 (2) ◽  
pp. 174-182 ◽  
Author(s):  
XiaoMei Wang ◽  
Chun Wang ◽  
WenTao Yu ◽  
YuFang Zhou ◽  
Xian Zhao ◽  
...  
Keyword(s):  
Dipole Moment ◽  
Charge Transfer ◽  
Barbituric Acid ◽  
Intramolecular Charge Transfer ◽  
Theoretical Calculations ◽  
Photon Absorption ◽  
Amino Groups ◽  
Element Analysis ◽  
Two Photon Absorption ◽  
Two Photon

A series of new chromophores, styryl-parent end-capped with various donors, and with barbituric acid, methyl-pyridinium, and methyl-quinolinium as the acceptors, have been synthesized and characterized by element analysis or X-ray diffraction. Using the Z-scan system, their two-photon absorption (TPA) cross-section values (δ) have been determined under excitation with 10 Hz, and 1064 nm, 35 ps mode-locked Nd:YAG laser pulse in DMF with do= 0.05 M. The effective δ value is as high as 10.9 × 10–48 cm4 s per photon for trans-4-(4'-N,N-diphenyl amino) styryl-N-methyl quinolinium iodide (DPASQI). The δ value increases from barbituric acid- to pyridinium- to quinolinium-derivatives apparently due to the increase in both the conjugated degree and planarity; however, when the acceptor is fixed, the δ value increases from dialkyl amino groups to diphenyl amino groups even though the latter is a weaker donor than the dialkyl amino groups. Theoretical calculations confirm that the increased distortion from planarity for the barbituric acid derivative makes its δ value decrease. The relatively large δ value for quinolinium- or pyridinium-derivatives originates from larger intramolecular charge transfer, which can be characterized by the difference of dipole moment (Δµge) between the S0 and S1, and the transition dipole moment (Mee') between S1 and S2.Key words: two-photon absorption, intramolecular charge transfer, styryl-quinolinium, styryl-pyridinium, styryl-barbituric acid.

Spectroscopic study of polyphenylquinolines—materials with efficient intramolecular charge transfer

2013 ◽  
Vol 114 (5) ◽  
pp. 737-750 ◽  
Author(s):  
E. L. Aleksandrova ◽  
V. M. Svetlichnyi ◽  
L. A. Myagkova ◽  
N. V. Matyushina ◽  
T. N. Nekrasova ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Spectroscopic Study ◽  
Intramolecular Charge Transfer

scholarly journals Nonresonant femtosecond second hyperpolarizabilities of intramolecular charge-transfer molecules with great excited- and ground-state dipole-moment differences

1999 ◽  
Vol 75 (1) ◽  
pp. 28-30 ◽  
Author(s):  
Mikio Yamashita ◽  
Shinji Kikuma ◽  
Yoshihisa Yamaoka ◽  
Hidetoshi Murakami ◽  
Ryuji Morita ◽  
...  
Keyword(s):  
Dipole Moment ◽  
Charge Transfer ◽  
Ground State ◽  
Intramolecular Charge Transfer ◽  
Ground State Dipole Moment
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