Solvent-induced polarization phenomena in the excited state of composite systems with identical halves. 2. Effects of solvent polarity upon the fluorescence of [2.2](1,3)pyrenophane

1977 ◽  
Vol 81 (5) ◽  
pp. 424-429 ◽  
Author(s):  
Toyoharu Hayashi ◽  
Noboru Mataga ◽  
Teruo Umemoto ◽  
Yoshiteru Sakata ◽  
Soichi Misumi
Keyword(s):  
Excited State ◽  
Solvent Polarity ◽  
Induced Polarization ◽  
Composite Systems ◽  
Polarization Phenomena

Influence of solvent polarity on the dual fluorescence of p-N,N-dimethylaminobenzonitrile: An AM1 theoretical study

1990 ◽  
Vol 55 (8) ◽  
pp. 1891-1895 ◽  
Author(s):  
Peter Ertl
Keyword(s):  
Excited State ◽  
Theoretical Study ◽  
Solvent Polarity ◽  
Semiempirical Method ◽  
Dual Fluorescence ◽  
Long Wavelength ◽  
Polar Media ◽  
Wavelength Emission ◽  
Ground State Geometry ◽  
Influence Of Solvent

Twisting of the NMe2 group in p-N,N-dimethylaminobenzonitrile (DMABN) was investigated using AM1 semiempirical method with configuration interaction. Effect of polar media was considered by placing + and - charge centers ("sparkles") at appropriate places opposite the molecule. Optimized ground state geometry of DMABN is slightly twisted with the lowest vertical excited state of 1B character. As the polarity of media increases and/or the - NMe2 group twists, the symmetric 1A excited state having considerable charge separation becomes energetically favorable. Anomalous long-wavelength emission of DMABN comes from this state.

scholarly journals Studies on Photophysical Properties of Mono-carbonyl Curcumin Analogues: Experimental and Theoretical approach

2018 ◽  
Vol 34 (4) ◽  
pp. 2170-2179
Author(s):  
Manjula Rayanal ◽  
Prasad Pralhad Pujar ◽  
Sridhar D
Keyword(s):  
Excited State ◽  
Ground State ◽  
Dipole Moments ◽  
Photophysical Properties ◽  
Stokes Shift ◽  
Solvent Polarity ◽  
Frontier Molecular Orbital ◽  
Curcumin Analogues ◽  
Td Dft ◽  
Ground State Dipole Moments

The solvatochromic fluorescence behaviour of mono-carbonyl curcumin analogues has been studied in ten different solvents ranging from non-polar to polar. The solvent effect on the spectral properties of analogues has been discussed. The ground state dipole moments were estimated experimentally by Bilot-Kawski equation which is a function of Stokes shift with the solvent polarity parameters and Guggenheim method and theoretically by TD-DFT studies. The excited state dipole moment was determined using Bilot-Kawski equations. The excited state dipole moments for the two molecules were found to be higher than their corresponding ground state dipole moments. Theoretically Frontier molecular orbital (HOMO/ LUMO) energies were determined by Gaussian 09 W software using TD-DFT.

scholarly journals Modulation of circularly polarized luminescence through excited-state symmetry breaking and interbranched exciton coupling in helical push–pull organic systems

2020 ◽  
Vol 11 (2) ◽  
pp. 567-576 ◽  
Author(s):  
Kais Dhbaibi ◽  
Ludovic Favereau ◽  
Monika Srebro-Hooper ◽  
Cassandre Quinton ◽  
Nicolas Vanthuyne ◽  
...  
Keyword(s):  
Excited State ◽  
Symmetry Breaking ◽  
Luminescence Intensity ◽  
Solvent Polarity ◽  
Circularly Polarized ◽  
Polarity Effect ◽  
Exciton Coupling ◽  
Organic Systems ◽  
Circularly Polarized Luminescence ◽  
Polarized Luminescence

Solvent polarity effect on circularly polarized luminescence intensity was assessed in helical push–pull organic systems through excited-state symmetry breaking and interbranched exciton coupling.

scholarly journals Ultrafast processes triggered by one- and two-photon excitation of a photochromic and luminescent hydrazone

2019 ◽  
Vol 15 ◽  
pp. 2438-2446 ◽  
Author(s):  
Alessandro Iagatti ◽  
Baihao Shao ◽  
Alberto Credi ◽  
Barbara Ventura ◽  
Ivan Aprahamian ◽  
...  
Keyword(s):  
Excited State ◽  
Cross Section ◽  
Absorption Cross Section ◽  
Transient Absorption ◽  
Solvent Polarity ◽  
Photon Absorption ◽  
Absorption Cross ◽  
Time Resolved ◽  
Two Photon Absorption ◽  
Two Photon

In this work we apply a combination of steady state and time resolved luminescence and absorption spectroscopies to investigate the excited-state dynamics of a recently developed molecular photoswitch, belonging to the hydrazone family. The outstanding properties of this molecule, involving fluorescence toggling, bistability, high isomerization quantum yield and non-negligible two-photon absorption cross section, make it very promising for numerous applications. Here we show that the light induced Z/E isomerization occurs on a fast <1 ps timescale in both toluene and acetonitrile, while the excited state lifetime of the Z-form depends on solvent polarity, suggesting a partial charge transfer nature of its low lying excited state. Time-resolved luminescence measurements evidence the presence of a main emission component in the 500–520 nm spectral range, attributed to the Z-isomer, and a very short living blue-shifted emission, attributed to the E-isomer. Finally, transient absorption measurements performed upon far-red excitation are employed as an alternative method to determine the two-photon absorption cross-section of the molecule.

scholarly journals Femtosecond Dynamics on 2-(2′-Hydroxy-4′-diethylaminophenyl)benzothiazole: Solvent Polarity in the Excited-State Proton Transfer

ChemPhysChem ◽  
2006 ◽  
Vol 7 (6) ◽  
pp. 1372-1381 ◽  
Author(s):  
Yi-Ming Cheng ◽  
Shih-Chieh Pu ◽  
Chia-Jung Hsu ◽  
Chin-Hung Lai ◽  
Pi-Tai Chou
Keyword(s):  
Excited State ◽  
Proton Transfer ◽  
Solvent Polarity ◽  
Femtosecond Dynamics ◽  
Excited State Proton Transfer
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