Solvatochromic shift of the π → π* transition in all-trans, cis-13, cis-11, cis-9, and cis-7 retinal isomers induced by water and methanol

2010 ◽  
Vol 110 (11) ◽  
pp. 2076-2087
Author(s):  
Alejandro López-Castillo ◽  
Antonio Carlos Borin
Keyword(s):  
Solvatochromic Shift ◽  
Retinal Isomers

Retinal Isomers in Photo- and Electroinduced Rhodopsin Intermediates

1991 ◽  
pp. 545-555 ◽  
Author(s):  
Tatyana B. Protasova ◽  
Irina B. Fedorovich ◽  
Michail A. Ostrovsky
Keyword(s):  
Retinal Isomers

Triplet-sensitized cis-trans isomerization of the protonated Schiff base of retinal isomers

1975 ◽  
Vol 97 (8) ◽  
pp. 2161-2166 ◽  
Author(s):  
A. Alchalel ◽  
B. Honig ◽  
Michael Ottolenghi ◽  
T. Rosenfeld
Keyword(s):  
Schiff Base ◽  
Trans Isomerization ◽  
Retinal Isomers

Solvent Effects upon the Electronic Absorption and Fluorescence Spectra of Pteridines and Riboflavin and Their Ground and First Excited Singlet State Dipole Moments

Pteridines ◽  
1991 ◽  
Vol 3 (3) ◽  
pp. 153-163 ◽  
Author(s):  
J.-J. Aaron ◽  
M. D. Gaye ◽  
C. Párkányi ◽  
C. Boniface ◽  
T. W. N Bieze ◽  
...  
Keyword(s):  
Electronic Absorption ◽  
Singlet State ◽  
Dipole Moments ◽  
Stokes Shift ◽  
Fluorescence Emission ◽  
Excited Singlet State ◽  
Theoretical Ground ◽  
Excited Singlet ◽  
Solvatochromic Shift ◽  
Wide Range

The electronic absorption. fluorescence excitation, and fluorescence emission spectra of a series of pteridines (lumazine, xanthopterin, isoxanthopterin, biopterin) and riboflavin (vitamin B2) were measured at room temperature (298 K) in a number of solvents covering a wide range of polarities (dioxane, ethyl ether, chloroform, ethyl acetate, 1-butanol. 2-propanol, ethanol, methanol, dimethylformamide, acetonitrile, and dimethyl sulfoxide). The effects of the solvent upon the spectral properties are discussed. Experimental groundstate dipole moments were measured for selected compounds and were used in combination with the spectral data to evaluate their first excited singlet-state dipole moments by means of the solvatochromic shift method (Bakhshiev's and Kawski-Chamma-Viallet's equations based on the variation of the Stokes shift with the solvent dielectric constant-refractive index term). The theoretical ground and excited singlet-state dipole moments for all pteridines and riboflavin were calculated as a vector sum of the π-component (obtained by the PPP method) and the a-component (obtained from a-bond moments). A second set of theoretical values was obtained by using the CNDO/2method. A good agreement was observed between the experimental and the theoretical values. Excited singlet-state dipole moments are higher than the ground state values by 1 to 6 Debye units for all the pteridines under study with the exception of xanthopterin.

scholarly journals Effect of the Substitution Position on the Electronic and Solvatochromic Properties of Isocyanoaminonaphthalene (ICAN) Fluorophores

Molecules ◽  
2019 ◽  
Vol 24 (13) ◽  
pp. 2434 ◽  
Author(s):  
Sándor Lajos Kovács ◽  
Miklós Nagy ◽  
Péter Pál Fehér ◽  
Miklós Zsuga ◽  
Sándor Kéki
Keyword(s):  
Radiative Decay ◽  
Fluorescence Emission ◽  
Solvent Polarity ◽  
Decay Rates ◽  
Quantum Yields ◽  
Time Resolved Fluorescence ◽  
Solvatochromic Shift ◽  
Fluorescence Emission Spectra ◽  
Time Resolved ◽  
Donor And Acceptor

The properties of 1,4-isocyanoaminonaphthalene (1,4-ICAN) and 2,6-isocyanoaminonaphthalene (2,6-ICAN) isomers are discussed in comparison with those of 1,5-isocyanoaminonaphthalene (1,5-ICAN), which exhibits a large positive solvatochromic shift similar to that of Prodan. In these isocyanoaminonaphthalene derivatives, the isocyano and the amine group serve as the donor and acceptor moieties, respectively. It was found that the positions of the donor and the acceptor groups in these naphthalene derivatives greatly influence the Stokes and solvatochromic shifts, which decrease in the following order: 1,5-ICAN > 2,6-ICAN > 1,4-ICAN. According to high-level quantum chemical calculations, this order is well correlated with the charge transfer character of these compounds upon excitation. Furthermore, unlike 1,5-ICAN, the 1,4-ICAN and 2,6-ICAN isomers showed relatively high quantum yields in water, that were determined to be 0.62 and 0.21, respectively. In addition, time-resolved fluorescence experiments revealed that both the radiative and non-radiative decay rates for these three ICAN isomers varied unusually with the solvent polarity parameter ET(30). The explanations of the influence of the solvent polarity on the resulting steady-state and time-resolved fluorescence emission spectra are also discussed.

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