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 3-Methylpiperidinyl Carbodithioates as Building Blocks for 1,3-Dithiolium Derivatives

2013 ◽  
Vol 21 (1) ◽  
pp. 47-56
Author(s):  
Laura G. Sarbu ◽  
Lucian G. Bahrin
Keyword(s):  
Charge Transfer ◽  
Sulfuric Acid ◽  
Absorption Band ◽  
Perchloric Acid ◽  
Building Blocks ◽  
Charge Transfer Absorption Band ◽  
Internal Charge Transfer ◽  
Internal Charge

Abstract New 1,3-dithiolium derivatives have been synthesized by heterocyclocondensation of various 3-methylpiperidinyl carbodithioates derived from 2-hydroxypropiophenones. Thus, 1,3-dithiolium perchlorates have been obtained by the treatment of the corresponding dithiocarbamates with a mixture of acetic and sulfuric acid, followed by the addition of perchloric acid. 1,3-Dithiolium perchlorates have been converted to the corresponding 2-(1,3-dithiolium) phenolates under weak basic conditions. These phenolates exhibit mesoionic character with an internal charge transfer absorption band.

Surface photochemistry: use of spiropyrans as indicators of surface polarity

1984 ◽  
Vol 62 (5) ◽  
pp. 1001-1002 ◽  
Author(s):  
Paul De Mayo ◽  
Ali Safarzadeh-Amiri ◽  
S. King Wong
Keyword(s):  
Absorption Band ◽  
Silica Gel ◽  
Solvent Polarity ◽  
Surface Polarity ◽  
Long Wavelength ◽  
Wavelength Absorption Band ◽  
Wavelength Absorption ◽  
Long Wavelength Absorption Band

The position of the long wavelength absorption band in the spectrum of a spiropyran is sensitive to solvent polarity. This property has been used to determine the polarity of the silica gel surface.

Synthesis and properties of open-cage fullerene C60 derivatives: impact of the extended π-conjugation

2018 ◽  
Vol 2 (2) ◽  
pp. 206-213 ◽  
Author(s):  
Yoshifumi Hashikawa ◽  
Hidefumi Yasui ◽  
Kei Kurotobi ◽  
Yasujiro Murata
Keyword(s):  
Charge Transfer ◽  
Intramolecular Charge Transfer ◽  
Fullerene C60 ◽  
Long Wavelength ◽  
Charge Transfer Transitions ◽  
Wavelength Absorption ◽  
C60 Derivatives

Novel open-cage fullerene C60 derivatives with extended π-conjugation bearing thiophene rings exhibit long wavelength absorption due to characteristic intramolecular charge transfer transitions.

Effect of Medium on the Electronic Spectra of 2-Nitroaniline Derivatives

1996 ◽  
Vol 61 (1) ◽  
pp. 155-159 ◽  
Author(s):  
Vojtěch Bekárek ◽  
Jan Jílek ◽  
Antonín Haviger
Keyword(s):  
Refractive Index ◽  
Absorption Band ◽  
Gaseous State ◽  
Long Wavelength ◽  
Nonpolar Solvents ◽  
Parameter Equation ◽  
Wavelength Absorption ◽  
Solute Interactions ◽  
Derivatives Of ◽  
Long Wavelength Absorption Band

The wavenumbers of the long-wavelength absorption band were measured for nine 4-substituted and 5-substituted derivatives of 2-nitroaniline in the gaseous state and in 13 solvents where only nonspecific solvent-solute interactions can be expected. For the series involving all the solvents used, the solvent effects can be well expressed by an one-parameter equation involving the product of the Born functions of the relative permittivity and of the refractive index of the solvent. For the series involving the nonpolar solvents and the gaseous state only, this equation reduces to an one-parameter equation involving the refractive index Born function squared.

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.

Die Dispersion des Kerr-Effektes. V.

1969 ◽  
Vol 24 (9) ◽  
pp. 1391-1400 ◽  
Author(s):  
H.G. Kuball ◽  
W. Galler ◽  
R. Göb ◽  
D. Singer
Keyword(s):  
Perturbation Theory ◽  
Absorption Band ◽  
Kerr Effect ◽  
Kerr Constant ◽  
Time Dependent ◽  
Long Wavelength ◽  
Wavelength Absorption ◽  
Definition Of ◽  
Long Wavelength Absorption Band ◽  
Kronig Relation

The definition of a complex Kerr constant follows from the description of the interaction of light with molecules in an electrostatic field. The treatment is based on the time-dependent perturbation theory, assuming a quasi continuum of librational states of the molecules concerned. The Kramers-Kronig relation for the Kerr effect and the electrochromism is deduced from the complex Kerr constant. The results are compared with the measurement of the Kerr effect of one azamerocyanine. For a number of molecules the amplitude of the optical polarizability and of the hyperpolarizability B is calculated for the long wavelength absorption band.

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