New organic luminophores on the basis of cyano- and dicyanopyridines

1986 ◽  
Vol 51 (5) ◽  
pp. 1061-1070 ◽  
Author(s):  
Štefan Marchalín ◽  
Jan Fähnrich ◽  
Milan Popl ◽  
Josef Kuthan
Keyword(s):  
Solvent Effect ◽  
Fluorescence Spectra ◽  
Spectral Characteristics ◽  
Stokes Shift ◽  
Conformational Structure ◽  
Absorption And Fluorescence Spectra ◽  
Organic Luminophores ◽  
The Relationship ◽  
Derivatives Of

Absorption and fluorescence spectra of solutions of cyanopyridine derivatives of polyphenylene type, II-VIII, were investigated. The spectral characteristics determined are interpreted in relation to the probable conformational structure of the investigated substances in the states S0 and S1. The relationship between the Stokes shift and the solvent effect on the fluorescence spectra is discussed.

scholarly journals Spectral Properties of Hybrid of Rhodamine (6G) Dyes Doped Epoxy Resin Dissolved in Chloroform

2019 ◽  
Vol 16 (3(Suppl.)) ◽  
pp. 0764 ◽  
Author(s):  
Al-Hamdani Et al.
Keyword(s):  
Epoxy Resin ◽  
Quantum Efficiency ◽  
Fluorescence Spectra ◽  
Room Temperature ◽  
Rhodamine 6G ◽  
Energy Gap ◽  
Radiative Lifetime ◽  
Stokes Shift ◽  
Fluorescence Emission ◽  
Absorption And Fluorescence Spectra

            The research is dealing with the absorption and fluorescence spectra for the hybrid of  an Epoxy Resin doped with organic dye Rhodamine (R6G) of different concentrations (5*10-6, 5*10-5, 1*10-5, 1*10-4, 5*10-4) Mol/ℓ at room temperature. The Quantum efficiency Qfm, the rate of fluorescence emission Kfm (s-1), the non-radiative lifetime τfm (s), fluorescence lifetime τf and the Stokes shift were calculated. Also the energy gap (Eg) for each dye concentration was evaluated. The results showed that the maximum quantum efficiency 62 % and maximum stokes shift 96 nm was obtained in dye concentration 5*10-6 and 1*10-4. The energy gap ranges between 1.066 eV to 1.128 eV depending proportionally on the dye concentrations.

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.

scholarly journals Study of physico-chemical properties of potential beta-adrenolytics

2014 ◽  
Vol 61 (2) ◽  
pp. 49-54
Author(s):  
M. Stankovičová ◽  
Ž. Bezáková ◽  
P. Mokrý ◽  
P. Salát ◽  
M. Kočík ◽  
...  
Keyword(s):  
Partition Coefficients ◽  
Spectral Characteristics ◽  
Chemical Properties ◽  
Side Chain ◽  
Log P ◽  
Structure Activity ◽  
Physico Chemical ◽  
The Relationship ◽  
Layer Chromatography ◽  
Derivatives Of

Abstract The aim of this paper is the study of physico-chemical properties of the chosen compounds, derivatives of 2-hydroxy-3-[2-(4-methoxyphenyl) ethylamino]propyl-4-[(alkoxycarbonyl)amino]benzoates and 2-hydroxy-3-[2-(2-methoxyphenyl)ethylamino]propyl-4-[(alkoxycarbonyl) amino]benzoates with potential ultra-short beta-adrenolytic activity. The studied compounds are different in the position of the substituent on the benzene ring in the side chain as well as in the aromatic ring in position 4 with alkyl- (methylto butyl-) carbamate. The physico-chemical characteristics, for example, lipophilicity, surface activity, adsorbability, acidobasic properties etc., are very important for the explanation of the relationship between structure and biological activity of the drug. These parameters serve as the base of quantitative structure-activity study. The goal of this work is to establish the spectral characteristics of studied compounds in UV-area, pKa values, the parameters of lipophilicity (the values of Rf and RM from thin layer chromatography, retention time t´R and capacity factor k´ from liquid chromatography and experimental partition coefficients log P´ values), surface tension, critical micelle concentrations, the adsorbability of compounds expressed by percent of adsorbed compound on active charcoal β% as well as by Freundlich adsorption isotherms. The obtained values are correlated with the parameters characterising the size of molecule, for example, the number of carbon atoms on carbamate functional group.

scholarly journals A study of the solvent effect on the low temperature spectra of benzoanthracene molecules

2019 ◽  
Vol 12 (24) ◽  
pp. 1-9
Author(s):  
Asmaa N. Ahmed
Keyword(s):  
Solvent Effect ◽  
Fluorescence Spectra ◽  
Room Temperature ◽  
Emission Cross Section ◽  
Solvent Polarity ◽  
Liquid Nitrogen Temperature ◽  
Absorption And Fluorescence Spectra ◽  
Nonpolar Solvents ◽  
Temperature Spectra ◽  
Peak Emission

been taken at room temperature down to liquid nitrogen temperature (77K). Polar and nonpolar solvents have been used to study the solvent effect on the absorption and fluorescence spectra of solute molecules. Some of the spectroscopic parameters have been determined as functions of solvent polarity and temperature. The results indicate that the band width FWHM increases with increasing the solvent polarity and temperature, while the peak emission cross section decreases with increasing of solvent polarity and decreases with increasing the temperatures. Clear vibrational structure spectra of benzoanthracene molecules have been observed in Nonane and Hexane solvents at 77K.

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