Photophysical and optical limiting properties of multifunctional hemi-ortho ester derivatives of fullerenol: Effects of TBAH doping, fullerenol concentration and solvent polarity

2011 ◽  
Vol 161 (9-10) ◽  
pp. 670-679 ◽  
Author(s):  
Rachana Singh ◽  
Thakohari Goswami
Keyword(s):  
Solvent Polarity ◽  
Optical Limiting ◽  
Ortho Ester ◽  
Derivatives Of

scholarly journals Substituent and Solvent Polarity on the Spectroscopic Properties in Azo Derivatives of 2-Hydroxynaphthalene and Their Difluoroboranes Complexes

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3387
Author(s):  
Agnieszka Skotnicka ◽  
Przemysław Czeleń
Keyword(s):  
Spectral Properties ◽  
Nmr Spectra ◽  
Fluorescent Dyes ◽  
Photophysical Properties ◽  
Solvent Polarity ◽  
Spectroscopic Properties ◽  
Azo Group ◽  
Group Rotation ◽  
Derivatives Of ◽  
Substituted 1

Novel fluorescent dyes such as difluoroborane complexes of 1-phenylazonaphthalen-2-ol derivatives were successfully synthesized and characterized with a focus on the influence of a substituent and a solvent on the basic photophysical properties. 1H, 11B, 13C, 15N, and 19F nuclear magnetic resonance (NMR) spectra of substituted 1-phenylazonaphthalen-2-ol difluoroboranes and their parent azo dyes were recorded and discussed. The absorption and emission properties of synthesized compounds were investigated in solvents of varying polarity. They were found to be fluorescent despite the presence of the azo group. The azo group rotation was blocked by complexing with -BF2 to get a red shift in absorption. Solvent-dependent spectral properties of compounds were investigated using Lipper-Mataga and Bakhshiev plot. The calculated DFT energies and Frontier Molecular Orbitals calculations of the studied compounds were proved to be consistent with the experimental observations.

Tautomerism of Isoguanosine and Solvent-Induced Keto-Enol Equilibrium

1976 ◽  
Vol 31 (7-8) ◽  
pp. 361-370 ◽  
Author(s):  
Jerzy Sepioł ◽  
Zygmunt Kazimierczuk ◽  
David Shugar
Keyword(s):  
Aqueous Media ◽  
Chloroform Solution ◽  
Solvent Polarity ◽  
Tautomeric Equilibrium ◽  
Enol Form ◽  
Amino Group ◽  
Infrared Absorption Spectroscopy ◽  
Dioxane Solution ◽  
Model Compounds ◽  
Derivatives Of

Abstract Ultraviolet and infrared absorption spectroscopy, in aqueous and non-aqueous media, have been employed to study the tautomerism of 9-substituted isoguanines, including the nucleoside iso­ guanosine. With the aid of a series of model compounds, it was shown that 9-substituted isogua­ nines, and isoguanosine, in aqueous medium are predominantly in the form N(1)H,2-keto-6-amino. In dioxane solution the tautomeric equilibrium is shifted in the direction of the enol form. The shift towards this form is accentuated for those analogues in which the exocyclic amino group is methylated. With the aid of N6,N6,9-trimethylisoguanine, and its 9-octyl analogue, the tautomeric constant was studied as a function of concentration, temperature, and solvent polarity, and the results applied to evaluate the tautomeric equilibria of 9-methylisoguanine and isoguanosine as a function of these variables. In general the enol form is favoured by a decrease in solvent polarity, by a decrease in concentration in dioxane, or an increase in temperature in chloroform solution. Syntheses are described for several N6-amino and methylamino derivatives of 2-methoxy-9-methylpurine, and 3-methyl-5-oxo-7,8-dihydroimidazo (2,1-i) purine, which served as an analogue of the unavailable 1,9-dimethylisoguanine.

Solvent Effects on the Phosphorescent State of Some Aromatic Carbonyls

1972 ◽  
Vol 50 (22) ◽  
pp. 3601-3606 ◽  
Author(s):  
James B. Gallivan
Keyword(s):  
Heavy Atom ◽  
Solvent Polarity ◽  
Triplet States ◽  
Absorption Bands ◽  
Fundamental Properties ◽  
Relative Contribution ◽  
Alkyl Derivatives ◽  
Solvent Environment ◽  
Derivatives Of ◽  
Phosphorescent State

Triplet state properties of chromone, 4-chromanone, acetophenone, and several alkyl derivatives of acetophenone were studied in a variety of solvent systems. The phosphorescence excitation method was used to monitor the energies and relative intensities of singlet–triplet absorption bands in the presence and absence of heavy atom solvents. The results, combined with earlier optical and magnetic resonance studies of such systems, illustrate the importance of solvent environment in determining fundamental properties of these excited states. Observed trends are interpreted in terms of contrasting effects of changing solvent polarity on proximate n,π* and π.π* triplet states. To describe the relative contribution of each orbital type to the phosphorescent state, the coefficients of each wavefunction must change with solvent. Correspondingly, the solvent environment should be specified whenever orbital designations are made.

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