Study of preferential solvation in binary solvent mixtures by the fluorescence-detected magnetic field effect

1994 ◽  
Vol 90 (1) ◽  
pp. 109 ◽  
Author(s):  
Nikolai Kh. Petrov ◽  
Vitalii N. Borisenko ◽  
Michael V. Alfimov
Keyword(s):  
Magnetic Field ◽  
Field Effect ◽  
Preferential Solvation ◽  
Magnetic Field Effect ◽  
Binary Solvent ◽  
Solvent Mixtures ◽  
Binary Solvent Mixtures

scholarly journals Magnetic field effect on exciplex-forming organic acceptor/donor system: a powerful tool for understanding the preferential solvation

2016 ◽  
Vol 19 (3) ◽  
pp. 65-75
Author(s):  
Hao Minh Hoang ◽  
Van Thi Bich Pham
Keyword(s):  
Magnetic Field ◽  
Field Effect ◽  
Preferential Solvation ◽  
Magnetic Field Effect ◽  
Solvation Shell ◽  
Dielectric Constants ◽  
Binary Solvents ◽  
Charge Transfer Complexes ◽  
Solvent Mixtures ◽  
Magnetic Field Effects

Many acceptor/donor systems can form excited-state charge-transfer complexes (exciplexes) in photo-induced electron transfer reactions. Exciplex can be detected by their luminescence. In addition, the exciplex luminescence is magneto-sensitive. Here, we employ an approach based on the magnetic field effect on the exciplex of 9,10- dimethylanthracene/N,N-dimethylaniline pair in micro-homogeneous and micro-heterogeneous binary solvents to investigate the effects of the preferential solvation processes on solute molecules in solutions. Micro-homogeneous solvent mixtures of propyl acetate (PA)/butyronitrile (BN) allow for a systematic variation of the static dielectric constants, s , in the range from 6.0 to 24.6. The mixtures of toluene (TO)/dimethylsulfoxide (DMSO) with varying the s values in the range from 4.3 to 15.5 are used as micro-heterogeneous binary solvents. In micro-heterogeneous environment, DMSO molecules get preferentially favoured in the solvation shell, forming micro-clusters surrounding the solute molecules. This solvation effect is reflected in the altered magnetic field effects, lifetimes and dissociation rate constants of the exciplexes.

scholarly journals Solvation in pure and mixed solvents: Some recent developments

2007 ◽  
Vol 79 (6) ◽  
pp. 1135-1151 ◽  
Author(s):  
Omar A. El Seoud
Keyword(s):  
Hydrogen Bonding ◽  
Hydrophobic Interactions ◽  
Preferential Solvation ◽  
Mixed Solvents ◽  
Effect Of Temperature ◽  
Binary Solvent ◽  
Solvent Mixtures ◽  
Dispersion Interactions ◽  
Binary Solvent Mixtures ◽  
Recent Developments

The effect of solvents on the spectra, absorption, or emission of substances is called solvatochromism; it is due to solute/solvent nonspecific and specific interactions, including dipole/dipole, dipole-induced/dipole, dispersion interactions, and hydrogen bonding. Thermo-solvatochromism refers to the effect of temperature on solvatochromism. The molecular structure of certain substances, polarity probes, make them particularly sensitive to these interactions; their solutions in different solvents have distinct and vivid colors. The study of both phenomena sheds light on the relative importance of the solvation mechanisms. This account focuses on recent developments in solvation in pure and binary solvent mixtures. The former has been quantitatively analyzed in terms of a multiparameter equation, modified to include the lipophilicity of the solvent. Solvation in binary solvent mixtures is complex because of the phenomenon of "preferential solvation" of the probe by one component of the mixture. A recently introduced solvent exchange model allows calculation of the composition of the probe solvation shell, relative to that of bulk medium. This model is based on the presence of the organic solvent (S), water (W), and a 1:1 hydrogen-bonded species (S-W). Solvation by the latter is more efficient than by its precursor solvents, due to probe/solvent hydrogen-bonding and hydrophobic interactions. Dimethylsulfoxide (DMSO) is an exception, because the strong DMSO/W interactions probably deactivate the latter species toward solvation. The relevance of the results obtained to kinetics of reactions is briefly discussed by addressing temperature-induced desolvation of the species involved (reactants and activated complexes) and the complex dependence of kinetic data (observed rate constants and activation parameters) in binary solvent mixtures on medium composition.

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