A high pressure study of the effect of viscosity on the light induced isomerization of DMABN in three linear alcohols, iso-butanol and glycerol

The light induced isomerization of 4-N,N-dimethylaminobenzonitrile (DMABN) has been measured versus pressure to 10 kbar in ethanol, n-butanol, n-pentanol, iso-butanol and glycerol. or the three straight chain alcohols a linear plot of log(ITICT/ILE) versus α log η (η=viscosity) was obtained with α = −0.5 ± 0.02. Iso-butanol gave a non-linear plot of the above variables and at any viscosity the value of ITICT/ILE was greater than for n-butanol, although those two alcohols have nearly identical values for their electronic and volumetric properties. The results for glycerol extend the viscosity range significantly and exhibit distinctly non-linear behavior for the above type of plot.

[1]  H. G. Drickamer,et al.  Evaluation of configuration coordinate parameters from high pressure optical data. I. Phenanthrene, anthracene, and tetracene , 1974 .

[2]  K. Eisenthal,et al.  Polarity-dependent barriers and the photoisomerization dynamics of molecules in solution , 1987 .

[3]  J. B. Birks,et al.  Organic Molecular Photophysics , 1975 .

[4]  H. G. Drickamer,et al.  High-pressure studies of photoluminescence and thermoluminescence of ZnS:Cu:Cl phosphors using laser selection excitation , 1992 .

[5]  W. Rettig,et al.  Fluorescence studies on solvent-induced intramolecular charge separation in symmetric biaryls , 1984 .

[6]  D. Waldeck,et al.  Breakdown of Kramers theory description of photochemical isomerization and the possible involvement of frequency dependent friction , 1983 .

[7]  N. Moiseyev,et al.  Thermal rate constants in collinear atom transfer reactions by optimizing the position of the reactants/products dividing surface , 1992 .

[8]  W. Gelbart,et al.  Nonradiative electronic relaxation under collision-free conditions , 1977 .

[9]  W. Rettig,et al.  Photophysics of Internal Twisting , 2007 .

[10]  W. Rettig,et al.  Kinetic studies of twisted intramolecular charge transfer in highly viscous solvents as a function of pressure and temperature , 1994 .

[11]  G. Fleming,et al.  Solvent influence on photochemical isomerizations: Photophysics of DODCI , 1982 .

[12]  W. Rettig External and internal parameters affecting the dual fluorescence of p-cyano-dialkylanilines , 1981 .

[13]  Wolfgang Rettig,et al.  Application of a simplified microstructural solvent interaction model to the solvatochromism of twisted intramolecular charge transfer (TICT) states , 1982 .

[14]  H. G. Drickamer,et al.  Unusual phosphorescence and its pressure dependence in 4-N,N-dimethylaminobenzonitrile dissolved in solid polymers , 1995 .

[15]  R. S. Mulliken,et al.  Advances in Molecular Spectroscopy , 1989 .

[16]  W. Rettig,et al.  A high-pressure study of fluorescence peak shifts for 1Lb, 1La, and TICT states , 1988 .