Polar and hydrogen-bonding effects of alcohols on the emission spectrum of styrene-triethylamine system

The emission spectra of styrene (ST)-triethylamine (TEA) systems were measured under steady-state illumination conditions in some THF-protic solvent mixtures. The fluorescence spectrum of the ST-TEA system in THF consists of two bands (band A at 304 nm (fluorescence of ST) and band B at 460 nm (emission from an exciplex)). The intensity of band A increased and that of band B decreased with increasing amounts of protic solvents in THF-protic solvent mixtures. The increase in the intensity of band A was explained by the decrease in the concentration of free amine owing to the hydrogen-bonding interaction (or protonation) between TEA and protic solvents. The decrease in the intensity of band B was considered to be caused by the decrease in the concentration of free amine on the addition of protic solvents and the enhanced conversion of the exciplex to an ion pair with increasing solvent polarity. The polar effect was expressed as a function of the relative permittivity of the solution.

Digital Object Identifer:10.1007/s10953-005-7690-0
Published with permission from the copyright holder. This is the author's copy of the work, as published in Journal of Solution Chemistry, 1 October 2005, Volume 34, Issue 10, Pages 1109-1119.
Publisher URL: http://dx.doi.org/10.1007/s10953-005-7690-0
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