Fluorescence Behavior and Hammett Relationships

Modification of the stilbene molecule by introducing different 4,4 -substituents. 

This leads to a Hammett-like relationship. Although LFERs usually deal with reaction rate and equilibrium data of chemical reactions, this approach can be extended to various photophysical parameters of the excited molecules. 

Solvent effects. Thermodynamically, solvation may be viewed along the same lines as substituent effects, the solvating molecules being equivalent to loosely attached substituents. 

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