An ab initio and TD-DFT study of solvent effect contributions to the electronic spectrum of Nile Red.

A CIS and TD-DFT study using a polarizable continuum solvent model has been conducted to assess non-specific solvent effects on the spectral shifts in Nile Red (NR). The results in this paper show that the electronic band shifts of Nile Red are a consequence of both a field effect on the transition energy and an effect due to a solvent induced geometry change. The S0-->S1 transition experiences a large red-shift with increasing solvent polarity but is relatively insensitive to geometric change.