Quadrupolar solvatochromism: 4-amino-phthalimide in toluene.
We present calculations of the temperature dependence of the solvent reorganization energy of 4-amino-phthalimide chromophore in quadrupolar toluene. The reorganization energy is a sum of the contributions from quadrupolar and induction solvation. We employ several calculation formalisms in order to evaluate their performance against the experiment. The point-dipole and full atomic distributions of solute charge are compared to show that the point-dipole approximation works well for this chromophore. We also show that most of the reorganization entropy comes from the quadrupolar response. Induction solvation amounts to about 10% of the entropy. Both the reorganization energy and the reorganization entropy are greatly affected by the local solute-solvent density profile (density reorganization) which contributes about half of their values. The induction reorganization energy is strongly affected by the microscopic, nonlocal nature of the density fluctuations of the solvent around the solute.
Milischuk
Anatoli A
AA
Department of Chemistry and Biochemistry and the Center for the Early Events in Photosynthesis, Arizona State University, P.O. Box 871604, Tempe, Arizona 85287-1604, USA.
Matyushov
Dmitry V
DV