Solvent effects on ground and excited electronic state structures of p-nitroaniline

摘要: Resonance Raman intensities of p-nitroaniline, a prototypical “push–pull” chromophore with large first hyperpolarizability (β), have been measured in dilute solution five solvents having wide range polarities (cyclohexane, 1,4-dioxane, dichloromethane, acetonitrile, and methanol) at excitation wavelengths spanning the strong near-ultraviolet charge-transfer absorption band. The absolute profiles spectra are simulated using time-dependent wave packet propagation techniques to determine excited-state geometry changes along or six principal Raman-active vibrations as well estimates solvent reorganization energies. total vibrational energy decreases increases increasing polarity all except methanol, where specific hydrogen-bonding interactions may be important. dimensionless normal coordinate obtained from resonance analysis conve...