Evaluating The Solvent Stark Effect From Temperature-Dependent Solvatochromic Shifts Of Anthracene

The solvent Stark effect on the spectral shifts of anthracene is studied with temperature-dependent solvatochromic measurements. The Stark contribution Delta v(Stark) to the absorption shift Delta v(p) in polar solvents is measured to be Delta v(Stark)=(53 +/- 35) cm(-1), in reasonable agreement with dielectric continuum theory estimate of 28 cm(-1), whereas the major shift Delta v(p)similar to 300 cm(-1) presumably originates from the solute quadrupole. We pay attention to the accurate correction of Delta v(p) for the nonpolar contribution that is crucial when the shifts are modest in magnitude.