The free-energy profile for the excited-state intramolecular proton transfer reaction of 1-[(dimethylamino)methyl]-2-naphthoI in acetonitrile solvent is studied with the reference interaction site model self-consistent field (RISM-SCF) method. The dynamical electron correlation effect is evaluated by the multireference Moller-Plesset (MRMP) method. We find that the reaction is exothermic and barrierless, due to both the solvation and dynamical correlation effects. Furthermore, we calculate the vertical transition energy of the solute, which is in excellent agreement with experiment. The solvation structures are also discussed in terms of the radial distribution functions between solute-solvent atomic sites. (C) 2004 Elsevier B.V. All rights reserved.