The electronic excited-state solvation dynamics of coumarin 314 (C314) adso
rbed at the air/water interface was investigated by femtosecond time-resolv
ed surface second-harmonic generation (TRSHG). This Letter presents the fir
st use of TRSHG to measure solvation dynamics and presents the theoretical
basis for monitoring electronic excited-state solvation with TRSHG. The int
erfacial electronic excited solvation time of C314 was measured to be 790 /- 30 fs. This is close to bulk results and is in agreement with simple die
lectric continuum models of solvation and the predictions of molecular dyna
mics simulations. (C) 1999 Elsevier Science B.V. All rights reserved.