Ultrafast vibrational Stark-effect spectroscopy: exploring charge-transfer reactions by directly monitoring the solvation shell response.
We present the first implementation of transient vibrational Stark-effect spectroscopy as an ultrafast probe of solvation dynamics. The method is applied to the phototriggered intramolecular charge-transfer reaction of Betaine-30, where the vibrational Stark shifts of the nearby solvent molecules--arising from the change in the electrostatic environment--are measured using a three-pulse photon echo probe. This new experiment provides a direct subpicosecond measure of the chromophore's excited-state dynamics and back electron transfer as viewed from the solvent's perspective. We develop a simple ab initio model that offers semiquantitative prediction of the experimental Stark shifts.
Baiz
Carlos R
CR
Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 40109, USA.
Kubarych
Kevin J
KJ
D001622:Betaine / Q000737:chemistry; D004579:Electron Transport; D008958:Models, Molecular; D008968:Molecular Conformation; D055668:Photochemical Processes; D012997:Solvents / Q000737:chemistry*; D013057:Spectrum Analysis; D013997:Time Factors; D014732:Vibration
D012997:Solvents; D001622:Betaine