1. Elucidating Structural Dynamics Coupled to Wire-Like Charge Transport in Donor-Bridge-Acceptor Molecules Using Time-Resolved Stimulated Raman Spectroscopy
Jenny V. Lockard, Department of Chemistry, Northwestern University.
The structural dynamics coupled to charge transport in electron donor-bridge-acceptor (D-B-A) molecules are the least well understood part of this fundamental process. In this work, femtosecond time-resolved stimulated Raman spectroscopy (FSRS) is employed to study the changes in molecular structure especially of the bridge that occur upon electron transfer in a series of D-B-A systems. The molecules under investigations contain a donor unit consisting of a 3,5-dimethyljulolidine molecule attached to anthracene (DMJ-A). Phenylene ethynyl units (PE) serve as the bridge to a naphthalenediimide (NI) acceptor. FSRS spectra of the DMJ-A-PE-NI molecules and the individual components were obtained and used to determine the important vibrational modes with the charge transfer process. 1 2 3
g,0
e,n
v t t1 t3
Actinic Pump
Raman Pump
Raman Probe Dt
FSRS