ARGONNE NATIONAL LABORATORY

Chemical Sciences and Engineering Division Seminar

 

       SPEAKER:     Jenny Lockard

                                    Northwestern University

 

            TITLE:            Probing the Structural Dynamics of Charge Transfer using Femtosecond

                                    Time-Resolved Stimulated Raman Spectroscopy

 

            DATE:            Wednesday afternoon

                                    December 5, 2007

 

            TIME:             1:30 pm

 

            PLACE:           Building 200, J-183

 

            HOST:            Lin X. Chen

 

Abstract:  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 investigation contain a donor unit consisting of a 3,5-dimethyljulolidine molecule attached to anthracene (DMJ-A). A phenylene ethynlene unit (PE) serves as the bridge to a naphthalenediimide (NI) acceptor.  FSRS spectra of the DMJ-A-PE-NI molecule and the individual donor, bridge and acceptor components are presented and used to determine the important structural changes associated with the charge transfer process.