title: Ultrafast energy transfer from rigid, branched side-chains into a conjugated, alternating copolymer.
abstract: We present the synthesis and characterization of a benzodithiophene/thiophene alternating copolymer decorated with rigid, singly branched pendant side chains. We characterize exciton migration and recombination dynamics in these molecules in tetrahydrofuran solution, using a combination of static and time-resolved spectroscopies. As control experiments, we also measure electronic relaxation dynamics in isolated molecular analogues of both the side chain and polymer moieties. We employ semi-empirical and time-dependent density functional theory calculations to show that photoexcitation of the decorated copolymer using 395 nm laser pulses results in excited states primarily localized on the pendant side chains. We use ultrafast transient absorption spectroscopy to show that excitations are transferred to the polymer backbone faster than the instrumental response function, ∼250 fs.
authors: Department of Chemistry, The James Franck Institute, Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois 60637, USA.
authors: Graham B
authors: GB
authors: Griffin
authors: Department of Chemical Engineering, Stanford University, Stauffer III, 381 North-South Mall, Stanford, California 94305, USA.
authors: Pamela M
authors: PM
authors: Lundin
authors: Department of Chemistry, The James Franck Institute, Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois 60637, USA.
authors: Brian S
authors: BS
authors: Rolczynski
authors: Department of Chemistry, The James Franck Institute, Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois 60637, USA.
authors: Alexander
authors: A
authors: Linkin
authors: Department of Chemistry, The James Franck Institute, Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois 60637, USA.
authors: Ryan D
authors: RD
authors: McGillicuddy
authors: Department of Chemical Engineering, Stanford University, Stauffer III, 381 North-South Mall, Stanford, California 94305, USA.
authors: Zhenan
authors: Z
authors: Bao
authors: Department of Chemistry, The James Franck Institute, Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois 60637, USA.
authors: Gregory S
authors: GS
authors: Engel
mesh_terms: D001555:Benzene Derivatives / Q000737:chemistry; D050091:Dendrimers / Q000737:chemistry*; D004735:Energy Transfer; D008027:Light; D008958:Models, Molecular; D011108:Polymers / Q000737:chemistry*; D013053:Spectrophotometry; D013876:Thiophenes / Q000737:chemistry*
chemical_list: D001555:Benzene Derivatives; D050091:Dendrimers; D011108:Polymers; D013876:Thiophenes