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Title: Ultrafast energy transfer from rigid, branched side-chains into a conjugated, alternating copolymer

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:
; ; ; ;  [1] ;  [2] ;  [3] ;  [2]
  1. Department of Chemistry, The James Franck Institute, Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois 60637 (United States)
  2. Department of Chemical Engineering, Stanford University, Stauffer III, 381 North-South Mall, Stanford, California 94305 (United States)
  3. (United States)
Publication Date:
OSTI Identifier:
22255253
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 140; Journal Issue: 3; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ABSORPTION SPECTROSCOPY; COPOLYMERS; DENSITY FUNCTIONAL METHOD; ENERGY TRANSFER; EXCITATION; EXCITED STATES; POLYCYCLIC SULFUR HETEROCYCLES; RESPONSE FUNCTIONS; SYNTHESIS; TETRAHYDROFURAN; THIOPHENE