C O M M U N I C A T I O N S
mophoric pairs in the self-assembled dimer provides a useful
comparison to electron transport within more extended organic
molecular materials, including other systems that self-assemble in
solution.28 Our results contrast with the full delocalization (bandlike
charge transport) found recently in highly crystalline molecular
materials.1,29 The alternative localized hopping mechanisms that
describe charge transport within some PDI-based materials are likely
more closely related to the results found here.1,30
Acknowledgment. This work was supported by the Division
of Chemical Sciences, Office of Basic Energy Sciences, U.S.
Department of Energy under Grant No. DE-FG02-99ER14999. We
thank Dr. David Tiede at the Argonne National Laboratory for
assistance with SAXS experiments. M.J.T. acknowledges the donors
of the American Chemical Society Petroleum Research Fund for
partial support of this research. The Bruker E-580 spectrometer
was purchased with partial support from NSF Grant No. CHE-
0131048.
Supporting Information Available: Synthesis and characterization
of 1, 4, and 5. Spectroscopic, SAXS, and GPC data as well as DFT
calculations. This material is available free of charge via the Internet
Figure 2. Proton ENDOR spectra in CH2Cl2-3% TEA solution of: (a)
•-
1•-, (b) 2•-, (c) 3•- at 290 K, and (d) self-assembled (4)2 at 297 K.
Microwave powers were 4-20 mW, RF power 300-800 W, with frequency
modulation depth 50 or 100 kHz.
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•-
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The ENDOR data clearly show that rapid electron hopping occurs
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observation of a >107 Hz electron hopping rate between chro-
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