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Redox-Active Star Molecules Incorporating the 4-Benzoylpyridinium Cation - Implications for the Charge Transfer Along Branches vs. Across the Perimeter in DendrimerDendrimers are self-repeating globular branched star molecules, whose fractal structure continues to fascinate, challenge, and inspire. Functional dendrimers may incorporate redox centers, and potential applications include antennae molecules for light harvesting, sensors, mediators, and artificial biomolecules. We report the synthesis and redox properties of four star systems incorporating the 4-benzoyl-N-alkylpyridinium cation; the redox potential varies along the branches but remains constant at fixed radii. Bulk electrolysis shows that at a semi-infinite time scale all redox centers are electrochemically accessible. However, voltammetric analysis (cyclic voltammetry and differential pulse voltammetry) shows that on1y two of the three redox-active centers in the perimeter are electrochemically accessible during potential sweeps as slow as 20 mV/s and as fast as 10 V/s. On the contrary, both redox centers along branches are accessible electrochemically within the same time frame. These results are explained in terms of slow through-space charge transfer and the globular 3-D folding of the molecules and are discussed in terms of their implications on the design of efficient redox functional dendrimers.
Document ID
20070038173
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Leventis, Nicholas
Yang, Jinua
Fabrizio,Even F.
Rawashdeh, Abdel-Monem M.
Oh, Woon Su
Sotiriou-Leventis, Chariklia
Date Acquired
August 24, 2013
Publication Date
January 1, 2004
Publication Information
Publication: Journal of American Chemical Society
Volume: 126
Issue: 13
Subject Category
Inorganic, Organic and Physical Chemistry
Funding Number(s)
CONTRACT_GRANT: NCC3-1064
CONTRACT_GRANT: NNC3-1064
Distribution Limits
Public
Copyright
Other