Redox-active star molecules incorporating the 4-benzoylpyridinium cation: implications for the charge transfer efficiency along branches vs across the perimeter in dendrimers.
We report the 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 only two of the three redox-active centers in the perimeter are electrochemically accessible during potential sweeps as slow as 20 mV s-1 and as fast as 10 V s-1. 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.
Leventis
Nicholas
N
NASA Glenn Research Center, 21000 Brookpark Road M.S. 49-1, Cleveland, Ohio, USA. Nicholas.Leventis@nasa.gov
Yang
Jinhua
J
Fabrizio
Eve F
EF
Rawashdeh
Abdel-Monem M
AM
Oh
Woon Su
WS
Sotiriou-Leventis
Chariklia
C