The 6,6-dicyanopentafulvene core: a template for the design of electron-acceptor compounds.
The electron-accepting ability of 6,6-dicyanopentafulvenes (DCFs) can be varied extensively through substitution on the five-membered ring. The reduction potentials for a set of 2,3,4,5-tetraphenyl-substituted DCFs, with varying substituents at the para-position of the phenyl rings, strongly correlate with their Hammett σp-parameters. By combining cyclic voltammetry with DFT calculations ((U)B3LYP/6-311+G(d)), using the conductor-like polarizable continuum model (CPCM) for implicit solvation, the absolute reduction potentials of a set of twenty DCFs were reproduced with a mean absolute deviation of 0.10 eV and a maximum deviation of 0.19 eV. Our experimentally investigated DCFs have reduction potentials within 3.67-4.41 eV, however, the computations reveal that DCFs with experimental reduction potentials as high as 5.3 eV could be achieved, higher than that of F4-TCNQ (5.02 eV). Thus, the DCF core is a template that allows variation in the reduction potentials by about 1.6 eV.
Laboratorium für Organische Chemie, ETH Zurich, Vladimir-Prelog-Weg 3, 8093 Zurich (Switzerland), Fax: (+41) 44-632-1109.
Aaron D
AD
Finke
Department of Chemistry, BMC, Uppsala University, Box 576, 751 23 Uppsala (Sweden), Fax: (+46) 18-471-3818.
Burkhard O
BO
Jahn
Department of Chemistry, BMC, Uppsala University, Box 576, 751 23 Uppsala (Sweden), Fax: (+46) 18-471-3818.
Anas
A
Saithalavi
Department of Chemistry, BMC, Uppsala University, Box 576, 751 23 Uppsala (Sweden), Fax: (+46) 18-471-3818.
Christian
C
Dahlstrand
Department of Chemistry, Ångström Laboratory, Uppsala University, Box 523, 751 20 Uppsala (Sweden).
Djawed
D
Nauroozi
Laboratorium für Organische Chemie, ETH Zurich, Vladimir-Prelog-Weg 3, 8093 Zurich (Switzerland), Fax: (+41) 44-632-1109.
Sophie
S
Haberland
Laboratoire d'Electrochemie et de Chimie Physique du Corps Solide, Institut de Chimie, UMR 7177, CNRS, Université de Strasbourg, 4 rue Blaise Pascal, 67081 Strasbourg Cedex (France).
Jean-Paul
JP
Gisselbrecht
Laboratoire d'Electrochemie et de Chimie Physique du Corps Solide, Institut de Chimie, UMR 7177, CNRS, Université de Strasbourg, 4 rue Blaise Pascal, 67081 Strasbourg Cedex (France).
Corinne
C
Boudon
Department of Chemistry, Ångström Laboratory, Uppsala University, Box 523, 751 20 Uppsala (Sweden).
Edgar
E
Mijangos
Laboratorium für Organische Chemie, ETH Zurich, Vladimir-Prelog-Weg 3, 8093 Zurich (Switzerland), Fax: (+41) 44-632-1109.
W Bernd
WB
Schweizer
Department of Chemistry, Ångström Laboratory, Uppsala University, Box 523, 751 20 Uppsala (Sweden).
Sascha
S
Ott
Department of Chemistry, BMC, Uppsala University, Box 576, 751 23 Uppsala (Sweden), Fax: (+46) 18-471-3818. henrik.ottosson@kemi.uu.se.
Henrik
H
Ottosson
Laboratorium für Organische Chemie, ETH Zurich, Vladimir-Prelog-Weg 3, 8093 Zurich (Switzerland), Fax: (+41) 44-632-1109. diederich@org.chem.ethz.ch.
François
F
Diederich
computational chemistry; density functional calculations; electron acceptors; molecular materials; reduction potentials