Intramolecular (electron) delocalization between aromatic donors and their tethered cation–radicals. Application of electrochemical and structural probes†
Sun, Duoli; Lindeman, Sergey V.; Rathore, Rajendra; Kochi, Jay K.; Sun Duoli; Department of Chemistry, University of Houston; Lindeman Sergey V.; Department of Chemistry, University of Houston; Rathore Rajendra; Department of Chemistry, University of Houston; Kochi Jay K.; Department of Chemistry, University of Houston
Журнал:
Journal of the Chemical Society, Perkin Transactions 2
Дата:
2001
Аннотация:
To study the mechanism of electronic transduction along (poly)phenylene chains, a series of aromatic donors with general formula Dâ Bâ D has been synthesized [where Dâ =â 2,5-dimethoxy-4-methylphenyl donor and Bâ =â (poly)phenylene bridge]; and the corresponding cationâ radical salts Dâ Bâ D<sup>+</sup>.rad; SbCl6<sup>â </sup> have been isolated for X-ray crystallographic analyses. The magnitude of the electronic interaction between the D and D<sup>+</sup>.rad; moieties through the various B bridges has been measured (i) as the difference between the first and the second oxidation potentials of Dâ Bâ D donors and (ii) as the structural changes induced in neutral D by the presence of the tethered D<sup>+</sup>.rad; group in Dâ Bâ D<sup>+</sup>.rad; cationâ radicals. The intramolecular interaction of D and D<sup>+</sup>.rad; groups was found to occur via Ï -conjugation of the bridging (poly)phenylene group. As such, the electronic interaction is highly dependent on the planarity of the (poly)phenylene bridge, and can be either inhibited or promoted by the deliberate modifications of the molecular conformation. Crystal structures of compounds A, B, B<sup>+</sup>.rad;<sup>+</sup>.rad;, 1, 1<sup>+</sup>.rad;, 2, 2<sup>+</sup>.rad;, 3<sup>+</sup>.rad;, 8 and 9<sup>+</sup>.rad; are reported.
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