Aggregation of 3,4,9,10-Perylenediimide Radical Anions and Dianions Generated by Reduction with Dithionite in Aqueous Solutions
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- 作者：Rodrigo O. Marcon† ; ; Sergio Brochsztain*‡ ;
- 刊名：Journal of Physical Chemistry A
- 出版年：2009
- 出版时间：March 5, 2009
- 年：2009
- 卷：113
- 期：9
- 页码：1747-1752
- 全文大小：337K
- 年卷期：v.113,no.9(March 5, 2009)
- ISSN：1520-5215
文摘
Aqueous solutions of N,N′-bis(2-phosphonoethyl)-3,4,9,10-perylenediimide (PPDI) were titrated with sodium dithionite, generating radical anions (PPDI−•) and dianions (PPDI2−). In aqueous ethanol (1:1 v/v), PPDI existed as monomers and remained in the monomeric form in all reduced states. In water, on the other hand, PPDI formed dimers, which were transformed into a π-stacked aggregated form upon one-electron reduction to PPDI−•. Addition of a second electron, however, resulted in dissociation of the aggregates, giving the dianion PPDI2− in the monomeric form. The presence of CTAB micelles prevented the aggregation of PPDI−• in water, indicating that the radical anions were incorporated into the micellar phase. Reduction of PPDI in ethanol solution, where the dye was aggregated, resulted in the formation of soluble mixed stacks containing both PPDI−• and PPDI2−. These mixed stacks stabilized the radical anion form, preventing further reduction to the dianion.