Long Range Electron Transfer Quenching in Polyamine Chains Bearing a Terminal N...

• Author(s): Pina, Fernando ; Lima, J. C. ; Lodeiro, Carlos ; Melo, J. Seixas de ; Díaz, Pilar ; Teresa Albelda, M. ; García-España, Enrique
• Date: 2002
• Persistent ID: http://hdl.handle.net/10316/10413
• Origin: Estudo Geral - Universidade de Coimbra
• Document Type: Article
• Language: English

Description

The fluorescence emission of a naphthalene unit attached to a polyamine chain is quenched by intramolecular electron transfer from the deprotonated amines to the excited fluorophore. Measurements of the respective quenching rate constants as a function of the distance, reveal an exponential dependence with β = 0.45 Å-1. Identical measurements carried out in deuterated water have shown a similar dependence with the distance β = 0.49 Å-1 but an average reduction of the absolute values of the rate constants of ca. 1.2. The polyamine chains seem to constitute a bridge through which the electron can find a route to its movement, more efficiently than through space. http://dx.doi.org/10.1021/jp025848j