title: Electron transfer in nonpolar solvents in fullerodendrimers with peripheral ferrocene units.
abstract: Two new fullerodendrimers, with two and four ferrocene units on their periphery, have been synthesized by 1,3-dipolar cycloaddition reactions between the corresponding azomethine ylides and C(60). These new compounds have been studied by using cyclic voltammetry and UV/Vis spectroscopy. Weak intramolecular interactions between the fullerene cage and the ferrocene groups have been found. The photochemical events of both fullerene-ferrocene dendrimers have been probed by means of steady-state and time-resolved techniques. The steady-state emission intensities of the fulleropyrrolidine-ferrocene dendrimers 1 and 2 were found to be quenched relative to the N-methylfulleropyrrolidine without substituents that was used as a model. The nanosecond transient absorption spectral studies revealed efficient charge separation in both systems, even in toluene. The lifetimes of the (C(60))(*-)-(dendron)(*+) are higher for the second-generation fullerodendrimer (with four ferrocene units) and they are of the order of tens of nanoseconds in toluene and hundreds of nanoseconds in polar solvents.
authors.affiliation: Facultad de Ciencias del Medio Ambiente, Universidad de Castilla-La Mancha, 45071 Toledo, Spain.
authors.forename: Laura
authors.initials: L
authors.lastname: Pérez
authors.forename: Joaquín C
authors.initials: JC
authors.lastname: García-Martínez
authors.forename: Enrique
authors.initials: E
authors.lastname: Díez-Barra
authors.forename: Pedro
authors.initials: P
authors.lastname: Atienzar
authors.forename: Hermenegildo
authors.initials: H
authors.lastname: García
authors.forename: Julián
authors.initials: J
authors.lastname: Rodríguez-López
authors.forename: Fernando
authors.initials: F
authors.lastname: Langa
mesh_terms: D003500:Cyclization; D004563:Electrochemistry; D005296:Ferrous Compounds / Q000737:chemistry*; D037741:Fullerenes / Q000737:chemistry*; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D000075163:Metallocenes; D012997:Solvents; D013050:Spectrometry, Fluorescence; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet; D013816:Thermodynamics
chemical_list: D005296:Ferrous Compounds; D037741:Fullerenes; D007202:Indicators and Reagents; D000075163:Metallocenes; D012997:Solvents; C004998:ferrocene