title: Monomeric azaheterofullerene derivatives RC59N: influence of the R moiety on spectroscopic and photophysical properties.
abstract: We have synthesised nine monomeric azaheterofullerene (AZA) derivatives, RC(59)N, with a wide variety of different side chains R and investigated their spectroscopic and photophysical properties in toluene and o-dichlorobenzene (ODCB). Measurements include their ground-state absorption spectra, molar absorption coefficient (epsilon(G)), fluorescence spectra, fluorescence quantum yields (Phi(F)), singlet-state lifetimes (tau(F)), triplet-state absorption spectra, triplet molar absorption coefficients (epsilon(T)), singlet oxygen (Phi(Delta)), and triplet state (Phi(T)) quantum yields. The replacement of a carbon by a nitrogen atom in the C(60) sphere strongly affects most of the spectroscopic and photophysical properties. The chemical nature of the R moiety has definite effects on these properties in contrast with minor effects on the chemical nature of the addends in [6,6]-ring bridged monoadduct methano[60]fullerene derivatives. These effects concern properties of the ground state, singlet excited state, and triplet states of our nine RC(59)N derivatives and in particular the values of photophysical parameters epsilon(G), epsilon(T), Phi(Delta), and Phi(T), which are significantly lower than those of analogous monoadduct [6,6]-ring bridged methano[60]fullerene derivatives.
authors.affiliation: Institut für Organische Chemie der Universität Erlangen-Nürnberg, Henkestrasse 42, 91054 Erlangen, Germany.
authors.forename: Frank
authors.initials: F
authors.lastname: Hauke
authors.forename: Otto
authors.initials: O
authors.lastname: Vostrowsky
authors.forename: Andreas
authors.initials: A
authors.lastname: Hirsch
authors.forename: Annamaria
authors.initials: A
authors.lastname: Quaranta
authors.forename: Winfried
authors.initials: W
authors.lastname: Leibl
authors.forename: Sydney
authors.initials: S
authors.lastname: Leach
authors.forename: Ruth
authors.initials: R
authors.lastname: Edge
authors.forename: Suppiah
authors.initials: S
authors.lastname: Navaratnam
authors.forename: René V
authors.initials: RV
authors.lastname: Bensasson
mesh_terms: D002722:Chlorobenzenes / Q000737:chemistry; D037741:Fullerenes / Q000737:chemistry*; D010777:Photochemistry; D026082:Singlet Oxygen / Q000737:chemistry; D013057:Spectrum Analysis; D014050:Toluene / Q000737:chemistry
chemical_list: D002722:Chlorobenzenes; D037741:Fullerenes; D026082:Singlet Oxygen; D014050:Toluene; C004726:2-dichlorobenzene