title: Azafullerene C59N-phthalocyanine dyad: synthesis, characterisation and photoinduced electron transfer.
abstract: The synthesis of a new azafullerene C(59)N-phthalocyanine (Pc) dyad is described. The key step for the synthesis of the C(59)N-Pc dyad was the formation of the C(59)N-based carboxylic acid, which was smoothly condensed with hydroxy-modified Pc. The structure of the C(59)N-Pc dyad was verified by (1)H and (13)C NMR spectroscopy, IR spectroscopy, UV/Vis spectroscopy and MS measurements. The photophysical and electrochemical properties of the C(59)N-Pc dyad were investigated in both polar and non-polar solvents by steady state and time-resolved photoluminescence and absorption spectroscopy, as well as by cyclic voltammetry. Different relaxation pathways for the photoexcited C(59)N-Pc dyad, as a result of changing the solvent polarity, were found, thus giving rise to energy-transfer phenomena in non-polar toluene and charge-transfer processes in polar benzonitrile. Finally, the detailed quenching mechanisms were evaluated and compared with that of a C(60)-Pc dyad, which revealed that the different excited-state energies and reduction potentials of the two fullerene spheres (i.e. C(59)N vs. C(60)) strongly diverged in the deactivation pathways of the excited states of the corresponding phthalocyanine dyads.
authors.affiliation: Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, 48 Vassileos Constantinou Avenue, 11635 Athens, Greece. tagmatar@eie.gr
authors.forename: Georgios
authors.initials: G
authors.lastname: Rotas
authors.forename: Jenni
authors.initials: J
authors.lastname: Ranta
authors.forename: Alexander
authors.initials: A
authors.lastname: Efimov
authors.forename: Marja
authors.initials: M
authors.lastname: Niemi
authors.forename: Helge
authors.initials: H
authors.lastname: Lemmetyinen
authors.forename: Nikolai
authors.initials: N
authors.lastname: Tkachenko
authors.forename: Nikos
authors.initials: N
authors.lastname: Tagmatarchis