title: Pyrazolino[60]fullerene-oligophenylenevinylene dumbbell-shaped arrays: synthesis, electrochemistry, photophysics, and self-assembly on surfaces.
abstract: Symmetrically substituted oligophenylenevinylene (OPV) derivatives bearing terminal p-nitrophenylhydrazone groups have been prepared and used for the synthesis of dumbbell-shaped bis(pyrazolino[60]fullerene)-OPV systems. In these triad arrays, the OPV-type fluorescence is dramatically quenched as a consequence of ultrafast OPV-->C60 singlet energy transfer. In its turn the fullerene singlet state is quenched by pyrazoline-->C60 electron transfer, in line with the behavior of the corresponding reference fullerene molecule. The occurrence of electron transfer in the multicomponent arrays is evidenced by recovery of fullerene fluorescence at 77 K in CH2Cl2 and in toluene at 298 K. Under these conditions the OPV-->C60 energy transfer is unaffected. The rate of this process turns out to be higher for the OPV trimer than for the corresponding pentameric OPV arrays, in agreement with energy-transfer theory expectations. Scanning tunneling microscopy (STM) and scanning force microscopy (SFM) revealed that the bis(pyrazolino[60]fullerene)-OPV can self-assemble into ordered layered crystalline architectures on the basal plane of highly oriented pyrolitic graphite.
authors.affiliation: Facultad de Ciencias del Medio Ambiente, Universidad de Castilla-La Mancha, 45071 Toledo, Spain. fernando.lpuente@uclm.es
authors.forename: Fernando
authors.initials: F
authors.lastname: Langa
authors.forename: Maria J
authors.initials: MJ
authors.lastname: Gomez-Escalonilla
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Rueff
authors.forename: Teresa M
authors.initials: TM
authors.lastname: Figueira Duarte
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Nierengarten
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Palermo
authors.forename: Paolo
authors.initials: P
authors.lastname: Samorì
authors.forename: Yannick
authors.initials: Y
authors.lastname: Rio
authors.forename: Gianluca
authors.initials: G
authors.lastname: Accorsi
authors.forename: Nicola
authors.initials: N
authors.lastname: Armaroli