Acceleration and deceleration of photoinduced electron transfer rates by an electric field in porphyrin-fullerene dyads

External Electric Field Effects on Emission of a Mixture of Tetraphenylporphyrin and Fullerene Doped in a Polymer Film

“…Exciplex formation following the intermolecular electron transfer from TPP* to C 60 is not considered in the present scheme since exciplex fluorescence was not observed in porphyrin and fullurene dyads where intramolecular photoinduced electron transfer occur. 21 As will be mentioned later, however, the [TPP-C 60 ]* state may be regarded as having a partial charge-separated character. E-F spectra as well as fluorescence spectra of the mixtures of TPP and C 60 were measured with a field strength of 1.0 MVcm -1 .…”

“…Similar electric field effects were observed for porphyrin and fullurene dyads where intramolecular photoinduced electron transfer occurs from the excited state of porphyrin to fullerene, and it was suggested that intramolecular electron transfer rate is decelerated and accelerated for the process from zinc porphyrin to fullurene and for the process from free-base porphyrin to fullurene, respectively. 21 The opposite behavior of the electric field effects on fluorescence between zinc and free-base compounds was attributed to the difference of the potential barrier for electron transfer between the excited state of porphyrin and C 60 . It was suggested that photoinduced electron transfer in zinc porphyrin-fullurene dyads occurs in the "barrierless regime", where the magnitude of the freeenergy gap for reaction is very close to the reorganization energy, while the barrier height is considerably large in linked compounds of free-base porphyrin and C 60 .…”

Electric Field Effects on Photoluminescence of CdSe Nanoparticles in a PMMA Film

“…E-PL spectra and E-A spectra were measured by the same system and procedures as reported elsewhere [13][14][15][16][17][18][19][20][21][22]. PMMA (MW = 120,000) was obtained from Aldrich and purified by a precipitation with a mixture of benzene and methanol.…”

“…We measured the so-called electroabsorption and electrophotoluminescence spectra (plots of the electric-field-induced change in absorption and PL intensity as a function of wavelength or wavenumber) to investigate molecular properties including intramolecular and intermolecular electron transfer [13][14][15], excimer formation [16], photoisomerization [17], and electrostatic interaction in protein [18]. Measurements of these spectra provide unique information about the differences in electric dipole moment (μ) and molecular polarizability (α) between the ground state and excited states.…”

Electric-field effects on photoinduced dynamics and function

“…As the well-ordered samples, Langmuir-Blodgett (LB) films were used to prepare such a molecular system [11,12]. As the randomly distributed samples, pairs of pyrene and dimethylaniline, carbazole and dimethyl-terephthalate, phenanthrene and phthalimide, pyrene and N-methylphthalimide, phenanthrene and N,N-dimethylaniline, porphyrin and C 60 were taken, and electric-field effects on PIET have been examined in poly(methyl methacrylate) (PMMA) [13][14][15][16][17][18][19][20][21].…”