Photoinduced Electron Transfer in Langmuir−Blodgett Monolayers of Double-Linked Phthalocyanine−Fullerene Dyads

Abstract

Photoinduced electron transfer (ET) in films of the double-linked free-base phthalocyanine-fullerene dyads (Pc-C 60 ) was studied in solid Langmuir-Blodgett (LB) films using femtosecond pump-probe and microsecond flash-photolysis methods. Excitation of the phthalocyanine (Pc) moiety of the dyad results in a rapid (0.8 ps) intramolecular ET from phthalocyanine to fullerene. The formed charge separated (CS) state relaxes in 35 ps, yielding an intermolecular CS state, which relaxes to the ground state in the microsecond time domain. The surface organization of the Pc-C 60 dyad monolayers was studied by atomic force microscopy for both pure Pc-C 60 films and Pc-C 60 mixed films with matrix molecules, octadecylamine (ODA). This study together with the estimations done based on surface pressure-mean molecular area isotherms reveals that the dyads tend to aggregate rather than form a homogeneous mixture with the ODA molecules. This enforces intermolecular interactions and leads to the formation of a long-lived intermolecular CS state.

Photoinduced processes in chromophore–gold nanoparticle assemblies

“…The two shorter-living components have both features from GNPs and phthalocyanines, but an important new feature is a photoinduced absorption band around 840-1000 nm. This looks very similar to a phthalocyanine radical cation band observed in films of phthalocyanine-fullerene dyads [36].…”

Photophysical Study of a Self-Assembled Donor–Acceptor Two-Layer Film on TiO2

“…20,21 In some cases, a short, <100 fs, component was needed for the fitting. This component is at the limit of the instrument's time resolution and most probably originates from imperfection in the dispersion compensation and estimation of the instrument response function.…”

Conjugated compounds in supramolecular informational systems: A review

“…Since then, molecular systems that exhibit bista bility-the ability to exist in two different electronic states and change their electronic state upon the effect of external actions-have attracted especial attention of researchers. The continuing interest in processes of reversible intramolecular electron transfer exists because these processes appear promising as a basis for develop ment of molecular sensors and nanosized devices for recording and storage of information [26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42].…”