Deactivation of excited states in nanostructures containing cu-porphyrin subunit

Abstract

Here, we present a semi-review of mutual Belarussian-German collaboration in the field of supramolecular chemistry and photophysics of tetrapyrrole compounds of various types: porphyrin chemical dimers, self-organized multiporphyrin complexes, ordered aggregates of photosynthetic pigments and nanoassemblies based on semiconductor CdSe/ZnS quantum dots and porphyrins. A special attention is paid to various nanostructures containing Cu-porphyrin subunits. Based on steady-state and time-resolved measurements, spectral properties as well as pathways and dynamics of non-radiative relaxation processes with participation of singlet and triplet excited states (energy transfer, photoinduced electron transfer, exchange d- p effects) are the subject of the analysis upon variation of the temperature (77-295 K) and polarity of the solvent. Finally, we consider recent results on “Quantum Dot-Porphyrin” nanoassemblies showing that self-assembly of only one Cu-porphyrin molecule with one CdSe/ZnS quantum dot modifies not only the photoluminescence intensity of quantum dot but creates new energetically clearly distinguishable electronic states opening additional effective relaxation pathways.