Identification and assignment of porphyrin–CdSe hetero-nanoassemblies

Hetero-nanoassemblies in toluene solution are formed via anchoring pyridyl substituted free base porphyrin molecules on the colloidal core-shell semiconductor nanocrystals CdSe/ZnS. The formation can be identified via quenching of semiconductor photoluminescence and followed via spectral changes of porphyrin spectral properties such as fluorescence, fluorescence decay and absorption. Interpreting these changes we estimate that even at high molar ratios on average only one molecule is anchored on one nanocrystal. Experimentally determined complexation constants are comparable to those observed for multi-porphyrin complexes.