title: Photophysical properties of CdSe quantum dot self-assemblies with zinc phthalocyanines and azaphthalocyanines.
abstract: The formation of self-assemblies between CdSe quantum dots (QDs) and Zn phthalocyanines (Pc) and azaphthalocyanines (AzaPc) bearing alkylsulfanyl substituents and the photophysical properties of these assemblies were studied using both steady-state and time-resolved luminescence/absorption spectroscopy. The formation of the self-assemblies was accompanied by a blue shift of the Q band of the dyes and by a quenching of the CdSe QDs luminescence. The largest spectral shift of the Q-band was approximately 7 nm and was observed for pentan-3-ylsulfanyl-functionalised phthalocyanine (). Assuming a 1 : 1 stoichiometry, the calculated binding constant was 4 × 10(4) M(-1). Pc substituted with the bulky tert-butylsulfanyl groups (1) exhibited a smaller shift of the Q band. The quenching of the CdSe QDs luminescence by 1 was more effective than that observed for 3. The results indicated that the luminescence quenching may be due to a photoinduced charge transfer between 1 or 3 and the CdSe QDs. In contrast, the AzaPc (2) with the same substituents as 1 had little effect on the QDs luminescence. For all cases, we found an inefficient resonance energy transfer between the attached dyes and the CdSe QD. The formation of the self-assemblies had negligible effects on the photogeneration of the singlet oxygen, O2((1)Δg), that was fully controlled only by the absorption of the light by the macrocycles.
authors: J. Heyrovský Institute of Physical Chemistry, v.v.i., Academy of Sciences of the Czech Republic, Dolejškova 3, 182 23 Praha 8, Czech Republic.
authors: Jan
authors: J
authors: Suchánek
authors: Kamil
authors: K
authors: Lang
authors: Veronika
authors: V
authors: Novakova
authors: Petr
authors: P
authors: Zimcik
authors: Zdeněk
authors: Z
authors: Zelinger
authors: Pavel
authors: P
authors: Kubát
mesh_terms: D019187:Cadmium Compounds / Q000737:chemistry*; D007211:Indoles / Q000737:chemistry*; D054833:Isoindoles; D009942:Organometallic Compounds / Q000737:chemistry*; D010316:Particle Size; D045663:Quantum Dots; D011789:Quantum Theory; D018036:Selenium Compounds / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D017967:Zinc Compounds
chemical_list: D019187:Cadmium Compounds; D007211:Indoles; D054833:Isoindoles; D009942:Organometallic Compounds; D018036:Selenium Compounds; D012997:Solvents; D017967:Zinc Compounds; C052159:Zn(II)-phthalocyanine; C058667:cadmium selenide; C013647:phthalocyanine