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Fluorescent nanocomposite that consists of 3-aminopropyltriethoxysilane coated magnetic iron nanoparticles (MN), mercaptopropionic acid capped CdTe quantum dots (QD) and octacarboxy metallophthalocyanine (MOCPc) with either aluminium ((OH)AlOCPc) or zinc (ZnOCPc) as central metals have been prepared with (linked MOCPc-QD-MN) and without (mixed MOCPc-QD-MN) linking agents. The results presented give evidence of linkage within the components of the linked MOCPc-QD-MN. A red shift in the emission peak of QD within the linked nanocomposite compared to emission peak of QD alone was observed. Photoexcitation of both linked and mixed MOCPc-QD-MN at the excitation wavelength of the QD resulted in energy transfer from QD to the respective MOCPc while at the excitation wavelength of the MOCPc, a shift in emission peak of the linked MOCPc-QD-MN was observed resulting in large Stokes' shifts. The linked and mixed MOCPc-QD-MN were found to exhibit high triplet state quantum yields compared to the MOCPcs alone.

The photochemistry and photophysics of six axially substituted silicon phthalocyanines are reported and show the importance of the axial groups in the photochemistry of these compounds. The fluorescence quantum yields are especially affected by the axial ligand. A very good correlation was found for the experimentally determined fluorescence lifetimes and the theoretically determined lifetimes using the Strickler-Berg equation for the unaggregated molecules.

In the course of a fundamental study of photosensitizers for photodynamic therapy of cancer, a non-peripheral substituted phthalocyanine analogue, zinc bis(1,4-didecylbenzo)bis(3,4-pyrido)porphyrazine and its position isomers were examined to measure their photoexcited triplet state lifetimes in poly(methyl methacrylate) film using laser-flash photolysis. The isomer mixture of zinc bis(1,4-didecylbenzo)bis(3,4-pyrido)porphyrazine showed the most intense absorption in the 660-710 nm region, and the longer triplet state lifetime. The lowest symmetry isomer of zinc bis(1,4-didecylbenzo)bis(3,4-pyrido)porphyrazine was found to have the longest triplet state lifetime when all isomers were separated. The compound is proposed to be suitable for use as a photosensitizer for photodynamic therapy of cancer.

The synthesis of phosphorous phthalocyanines, triazatetrabenzcorroles, and tetrabenzotriazaporphyrins with a variety of axial ligands is reported. The new complexes are: phosphorous dihydroxy tetrabenzotriazaporphyrin (5, P^V(OH)₂TBTAP), diphenyl phosphorous phthalocyanine (6, [P^V(Ph)₂Pc](OH)), diphenyl phosphorous triazatetrabenzcorrole (7, P^V(Ph)₂TBC), and dioctyl phosphorous triazatetrabenzcorrole (8, P^V(C₈H₁₇)₂TBC). The complexes are not aggregated in dimethylsulfoxide (DMSO) and pyridine. Upon axial coordination of a phenyl or octyl group, the complexes are soluble (and not aggregated) in dichloromethane (DCM) and tetrahydrofuran (THF). The triplet lifetimes range from 395 to 546 μs (for complexes 5 to 8), with the P(Ph)₂TBC (7) complex showing the longest triplet lifetime (546 μs), while the smallest triplet quantum yield (Φ_T = 0.27) was obtained for the [P(Ph)₂Pc](OH) (6) complex. [P(OH)₂Pc](OH) (3) showed the shortest triplet lifetime (113 μs) and the largest triplet quantum yield (Φ_T = 0.52).

Phthalocyanine and their related compounds are utilized as various applications, such as photosensitizing agents for photodynamic therapy of cancer. In this study, zinc bis(thiodidecylbenzo)-bis(pyrido)porphyrazines, especially zinc bis(1,4-didecylthiobenzo)-bis(3,4-pyrido)porphyrazine and zinc bis(1,4-didecylthiobenzo)-bis(2,3-pyrido)porphyrazine were synthesized. Quaternation of the pyridine nitrogen in these provides an amphiphilic property. Photoexcited triplet lifetime of synthesized and quaternized zinc bis(1,4-didecylthiobenzo)-bis(3,4-pyrido)porphyrazine and zinc bis(1,4-didecylthiobenzo)-bis(2,3-pyrido)porphyrazine were reported using laser-flash photolysis and singlet oxygen quantum yields by the 1,3-diphenylisobenzofurne method.