Synthesis, photophysical and thermal studies of symmetrical and unsymmetrical zinc phthalocyanines

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• 作者：Ahmet Lü ; tfi U?ur^a ; ^{alugur3@hotmail.com} ; Hatice A. Dinç ; er^b ; ^{dincerhat@itu.edu.tr} ; Ali Erdo?mu?^a
• 关键词：Unsymmetrical substituted phthalocyanine ; Symmetrically substituted phthalocyanine ; Aggregation ; Fluorescence ; Photophysics ; Thermal properties
• 刊名：Polyhedron
• 出版年：2012
• 出版时间：4 January, 2012
• 年：2012
• 卷：31
• 期：1
• 页码：431-437
• 全文大小：533 K

文摘

The novel zinc phthalocyanine (rong class=""boldFont"">3rong>) with malonylester and chloro groups on each benzo unit was synthesized from 4-diethoxymalonyl-5-chloro-phthalonitrile (rong class=""boldFont"">1rong>). The unsymmetrically substituted zinc phthalocyanine (rong class=""boldFont"">5rong>), carrying hexylthio, malonylester and chloro groups at the periphery, was obtained from 4-diethoxymalonyl-5-chloro-phthalonitrile (rong class=""boldFont"">1rong>) and 4,5-bis-hexylsulfanyl-phthalonitrile (rong class=""boldFont"">2rong>) by a statistical condensation method as an A₃B type unsymmetrical phthalocyanine compound. Transesterification of the malonyl esters of the new symmetrical and unsymmetrical phthalocyanines occurred during the cyclotetramerization of dinitriles with Zn(CH₃COO)₂ in 1-pentanol in the presence of DBU. Octa-hexylthio-substituted zinc phthalocyanine (rong class=""boldFont"">4rong>) was prepared according to the literature. The photophysical and thermal properties of all the phthalocyanine complexes are described for the first time. These novel symmetrical and unsymmetrical phthalocyanine macrocycles have been characterized by a series of spectroscopic methods including ¹H NMR, electronic absorption, IR and mass spectroscopy, in addition to elemental analysis. Their narrow long wavelength absorption band shows that the bulky substituents on the periphery prevent aggregation. The unsymmetrically substituted phthalocyanine (rong class=""boldFont"">5rong>) gave a greater fluorescence quantum yield in chloroform than the symmetrical analogues (rong class=""boldFont"">3rong> and rong class=""boldFont"">4rong>).