Prakash Rao H Surya, Kamalraj M, Prabakaran M
Department of Chemistry, Pondicherry University Pondicherry India
Sharda University Knowledge Park III Greater Noida Uttar Pradesh India 201306.
RSC Adv. 2019 Feb 5;9(8):4499-4506. doi: 10.1039/c8ra09998g. eCollection 2019 Jan 30.
Although a large number of natural and non-natural metalloporphyrins are known, examples with fluorescence and fat-soluble properties are rare. We have achieved the synthesis of a fluorescent and fat-soluble zinc porphyrin incorporating four units of hydrogenated cardanol (H-cardanol). The synthesis is sustainable since the product is derived from cashew-nut shell liquid (CNSL), which is a renewable and bio-waste material. The H-cardanol triazole zinc porphyrin conjugate (HTZPC) was synthesized through applying a copper(i) catalyzed azide-alkyne cycloaddition (CuAAC) reaction between a H-cardanol derived azide and a tetraarylporphyrin derived alkyne. The absorption and emission properties of the hydrocarbon solvent soluble HTZPC were evaluated using UV-vis and fluorescence emission spectra obtained in various solvents. The results were compared with related molecules like a triazole-zinc porphyrin conjugate (TZPC), zinc tetra-C(4)-methoxyphenyl porphyrin (ZP), and a H-cardanol-triazole conjugate (HTC). The results showed that HTZPC undergoes J-type aggregation in both non-polar and highly polar solvents, which is dictated by van der Waals attractive forces between H-cardanol units in polar solvents ( methanol and dimethylformamide) and π-π stacking interactions between porphyrin units in non-polar solvents (hexane). Moreover, the spectra indicated that the triazole units could stabilize the zinc porphyrin intermolecular coordinate-complex formation. We anticipate that fat-soluble HTZPC could find applications in medical fields ( in the photodynamic therapy of fat tissue).
虽然已知大量天然和非天然金属卟啉，但具有荧光和脂溶性的例子却很少见。我们已经合成了一种包含四个氢化腰果酚（H-腰果酚）单元的荧光脂溶性锌卟啉。该合成方法具有可持续性，因为产物源自腰果壳液（CNSL），这是一种可再生的生物废料。通过在H-腰果酚衍生的叠氮化物和四芳基卟啉衍生的炔烃之间应用铜（I）催化的叠氮化物-炔烃环加成（CuAAC）反应，合成了H-腰果酚三唑锌卟啉共轭物（HTZPC）。使用在各种溶剂中获得的紫外可见光谱和荧光发射光谱，对可溶于烃类溶剂的HTZPC的吸收和发射特性进行了评估。将结果与相关分子进行了比较，如三唑-锌卟啉共轭物（TZPC）、四-C（4）-甲氧基苯基锌卟啉（ZP）和H-腰果酚-三唑共轭物（HTC）。结果表明，HTZPC在非极性和高极性溶剂中均会发生J型聚集，这是由极性溶剂（甲醇和二甲基甲酰胺）中H-腰果酚单元之间的范德华吸引力以及非极性溶剂（己烷）中卟啉单元之间的π-π堆积相互作用所决定的。此外，光谱表明三唑单元可以稳定锌卟啉分子间配位络合物的形成。我们预计脂溶性HTZPC可在医学领域（脂肪组织的光动力疗法）找到应用。
