Two features of meso‐Aryl‐substituted expanded porphyrins suggest suitability as theranostic agents. They have excellent absorption in near infrared (NIR) region, and they offer the possibility of introduction of multiple fluorine atoms at structurally equivalent positions. Here, hexaphyrin (hexa) was synthesized from 2,6‐bis(trifluoromethyl)‐4‐formyl benzoate and pyrrole and evaluated as a novel expanded porphyrin with the above features. Under NIR illumination hexa showed intense photothermal and weak photodynamic effects, which were most likely due to its low excited states, close to singlet oxygen. The sustained photothermal effect caused ablation of cancer cells more effectively than the photodynamic effect of indocyanine green (a clinical dye). In addition, hexa showed potential for use in the visualization of tumors by 19F magnetic resonance imaging (MRI), because of the multiple fluorine atoms. Our results strongly support the utility of expanded porphyrins as theranostic agents in both photothermal therapy and 19F MRI. 相似文献
Continuous flow reactors are enabling tools that can significantly benefit chemical reactions, especially those that are path length dependent (e.g., photochemical), mixing or transport dependent (e.g., gas-liquid), exothermic, or utilize hazardous or unstable intermediates. In this review, it is demonstrated how the nearly instantaneous mixing, exceptionally fast mass transfer, safe access to high temperatures and pressures, and high surface area to volume ratio can be leveraged to improve product yield, reaction rates and/or selectivity. By showcasing five synthetic methodologies examined by our group, it is hoped that the reader will gain an appreciation of the accessible and transformative nature of flow chemistry for improving existing transformations, enabling rapid optimization, and for developing new methodologies that depend on precise parameter controls. 相似文献
Hydrogenation/oxidation processes are regarded as the most widely used catalytic reactions in modern chemical development. However, the traditional reaction process always requires harsh reaction conditions (such as high temperature, high pressure, a lot of hydrogen/oxygen consumption, etc), the high cost, overconsumption of energy and low selectivity is always limiting its further development. Therefore, conducting the hydrogenation/oxidation reaction efficiently under mild conditions is one of the greatest challenges in this field. Photoelectrocatalysis has been widely studied due to its wide, clean and sustainable energy sources, which combines the advantages of both photocatalysis and electrocatalysis. Moreover, the process of generating H2/O2 by photoelectrocatalytic water splitting involves the production of highly reactive intermediate species (active hydrogen *H and active oxygen *O) which can be used by directly coupling the hydrogenation/oxidation catalytic processes, and the efficiency of coupled reaction will be greatly improved. The review here summarizes the research progress of photoelectrocatalysis from three aspects: active species of intermediate products produced by photoelectrochemical water splitting, hydrogenation/oxidation reaction of the traditional chemical industry, and coupling photoelectrochemical water splitting with hydrogenation/oxidation process using layered double hydroxides (LDHs)-based nanomaterials. It is expected to provide ideas for the high selectivity and low cost preparation of high value-added organic chemicals. 相似文献
The photochemically induced grafting polymerization of various alkyl acrylates onto cross‐linked poly(hydroxyethyl methacrylate) (PHEMA) was performed to reduce the hydrophilicity of the swellable network. Butyl, 2‐ethylhexyl and lauryl acrylate were used as monofunctional monomers for increasing the hydrophobic character, whereas hexanediol diacrylate was used as a multifunctional monomer with the additional feature of forming networks. The various steps of the grafting procedure were examined sequentially so as to optimize the overall hydrophobing effect. The grafting yield was shown to depend primarily of PHEMA swelling in the considered ethanol/monomer mixture. In spite of their high specific hydrophobic character, alkyl monoacrylates were shown to be less efficient because of lower grafting yield. Grafting initiation by hydrogen abstraction with benzophenone or by homolytic cleavage of a hydroxyalkyl‐phenone resulted in comparable grafting yields even with monofunctional monomers. The hardness measured for the water swollen rubbery materials correlated well to the equilibrium water content.
Shore A hardness as a function of the swelling ratio in water at T = 22 °C for grafted and ungrafted PHEMA hydrogels (same samples as those described in Table 5 ). 相似文献