Unsurpassed cage effect for the photolysis of dibenzyl ketones in water-soluble dendrimers |
| |
Authors: | Yuan Zhao Chen Jinping Zeng Yi Li Ying-Ying Han Yongbin Li Yi |
| |
Institution: | Key Laboratory of Photochemical Conversion and Optoelectronic Materials,Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, P R China. |
| |
Abstract: | Amphiphilic water-soluble poly(alkyl aryl ether) dendrimers Gn (n = 1-3) with charge-neutral tetraethylene glycol monomethyl ethers at their periphery were synthesized as microreactors to control the photochemical reactions of dibenzyl ketone derivatives in aqueous solutions. Photophysical studies demonstrated that Gn can encapsulate organic molecules and provide a hydrophobic microenvironment. The product distribution of photolysis of dibenzyl ketone derivatives can be successfully controlled by encapsulating the substrates within dendrimers, and an unsurpassed cage effect of 1.00 is reached in high generation dendrimers, revealing that a thick and compact "shell" was formed at the periphery of the dendrimers. The cage effect is also significantly influenced by the substituent at the para-position of the guest molecules. The higher generation dendrimers exhibit a better confined microenvironment and the aggregates possess more compact cavities to "lock" the guests than the corresponding unimolecular dendrimers. After photolysis, the separation of products can be easily achieved by extracting from the dendrimer solutions and the dendrimers are simply recovered and reused. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |
|