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Influence of water-controlled release process on the physical and chemical property of nanosize TiO <sub/>2</sub> particles
摘要： The water-controlled release process (WCRP) was utilized for the synthesis of TiO2 photocatalyst. The effect of alkylated esterified WCRP system on the morphology, specific surface area (SSA) and photocatalytic activity of TiO2 were studied systematically. By changing the structure of alcohol and acid involved in the esterification reaction, we found that the SSA and photocatalytic activity of TiO2 obtained in an ethanol/acetic acid reaction mixture showed the best results. Interestingly, the TiO2 obtained in t-butanol/acetic acid contains both the anatase and rutile phase, while the other systems only possessed anatase phases. The conditions of ethanol and acetic acid esterification were optimized and the experimental results showed that the SSA of nano-TiO2 was improved by shorting the reaction time or adding an organic solvent, which can form an azeotrope with water, but no effect on the photocatalytic activity could be observed. The reaction mechanism of esterified WCRP system was furthermore studied by NMR spectroscopy, showing three kinds of reaction, namely esterification, etherification and hydrolysis.
关键词： water-controlled release process(WCRP),p-toluenesulfonic acid,esterification,photocatalytic,titania
更新于2025-11-14 17:04:02
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Extended π-Conjugated Structures via Dehydrative C–C Coupling
摘要： We describe a methodology for the synthesis of extended aromatic structures through dehydrative C?C coupling from readily accessible diols. Treatment of the diols with a Br?nsted acid (para-toluenesulfonic acid) induces the nucleophilic addition of an arene or heteroarene, yielding fully aromatic products in high to quantitative yields with thiophenes, furan, indole, and N,N-dimethylaniline as coupling partners. The C?C coupling reactions proceed under mild, open flask conditions and offer high atom economy, while providing an attractive alternative approach to metal-catalyzed cross-coupling.
关键词： metal-catalyzed cross-coupling,extended aromatic structures,atom economy,para-toluenesulfonic acid,dehydrative C?C coupling,Br?nsted acid
更新于2025-09-04 15:30:14