Studies On Copper Salt Catalyted Phenol Chlorination And8-hydroxyquinoline Iron Catalyze Selective Oxidation Of Cyclohexane

In order to avoid the environment pollution during oxidation process, some environmental-friendly oxidants, such as molecular oxygen, and hydrogen peroxide were used to replace the traditional use of stoichiometric oxidants. This represents the key technology to realize the environmental-friendly. In this thesis, the visible light-triggered copper salt to catalyze oxo-chlorination of phenol by molecular oxygen and the8-hydroxyquinoline iron complexes-catalyzed selective oxidation of cyclohexane with H2O2were investigated, the results are as follows:(1) By use of a self-assembly photo-reactor, the copper salts-catalyzed oxo-chlorination of phenol with LiCl was performed under visible light irradiation and O2atmosphere. The effects of various copper salts and solvents, as well as reaction temperature and time on this photo-oxochlorination were cheked in details. Results showed that:this visible light-driven oxo-chlorination in acetonitrile could occur using Cu(OAc)2and especially CuCl2as a catalyst. Notably, a suitable amount of acetic acid could significantly promote this oxo-chlorination photo-catalyzed by Cu(OAc)2, which achieved31.8%phenol conversion with82.7%p-chlorophenol selectivity under the optimized reaction conditions. The development of this photocatalytic system has the advantages of cheap catalyst, mild reaction conditions, simple operation and good chlorination efficiency.(2) Based on a fact that hexadentate binding8-quinolinolato iron (III) complexes ((Qa-c)3FeⅢ) with a symmetrical octahedral structure commonly show a low catalysis rate for the selective oxidation of organic compounds with H2O2, for the first time we tried to use some carbon-based carriers to promote the (Qa-c)3FeⅢ complexes-catalyzed the cyclohexane oxidation to cyclohexanol and cyclohexanone by H2O2. In that, the Qa3FeⅢ and Qc3FeⅢ complexes were respectively supported on the carbon carriers multi-walled carbon nanotubes (MWCNTs), graphene oxide (GO), activated carbon (AC) and biochar carbon (BC-350) by physical adsorption method, these supported complexes were characterized by solid UV-Vis spectra and TG-DTA and their catalysis performance checked using cyclohexane oxidation with H2O2as a probing reaction. Among the supported complexes examined, only the MWCNTs supported Qa3FeⅢ and Qc3FeⅢ complexes showed a significant promote effect on the present catalysis oxidation and could shorten reaction time and improve cyclohexane conversion. Furthermore, directly adding the carrier MWCNTs to the oxidation system catalyzed by (Qa-c)3FeⅢ complexes also showed a similar promoting effect to the corresponding MWCNTs supported (Qa-c)3FeⅢ catalysts. This may be attributed to a moderate interaction between the carrier MWCNTs and the some ligand in Qa3FeⅢ or Qc3FeⅢ, which can lead to a weak distortion of iron complexes.(3) With5-chloro-8-hydroxyquinoline as a ligand, both the tetradentate binding8-quinolinolato iron complexes Qa2FⅡ and Qa2FeⅢ Cl were designed and synthesized. The complexometric titration was used to measure both the iron contents and the thermogravimetric analysis to characterize the thermol stability of both the complexes. The catalytic performance of both the complexes was checked using the selective oxidation of cyclohexane by hydrogen peroxide. The results showed that:the stability of Qa2FeⅢCl and Qa2FeⅡ was better than the corresponding hexadentate Qa3FeⅢ. The catalytic rate over Qa2FeⅡ was lower than that over Qa3FeⅢ. And the catalytic rate over Qa2FeⅢCl was slightly lower than that over Qa3FeⅢ in the early stage of reaction but faster than that over Qa3FeⅢ in the later, the ultimate conversion over Qa2FeⅢCl was26.5%, being higher than that over Qa3FeⅢ (20.6%).