In Situ Monitoring Chemical Reactions By NMR Combined With Electrochemical And Flow Apparatus

The monitoring of chemical reaction process is very important in the study of reaction mechanism.The combination of nuclear magnetic resonance(NMR)spectroscopy and electrochemistry is applied to the study of chemical reaction process.In-situ experiments can be used to realize the real-time detection of chemical reaction products which will be helpful to study the reaction mechanism.At the same time,compared with the one-dimensional NMR spectrum,the two-dimensional spectrum improves the phenomenon of peak overlap and improves the resolution of the spectrum.However,the sampling time of conventional two-dimensional high-resolution NMR spectroscopy is longer,and it is impossible to monitor the reaction process effectively for some fast reactions.The new Ultra-fast sampling technique based on spatial coding can obtain two-dimensional or multi-dimensional spectral data only by a single scan,which greatly shortens the experimental time and is beneficial to the monitoring of the reaction process.Combined with NMR spectroscopy,through electrochemical and automatic sampling devices,we can monitor the electrochemical reaction process.The conditions of the reaction were optimized and the improved reaction device were further tested with obtaining the real time one-dimensional NMR spectra and two-dimensional spectra of the intermediate products.Based on the analysis of high-resolution one-dimensional and two-dimensional NMR signals,the possible reaction mechanism of reactants in different solution environments is further deduced to realize the study of chemical reaction mechanism.The main contents of the study are as follows:1.In this study,we used the conductive glass to load carbon-loaded platinum as the working electrode to electrocatalyze the oxidation of glucose.In addition,we also change the solution environment under the action of this electrode to study the mechanism of electrocatalytic oxidation of glucose,including composition distribution ratio,voltage,pH,the amount of catalyst and other factors on the electrocatalytic oxidation of glucose.2.A multi-channel flow system is designed,which is oriented to a class of host-object interaction.Using cyclodextrin(CD)derivative as main body and ferrocene(Fc)derivative as guest,Fc valence state was controlled by electric field to control its interaction with CD.Using ultra-fast NMR multi-dimensional spectrum to monitor the reaction process,the effective information of its interaction in ultra-fast NOESY spectrum is studied.The monitor of reaction intermediates provides useful information for the study of reaction mechanism and kinetic process.