A novel and efficient method for distinguishing between chiral diols and diphenols has been established through the use of^(19)F NMR spectroscopy.Central to this system's efficacy is a chiral amine,strategically m...A novel and efficient method for distinguishing between chiral diols and diphenols has been established through the use of^(19)F NMR spectroscopy.Central to this system's efficacy is a chiral amine,strategically modified with a CF_(3)group.This amine reacts in-situ with 2-formylphenylboronic acid to create a chiral^(19)F-labeled probe.This probe demonstrates discriminatory capabilities by interacting with hydroxy-containing analytes to form boronic esters.These esters produce distinct^(19)F NMR signals that vary according to their stereoconfiguration,facilitating accurate chiral differentiation.The method's resolution capacity was demonstrated by successfully identifying 12 distinct chiral analytes(six pairs of enantiomers)in complex mixtures,highlighting its extensive potential in diverse chiral analysis applications.展开更多
建立了核磁共振氟谱法测定氰化物的氟化衍生化合物1-氰基-2,2,2-三氟-1-苯乙基乙酸酯(CTPA)含量的方法。以乙酸3-氟苄酯为内标,采用5mm Auto XBB探头,探头温度298.2K,考察了不同浓度化合物的定量条件;通过比较化合物样品定量峰与内标物...建立了核磁共振氟谱法测定氰化物的氟化衍生化合物1-氰基-2,2,2-三氟-1-苯乙基乙酸酯(CTPA)含量的方法。以乙酸3-氟苄酯为内标,采用5mm Auto XBB探头,探头温度298.2K,考察了不同浓度化合物的定量条件;通过比较化合物样品定量峰与内标物质响应峰面积,计算化合物的含量。结果该化合物的19 F-NMR检测方法在0.5~50μg/mL具有良好的线性(r2=0.9966),该方法的定量限0.5μg/mL,检出限0.2μg/mL;同时考察了该化合物在不同浓度下的测量准确度。展开更多
Ion mobility in solid solutions of the fluorite structure 50Pb2–30BiF3–20KF (I) and 50Pb2–30BiF3–20NaF (II) was studied by NMR method. Analysis of 19F, 23Na NMR spectra made it possible to reveal the character of ...Ion mobility in solid solutions of the fluorite structure 50Pb2–30BiF3–20KF (I) and 50Pb2–30BiF3–20NaF (II) was studied by NMR method. Analysis of 19F, 23Na NMR spectra made it possible to reveal the character of ion motions in the fluoride and sodium sublattices with temperature variation, to determine the types and temperature ranges in which they took place. It was found that the dominant form of ionic mobility in the samples I and II above 380 K was the diffusion of fluoride and sodium ions. According to preliminary results of electro-physical studies, the conductivity reached values of ~ 2×10–2 – 10–3 S/cm above 500 K. The solid solutions I and II can be recommended as a basis for use in the development of new functional materials.展开更多
基金supported by the National Key Research and Development Program(2021YFF0701700)the National Natural Science Foundation of China(22271305).
文摘A novel and efficient method for distinguishing between chiral diols and diphenols has been established through the use of^(19)F NMR spectroscopy.Central to this system's efficacy is a chiral amine,strategically modified with a CF_(3)group.This amine reacts in-situ with 2-formylphenylboronic acid to create a chiral^(19)F-labeled probe.This probe demonstrates discriminatory capabilities by interacting with hydroxy-containing analytes to form boronic esters.These esters produce distinct^(19)F NMR signals that vary according to their stereoconfiguration,facilitating accurate chiral differentiation.The method's resolution capacity was demonstrated by successfully identifying 12 distinct chiral analytes(six pairs of enantiomers)in complex mixtures,highlighting its extensive potential in diverse chiral analysis applications.
文摘建立了核磁共振氟谱法测定氰化物的氟化衍生化合物1-氰基-2,2,2-三氟-1-苯乙基乙酸酯(CTPA)含量的方法。以乙酸3-氟苄酯为内标,采用5mm Auto XBB探头,探头温度298.2K,考察了不同浓度化合物的定量条件;通过比较化合物样品定量峰与内标物质响应峰面积,计算化合物的含量。结果该化合物的19 F-NMR检测方法在0.5~50μg/mL具有良好的线性(r2=0.9966),该方法的定量限0.5μg/mL,检出限0.2μg/mL;同时考察了该化合物在不同浓度下的测量准确度。
文摘Ion mobility in solid solutions of the fluorite structure 50Pb2–30BiF3–20KF (I) and 50Pb2–30BiF3–20NaF (II) was studied by NMR method. Analysis of 19F, 23Na NMR spectra made it possible to reveal the character of ion motions in the fluoride and sodium sublattices with temperature variation, to determine the types and temperature ranges in which they took place. It was found that the dominant form of ionic mobility in the samples I and II above 380 K was the diffusion of fluoride and sodium ions. According to preliminary results of electro-physical studies, the conductivity reached values of ~ 2×10–2 – 10–3 S/cm above 500 K. The solid solutions I and II can be recommended as a basis for use in the development of new functional materials.
基金the National Key Research and Development Program of the Ministry of Science and Technology,People’s Republic of China(2016YFA0501203)the National Natural Science Foundation of China(31470727)+1 种基金the interdisciplinary medicine Seed Fund of Peking Universitythe 1000 Plan for Young Talent Program of China
