核磁共振(NMR)波谱学原理及其应用

1、Data processingrf consoleTransmitterReceiverMagnetSample tubeProbe 020406080100120140PPMrf pulseB0Sample tubeinside coil FTSpectrumFIDpeakE0 B0nodetroughEBt0 if abscissa scale is time if abscissa scale is lengthElectromagnetic wave with electric vector E and magnetic vector B 1to B0m=+m=-半整数214P B0m

2、=+m=-PZ=PZ=-m=+1m=0m=-1PZ=PZ=0PZ=-m=+ ( )m=- ( )z, BO 自旋为自旋为的核在磁场中的两个进动锥体的核在磁场中的两个进动锥体 2B0m=- ( )E =+ B0m=-1m=+ ( )E =- B0m=+1E-1= B0m=0E+1=- B0E0=0E0I=1H, 13CI=12H, 14N E E2EB0B1B2m=+ ( )m=- ( )0N N =e- E/K T 1- EK T1-=K T B0N (m=- )N (m=+ )=exp EKT=exp1.66x10-25J1.38x10-23JK-1 298K=0.99996z, BO m=

3、+m=-N N M0E-=+ B0E+=- B0EBB00 E= 1质子在静磁场中的能级差质子在静磁场中的能级差 2BEB00m=-1m=+1m=0E-1= B0E0=0E+1=- B014N(I=1)在静磁场中的能级差在静磁场中的能级差tpf1f单个射频的脉冲单个射频的脉冲脉冲脉冲核自旋系数FT激励响应FID波谱脉冲激励的系统脉冲激励的系统 2 2B测-B标B标x106SiCH3H3CCH3CH3SiCH3H3CCH3SO3-Na+TMSDDS9876543210ppm0.0000.9280.9460.9651.3751.3941.9021.9211.9404.0264.3144.3324.

4、3507.6477.7048.8774.2519.7213.2314.100.5032.5710.305.33H1 solvent:aectone C4mimPF6 2004.12.13 T1X=0.05 good140130120110100908070605040302010ppm13.6119.9129.4929.6829.8730.0630.2632.6436.5350.20123.33124.70137.31C13 solvent:aectone C4mimPF6 2004.12.13 T1X=0.05电负性递增去屏蔽递增5.59OO6.488.05OOMeOOHMeO6.607.9

5、57.05O4.436.61HHx+苯环的屏蔽作用十八轮烯烯质子:7.97.0HHHHHHHHHHHHHHHHHH9.28-2.9HHHH-1.20.90.9CO+CC+双键的磁各向异性CCRH+叁键a和单键b的磁各向异性abCC+HHHH+单键的磁各向异性对直立和平伏氢的影响H3CO H3 .3 43 .3 7H3CCHCH3OH1.133.903.20H2COHH3C1.163.594.00H3CH2CCOCH32.062.391.02H2CCCH3CHOCH3H2CCN2.291.761.125.16BrH2CClH2COCH3H2CCN2.643.623.46FCHFCOOH7.406

6、.10一些sp3杂环碳上氢核的化学位移0.221.961.511.441.541.78O1.65O3.031.96O2.062.02O2.221.81.8O2.38O2.301.941.521.52一些环状化合物sp3杂环碳上氢核的化学位移HH3CCO2CH3CH36.731.73H3CHCO2CH3CH31.975.98一些烯氢的化学位移1.651.965.595.805.902.157.267.667.308.317.917.39N7.647.258.50NN7.509.24NN8.777.379.26NH6.307.176.98CHO9.4511.0一些芳环和芳杂环氢的化学位移CCHH1

7、.80CCHR1.73-1.88CCHAr2.71-3.37CCHCO2H2.23CCHC1.95CR一些炔氢的化学位移一些氢键质子的化学位移范围一些氢键质子的化学位移范围0123PPM1H13C195HzV195HzV1H13CHHHHHH CCCCCCV1H-13C标量偶合对1H的能级和谱线的影响JJVAAXAJ/4J/4J/4J/4XAXAXAAXAXAVAVAVXVXAAXXVV(a)(b)(c)自旋自旋A和X能级图和波谱(a)核与磁场0的相互作用(b) X核与磁场0的相互作用(c) 标量偶合 J=JAX0JA XJA XJA MMMXXXXMMSpin-spin coupling i

8、n an AMX spin systemJA XJA XJA X(3) 与二个等性核()AX2的偶合JA XJA XJA X(4) 与三个等性核()AX3的偶合Spin-spin coupling in an AX3 spin system1111211331146411510105116152015610123-1-2-3AA XA X2A X3A X4A X5A X6(V -VA)/JA X(5) 与n个等性核()AXn的偶合VAVAVXVXVX-1+10(a)(b)(c)(6)核的偶合例1:14NH(I=1)HBHBHHHHbridge protons300MHz500MHztermin

9、al protons例2:11B(I=3/2)CCHHFFCHHFFHHHHHHHHOOHHHH0.8HzHOH0.4HzCCCH3CH3CHH3.0HzH2CCCHCH2CH32.6HzXHHHX=O, HNup to 0.7HzHH3CHHHHHHHHHH123456 烷烃的13C化学位移 丙烷衍生物的丙烷衍生物的13C化学位移化学位移 环烷烃的环烷烃的13C化学位移化学位移 直链烯烃的直链烯烃的13C化学位移化学位移 单取代乙烯的单取代乙烯的13C化学位移化学位移 128.5127.7125.6133.3126.2128.1125.3131.8126.6128.3126.3126.3122.4131.9130.119.6136.4129.9126.116.9132.3单取代基苯环的单取代基苯环的13C化学位移化学位移 CCCHHHH212.673.5 醛和酮的醛和酮的13C化学位移化学位移 醋酸衍生物的醋酸衍生物的13C化学位移化学位移 取代醋酸的取代醋酸的13C化学位移化学位移 90 x90 xbroadbanddecouplingv1(13C)v2