核磁共振谱测定的是无线电频率范围内的电 可磁辐射的吸收情况 与UV,Ⅵs和|R不同的是,原子核在吸收 过程中扮演着比电子更重要的角色。 质量数或原子序数中有一个为奇数的原子核 有自旋运动。 已原子核的自旋产生磁矩。 自旋量子数为12的原子核有2种自旋状态: +1/2和-12(H,3C,15N,1F,3P)
Organic Chemistry Organic Chemistry Xiamen Xiamen University University 核磁共振谱测定的是无线电频率范围内的电 磁辐射的吸收情况。 与 UV, VIS 和 IR 不同的是，原子核在吸收 过程中扮演着比电子更重要的角色。 质量数或原子序数中有一个为奇数的原子核 有自旋运动。 原子核的自旋产生磁矩。 自旋量子数I为1/2的原子核有 2种自旋状态： +1/2 和 –1/2 ( 1H, 13C, 15N, 19F, 31P )
18.2.2 Nuclear Magnetic Resonance
Organic Chemistry Organic Chemistry Xiamen Xiamen University University 18.2.2 Nuclear Magnetic Resonance
核自旋 H No field With field ①D ⑨D H No Field With field
Organic Chemistry Organic Chemistry Xiamen Xiamen University University 核自旋
E2 E2 △E=0 △E △E El El Increasing magnetic field h rh △E 2丌 Ho 2丌 ①D r--magnatoggric ratio for h. r=26750 ⑨D 210 v=700MHz,Ho=164407Gs
Organic Chemistry Organic Chemistry Xiamen Xiamen University University ∆E = rh 2 π H 0 r - - m agnatoggric ratio for H, r = 26 7 5 0 hv = rh 2 π H 0 v = r 2 π H 0 v = 7 00 M Hz, H 0 = 164407 Gs E1 E1' E2 E2' ∆E = 0 ∆ E ∆E' H 0' H 0 I n c reasing magne tic field
扫场和扫频 nMR spectrometers can be designed so that irradiate the compound with electromagnetic energy of a constant frequency while the magnetic field strength is varied(扫场) or swept(扫频) Ho ①D radio firequency ⑨D
Organic Chemistry Organic Chemistry Xiamen Xiamen University University 扫场和扫频 NMR spectrometers can be designed so that irradiate the compound with electromagnetic energy of a constant frequency while the magnetic field strength is varied (扫场)or swept(扫频)