Chemical Shift Table4.3.3各类化合物的13C化学位移1饱和碳的化学位移值饱和烷烃:饱和烷烃的碳为sp3杂化,其化学位移值一般在2.555ppm。与1H NMR相似,也可进行经验计算,这里不做详细介绍。2烯碳的化学位移值烯碳为sp2杂化,其化学位移为100165ppm。3炔烃的化学位移值 炔基碳为sp杂化,其化学位移介于sp3与sp2杂化碳...
13CNMR核磁共振碳谱化学位移总览表 4.1核磁共振碳谱的特点13C核磁共振谱的信号是1957年由P.C.Lauterbur首先 观察到的。碳是组成有机物分子骨架的元素，人们清楚认识到13CNMR对于化学研究的重要性。由于13C的信号很弱，加之1H核的偶合干扰，使13CNMR信号变得很复杂，难以测得有实用价值的谱图。20世纪70年代后期...
CNMR谱基础 二、化学位移chemicalshift •化学位移范围：0～250ppm；核对周围化学环境敏感，重叠少 •氢谱与碳谱有较多共同点；•碳谱化学位移规律：(1)高场低场 碳谱：饱和烃碳、炔烃碳、烯烃碳、羧基碳氢谱：饱和烃氢、炔氢、烯氢、醛基氢；(2)与电负性基团相连，化学位移向低场移动；3 碳谱（13C-NMR...
常见的13CNMR 核磁共振碳谱化学位移总览表== 13CNMR 核磁共振碳谱化学位移总览表有机波谱分析 13C核磁共振谱的信号是1957年由P. C. Lauterbur首先观察到的。碳是组成有机物分子骨架的元素,人们清楚认识到13C NMR对于化学研究的重要性。由于13C的信号很弱,加之1H核的偶合干扰,使13C NMR信号变得很复杂,难以测...
13C NMRChemical shift assignmentsCarbazole derivatives13C NMR chemical shift assignments have been made for a series of 1-substituted carbazoles, 8-substituted 1,2,3,4-tetra-hydrocarbazoles, 1-substituted benzo[a]carbazoles and 6-substituted dibenzo-[c,g]carbazoles. Single examples were examined ...
A table representing the chemical shift ranges for all carbon atoms with varying -substituents (one sphere HOSE codes) has been generated from a collection of 58 000 reference spectra, providing an overview of the influence of substitution on 13C NMR chemical shifts.doi:10.1002/mrc.1260230413...
13CNMR核磁共振谱化位移谱谱表碳学13C核磁共振谱的信是号1957年由P.C.Lauterbur首先谱察到的。是谱成有机物分子骨架的元素,人谱楚谱谱到碳清13CNMR谱于化究的重要性。由于学研13C的信弱,加之号很1H核的偶合干谱,使13CNMR信谱得谱谱,谱以谱得有谱用价谱的号很谱谱。20世谱70年代后期,谱子去偶和...
substituenton13C=chemicalshift基团γβαα′β′γ′>C<-1.57.210.6-7.9-1.81.5OH,OCH3,N<-3.54.5OAc-5.05.0COCH3-8.05.0COOH(R)-3.53.5CH2OH-3.53.5CH=CH21.50.0C=O1.5-2.0CH=CH20.05.0OH1.55.0OAc-1.07.0COOH(R)-3.03.0CH2OH10.5-10.0C=O18.0-12.0OH(双键另一侧α位有C=O)1.8-7.6校正...
The 13C NMR chemical shift of sp2 carbon atoms in acyclic alkenes was estimated with multilayer feedforward artificial neural networks (ANNs) and multilinear regression (MLR), using as structural descriptors a vector made of 12 components encoding the environment of the resonating carbon atom. The ...
The latter two conformations for L -alanine residues are achieved when L -alanine residues are incorporated into poly(β-benzyl L -aspartate). We found that the alanine C β carbon show significant 13 C chemical shift displacement depending on conformational change, and gave the 13 C chemical ...