NMR15N13C benzonitrilesmagnetic susceptibilitychemical shiftsab initio calculationsHammett correlationPCA treatmentDSP analysisSCS15N chemical shifts in an extensive series of para (15) and meta (15) as well as ortho (8) substituted benzonitriles, XC6H4CN, were measured in deuteriochloroform solutions...
The15N NMR resonances were assigned by 2D15N-resolved1H experiments, which also allowed the identification of a number of sequential and medium-range1H1H contacts that are obscured by chemical shift degeneracy in homonuclear experiments. The15...
本文在系统的总结和分析前人对15N-NMR化学位移的研究成果的基础上,对15N-NMR化学位移的规律进行研究,最终确定用回归分析中的最小二乘法来确定计算15N-NMR化学位移的公式,并用F-检验法对所得计算公式进行检验。按照化合物类型和所含氮原子的结构,分别提出了19个15N-NMR化学位移计算公式,如下: 1.含碳氮单键化合物...
NMR15N NMRelectronic structurestetrazepinone derivativesThe 15N NMR spectra of the novel seven-membered 1,2,3,5-tetrazepinone ring systems were studied. The chemical shift of N-2 was found to be significantly responsive to substituent changes at the phenyl ring. As the electron-withdrawing ...
陕西科技大学 硕士学位论文 <'15>N-NMR化学位移规律的研究 姓名:*** 申请学位级别:硕士 专业:应用化学 指导教师:**生;兰云军 20060401 (5)取代苯酰胺、以肛二甲基取代苯酰胺以及硫代的取代苯酰胺 R。Nc0(S)C。地一X型(R表示一H、一CH.)中酰胺基氮原子”N-NMR化学 位移计 算公式:万。。1=艿o。+c(...
2)1H/15 N chemical shift1H/15N化学位移 3)15 N-NMR15N-NMR 4)14C,15N14C、15N 5)transport[英][tr?ns'p?:t,-sp?:rt][美][tr?ns'p?rt, -'port]运移 1.Retardation of geological barriers to transport of harmful substance;地质屏障对有害物质在环境中运移的阻滞效应 2.Numerical simulation of...
A similar sensitivity enhancement was also obtained for 2D 15N–1H dipolar and 15N chemical shift correlation spectroscopy, by means of a 3D 1H/15N–1H/15N correlation experiment. We demonstrate this technique, termed PRINS for proton indirectly detected nitrogen static NMR, on a crystalline model ...
The chemical shift tensor of N5 is over 720 ppm wide, in accordance with the predictions of theory and our calculations. The signal of N3 can be distinguished on the basis of coupling to 1H absent for N1 and N5, as well as the shift tensor span of only 170 ppm, consistent with N3's...
Gray GA (1983) Multinuclear two-dimensional NMR: Assignments of natural abundance polypeptide 13-C, 1-H and 15-N chemical shifts and demonstration of isomer interconversion. Org Mag Res 21:111–118G.A. Gray, Multinuclear two—dimensional NMR: Assignments of natural abundance polypeptide 13 C, ...
15NNMR化学位移的经验公式:δcal(15N)=-380.2+ΣΔα+ΣΔβ+ΣΔγ+ΣΔδ+Σ犆,结合最小二乘法通过线性回归得到了11种取代基参数,计算结果以133种化合物的133个15NNMR化学位移数据为样本点进行回归检验,置信度为99.5%,约有94.7%的15NNMR化学位移计算值的计算误差小于5.0(相对误差小于0.5%).关键词:15NNMR...