Nmr spectra nitrogen

Most of the experimental work on the annular tautomerism of 5-substituted tetrazoles has been carried out on solutions and a number of major studies are described in CHEC-I <84CHEC-I(5)79l>. Nitrogen-15 NMR spectra of 5-substituted tetrazoles and their N-1 and N-2-methyl isomers show... 

Nitrogen-15 nmr spectra were obtained at 9.12 and 20.72 MHZ on spectrometers using external time-share, field-frequency lock. Details of the spectrometer modifications are published elsewhere (19). 

The nitrogen-15 nmr spectra (Figure 3) of sodium exchanged Alaskan and HB33 mordenites were analyzed for the chemical shift anisotropy tensors. The chemical shift anisotropy tensors have been measured for solid nitrogen at 4.2K(23) and calculated to be 603 28 ppm for the static molecule. The observed chemical shift tensors can be used to calculate an orientational parameter , where... 

Nitrogen-15 NMR spectra of 1,2,3-triazines have been reported in several papers <85LA1732, 86JCS(P1)1249, 88JCS(P1)1509>, and the data are listed in Table 6. The N-2 positions show larger downfield shifts than N-NMR signals of pyridazine S = -1-20.3) or 1,2,4-triazine (N-1 5 = -1-62 shifts downfield of external nitromethane). 

Triazines and their Benzo Derivatives Table 5 Nitrogen-15 NMR spectra of some 1,2,4-triazines. 

Figure 14. Superposition of broadband Nitrogen-15 NMR spectra of NC at 25 C and at 110° C. Spectra obtained at 30.9 MHz.

Thom, K. A., and L. G. Cox. 2009. N-15 NMR spectra of naturally abundant nitrogen in soil and aquatic natural organic matter samples of the International Humic Substances Society. Organic Geochemistry no. 4 484-499. doi 10.1016/j.orggeochem. 2009.01.007. 

Fig. 37 Nitrogen-15 spectra of two aminophosphonates (structures as shown). 10-mm NMR tube, concentration 25% in CDC13, proton decoupling, relaxation delay 15 sec, measurement time 12 hours...

Table 2 gives the approximate range of nitrogen chemical shifts in the organic compounds with which this book deals. The 14N and 15N NMR spectra of amino- and nitro-aliphatic compounds have been reviewed1,2,15 and the effects of the alkyl group on the 15N chemical shifts have been investigated. 

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