Nuclear magnetic resonance spectroscopy. Ring-current effects upon carbon-13 chemical shifts
β Scribed by Ronald H. Levin; John D. Roberts
- Publisher
- Elsevier Science
- Year
- 1973
- Tongue
- French
- Weight
- 178 KB
- Volume
- 14
- Category
- Article
- ISSN
- 0040-4039
No coin nor oath required. For personal study only.
β¦ Synopsis
Ring currents have played a crucial role in modern chemistry, but they have been analyzzd and discussed almost entirely in terms of their effect upon proton nmr chemical shifts. 2,3
The applica,ion of carbon magnetic resonance spectroscopy to this area has received relatively little attention.
π SIMILAR VOLUMES
## Abstract Carbonβ13 chemical shifts of the cyclopropyl carbons of eleven 4βsubstituted cyclopropylbenzenes have been measured under conditions effectively corresponding to infinite dilution in DCCI~3~. The substituentβinduced chemical shifts (SCS) of __both__ the Ξ± and Ξ² carbons of the cyclopropa
The "C NMR spectra of 21 catechin derivatives substituted at C-6/C-S by bromine and/or hydrogen and at oxygen by methyl, acetyl and/or hydrogen have been analysed in deuteriated acetone and chloroform. When a methoxy group is flanked by two bulky orrho substituents (6-Br and C4), the M e 0 and ortho
## Abstract The carbonβ13 n.m.r. spectra of several oxaziridines were measured. Aliphatic and aromatic __ipso__ carbon atoms __trans__ to the lone pair of nitrogen in oxaziridines were shifted upfield by __c.__ 9 ppm, and 3.4 ppm, respectively, in comparison with isomers of inverted configuration.
A major problem in the use of i3C-NMR spectroscopy for structure identification is to estimate the 13C shifts of compounds known or suspected to be present in the spectrum. The substituent chemical shifts of different functional groups were studied and new, detailed empirical rules are reported. Tre