## Abstract ^13^C NMR (CMR) spectra of a number of di‐ and trisubstituted ethylenes have been measured. Very consistent values are found for the differential shieldings of allylic carbons in a number of linear, (Z)‐ and (E)‐disubstituted ethylenes. The discrepancies between the several structural e
13C and 15N NMR study of acyclic vicinal diastereoisomers. Conformational effects
✍ Scribed by George C. Levy; T. Pehk; E. Lippmaa
- Publisher
- John Wiley and Sons
- Year
- 1980
- Tongue
- English
- Weight
- 568 KB
- Volume
- 14
- Category
- Article
- ISSN
- 0749-1581
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✦ Synopsis
Abstract
Conformations of aliphatic diastereoisomers with vicinal asymmetric centers (2,3‐disubstituted butanes and 5,6‐disubstituted n‐decanes) are discussed in terms of their ^13^C and, in some cases, ^15^N chemical shifts and spin‐lattice relaxation times. Solvent and protonation effects are explained by conformational changes in the isomers.
📜 SIMILAR VOLUMES
## Abstract ^13^C and ^15^N NMR data for twelve __N__‐unsubstituted pyrrolidines are reported and __cis__ and __trans__ stereomers are assigned for 2,3‐, 2,4‐ and 2,5‐disubstituted compounds.
## Abstract A series of (>90% isotopic purity) ^13^C‐labeled aliphatic alcohols of the general structure CCC^13^COH were synthesized and studied by ^13^C n.m.r. to obtain all ^13^C^13^C couplings involving the labeled carbon. The ^2^__J__(CC) values were small (<0.5 Hz) and contrast with the l
## Abstract ^13^C NMR of diastereoisomeric pairs of 2,3‐diaryl‐2‐methylbutyronitriles revealed a difference in the chemical shift of the carbon atoms between the diastereoisomers and the observed shifts were greatly influenced by the presence of an __ortho__ substituent in the 3‐phenyl ring.
13C and "N NMR spectroscopic assignments are given for a series of N-aryl-N-cyanoguanidines in DMSO-d, along with those for a few related cyanoguanidines. The NMR data are interpreted in terms of minimal overlap of the amino lone pair with the attached aryl ring, and a planar guanidine structure wit
## Abstract ^13^C and ^15^N NMR spectra of eight substituted 1,2,4‐triazines were measured and assigned. The assignments of the ^13^C NMR spectra were based on the substituent chemical shifts and ^__n__^__J__(C,H) coupling constants. ^15^N NMR chemical shifts generally showing well separated ranges