13C-NMR spectroscopy in the helicene series: heptahelicene, hexahelicene and the lower benzologues.
β Scribed by Nicole Defay; D. Zimmermann; R.H. Martin
- Publisher
- Elsevier Science
- Year
- 1971
- Tongue
- French
- Weight
- 193 KB
- Volume
- 12
- Category
- Article
- ISSN
- 0040-4039
No coin nor oath required. For personal study only.
β¦ Synopsis
The l3 C-NMR spectra of naphthalene, phenanthrene (I), benzo[c]phenanthrene (II), pentahelicene(dibenzo[c,g]phenanthrene) (III), hexahelicene (IV) (Fig.11 and heptahelicene (V) (Fig.11 have been recorded on a Brucker HX high
π SIMILAR VOLUMES
## Abstract The __cis__ and __trans__ isomers of eight 1,2βdiarylethylenes, precursors of helicenes, have been studied by NMR. spectroscopy. The observed differences in chemical shifts, specific solvent effects and steric effects (bromo derivatives) can be explained by the contribution of βhelicene
## Abstract The structural analysis of carbamates derived from 2β(Ξ±βfuryl)benzaldoximes and 2β(Ξ±βfuryl)benzyl alcohols was carried out by ^1^H and ^13^C NMR spectroscopy. The conjugative and steric effects of alkyl substituents introduced on the benzene rings were found to modify the relative orien
The complete analysis of the "C NMR spectra of 30 cedrane derivatives with various functionalities on the 2,6, 6,8-tetramethyltricycl0[5.3.1\*~~0~~~]undecane skeleton is reported. The assignment of the signals to the appropriate carbons bas been made using the various functionalities on the molecula
## Abstract The signal shifts caused by replacing the carbonyl oxygen by sulphur represent a valuable method of assignment of the ^13^C NMR signals in coumarins and furocoumarins substituted at the benzoic and furanoic rings.