## Abstract The ^13^C^13^C spin–spin coupling constants in natural abundance oxetane, thietane, cyclobutanone, bromo‐and chlorocyclobutane have been measured. Furthermore, the ^13^C isotope‐induced changes in the chemical shifts of the different ^13^C nuclei in the molecules mentioned above are re
1H and 13C NMR chemical shifts and spin–spin coupling constants in trans- and cis-decalins
✍ Scribed by Helena Dodziuk; Michał Jaszuński; Wojciech Schilf
- Publisher
- John Wiley and Sons
- Year
- 2005
- Tongue
- English
- Weight
- 132 KB
- Volume
- 43
- Category
- Article
- ISSN
- 0749-1581
- DOI
- 10.1002/mrc.1598
No coin nor oath required. For personal study only.
✦ Synopsis
The NMR parameters characterizing the spectra of trans- and cis-decalins were determined from theoretical calculations and experimental spectra. The calculated values of the shielding constants are in good agreement with the measured chemical shifts, with a small but noticeable difference in accuracy for the bridgehead atoms. Of all the spin-spin coupling constants, only most of (1)J(C,C) and (1)J(C,H) values could be extracted from the spectra, and the corresponding computed values are in good agreement with experiment. It appears that the applied density functional theory (DFT) approach overestimates slightly the J(C,C) coupling and underestimates the differences between one-bond (1)J(C,H) coupling constants. For all these constants [J(C,C), J(C,H) and J(H,H)] through one to three bonds, which could not be obtained experimentally, the predicted values are in good agreement with the general rules relating spin-spin coupling to the number and spatial arrangement of the intervening bonds.
📜 SIMILAR VOLUMES
The nuclear shielding of (99)Ru in a wide variety of complexes was investigated computationally by DFT methods, including relativistic effects (by means of the Pauli and ZORA approximations), up to spin-orbit coupling and Slater all-electron or frozen-core basis sets. Mononuclear complexes, a trinuc
## Abstract The spectral parameters of the title compounds were redetermined to resolve discrepancies between data reported in the literature.
## Abstract ^13^C, ^1^H spin coupling constants of dimethylacetylene have been determined by the complete analysis of the proton coupled ^13^C NMR spectrum. For the methyl carbon ^1^__J__(CH) = + 130.6~4~ Hz and ^4^__J__(CH) = + 1.5~8~ Hz, and for the acetylenic carbon ^2^__J__(CH) = − 10.34 Hz and
Before and after cis-trans isomerization, the observed 13 C-NMR chemical shifts of poly(phenylacetylene) (PPA) in the solid state were investigated on the basis of 13 C-NMR chemical shift calculations within AM1 for the cis-transoidal and deflected trans-transoidal forms. Two 13 C-resonance peaks in
## Abstract One‐bond heteronuclear spin‐spin coupling constants ^1^__J__~PX~ (XH, O, S, Se, C and N) between the phosphorus atom and axial and equatorial substituents in dioxaphosphorinanes are computed using density functional theory (DFT). The experimental values of these coupling constants for