𝔖 Bobbio Scriptorium
✦   LIBER   ✦

The alkali cation effect on the 1H NMR chemical shifts of the indenyl carbanion

✍ Scribed by C. Gooijer; N. H. Velthorst

Publisher
John Wiley and Sons
Year
1979
Tongue
English
Weight
311 KB
Volume
12
Category
Article
ISSN
0749-1581

No coin nor oath required. For personal study only.

✦ Synopsis

Abstract

The complex character of the temperature dependence of the ^1^H NMR chemical shifts of indenyl‐lithium and ‐sodium in dimethoxyethane is explained. It is shown that the cation causes a polarisation of the CH bonds and thus influences the proton shifts of the anion, both directly by its electric field along the bonds (the direct effect) and indirectly via its effect on the π‐electron distribution (the indirect effect). The indirect effect is inferred from ^13^C NMR chemical shift data. By subtracting the temperature dependent contribution of the indirect effect from the experimental ^1^H data, the direct effect is visualised. It appears that information on ion paris obtained by ^1^H and ^13^C NMR on the one hand and optical spectroscopy on the other hand is complementary. Apparently, aggregation of ion pairs does not seriously affect the chemical shift data.

📜 SIMILAR VOLUMES

1H chemical shifts in NMR: Part 23, the
1H chemical shifts in NMR: Part 23, the effect of dimethyl sulphoxide versus chloroform solvent on 1H chemical shifts
✍ Raymond J. Abraham; Jonathan J. Byrne; Lee Griffiths; Manuel Perez 📂 Article 📅 2006 🏛 John Wiley and Sons 🌐 English ⚖ 220 KB

## Abstract The ^1^H chemical shifts of 124 compounds containing a variety of functional groups have been recorded in CDCl~3~ and DMSO‐__d__~6~ (henceforth DMSO) solvents. The ^1^H solvent shift Δδ = δ(DMSO) − δ(CDCl~3~) varies from −0.3 to +4.6 ppm. This solvent shift can be accurately predicted (

On the 1H NMR chemical shift assignments
On the 1H NMR chemical shift assignments for ampicillin
✍ Janet C. Tung; Angelo J. Gonzales; Jack D. Sadowsky; Daniel J. O’Leary 📂 Article 📅 2000 🏛 John Wiley and Sons 🌐 English ⚖ 58 KB 👁 1 views

The 1 H NMR spectrum of ampicillin in aqueous solution at pD 8 and 4 was assigned using a combination of 2D T-ROESY and 1D GOESY techniques. The Me-˛and Me-ˇchemical shift assignments, determined at pD 8, are opposite to existing literature values obtained under similar conditions. Additionally, the

The anisotropic effect of 4-substituents
The anisotropic effect of 4-substituents on the 1H NMR chemical shift of H-5 in phenanthrenes
✍ R. M. Letcher 📂 Article 📅 1981 🏛 John Wiley and Sons 🌐 English ⚖ 359 KB

## Abstract Chloro‐, methoxy‐ and methyl‐substituents in the 4‐position of phenanthrenes exert a profound and diagnostic influence on the ^1^H chemicalshift of H‐5, and from ^13^C measurements it is considered to be dueto an anisotropic effect.

Substituent effects on the 13C NMR chemi
Substituent effects on the 13C NMR chemical shifts of 1-hydroxyalkylphosphonic acids
✍ Zdzisław Glowacki; Maria Hoffmann 📂 Article 📅 1990 🏛 John Wiley and Sons 🌐 English ⚖ 208 KB

## Abstract ^13^C chemical shifts and ^31^P,^13^C coupling constants are reported for nine 1‐hydroxyalkylphosphonic and two additional phosphonic acids. The α‐substituent‐induced chemical shifts (α‐SCS) of the phosphonate group were calculated and their non‐additivity was observed. Good linear corr

Effect of Cation Binding on the Proton C
Effect of Cation Binding on the Proton Chemical Shifts and the Spin–Spin Coupling Constant of Citrate
✍ Marinette van der Graaf; Arend Heerschap 📂 Article 📅 1996 🏛 Elsevier Science 🌐 English ⚖ 114 KB

The cation concentrations in the samples measured in this Human prostatic epithelial cells synthesize large quantities study were selected in accordance with the cation levels of citrate, which are secreted into the luminal space of the for prostatic fluid as reported by Kavanagh (11). In that prost