𝔖 Bobbio Scriptorium
✦   LIBER   ✦

13C nuclear magnetic resonance studies on acetophenones: Barriers to internal rotation

✍ Scribed by Torbjörn Drakenberg; Jean M. Sommer; Roland Jost

Publisher
John Wiley and Sons
Year
1976
Tongue
English
Weight
348 KB
Volume
8
Category
Article
ISSN
0749-1581

No coin nor oath required. For personal study only.

✦ Synopsis

Abstract

The barrier to internal rotation in a series of p‐substituted acetophenones has been determined by means of low temperature carbon‐13 n.m.r. and total bandshape analysis, resulting in: Δ__G__ = 5·4 ± 0·1 kcal mol^−1^ (22·4 ± 0·4 kJ mol^−1^) for the unsubstituted acetophenone. The substituent effects on the barrier are found to be the same as for the corresponding benzaldehydes. The barrier height is discussed in terms of contributions from resonance and steric effects.

📜 SIMILAR VOLUMES

Nuclear magnetic resonance studies of in
Nuclear magnetic resonance studies of internal rotation. V—Rotational barriers of acetylenic amides
✍ S. L. Spassov; V. S. Dimitrov; M. Agova; I. Kantschovska-Dimicoli; R. Todorova-M 📂 Article 📅 1974 🏛 John Wiley and Sons 🌐 English ⚖ 197 KB

## Abstract The rotational barriers about the CN bond of the __N__,__N__‐dimethylamides of propiolic, methylpropiolic and phenylpropiolic acids have been determined by the iterative total line shape nuclear magnetic resonance method.

Nuclear magnetic resonance studies of in
Nuclear magnetic resonance studies of internal rotation: IV—rotational barriers and conformation of phthalic amides
✍ S. L. Spassov; V. S. Dimitrov; I. Kantschovska 📂 Article 📅 1974 🏛 John Wiley and Sons 🌐 English ⚖ 258 KB

## Abstract The rotational barriers about the CN bond of the N,N,N′,N′‐tetramethyldiamides of phthalic, isophthalic and terephthalic acids have been determined by the iterative total line shape NMR method. Some evidence about the conformation of these compounds in solution has also been obtained b

Barriers to internal rotation in 1,3,5-t
Barriers to internal rotation in 1,3,5-trineopentylbenzenes: V—conformational studies by carbon-13 magnetic resonance
✍ Bertil Nilsson; Torbjörn Drakenberg 📂 Article 📅 1974 🏛 John Wiley and Sons 🌐 English ⚖ 494 KB

## Abstract The temperature dependence of the carbon‐13 NMR signals in three completely substituted 1,3,5‐trineopentylbenzenes has been studied by the Fourier transform technique. The assignment of all peaks was based on studies of 1,3,5‐trineopentylbenzene and some of its mono‐ and disubstituted d

1H NMR studies on thioamides: Barriers t
1H NMR studies on thioamides: Barriers to internal rotation
✍ J. A. Lepoivre; H. O. Desseyn; F. C. Alderweireldt 📂 Article 📅 1974 🏛 John Wiley and Sons 🌐 English ⚖ 365 KB 👁 1 views

The barrier to the internal rotation of the dirnethylamino group in thioamides of structure R-CS-N(CH,),, R being (CH,),N-CS--, CH,O,C-or N=C--, is studied by proton magnetic resonance, using the lineshape analysis method of Nakagawa. In the solvents o-dichlorobenzene, naphthalene and nitrobenzene a

13C nuclear magnetic resonance studies o
13C nuclear magnetic resonance studies on some substituted isoxazoles
✍ James Gainer; Graham A. Howarth; William Hoyle; Stanley M. Roberts 📂 Article 📅 1976 🏛 John Wiley and Sons 🌐 English ⚖ 124 KB 👁 1 views

## Abstract ^13^C n.m.r. spectra of some substituted isoxazoles have been examined to ascertain the reactive site in the metallation of 4‐substituted 3,5‐dimethylisoxazoles. The results obtained indicate that metallation occurred exclusively at the C‐5 methyl.