𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Electron excitation effects on NMR shieldings in small organic molecules

✍ Scribed by Joseph D. Augspurger; Clifford E. Dykstra

Publisher
Elsevier Science
Year
1995
Tongue
English
Weight
328 KB
Volume
238
Category
Article
ISSN
0009-2614

No coin nor oath required. For personal study only.

✦ Synopsis

As an initial examination of the effects of electron excitation on chemical shieldings of protons, carbon-13 and oxygen-17 nuclei, we report values obtained from ab initio calculations invoking a substituted orbital description of the excited states. For the series of molecules studied, excitation from the highest occupied molecular orbital to the lowest unoccupied molecular orbital gives shifts from -10 to 31 ppm for carbon-13 but less than 1 ppm for hydrogen centers. In contrast, excitation from an oxygen n (2~) orbital in formaldehyde has an effect on oxygen shielding of several hundred ppm.

📜 SIMILAR VOLUMES

Ortho effects in organic molecules on el
Ortho effects in organic molecules on electron impact. VI—Ortho effects of a carboxyl group in N-substituted anilines
✍ D. V. Ramana; M. Vairamani 📂 Article 📅 1979 🏛 John Wiley and Sons 🌐 English ⚖ 228 KB

## Abstract The unusual fragments noticed in the mass spectra of __N__‐benzyl‐ and __N,N__‐dibenzylanthranilic acids have been explained on the basis of the __ortho__ interaction of the carboxyl group with the __N__‐benzyl‐ and __N,N__‐dibenzyl moieties.

Ortho, Effects in organic molecules on e
Ortho, Effects in organic molecules on electron impact: X—unusual ortho effects of the methyl group in o-picolinotoluidide
✍ D. V. Ramana; N. Sundaram 📂 Article 📅 1982 🏛 John Wiley and Sons 🌐 English ⚖ 451 KB

## Abstract The mass spectrum of __o__‐picolinotoluidide gives rise to three major fragments at m/z 184, m/z 169 and m/z 168, corresponding to the loss of CO from the molecular ion followed by the loss of ṄH~2~ and ĊH~3~ by independent pathways. It has been shown that the __ortho__ methyl group and