𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Substituent chemical shifts in NMR. 2—Bromine SCS in rigid molecules

✍ Scribed by Raymond J. Abraham; Julie Fisher

Publisher
John Wiley and Sons
Year
1985
Tongue
English
Weight
672 KB
Volume
23
Category
Article
ISSN
0749-1581

No coin nor oath required. For personal study only.

✦ Synopsis

The complete analysis and assignment of the 'H NMR spectra of 2-exo-bromonorbornane (1) and 2-bromoadamantane is reported, using high-field NMR and COSY and proton-carbon correlation experiments to assign the spectra. These data, together with those for the parent hydrocarbons, when combined with previous analyses of 1-bromoadamantane, 1-bromooctadeuterocyclohexane and the simple alkyl bromides, provide a data set of 38 proton SCS values for bromine in molecules of accurately known geometry. The effect of solvent on the SCS was investigated for 1 in five common solvents of very different polarity (C,D,, to DMSO). Only small ( < 0.1 ppm) solvent shifts were observed, apart from the 2-endo and 7s protons. A noteworthy feature of the SCS is the downfield shift of the CHX proton in all the series investigated, as X changes from C1 to Br to I. This is the reverse of the 'normal' trend and cannot be explained by present theories of SCS.

📜 SIMILAR VOLUMES

ChemInform Abstract: Proton Chemical Shi
ChemInform Abstract: Proton Chemical Shifts in NMR. Part 10. Bromine and Iodine Substituent Chemical Shifts (SCS) and an Analysis of the Contributions to the SCS in Halocyclohexanes.
✍ R. J. ABRAHAM; M. A. WARNE; L. GRIFFITHS 📂 Article 📅 2010 🏛 John Wiley and Sons ⚖ 27 KB 👁 2 views

1998 magnetic resonance, nuclear quadrupole resonance magnetic resonance, nuclear quadrupole resonance (organic substances) K 2560 ## 09 -012 Proton Chemical Shifts in NMR. Part 10. Bromine and Iodine Substituent Chemical Shifts (SCS) and an Analysis of the Contributions to the SCS in Halocyclohex

Substituent chemical shifts in NMR. Part
Substituent chemical shifts in NMR. Part 4—1H SCS in some 2-substituted norbornanes and bornanes
✍ Raymond J. Abraham; Andrew P. Barlow; Alan E. Rowan 📂 Article 📅 1989 🏛 John Wiley and Sons 🌐 English ⚖ 761 KB

Box 147, Liverpool L69 3BX, UK The 'H chemical shifts and substituent chemical shifts (SCS) were recorded for several monosubstituted norbornanes and bornanes. The observed substituent effects are generally similar for the two ring systems, but differ considerably from those observed for the cycloh

1H chemical shifts in NMR. Part 20 — Ani
1H chemical shifts in NMR. Part 20 — Anisotropic and steric effects in halogen substituent chemical shifts (SCS), a modelling and ab initio investigation
✍ Raymond J. Abraham; Mehdi Mobli; Richard J. Smith 📂 Article 📅 2004 🏛 John Wiley and Sons 🌐 English ⚖ 194 KB

## Abstract The ^1^H NMR spectra of 1‐halonaphthalenes were recorded and assigned. These data together with the known ^1^H chemical shifts of the halobenzenes and of H‐5 in 4‐halophenanthrenes were used to investigate different models of halogen SCS using the CHARGE program. Good agreement was obta