𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Two-bond deuterium isotope effects on 13C chemical shifts. A measure of carboncarbon bond lengths

✍ Scribed by D. J. Sardella; Alyaa Emad El-Din

Publisher
John Wiley and Sons
Year
1989
Tongue
English
Weight
497 KB
Volume
27
Category
Article
ISSN
0749-1581

No coin nor oath required. For personal study only.

✦ Synopsis

Two-bond deuterium-induced isotope effects ('A) have been studied in several neutral x-systems (64dimethylfulvene, cyclohexene and cyclohexa-1,ldiene). Isotope effects on the 13C shifts of adjacent carbons are invariably to higher field, and vary from -84 to -139 ppb. In combination with literature data for a number of aromatic systems, these results establish that, for fragments of the type D_c(~p')--'~C(sp~) in fiveor sixmembered rings, 'A correlates linearly with carbon-carbon bond length, the average deviation between calculated and experimental bond lengths being 0.01 A. The correlation embraces bridgehead and non-bridgehead carbons in both five-and six-membered rings. As a test of the utility of this empirical relationship, 'A in ferrocene-d was determined to be -91 ppb, corresponding to a carbon-carbon bond length of 1.42 A, in good agreement with the experimental value of 1.43 A. KEY WORDS Two-bond deuterium-induced isotope effects bond length This work was partially supported by a Boston College Summer material, except for a two-fold reduction in the intensities of the vinylic proton and carbon peaks.

Faculty Grant (D.J.S.). A.E.E.-D. gratefully acknowledges the financial support of the Egyptian Government during the period 1985-86.

📜 SIMILAR VOLUMES

Deuterium isotope effects on 13C chemica
Deuterium isotope effects on 13C chemical shifts of nitromalonamide
✍ Poul Erik Hansen 📂 Article 📅 2008 🏛 John Wiley and Sons 🌐 English ⚖ 154 KB

## Abstract The OH chemical shift of the enol form of nitromalonamide is found at 18.9 ppm both in DMSO‐__d__~6~ and in DMF‐__d__~7~ indicating a very strong hydrogen bond. The OH chemical shift is insensitive to temperature changes. Contrary to the large OH chemical shift, a small two‐bond deuteri

17O chemical shifts and deuterium isotop
17O chemical shifts and deuterium isotope effects on 13C chemical shifts of intramolecularly hydrogen-bonded compounds
✍ Lech Kozerski; Robert Kawȩcki; Piotr Krajewski; Brunon Kwiecień; David W. Boykin 📂 Article 📅 1998 🏛 John Wiley and Sons 🌐 English ⚖ 133 KB 👁 2 views

17O chemical shifts were measured in 40 enamines activated in the b-position by CxO, COO, NO 2 , SO and groups. Data for the oxygen-containing series of o-hydroxyacyl aromatics are also included for com-SO 2 parison. Intramolecular hydrogen bonding in the enamines is discussed in terms of the accept

Deuterium Isotope Effects on 13C Chemica
Deuterium Isotope Effects on 13C Chemical Shifts of o-Hydroxyacyl Aromatics. Intramolecular Hydrogen Bonding
✍ Poul Erik Hansen; Simon Bolvig 📂 Article 📅 1997 🏛 John Wiley and Sons 🌐 English ⚖ 468 KB 👁 2 views

The interesting deuterium isotope e †ects of gossypols have been reinvestigated and the very large two-bond isotope e †ect, 2DC-6(OD), is ascribed to electric Ðeld e †ects. Common to the investigated compounds is the presence of intramolecular hydrogen bonds. A feature strongly related to the streng

Deuterium Isotope Effects on13C NMR Chem
Deuterium Isotope Effects on13C NMR Chemical Shifts of Amides
✍ Ronald M. Jarret; Ny Sin; Matthew Dintzner 📂 Article 📅 1997 🏛 Elsevier Science 🌐 English ⚖ 46 KB

Exchange of amide protons with deuterium results in changes of 13 C chemical shifts for carbon atoms near the site of substitution (CH{N and N{C|O). There is a measurable decrease in the isotopic shifts of CH{N for cycloalkylacetamides as ring size increases from 3 to 8 and for lactams as ring size

Long-range deuterium isotope effects on
Long-range deuterium isotope effects on 13C chemical shifts of intramolecularly hydrogen-bonded compounds. Purpurogallins
✍ Poul Erik Hansen 📂 Article 📅 1993 🏛 John Wiley and Sons 🌐 English ⚖ 351 KB 👁 1 views

## Abstract Long‐range deuterium isotope effects on ^13^C chemical shifts, ^__n__^ΔC(OD), were studied in the intramolecularly hydrogen‐bonded purpurogallins (benzotropolones). A very large long‐range isotope effect from the hydrogenbonded 4‐OH(D) is observed over six bonds at C‐7. Further, long‐ra

Dependence of one-bond deuterium isotope
Dependence of one-bond deuterium isotope shifts in 13C NMR on CH bond lengths for substituted and unsubstituted aromatic compounds
✍ Yasuki Nakashima; Takashi Teranishi; Toshiya Suzuki; Tyo Sone; Kensuke Takahashi 📂 Article 📅 1994 🏛 John Wiley and Sons 🌐 English ⚖ 319 KB

## Abstract One‐bond deuterium‐induced isotope shifts of ^13^C NMR (^1^Δ) for 106 sp^2^‐hybridized carbons are discussed in terms of CH bond lengths. ^1^Δ correlates linearly with the related CH bond length calculated by the MNDO MO method by the equation ^1^Δ(ppb)=8350 __r__~CH~ (Å) – 8824.