ISSN:
0749-1581
Keywords:
Two-bond deuterium-induced isotope effects
;
Neutral π systems
;
6,6-Dimethylfulvene
;
Carbon-Carbon bond length
;
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Two-bond deuterium-induced isotope effects (2Δ) have been studied in several neutral π-systems (6,6-dimethylfulvene, cyclohexene and cyclohexa-1,3-diene). 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(sp2)—13C(sp2) in five- or six-membered rings, 2Δ correlates linearly with carbon—carbon bond length, the average deviation between calculated and experimental bond lengths being 0.01 Å. 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, 2Δ in ferrocene-d was determined to be -91 ppb, corresponding to a carbon—carbon bond length of 1.42 Å, in good agreement with the experimental value of 1.43 Å.
Additional Material:
1 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/mrc.1260270312
Permalink
