In:
Magnetic Resonance in Chemistry, Wiley, Vol. 54, No. 2 ( 2016-02), p. 126-131
Abstract:
We report through‐space (TS) 19 F– 19 F coupling for ortho ‐fluoro‐substituted Z ‐azobenzenes. The magnitude of the TS‐coupling constant ( TS J FF ) ranged from 2.2–5.9 Hz. Using empirical formulas reported in the literature, these coupling constants correspond to non‐bonded F–F distances ( d FF ) of 3.0–3.5 Å. These non‐bonded distances are significantly smaller than those determined by X‐ray crystallography or density functional theory, which argues that simple models of 19 F– 19 F TS spin–spin coupling solely based d FF are not applicable. 1 H, 13 C and 19 F data are reported for both the E and Z isomers of ten fluorinated azobenzenes. Density functional theory [B3YLP/6‐311++G(d,p)] was used to calculate 19 F chemical shifts, and the calculated values deviated 0.3–10.0 ppm compared with experimental values. Copyright © 2015 John Wiley & Sons, Ltd.
Type of Medium:
Online Resource
ISSN:
0749-1581
,
1097-458X
Language:
English
Publisher:
Wiley
Publication Date:
2016
detail.hit.zdb_id:
1475029-6
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