Carbon-13 chemical shift tensors in aromatic compounds. 4. Substituted naphthalenes

Journal Article · Wed Apr 08 04:00:00 EDT 1992 · Journal of the American Chemical Society

DOI:https://doi.org/10.1021/ja00034a012· OSTI ID:236333

Orendt, A M; Sethi, N K; Facelli, J C; Horton, W J; Pugmire, R J; Grant, D M ^[1]

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1. Univ. of Utah, Salt Lake City, UT (United States)

The principal values of the {sup 13}C chemical shift tensor were measured for the aromatic carbons of 1,4,5,8-tetramethylnaphthalene, 1,2,3,6,7,8-hexahydropyrene, and pyracene using the variable angle spinning technique. Ab initio calculations of the complete shielding tensors are also reported and provided the orientation of the principal values in the molecular frame. Good agreement between theory and experiment is obtained. The chemical shift principal values and orientations of these substituted napthalenes correspond to those found in napthalene; the observed differences can be rationalized in terms of the strain introduced by the alkyl substituent. In the napthalenic derivatives studied; the bridgehead carbons exhibit relatively extensive {pi}-electron delocalization not found in some bridgeheads in more highly condensed aromatic systems. 30 refs., 3 fig., 1 tab.

• Sponsoring Organization: USDOE
• OSTI ID: 236333
• Journal Information: Journal of the American Chemical Society, Journal Name: Journal of the American Chemical Society Journal Issue: 8 Vol. 114; ISSN JACSAT; ISSN 0002-7863
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
ALKYLATED AROMATICS
CARBON 13
CHEMICAL SHIFT
CONDENSED AROMATICS
MATHEMATICAL MODELS
NUCLEAR MAGNETIC RESONANCE