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Deuterium isotope effects on 13C NMR chemical shifts in 7,12-dimethylbenz[a]anthracene

✍ Scribed by D. W. Jones; J. D. Shaw

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

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✦ Synopsis

The 100.6MHz =C off-resonance-decoupled and polarization-lransfer NMR spectra of 7,12dimethylbenz[a]anthracene and its 5-deuteriated analogue in deuteriated chloroform solution enabled assignments of the shifts of C-3 and C-5 to be revised, and other spectral ambiguities to be reduced. Negative, i.e. upfield, deuterium-induced secondary isotope shifts, A6 = 6(C ---D) -6(C --* H), were evident over one, two, three and four bonds and, also, small apparently significant positive shifts to the methyl carbons at the 7-and 12-positions, i.e. over five and six bonds, respectively. "C-IH coupling constants were unaffected by the deuteriation.

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