13C NMR spectra of azachalcones
1981 ◽
Vol 46
(6)
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pp. 1486-1491
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Keyword(s):
13C Nmr
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13C NMR spectral parameters were obtained for chalcone and fourteen its aza- and diazaanalogues. Relative conformation of the carbonyl group with respect to the double bond was studied using changes in 3J(C(1')-Hα) and PCILO method. PCILO calculations together with experimental results show that with 2'-, 3'-, and 4'-azachalcones the s-cis isomer is the most stable form. Whereas the molecule of 2'-azachalcone is planar or nearly planar, in 3'- and 4'-azachalcones the carbonyl group and the olefinic bond planes make angle of 45°.
1979 ◽
Vol 34
(3)
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pp. 516-519
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1985 ◽
Vol 50
(5)
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pp. 1176-1183
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