ISSN:
0749-1581
Keywords:
β-Sulphinylenamines
;
Geometrical isomerism
;
NH chemical shifts
;
Temperature effects
;
15N chemical shifts
;
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
NOE experiments at low temperature were used to establish the structure of the E- and Z-isomers of the enamine ButSOCH=CHNHBut. The NOE experiments revealed large intermolecular NOE effects between E- and Z-isomers indicating the formation of dimers of specific orientation. NH chemical shifts and their temperature dependence showed that the E- and Z- isomers behave differently. The NH chemical shifts of the former go to higher frequencies on lowering the temperature, whereas the opposite holds for the (Z)-NH resonance. Similar trends are found on increasing the concentration. The orientation around the C1—N bond can be probed by 3J(H1,NH) or by 1J(N,H). The 15N chemical shifts were also investigated in a series of β-sulphinylenamines. They are mainly dominated by α- and β-effects and show only a slight dependence on the E/Z isomerism, which seems to indicate a weak hydrogen bond in the Z-isomer at high concentration. Pertinent NMR parameters are now available for a general structure determination of geometrical isomers of β-sulphinylenamines.
Additional Material:
1 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/mrc.1260320904
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