ISSN:
0749-1581
Keywords:
13C NMR
;
15N NMR
;
Thioureas
;
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
13C and 15N NMR chemical shifts were measured for N1-alkyl-N2-arylthioureas. The absence of decoalescence of the N1-alkyl group carbon signals down to 190 K, the europium-induced chemical shifts and the molecular mechanics calculations indicate that the preferred conformation is E,Z. Solvent effects suggest that N1-alkyl-N2 arylthioureas exist as dimers, forming an eight-membered ring hydrogen bonded complex. In N1, N1-dimethyl-N2-phenylthiourea the barrier to rotation around the C—N1 bond is 47 kJ mol-1 (from 13C NMR, in CD2Cl2). The upfield N1-CH3 signal in both the 1H and 13C NMR spectra results from the methyl group anti to the C=S and the low-field signal from the syn methyl group.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/mrc.1260310413
