ISSN:
0749-1581
Keywords:
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The 1H and 13C NMR spectra of 4,4′-bis(N-isopropyl-N-nitrosoamino)biphenyl at 22°C were consistent with the presence of three isomers due to slow rotation about the N - N bonds of the two N-nitroso groups. The structures of the three isomers were assigned by means of their symmetries and from the known effects of the two orientations of the N-nitroso group on 1H and 13C NMR chemical shifts. Each conversion of an N-nitroso group from anti to syn to an aryl group was associated with the same free energy difference (0.26 kcal mol-1) after symmetry corrections were made. The changes in the 13C NMR spectra recorded from 95 to 150°C were simulated using a program for classical four-site exchange. The potential barrier to rotation was calculated to be 20.76±0.06 kcal mol-1 at 400 K.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/mrc.1260240705
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