The vibrational modes of 1-oxyl-2,2'-disubstituted-3-one-indoline and
of 1-oxyl-2,2'-disubstituted-3-arylimino-indoline radicals have been a
ttributed and compared with those of a homogeneous series of 3-indolin
ones. The frequencies and profiles of C=O, C=N and Witkop bands depend
on the nature of the substituent in the 2-position and para to the ph
enylimino group. (C) 1997 Elsevier Science B.V.