,3,3,4,4,5,5,5-NONAFLUOROPENTYL)IMIDAZOLIDIN-4-ONE AT 100-K

The imidazolidinone ring of the title compound, C20H21F9N2O2(2), adopt s an envelope conformation with the tert-butyl and nonafluoropentyl gr oups in a trans arrangement with respect to the ring. The angles at ea ch N atom total nearly 360 degrees, indicating a very small degree of pyramidalization at the two amides. The torsional angles C(1)-N(2)-C(2 )-O(1), C(3)-N(1)-C(4)-O(2) and C(1)-N(1)-C(4)-O(2) deviate from 180 o r 0 degrees by 7.1, 25.5 and 10.4 degrees, respectively. This is consi stent with considerable conjugative stabilization in both amide groups .