D/H isotope effects in π-complexes of deuterated hexamethylbenzenes with the nitrosonium cation.

The isotope effects of deuterium, manifested in theC NMR spectra of complexes of deuterated hexamethylbenzenes C(CD)·(CH) with the nitrosonium cation, have been studied. The small values observed for the isotopic perturbation are evidence of π-bonding of the NO group the hexamethylbenzene molecule. The applicability of an additive scheme of calculation of isotope effects for the ring carbon atoms of the complexes, based on the increments of replacement of the CH group by CD in hexamethylbenzene, has been demonstrated. [ABSTRACT FROM AUTHOR]