AB-INITIO CONFIGURATION-INTERACTION CALCULATION OF ISOTROPIC SPIN-DENSITIES IN NITRONYL AND IMINONITROXIDES

A complete ab initio optimization of the unsubstituted nitronyl and im inonitroxides was performed at the UHF-SCF level, using a 6-311G* bas is set, followed by a gradient optimization of the NO bond at the MP2 level. Experimental structural and spectroscopic findings are well rep roduced by the calculations. A precise attribution of the couplings of the two inequivalent nitrogens in the iminonitroxide has been achieve d, underlining the need for highly correlated wave functions in order to obtain accurate results.