Unstable intermediates. Part L. The NO3 2? impurity centre in irradiated calcium carbonate

Abstract
The radical NO3 2–, prepared by the action of γ-rays on calcium carbonate doped with nitrate, has been identified by its e.s.r. spectrum and is found to be remarkably stable in this host lattice. The results are used to obtain a 2p/2s value of 7·8 for the molecular orbital of the unpaired electron on nitrogen. This is compared with the results for the isoelectronic radicals CO3 3–(5·25) and CF3(3) and reasons for the marked differences are proposed.