Abstract
Four new rotational lines, each of these divided into a multiplet by magnetic interactions, have been observed in the microwave spectrum of N14O216, bringing the total number of observed lines to five. A rigid rotor analysis has been performed to identify four of these, and probably the fifth. This new analysis removes the disagreement between McAfee's microwave assignment and Moore's infrared results, and explains the absence of N15O2 lines in the region search by Muller. Molecular parameters obtained are: angle ONO = 134° 15′, rN–O = 1.197 A. A combination rule for magnetic fine structure spacings is discussed. General conclusions are drawn regarding future investigations of asymmetric rotor free radicals.