The microwave rotational spectrum of the van der Waals complex Kr–N2

Abstract

Pure rotational transitions in the vibrational ground state of the van der Waals complex Kr–N2 have been measured using a cavity microwave Fourier transform spectrometer. For the isotopomers 84Kr–14N2, 86Kr–14N2, 84Kr–15N2, 86Kr–15N2, 82Kr–15N2, and 83Kr–15N2 a-type transitions with Ka=0 and 1 have been measured, confirming a C2v symmetry of the complex. A value for the 14N nuclear quadrupole coupling constant in free nitrogen 14N2 has been estimated from an analysis of the nuclear hyperfine structure in complexes of 14N2. 15N spin–rotation hyperfine structure could be observed and analyzed in the 21,2–11,1 and 21,1–11,0 rotational transitions of 84Kr–15N2. Rotational transitions of 83Kr–15N2 showed a nuclear hyperfine splitting due to 83Kr with nuclear spin 9/2 which has been attributed to the weak bonding with 15N2. For 84Kr–14N15N and 86Kr–14N15N, only transitions involving energy levels with Ka=0 have been found.