15min:
THE ROTATIONAL SPECTRUM OF CHLORINE NITRATE (ClONO2) IN THE THREE LOWEST n nu9 POLYADS.

Z. KISIEL, E. BIA\L KOWSKA-JAWORSKA, Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warszawa, Poland; R. A. H. BUTLER, Department of Physics, Pittsburg State University, Pittsburg, KS 66726; D. T. PETKIE, Department of Physics, Wright State University, Dayton, OH 45435; P. HELMINGER, Department of Physics, University of South Alabama, Mobile, AL 36688; F. C. DE LUCIA, Department of Physics, The Ohio State University, Columbus, OH 43210.

The rotational spectrum of the stratospherically important ClONO2 molecule has recently been subjected to an extended analysis, which covered four states ranging from the ground state to the nu5/ nu6 nu9 dyad at ~560 cm-1. The analysis was based on a newly recorded broadband FASSST spectrum with an almost complete coverage of the 118-378 GHz region.

.2cm

The remaining vibrational states below 560 cm-1 are the three polyads associated with successively higher excitation of the nu9 mode. These are the (2 nu9/ nu7) dyad, the (3 nu9/ nu7 nu9) dyad, and the (4 nu9/ nu72 nu9/2 nu7) triad. Rotational transitions in the triad were assigned for the first time and data sets for the two dyads were considerably improved over those obtained previously. Transition frequencies in all three polyads, for both 35ClONO2 and 37ClONO2, were fitted to within experimental accuracy by using a new coupling scheme which accounted in a unified manner for the pertinent Fermi and Coriolis interactions. Various tests used to ensure that the 'true' solution has been reached are discussed.