ANDREA J. MINEI AND STEWART E. NOVICK, Department of Chemistry, Wesleyan University, Middletown, CT 06459.
Recently Afshari and coworkers reported on the detection of a new infrared band which was assigned to the ``long-anticipated polar isomer of the OCS dimer''. We report here the microwave confirmation of their results. The lowest energy, non-polar isomer of (OCS)2 has long been known from IR spectroscopy, while the polar form has only been deduced from qualitative beam ``refocussing'' experiments. The higher energy, polar isomer of (OCS)2 has been produced by high pressure expansion of dilute OCS in helium. A surprisingly strong microwave spectrum of Cs (OCS)2 has been observed and assigned. The structure of the dimer has been determined.