Observation of the missing polar OCS dimer

A new infrared band at 2069.3 cm(-1) is observed and assigned to the long-anticipated polar isomer of the OCS dimer, helping to explain apparent discrepancies among earlier studies. The data reported here should enable direct observation of the microwave spectrum of polar (OCS)(2) and motivate new theoretical works on the energetics of OCS dimer isomers and interconversion energy barriers. (c) 2007 American Institute of Physics.