Subhyphen;Doppler infrared spectrum of the carbon dioxide trimer

摘要

A spectrum of the carbon dioxide trimer van der Waals species has been recorded near 3614 cmminus;1at subhyphen;Doppler resolution using an optothermal (bolometerhyphen;detected) molecularhyphen;beam colorhyphen;center laser spectrometer. A planar, cyclic structure withC3hsymmetry has been determined for the complex with a carbonndash;carbon separation of 4.0382(3) Aring;. The observed perpendicular band, corresponding to an inhyphen;planeEprime;hyphen;symmetry vibration of the trimer, has been attributed to a localized excitation of the 2ngr;02+ngr;3combination mode of a CO2subunit by virtue of its small blue shift (sim;0.98 cmminus;1) from that of the isolated monomer.