Intermolecular vibrational frequencies of the C-bonded CO2CO dimer and observation of HeCO2CO trimers

• Published in: Chemical physics letters Vol. 651; pp. 62 - 65
• Main Authors: Barclay, A.J., Sheybani-Deloui, S., Michaelian, K.H., McKellar, A.R.W., Moazzen-Ahmadi, N.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.05.2016
• ISSN: 0009-2614; 1873-4448
• DOI: 10.1016/j.cplett.2016.03.019

•Determination of intermolecular mode frequencies for the lowest energy C-bonded form of COCO2.•Values of 24.34cm−1 for the in-plane CO rock and 43.96cm−1 for the out-of-plane CO rock were measured.•New results are reported for two isomers of 12C18O2-substituted of the COCO2.•Weak bands were tentatively assigned to two isomers of HeCO2CO trimer. Infrared spectra of the CO2CO dimer are observed in the carbon monoxide CO stretch region (≈2150cm−1). Combination bands yield the first experimental determinations of intermolecular mode frequencies for the planar T-shaped C-bonded form (‘isomer 1’): 24.34cm−1 for the in-plane CO rock and 43.96cm−1 for the out-of-plane CO rock. These values are significantly higher than the analogous modes of the O-bonded form (‘isomer 2’), previously determined to be 14.19 and 22.68cm−1, respectively. New results are also reported for both isomers of the 12C18O2-substituted form of the dimer. Weak ‘satellite bands’ observed for both isomers are tentatively assigned to the trimer HeCO2CO.