Moazzen-Ahmadi, NasserBarclay, Aaron James2022-07-262022-07-262022-07-12Barclay, A. J. (2022). Mid Infrared Investigations of Van Der Waals Complexes of Atmospheric Molecules (Water, CO, CO2, N2) (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.http://hdl.handle.net/1880/114878https://dx.doi.org/10.11575/PRISM/39937Mid infrared investigation into van der Waals complexes containing atmospheric molecules (water, CO, CO2 and N2) are studied by their rovibrational spectra. Complexes are generated using a pulsed supersonic slit jet apparatus and are studied using an optical parametric oscillator or quantum cascade laser radiation source. Investigations of water-CO complexes include H2O-CO, D2O-CO, HOD-CO and DOH-CO in the CO stretch region (~2200 cm-1 ) and the O-D stretch region (2700 cm-1 ) when applicable. Larger complexes of (water)n-CO, where n = 2, 3 or 4 are studied in the CO stretch region. The measurements for the dimers H2O-CO and D2O-CO are used to validate recent theoretical work and new quantum chemical calculations are employed to aid in determining geometry of larger complexes. Infrared bands of water dimer in the O-D stretch region (~2600-2800 cm-1 ) are measured and investigations into tunneling splittings and lifetimes are discussed. Although previously studied, our new measurements return to the assigned spectral bands with an experimental width at least a tenth smaller, resolving the six tunneling states for the first time in the O-D stretch region. Trimer and tetramer sized complexes containing CO2 with CO and/or N2 are probed in the CO2 asymmetric stretch region (~2350 cm-1 ). Assignments are aided by new high level ab initio calculations. The trimers studied include, (CO2)2-CO, (CO2)2-N2, CO2-(CO)2, CO2-(N2)2 and CO2-CO-N2. The tetramers studied include, CO2-(CO)3 and CO2-(N2)3, CO2-(CO)2-N2 and CO2- CO-(N2)2.engUniversity of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.SpectroscopyInfraredvan der Waals complexesClustersSupersonic jet expansionPotential energy surfaceOPOQCLAtmospheric moleculesWaterEducation--SciencesBiology--MolecularChemistry--RadiationPhysicsAtmospheric Sciencedoctoral thesis