Mid infrared investigation of vinyl fluoride-N2O and 1,1-difluoroethylene-N2O weakly bound dimers

Date
2023-09-22
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Abstract
Investigating weakly bound complexes can provide insights into the nature of intermolecular interactions. Understanding the nature of these interactions are important as they play a crucial role in various physical, chemical and biological processes. Vinyl fluoride, 1,1-difluoroethylene and N2O are industrially important molecules. Anthropogenic emission makes these gases adequately abundant in atmosphere. Therefore, recognizing their complexation properties are vital to industrial and atmospheric chemistry. By studying the infrared spectra of these weakly bound complexes, we can gain a better understanding of their structure and stability. The work outlined in this thesis analyses the results obtained for vinyl fluoride-N2O (C2H3F-N2O) and 1,1-difluoroethylene-N2O (C2H2F2-N2O) dimers. Infrared spectra for fundamental bands of C2H3F-N2O and C2H2F2-N2O dimers were recorded in the ν3 asymmetric stretching region of N2O (~ 2223 cm-1). These weakly bound dimers were formed in a supersonic jet expansion apparatus and probed using a tunable external cavity quantum laser setup (EC-QCL). The van der Waals dimers observed have top bonded planar structures, similar results were obtained for their CO2 bonded counter parts. Geometry optimizations for these N2O bonded dimers were carried out at MP2 level of theory in conjunction with 6-311++G(2d,2p) basis set. The binding energy calculations were performed at the same level of theory and corrected for BSSE and ZPE. The experimental rotational constants are in agreement with the ab initio calculated values. However, the experimental evidence contradicts the predicted theoretical stability order. Similar results were found for their CO2 bonded counterparts. More experimental studies on N2O and CO2 bonded isomers of these dimers and ab initio calculations at a higher level of theory are required to address the discrepancies between the experimental findings and the stability order.
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Keywords
rovibrational spectroscopy
Citation
Seyyadu Muhammadu, I. A. M. (2023). Mid infrared investigation of vinyl fluoride-N2O and 1,1-difluoroethylene-N2O weakly bound dimers (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.