Moazzen-Ahmadi, NasserYousefi Koopaei, Mahdi2015-07-202015-11-202015-07-202015http://hdl.handle.net/11023/2357Density Functional Theory (DFT) calculations using CAM-B3LYP hybrid functional were performed on the binary and ternary van der Waals complexes formed from CS2 and C2D2 monomers. Theoretical stationary structures were found. The geometrical parameters of stationary structures were optimized and their theoretical rotational constants were obtained. The calculations predict a planar parallel configuration with C2v symmetry as the lowest energy isomer of CS2-C2D2 dimer. These calculations also show that a T-shaped structure with C2v symmetry is the higher energy isomer. They also indicate that a twisted-barrel configuration with C2 symmetry is the minimum energy isomer of (CS2)2-C2D2 mixed trimer. In addition, the two minimum energy isomers of CS2-(C2D2)2 trimer were found. The global minimum structure has a distorted T-shaped C2D2 dimer unit with a CS2 monomer “above” the dimer and the higher energy isomer has a planar configuration. In agreement with the DFT calculations, rotationally-resolved infrared spectra of the parallel isomer of CS2-C2D2 and the twisted barrel shaped isomer of (CS2)2-C2D2 trimer were observed and simulated in the region of C2D2 v3 (~2439 cm-1) stretching fundamental. The complexes were generated in a supersonic slit-jet apparatus and probed using an Optical Parametric Oscillator (OPO). The observed band of CS2-C2D2 dimer is centered at 2438.16 cm-1 whereas the band for the (CS2)2-C2D2 trimer is centered at 2436.73 cm-1. Both bands indicate red shifts with respect to C2D2 v3 fundamental band origin (2439.244 cm-1). The observed rotational constants are in good agreement with those obtained from the DFT calculationsengUniversity 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.Physics--MolecularDensity Functional TheorySpectroscopyInfraredOptical Parametric Oscillatorcomplexmaster thesis10.11575/PRISM/26529