Fourier transform microwave spectra of a “new” isomer of OCS-CO2

Abstract

The rotational spectrum of a "new" isomer of OCS-CO(2) has been measured between 5 and 18 GHz using Fourier transform microwave spectroscopy. Both a- and b-type transitions of the parent dimer and the (13)CO(2)-containing isotopologue were fit and the resulting spectroscopic constants confirm that this is the planar O-interior, not-quite-as-parallel isomer that was experimentally observed for the first time in the recent infrared investigation of Dehghany et al. [J. Chem. Phys. 130, 224310 (2009)]. As in the infrared study, the microwave transitions of this isomer appear stronger than those of the previously reported lower energy isomer of OCS-CO(2) when helium is used as the backing gas for the supersonic expansion.

Investigation of structural trends in difluoropyridine rings using chirped-pulse Fourier transform microwave spectroscopy and ab initio calculations

“…Samples of each compound were prepared as a gas mixture of 0.04-0.08% difluoropyridine in neon and delivered to the pulsed nozzle with a backing pressure of 5-10 psi. These initial survey spectra guided our experiments using the more sensitive Balle-Flygare FTMW spectrometer [12] which was used to record individual hyperfine components with higher resolution ($7 kHz FWHM) and to seek lower intensity transitions. Gas mixtures for the FTMW measurements were more dilute (0.03%) and maintained at a higher backing pressure (80 psi) to optimize the signal.…”

Theoretical studies of the N2O van der Waals dimer: Ab initio potential energy surface, intermolecular vibrations and rotational transition frequencies

“…1 It has been reported that one molecule of N 2 O has approximately 300 times the greenhouse warming potential of one molecule of CO 2 . The van der Waals (vdW) complexes of these "CO 2 family" molecules, especially their dimers [4][5][6][7][8][9][10][11][12][13][14][15][16][17] and trimers, [18][19][20] have been the focus of both experiment and theory over the past few years. 2,3 Therefore, the N 2 O molecule and N 2 O-including complexes are of particular interest in the field of atmospheric chemistry.…”

“…2,3 Therefore, the N 2 O molecule and N 2 O-including complexes are of particular interest in the field of atmospheric chemistry. 16 Some interesting questions were raised, such as the relative stability of the isomers and the interconversion mechanism between these isomers. The wellknown "CO 2 family" of molecules consists of CO 2 , N 2 O and OCS, due to their isovalent electron number.…”

A combined ab initio, Fourier transform microwave and Fourier transform infrared spectroscopic investigation of β-propiolactone: The ν8 and ν12 bands

“…The microwave spectrum of b-propiolactone was recorded using a Balle Flygare-type Fourier transform microwave (FTMW) spectrometer that has been described previously [11]. In comparison to older microwave techniques, linewidths on the order of 7 kHz can be achieved with FTMW spectroscopy and line positions are rou- tinely measured to an accuracy of ±1 kHz.…”