Infrared absorption spectroscopy of rare-gas ? CO2 clusters produced in supersonic expansions

Abstract

Infrared absorption spectra are reported for rare-gas-carbon dioxide van der Waals complexes in the region of the v3 fundamental vibrational transition of C 0 2 using a pulsed molecular beam and a diode laser. The observed linewidths of 90 MHz (f.w.h.m.) allowed the determination of rotational constants for the ground and first excited vibrational states along with the frequencies of the band origins and centrifugal distortion constants which were constrained to be equal in both vibrational states. Effective structures of the complexes have been determined.

Study of the Rotational Spectrum of the Ne–N2O van der Waals Dimer with a Fourier Transform Microwave Spectrometer

“…The values of the inertial defects ⌬ 0 of the various isotopomers listed in Table 2 are in the order of 3.1 amu Å 2 . Similar magnitudes have also been observed for other related van der Waals complexes with planar equilibrium geometries, for example, 4.4 amu Å 2 for Ne-OCS (5) and 3.9 amu Å 2 for Ne-CO 2 (10). The values for ⌬ Z are on the order of 0.085 amu Å 2 .…”

Lineshape analysis of stimulated Raman spectra of the near‐nozzle region of free jet expansions

“…This line profile was finally attributed [5] to clustering that is concentrated on the axis and depletes the proportion of monomers with Doppler shift around zero, yielding a dip in the absorption profile. This type of infrared absorption lineshape has been also observed in pulsed expansions of mixtures of CO 2 with rare gas, [38] in continuous expansions of methane, [6] though no absorption features attributable to methane clusters could be found by the authors of this last work, and in continuous expansions of acetylene. [11] Other works using FTMW spectroscopy on pulsed expansions of OCS and rare gas complexes of OCS have described a Doppler splitting of rotational lines, [39] concluding that much of this doubling effect is based on an axial depletion of the monomer in the core of the jet because of polymerization.…”

High-Resolution Infrared Diode Laser Spectroscopy of Ne–N2O, Kr–N2O, and Xe–N2O

“…[7] b The values were estimated using the combining rule (see text). The resulting change in the well depth is given by Copyright ᭧ 1998 by Academic Press…”

“…Consequently, there have been numerous previous studies on Although individual van der Waals ''bonds'' are much the interactions of these molecules with a variety of species. weaker than normal chemical bonds, a number of possible In particular, complexes associated with rare gas atoms and interactions in these systems lead to a significant effect on CO 2 (7)(8)(9)(10)(11) or OCS (12, 13) have been thoroughly studied properties and structures. A substantial amount of research experimentally.…”