## Files in this item

FilesDescriptionFormat

application/vnd.openxmlformats-officedocument.presentationml.presentation

1219174.pptx (3MB)
PresentationMicrosoft PowerPoint 2007

application/pdf

3322.pdf (18kB)
AbstractPDF

## Description

 Title: SUB-DOPPLER INFRARED SPECTROSCOPY OF JET COOLED HCCL DIRADICAL: THE CH STRETCH AND VIBRATIONAL COUPLING IN THE GROUND ELECTRONIC STATE Author(s): Scrape, Preston G. Contributor(s): Nesbitt, David; Lesko, Daniel; Kortyna, Andrew Subject(s): Radicals Abstract: Diradical carbenes have long been recognized as important intermediates in a range of chemical processes, with the carbene's chemical reactivity being sensitive to the particular ground-state electronic structure. We have undertaken an investigation of chlorocarbene (HCCl) by seeding CHCl$_3$ into a Ne/He/H$_2$ mixture and passing this mixture through a pulsed slit discharge. In the discharge environment, the CHCl$_3$ undergoes a double Cl atom removal process through a combination of electron dissociative attachment and hydrogen abstraction. The subsequent jet expansion cools the HCCl diradical to a 32 K rotational temperature. With the goal of assisting the search for HCCl chemistry in interstellar molecular clouds, the rotational constants for the ground singlet state of both the $^{35}$Cl and $^{37}$Cl isotopologues are determined through least-squares fits of ground-state combination differences to an asymmetric top Watson Hamiltonian. A Watson Hamiltonian is also used to extract rotational constants for the nominally (100) vibrationally excited state, with a highly mixed combination band (nominally (012), one quantum of H-C-Cl bend plus two quanta of C-Cl stretch) of comparable intensity found within a few wavenumbers (cm$^{-1}$) of the CH stretch band origin. The proximity of these two bands and the comparable infrared intensities of both combination and fundamental bands points towards a highly mixed state with strong anharmonic coupling between these two zeroth order modes. We quantify the anharmonic coupling in a 2x2 matrix deperturbation treatment and find it to be similar in magnitude to the previously measured spin-orbit coupling constants between the singlet and nearby lying triplet manifold of states. Issue Date: 06/20/18 Publisher: International Symposium on Molecular Spectroscopy Citation Info: APS Genre: Conference Paper / Presentation Type: Text Language: English URI: http://hdl.handle.net/2142/100703 DOI: 10.15278/isms.2018.WD01 Other Identifier(s): WD01 Date Available in IDEALS: 2018-08-172018-12-12
﻿