Characterization Of The A²Σ⁺ State Of Sh/sd Radicals By Photodissociation Spectroscopy

Qin, Yuan

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https://hdl.handle.net/2142/111269 Copy

Description

Title

Characterization Of The A²Σ⁺ State Of Sh/sd Radicals By Photodissociation Spectroscopy

Author(s)

Qin, Yuan

Contributor(s)

• Zhang, Jingsong
• Sun, Ge
• Song, Yu
• Zheng, Xianfeng

Issue Date

2021-06-25

Keyword(s)

Small molecules

Abstract

Vibrational levels of the A$^{2}\Sigma^{+}$ state of SH ({\it v}$^{\prime}$ = 0-7) and SD ({\it v}$^{\prime}$ = 0-8) radical are investigated via photodissociation using high-{\it n} Rydberg atom time-of-flight technique. By measuring the H-atom product translational energy distributions, contributions from overlapping transitions can be separated, and the H/D-atom photofragment yield (PFY) spectra are obtained across various SH/SD A$^{2}\Sigma^{+}\gets$ X$^{2}\Pi$ rovibrational bands. The upper A$^{2}\Sigma^{+}$ state vibrational levels {\it v}$^{\prime}$ = 5-7 of SH and {\it v}$^{\prime}$ = 3-8 of SD are observed for the first time. Analysis of the PFY spectra using the simulation program PGOPHER\footnote{Western, {\it J. Quant. Spectrosc. Radiat. Transfer}, 186, 221 (2016)} gives vibrational origins along with rovibrational linewidths of the A$^{2}$$\Sigma$$^{+}$ state of SH/SD. The fitted linewidths in the PFY spectra for SH {\it v}$^{\prime}$ = 1-6 and SD {\it v}$^{\prime}$ = 2-6 states are broad ($\ge$ 1.5 cm$^{-1}$), demonstrating that those levels undergo rapid predissociation with lifetimes on the order of picosecond. While the lifetime of SD {\it v}$^{\prime}$ = 0, {\it N}$^{\prime}$= 1 and 2 levels are determined to be 247 $\pm$ 30 ns and 168 $\pm$ 40 ns from pump-probe time delay measurements, respectively. The experimental lifetimes are in reasonable agreement with the theoretical predictions.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

Text

Language

eng

Permalink

http://hdl.handle.net/2142/111269

DOI

10.15278/isms.2021.FD13

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