Systematical study on photodissociation dynamics of BrCN from 225 nm to 260 nm

Abstract

The photodissociation dynamics of Br − C bond cleavage for BrCN in the wavelength region from 225 nm to 260 nm has been studied by our homebuilt time-slice velocity-map imaging setup. The images for both of the ground state Br(2P3/2) and spin-orbit excited Br*(2P1/2) channels are obtained at several photodissociation wavelengths. From the analysis of the translational energy release spectra, the detailed vibrational and rotational distributions of CN products have been measured for both of the Br and Br* channels. It is found that the internal excitation of the CN products for the Br* channel is colder than that for the Br channel. The most populated vibrational levels of the CN products are v=0 and 1 for the Br and Br* channels, respectively. For the Br channel, the photodissociation dynamics at longer wavelengths are found to be different from those at shorter wavelengths, as revealed by their dramatically different vibrational and rotational excitations of the CN products.

A New Band System of the Dicarbon Molecule in the Vacuum Ultraviolet Region

“…The experiment was performed on a modified time-of-flight mass spectrometer, which is equipped with a tabletop tunable VUV laser radiation source generated by the two-photon resonance-enhanced four-wave mixing scheme. − The detailed experimental procedures are provided in the Supporting Information. Briefly, C 2 molecules were produced by a homemade dc discharge setup followed by the supersonic expansion of 0.5% acetylene (C 2 H 2 ) seeded in Ar.…”

Spectroscopic Study of a New Electronic Band System 33Δg-a3Πu of C2

“…The experimental setup, which includes a time-of-flight (TOF) mass spectrometer and a tunable VUV laser source, has been described in detail elsewhere. ,− The C 2 molecules are produced in a supersonic expansion of C 2 H 2 (0.5%) seeded in argon gas (4 bar) followed by a DC discharge (800–1000 V, duration of 200 μs) device. A filament is put in front of the discharge device to stabilize the discharge process.…”

Core-level spectroscopy of the photodissociation process of BrCN molecule

“…[3] The photodissociation of XCN is a key process in the atmospheric chemistry of halogens and nitrogen, as it can lead to the formation of halogen atoms, which can then react with other atmospheric species, leading to the formation of halogen oxides and other reactive intermediates. [4] Meanwhile, the CN radical is recognized as one of the most significant species in interstellar space, planetary atmospheres, and cometary coma. [5] XCN, the simplest linear triatomic molecule, has attracted significant attention for its photodissociation dynamics in the A continuum (210 nm-350 nm).…”

“…[5] XCN, the simplest linear triatomic molecule, has attracted significant attention for its photodissociation dynamics in the A continuum (210 nm-350 nm). [6][7][8][9][10][11][12][13][14][15] Two reaction channels have been established through early-stage experimental and theoretical studies [4,16] XCN + hν → X * ( 2 P 1/2 ) + CN(X 2 Σ + ), XCN + hν → X( 2 P 3/2 ) + CN(X 2 Σ + ).…”

“…[30] Yin et al studied the photodissociation dynamics of BrCN from 225 nm to 260 nm by time-slice VMI setup, and their findings showed that the internal excitation of CN products in the Br* channel is colder than Br channel, in addition, the photodissociation dynamics at longer wavelengths is found to be different from those at shorter wavelengths in the Br channel. [4] Costen et al used high-resolution transient frequency modulated absorption spectroscopy to study the nascent Doppler profiles of CN fragments from the A band photodissociation of room temperature ICN. [31] Gao et al investigated the dissociative electron attachment process with high-resolution anion VMI apparatus.…”