Mode specific photodissociation of CS2+via the A2Πu state: a time-sliced velocity map imaging study

Abstract

The vibrationally mediated photodissociation of CS(2)(+) cations via the A(2)Π(u)(ν(1),ν(2),0) state has been studied by means of the velocity map ion imaging technique. The measurements were made with a double resonance strategy. The CS(2)(+) cations were prepared by a (3 + 1) resonance enhanced multiphoton ionization method. The photo-fragment excitation spectrum of S(+) was recorded by scanning the photolysis laser via the A(2)Π(u)(ν(1),ν(2),0) state. By fixing the photolysis laser wavelength at the specific vibrational state, the (1 + 1) photodissociation images of S(+) photofragments from numerous vibrationally mediated states have been accumulated. The translational energy release spectra derived from the resulting images imply that the co-fragments, CS radicals, are both vibrationally and rotationally excited. The one-photon photodissociation without the vibrational state selection has also been performed. Comparing the vibrationally mediated photodissociation with one-photon photodissociation observations, clear evidence of vibrational state control of the photodissociation process is observed.

High-Resolution Imaging Study on Photodissociation of OCS+ [A2ΠΩ=1/2,3/2 (ν1 0 ν3)]

“…Molecular ions are important constituents and exert significant impacts on numerous chemical reaction processes in interplanetary and terrestrial atmospheres. , The linear triatomic molecules, such as CO 2 , CS 2, and carbonyl sulfide (OCS), along with their corresponding cations, serve as the basic model for exploring important intramolecular interactions, including the spin–orbit interaction, vibrational coupling (Renner–Teller effect), and Fermi resonance. − While numerous in-depth investigations of photodissociation dynamics have been conducted in molecules at a quantum state-resolved level, , there have been comparatively few studies undertaken on molecular ions. The application of resonance-enhanced multiphoton ionization (REMPI) to selectively generate molecular ions in specific quantum states, combined with the implementation of double-resonance strategies, has significantly expanded the scope of research on the photodissociation of molecular ions in the past few decades. − The introduction of high-resolution velocity map ion imaging (VMI) techniques for detection allows for the acquisition of more intricate details regarding product ions, providing deeper insights into photodissociation dynamics.…”

Bonding, Thermodynamics, and Dissociation Dynamics of NiO+ and NiS+ Determined by Photofragment Imaging and Theory

“…Further experimental studies on the electronic structure and dynamics of NiO + and NiS + are needed to bolster theory and to better understand chemical bonding and thermodynamics in these systems. Photofragment velocity map imaging (VMI) has proven to be a useful experimental tool for measuring precise bond dissociation energies and dissociation dynamics in small molecules − and ions. ,− When complemented with spectroscopic measurements and theory, VMI gives an informative picture of how a photoexcited molecule moves around its potential energy surfaces. In this study, we probe the electronic structure, thermodynamics, and photodissociation dynamics of NiO + and NiS + with a combination of theory, photofragment spectroscopy, and ion velocity map imaging.…”

Note: Vibrationally mediated photodissociation of carbon dioxide cation

“…The experiments were performed on a home-built VMI apparatus, details of which and the experimental procedures can be found elsewhere. [10][11][12][13] A schematic diagram of the relevant energetics of CO 2 and CO + 2 is given in Fig. 1(a).…”