State-selected photodissociation dynamics of CS2+ in the C̃  2Σg+ state

Abstract

Articles you may be interested inDissociation of internal energy-selected methyl bromide ion revealed from threshold photoelectron-photoion coincidence velocity imaging J. Chem. Phys. 140, 044312 (2014); 10.1063/1.4862686Photodissociation mechanisms of the CO2 2+ dication studied using multi-state multiconfiguration second-order perturbation theory [1 + 1] photodissociation of CS 2 + ( X ̃ 2 Π g ) via the vibrationally mediated B ̃ 2 Σ u + state: Multichannels exhibiting and mode specific dynamics J. Chem. Phys. 134, 114309 (2011); 10.1063/1.3567071 Unimolecular decay pathways of state-selected CO 2 + in the internal energy range of 5.2-6.2 eV: An experimental and theoretical study State-selected photodissociation dynamics of CS 2 ϩ molecular ion has been investigated by an optical-optical double resonance technique. The CS 2 ϩ molecular ions were prepared by ͓2ϩ1͔ REMPI and the predissociative C 2 ⌺ g ϩ state was populated by the B 2 ⌺ u ϩ ←X 2 ⌸ g,3/2 followed byThe product branching ratios, CS ϩ /S ϩ , for selected vibrational levels in the C state and average kinetic energy releases in the CS ϩ and S ϩ production channels were measured from the time-of-flight mass spectra. It has been found that excitation of the bending vibration enhances the CS ϩ production channel more than the S ϩ channel. In addition, an isotropic fragment distribution for different polarizations of the dissociating laser light has been observed, from which the dissociation time was estimated to be longer than 20 ps. Dynamical aspect of the reaction revealed by the present investigation is discussed together with the previous spectroscopic results.

Study on the Photodissociation Spectra of CS2+ via B̃2Σu+ and C̃2Σg+ Electronic States

“…Also listed in Table are the spectral data deduced from the emission spectrum 12 and the photoionization spectrum . Although the photoexcitation of the B̃ 2 Σ u + (000) ← X̃ 2 Π g,3/2 (000) transition was used in previous studies, − the report about the photoexcitation spectrum of the B̃ 2 Σ u + (υ 1 υ 2 0) ← X̃ 2 Π g,3/2 (000) transition has gone largely unnoticed until now. Since the vibrational frequencies of CS 2 + have the approximation ν 1 ∼ 2ν 2 , Fermi resonance interaction is expected to occur between the (υ 1 ,υ 2 ,υ 3 ) and (υ 1 −1,υ 2 +2,υ 3 ) vibrational levels.…”

“…As an important species in astrophysics and atmospheric physics, the spectroscopy and dissociation dynamics of the linear CS 2 + ion have been studied by a variety of experimental techniques. − Optical emission from the à and B̃ states of CS 2 + was observed, and the vibrational frequencies and rotational constants were precisely determined from the spectra. , The dissociation dynamics from the electronically excited states of CS 2 + were also studied by mass spectroscopy, electron impact technique, photoelectron photoion coincidence spectroscopy, and photofragment excitation spectroscopy. − The C̃ state of CS 2 + was found to be totally predissociative and correlated to the CS + and S + fragment ions. Eland and co-workers 2 provide an interpretation for predissociation of the C̃ state, beginning with internal conversion to high vibrational levels of a lower state, perhaps the B̃ state (through odd ν 3 vibrational coupling), that is, the vibronic coupling between two electronic states.…”

“…Momigny et al presumed that the predissociations of the B̃ 2 Σ u + and C̃ 2 Σ g + states by the 4 Σ - state can take place via the large spin−orbit coupling, the slower predissociaton process of the C̃ 2 Σ g + state can be attributed to the vibronic coupling between the C̃ 2 Σ g + and 2 Σ - states, where 4 Σ - and 2 Σ - are fully repulsive states. Two-photon absorption spectroscopy with a mass-selected beam of CS 2 + was used to study the predissociative C̃ state of CS 2 + by Maier and co-workers 4,5 and recently by Hwang et al The rotationally resolved absorption spectrum of the C̃ state of CS 2 + was obtained, and the predissociative lifetime of each vibrational level in C̃ state was determined from the line width of a single rovibrational transition. , From the product branching ratios, CS + /S + , for selected vibrational levels in the C̃ state and the average kinetic energy releases in the CS + and S + production channels measured from time-of-flight mass spectra, Hwang et al . concluded that the excitation of the bending vibration enhances the CS + production channels more than the S + channel.…”

Ultrafast dynamics and dissociative ionization of CS2 molecules studied via the femtosecond pump-probe method

“…Thus, a one-photon 267-nm excitation process will not occur. According to the (2+1) REMPI experimental study by Morgan et al [15], [21].…”

“…Rydberg series were investigated in a wide range of excitation energies using the (2+1) and (3+1) REMPI methods [15]. In addition to the neutral CS 2 molecule, the structure and dynamics of the ground and excited ionic state, CS 2 + , have been investigated by several groups, using synchrotron-based pulse-field-ionization photoelectron spectroscopy [16], the photoelectron photoion coincidence technique [17], photofragment excitation spectroscopy [18][19][20], and the optical-optical double resonance technique [21]. These spectroscopic and dissociation studies demonstrated that CS 2 exhibits many typical physical processes within molecular system, such as spin-orbit coupling, Fermi resonance, intersystem crossing and internal conversion.…”