Vibrational level dependence of lifetime of NO2 in the 2B2 state

Tsuji, Kentaro; Ikeda, Masashi; Awamura, Junichi; Kawai, Akio; Shibuya, Kazuhiko

doi:10.1016/s0009-2614(03)00774-7

Cited by 13 publications

(9 citation statements)

References 23 publications

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“…Given the temporal profile of our laser, this is entirely consistent with a two-photon excitation of the (2) 2 B 2 state, which for excitation energies above its lowest vibrational state is wellknown to undergo rapid predissociation on a time scale of about 35 fs. 27 Although the lowest lying vibrational state of the (2) 2 B 2 is long-lived, 28,29 with a lifetime of about 42 ps, this does not help explain the observations because the vibrational frequency is too high and one cannot make a wavepacket with a single stationary state.…”

Section: Discussionmentioning

confidence: 97%

Quantum Interference in NO₂

et al. 2010

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This paper investigates the origin of a quantum interference observed when NO(2) is dissociatively ionized by short pulses of ultraviolet light. We describe time-resolved measurements of NO(+), O(+), and NO(2)(+) ions produced following the interaction of NO(2) with a approximately 70 fs duration pulse centered close to 400 nm and a subsequent time-delayed probe pulse close to 269, 205, or 400 nm. A quantum beat oscillation with a period of 524 fs and a characteristic damping time of 8 ps is observed on all transient ion signals. We investigate the effect of tuning the central wavelength of the excitation pulse over a 12 nm range, and we discuss the potential importance of three possible multiphoton pathways involving one, two, and three pump photons. We conclude that the ionization pathway responsible for the beat signal is most likely due to a process involving the absorption of two pump photons and two probe photons. This presents an interesting problem with respect to the interpretation of the mechanism responsible for the quantum interference signature since the electronic states of NO(2) reached at the two-photon level are all thought to be extremely short-lived and to dissociate on a time scale that is far shorter than the characteristic damping time of the oscillatory signals. We suggest that a possible explanation for the observed dynamics is associated with a minor dissociation channel of the (2)(2)B(2) state of NO(2) through its interaction with the longer lived (2)(2)A(1) state.

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Section: Discussionmentioning

confidence: 97%

Quantum Interference in NO₂

et al. 2010

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“…TheD 2 B 2 state is expected to predissociate within 100 fs [58] via one of two dissociation thresholds, producing either NO( 2 Π) + O( 1 D) (the second dissociation limit at 5.08 eV) or NO( 2 Π) + O( 3 P) (the first dissociation limit at 3.11 eV, see Fig. 9) [27,59].…”

Section: B the Role Of Multiphoton Pump Excitation And Relaxation Dymentioning

confidence: 99%

Excited state wavepacket dynamics in NO2 probed by strong-field ionization

Forbes

Boguslavskiy

Wilkinson

et al. 2017

The Journal of Chemical Physics

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We present an experimental femtosecond time-resolved study of the 399 nm excited state dynamics of nitrogen dioxide using channel-resolved above threshold ionization (CRATI) as the probe process. This method relies on photoelectron-photoion coincidence and covariance to correlate the strong-field photoelectron spectrum with ionic fragments, which label the channel. In all ionization channels observed, we report apparent oscillations in the ion and photoelectron yields as a function of pump-probe delay. Further, we observe the presence of a persistent, time-invariant above threshold ionization comb in the photoelectron spectra associated with most ionization channels at long time delays. These observations are interpreted in terms of single-pump-photon excitation to the first excited electronic X̃ A state and multi-pump-photon excitations to higher-lying states. The short time delay (<100 fs) dynamics in the fragment channels show multi-photon pump signatures of higher-lying neutral state dynamics, in data sets recorded with higher pump intensities. As expected for pumping NO at 399 nm, non-adiabatic coupling was seen to rapidly re-populate the ground state following excitation to the first excited electronic state, within 200 fs. Subsequent intramolecular vibrational energy redistribution results in the spreading of the ground state vibrational wavepacket into the asymmetric stretch coordinate, allowing the wavepacket to explore nuclear geometries in the asymptotic region of the ground state potential energy surface. Signatures of the vibrationally "hot" ground state wavepacket were observed in the CRATI spectra at longer time delays. This study highlights the complex and sometimes competing phenomena that can arise in strong-field ionization probing of excited state molecular dynamics.

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“…The state has a lifetime of 41.0 AE 1.6 ps at the vibrational origin, but this falls to sub-100 fs for excitation energies 100 meV or less above the origin. 32,98 Following excitation to this state, non-adiabatic interactions are known to have a significant effect on the decomposition process. 97,99,100 This is principally displayed by the approximately equal yields of O( 3 P J ) and O( 1 D 2 ) fragments on excitation above the NO (1) 2 P1 2 +O( 1 D 2 ) dissociation limit (5.082 91 eV).…”

Section: Valence-valence Transitionsmentioning

confidence: 99%

“…This is consistent with the proposed dissociative mechanism of excitation to the (1) 2 B 2 state followed by the absorption of another pump photon to the (2) 2 B 2 potential. Based on the rotational constants of NO 2 in the electronically excited state 26 and the lifetime of the (2) 2 B 2 state after single photon excitation, 32,98 the reduction of the photofragment translational anisotropy from a pure cos 4 y distribution was attributed to a small degree of excited state mixing at the level of the first photon. This excitation range has also been advocated to explain the observations of the recent time-resolved experiments 14 although recent nanosecond experiments in our laboratory 120 suggest that alternative multiphoton excitation processes can occur at the expense of this pathway depending on the laser frequency and intensity employed (see below).…”

Section: Valence-valence Transitionsmentioning

confidence: 99%

Some remarks on the photodynamics of NO2

Wilkinson

Whitaker

2010

Annu. Rep. Prog. Chem., Sect. C: Phys. Chem.

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We review the literature concerning the electronic structure and spectroscopy of nitrogen dioxide for excitation energies up to 20 eV. Our aim is not to be exhaustive but rather to summarize important results and observations which we have found useful in the interpretation of recent experiments in both the frequency and time domain in which competing and often multiphoton excitation paths access high lying Rydberg and valence states. The photodynamics in NO 2 are particularly fascinating and complicated by numerous non-adiabatic couplings between the various electronic states which, despite the molecule's apparent simplicity as a triatomic species, leads to a very rich photochemistry that exemplifies many features occurring in the photochemistry of much larger molecules.

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Vibrational level dependence of lifetime of NO2 in the 2B2 state

Cited by 13 publications

References 23 publications

Quantum Interference in NO₂

Quantum Interference in NO₂

Excited state wavepacket dynamics in NO2 probed by strong-field ionization

Some remarks on the photodynamics of NO2

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Vibrational level dependence of lifetime of NO2 in the 2B2 state

Cited by 13 publications

References 23 publications

Quantum Interference in NO2

Quantum Interference in NO2

Excited state wavepacket dynamics in NO2 probed by strong-field ionization

Some remarks on the photodynamics of NO2

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Product

Resources

About

Quantum Interference in NO₂

Quantum Interference in NO₂