Some remarks on the photodynamics of NO2

Wilkinson, Iain; Whitaker, Benjamin J.

doi:10.1039/b924653n

Cited by 37 publications

(65 citation statements)

References 153 publications

(361 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We chose NO 2 , a radical, because of its model status for theories of unimolecular dissociation (12)(13)(14) and conical intersection dynamics (15)(16)(17)(18)(19). Our results translate the previously recognized sensitivity of HHS to electronic structure into a tool for elucidating chemical reaction dynamics.…”

mentioning

confidence: 62%

“…The determined parameters are given in Table 1 (14). The deep modulation of the signals demonstrates that the probed dynamics are dominated by one-photon absorption, which is in general difficult to achieve in femtosecond time-resolved measurements on molecules due to multiphoton processes (19). The strong-field ionization probability of vibrationally excited NO 2 molecules is larger than that of unexcited molecules [vertical ionization potential (I p )=11.2 eV] by a factor of ( To rationalize these observations, we introduce a simple model based on diabatic electronic states and coordinate-independent transition moments (more detailed calculations are given in the SOM).…”

mentioning

confidence: 99%

“…Previous studies using laser-induced fluorescence have characterized the picosecond dissociation in detail (14,28). However, the femtosecond conical intersection dynamics has been largely obscured by competing multiphoton processes (see (19) and references therein), requiring elaborate coincidence detection methods (29).…”

mentioning

confidence: 99%

See 2 more Smart Citations

Conical Intersection Dynamics in NO ₂ Probed by Homodyne High-Harmonic Spectroscopy

Wörner

Bertrand

Fabre

et al. 2011

Science

252

239

View full text Add to dashboard Cite

Conical intersections play a crucial role in the chemistry of most polyatomic molecules, ranging from the simplest bimolecular reactions to the photostability of DNA. The real-time study of the associated electronic dynamics poses a major challenge to the latest techniques of ultrafast measurement. We show that high-harmonic spectroscopy reveals oscillations in the electronic character that occur in nitrogen dioxide when a photoexcited wave packet crosses a conical intersection. At longer delays, we observe the onset of statistical dissociation dynamics. The present results demonstrate that high-harmonic spectroscopy could become a powerful tool to highlight electronic dynamics occurring along non-adiabatic chemical reaction pathways. 1The outcome of chemical reactions is determined by the valence electronic structure of molecules. Therefore, the elucidation of elementary reaction mechanisms requires an understanding of the valence electron dynamics. Recently developed techniques that are efficient in probing valence electron dynamics include attosecond transient absorption (1), extreme ultraviolet photoelectron spectroscopy (XUV-PES) (2), high-order harmonic spectroscopy (HHS) (3-5) and strong-field ionization (6). Both time-resolved PES (7) and time-resolved HHS are sensitive to valence electron dynamics through the molecular photoionization matrix elements.Electronic dynamics in molecules are particularly challenging to observe when they are strongly coupled to nuclear dynamics. Such situations often arise in polyatomic molecules where conical intersections between the potential energy surfaces induce very rapid radiationless transitions at particular nuclear configurations (see inset of Fig. 1) (8, 9). These features channel electronic excitation into atomic motion in such diverse contexts as the primary steps of vision (10) and the dynamics underlying electron transfer and the photostability of DNA bases (11).Here we show that high-harmonic spectroscopy reveals the variations in electronic character during the conical intersection dynamics and the subsequent dissociation of nitrogen dioxide (NO 2 ). We chose NO 2 , a radical, because of its model status for theories of unimolecular dissociation (12-14) and conical intersection dynamics (15)(16)(17)(18)(19). Our results translate the previously recognized sensitivity of HHS to electronic structure into a tool for elucidating chemical reaction dynamics.High-harmonic spectroscopy can be factored into three steps: removal of an electron by an intense femtosecond laser field, acceleration of the electron in the laser field and photorecombination (20, 21). Each step contributes an amplitude and a phase to the emitted XUV radiation (20,(22)(23)(24)(25). The measurement relies on a coherent detection scheme in a transient grating geometry, using unexcited molecules as a local oscillator (4, 5). It is thus sensitive to 2 both amplitude and phase of the photorecombination matrix elements, a quantity that has recently attracted a lot of interest (26,27). Time-resolved...

show abstract

mentioning

confidence: 62%

mentioning

confidence: 99%

See 1 more Smart Citation

Conical Intersection Dynamics in NO ₂ Probed by Homodyne High-Harmonic Spectroscopy

Wörner

Bertrand

Fabre

et al. 2011

Science

252

239

View full text Add to dashboard Cite

show abstract

“…Ultrafast IC is also responsible for avoiding harmful photochemical reactions of DNA [8,9] and proteins, [10][11][12][13] protecting organisms from UV radiation. IC is also present in the photochemistry of small molecules, for example O 2 and O 3 , [14] SO 2 , [15] NO 2 , [16] and other nitrogen oxides. [17] The absorption of sunlight by these molecules and the subsequent photochemistry are central to atmospheric chemistry and the study of the environment and pollution.…”

Section: Introductionmentioning

confidence: 99%

A general method to describe intersystem crossing dynamics in trajectory surface hopping

Mai

Marquetand

González

2015

Int J of Quantum Chemistry

271

406

View full text Add to dashboard Cite

Intersystem crossing is a radiationless process that can take place in a molecule irradiated by UV‐Vis light, thereby playing an important role in many environmental, biological and technological processes. This paper reviews different methods to describe intersystem crossing dynamics, paying attention to semiclassical trajectory theories, which are especially interesting because they can be applied to large systems with many degrees of freedom. In particular, a general trajectory surface hopping methodology recently developed by the authors, which is able to include nonadiabatic and spin‐orbit couplings in excited‐state dynamics simulations, is explained in detail. This method, termed SHARC, can in principle include any arbitrary coupling, what makes it generally applicable to photophysical and photochemical problems, also those including explicit laser fields. A step‐by‐step derivation of the main equations of motion employed in surface hopping based on the fewest‐switches method of Tully, adapted for the inclusion of spin‐orbit interactions, is provided. Special emphasis is put on describing the different possible choices of the electronic bases in which spin‐orbit can be included in surface hopping, highlighting the advantages and inconsistencies of the different approaches. © 2015 Wiley Periodicals, Inc.

show abstract

“…Consequently, overtime it became a benchmark system for a variety of spectroscopic and dynamics studies concerning theoretical and experimental aspects of photodissociation, intramolecular vibrational redistribution, nonadiabatic couplings [1,2,3,4,5,6,7,8,9,10,11,12,13]. The numerous nonadiabatic interactions are reflected in a complex photodissociation dynamics.…”

Section: Introductionmentioning

confidence: 99%

Imaging fast relaxation dynamics of NO₂

et al. 2009

View full text Add to dashboard Cite

Time-resolved spectroscopy combined with velocity map imaging technique have been used to investigate the multiphoton dynamics of NO 2 molecule. Two different pump-probe excitation schemes were used to explore different potential energy surfaces (PESs) located in the first dissociation region and in the Rydberg region around 9.2 eV. Integrated and energy resolved signals of NO + 2 , NO + and photoelectrons were recorded as a function of time. When exciting with 403 nm photons, the NO + signal exhibits an intriguing oscillatory behaviour with a period of 512 fs. The NO + and photoelectron kinetic energy distributions produced by this pump wavelength were cold, while those produced when employing 269 nm photons as pump were very rich, evidencing the presence of multiple excitation channels. A couple of sharp long lived photoion-photoelectron peaks represents the most salient feature of latter. They were assigned to an excitation by two 269 nm photons to a Rydberg state dissociating into NO(A 2 Σ + )+O( 3 P ). This NO + peak as well as another one located at 0 eV display very complex time dependencies including the signatures of two dissociation dynamics on timescales of 400 and 600 fs. The different pathways responsible of this temporal behaviour are discussed in view of shedding light onto the underlying multichannel multiphoton dynamics.

show abstract

Some remarks on the photodynamics of NO2

Cited by 37 publications

References 153 publications

Conical Intersection Dynamics in NO ₂ Probed by Homodyne High-Harmonic Spectroscopy

Conical Intersection Dynamics in NO ₂ Probed by Homodyne High-Harmonic Spectroscopy

A general method to describe intersystem crossing dynamics in trajectory surface hopping

Imaging fast relaxation dynamics of NO₂

Contact Info

Product

Resources

About

Some remarks on the photodynamics of NO2

Cited by 37 publications

References 153 publications

Conical Intersection Dynamics in NO 2 Probed by Homodyne High-Harmonic Spectroscopy

Conical Intersection Dynamics in NO 2 Probed by Homodyne High-Harmonic Spectroscopy

A general method to describe intersystem crossing dynamics in trajectory surface hopping

Imaging fast relaxation dynamics of NO2

Contact Info

Product

Resources

About

Conical Intersection Dynamics in NO ₂ Probed by Homodyne High-Harmonic Spectroscopy

Conical Intersection Dynamics in NO ₂ Probed by Homodyne High-Harmonic Spectroscopy

Imaging fast relaxation dynamics of NO₂