Photodissociation dynamics of H2O at 111.5 nm by a vacuum ultraviolet free electron laser

Wang, Heilong; Yu, Yanke; Chang, Yao; Su, Shao; Yu, Shengrui; Li, Qinming; Tao, Kai; Ding, Hongli; Yang, Jaiyue; Wang, Guanglei; Che, Li; He, Zhigang; Chen, Zhichao; Wang, Xingan; Zhang, Weiqing; Dai, Dongxu; Wu, Guorong; Yuan, Kaijun; Yang, Xueming

doi:10.1063/1.5022108

Cited by 32 publications

(23 citation statements)

References 55 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We also note that the high yields of vibrationally excited OH super rotors from H 2 O are limited to photolysis wavelengths λ ~ 115.2 nm. Such products are not observed in the photodissociation of H 2 O at even shorter photolysis wavelengths 33,34 , thus highlighting the peculiar non-adiabatic dissociation dynamics that prevail in this narrow wavelength range.…”

Section: Resultsmentioning

confidence: 94%

Hydroxyl super rotors from vacuum ultraviolet photodissociation of water

Chang

Wang

et al. 2019

Nat Commun

Self Cite

View full text Add to dashboard Cite

Hydroxyl radicals (OH) play a central role in the interstellar medium. Here, we observe highly rotationally excited OH radicals with energies above the bond dissociation energy, termed OH “super rotors”, from the vacuum ultraviolet photodissociation of water. The most highly excited OH(X) super rotors identified at 115.2 nm photolysis have an internal energy of 4.86 eV. A striking enhancement in the yield of vibrationally-excited OH super rotors is detected when exciting the bending vibration of the water molecule. Theoretical analysis shows that bending excitation enhances the probability of non-adiabatic coupling between the and states of water at collinear O–H–H geometries following fast internal conversion from the initially excited state. The present study illustrates a route to produce extremely rotationally excited OH(X) radicals from vacuum ultraviolet water photolysis, which may be related to the production of the highly rotationally excited OH(X) radicals observed in the interstellar medium.

show abstract

Section: Resultsmentioning

confidence: 94%

Hydroxyl super rotors from vacuum ultraviolet photodissociation of water

Chang

Wang

et al. 2019

Nat Commun

Self Cite

View full text Add to dashboard Cite

show abstract

“…The experiments employ a newly constructed apparatus for molecular photochemistry, which is centered on the vacuum ultraviolet free electron laser (VUV-FEL) beam line at the Dalian Coherent Light Source (DCLS) 27 . Brie y, the VUV-FEL facility runs in the high gain harmonic generation (HGHG) mode, in which the seed laser is injected to interact with the electron beam in the modulator (Fig.…”

Section: Methodsmentioning

confidence: 99%

Three-Body Photodissociation of Water Molecule: An Important Prebiotic Oxygen Source

Chang

et al. 2021

Preprint

Self Cite

View full text Add to dashboard Cite

The provenance of oxygen on the Earth and other Solar planetary bodies is a fundamental issue. It has been widely accepted that the only prebiotic pathway to produce oxygen in the Earth’s primitive atmosphere was via vacuum ultraviolet (VUV) photodissociation of CO2 and subsequent two O atom recombination. Here, we provide experimental evidence of three-body dissociation (TBD) of H2O to produce O atoms in both 1D and 3P states upon vacuum ultraviolet (VUV) excitation using the newly developed tunable VUV free electron laser. Experimental results show that the TBD is the dominant pathway in the VUV H2O photochemistry at wavelengths between 90 and 107.4 nm. The relative abundance of water in the interstellar space with its exposure to intense VUV radiation suggests that the TBD of H2O and subsequent O atoms recombination should be an important prebiotic O2-production, which may need to be incorporated into interstellar photochemical models.

show abstract

“…Recently, with the development of Dalian Coherent Light Source (DCLS), which is a seeded free electron laser (FEL) facility with a continuously tunable wavelength range of 50−150 nm and extremely high brightness, Yang and coworkers have demonstrated that much more signals can be obtained when using DCLS compared with that using the TPR-FWM generated VUV as the photolysis source [11]. With this new setup, they have studied the photodissociation dynamics of H 2 O at 111.5 nm which excited the molecules into the F state [60]. The outcome from the photodissociation of this state was found to be very similar to that of B state, which was attributed to the fast multi-step internal conversions from the initial excited F state to the B state.…”

Section: A H 2 O (Hod D 2 O)mentioning

confidence: 99%

“…While the newly constructed DCLS free electron VUV laser has reported to generate tunable VUV radiation in the range of 50−150 nm with unprecedented intensities [11,60]. These distinctive capabilities promise to push the VUV photodissociation experiment to the next level.…”

Section: Future Prospectsmentioning

confidence: 99%

Quantum state-to-state vacuum ultraviolet photodissociation dynamics of small molecules

Gao

2019

Chinese Journal of Chemical Physics

View full text Add to dashboard Cite

The present review focused on selected, recent experimental progress of photodissociation dynamics of small molecules covering the vacuum ultraviolet (VUV) range from 6 eV to 20 eV. These advancements come about due to the available laser based VUV light sources, along with the developments of advanced experimental techniques, including the velocitymap imaging (VMI), H-atom Rydberg tagging time-of-flight (HRTOF) techniques, as well as the two-color tunable VUV-VUV laser pump-probe detection method. The applications of these experimental techniques have allowed VUV photodissociation studies of many diatomic and triatomic molecules to quantum state-to-state in detail. To highlight the recent accomplishments, we have summarized the results on several important molecular species, including H 2 (D 2 , HD), CO, N 2 , NO, O 2 , H 2 O (D 2 O, HOD), CO 2 , and N 2 O. The detailed VUV photodissociation studies of these molecules are of astrochemical and atmospheric relevance. Since molecular photodissociation initiated by VUV excitation is complex and is often governed by multiple electronic potential energy surfaces, the unraveling of the complex dissociation dynamics requires state-to-state cross section measurements. The newly constructed Dalian Coherent Light Source (DCLS), which is capable of generating coherent VUV radiation with unprecedented brightness in the range of 50−150 nm, promises to propel the photodissociation experiment to the next level.

show abstract

Photodissociation dynamics of H2O at 111.5 nm by a vacuum ultraviolet free electron laser

Cited by 32 publications

References 55 publications

Hydroxyl super rotors from vacuum ultraviolet photodissociation of water

Hydroxyl super rotors from vacuum ultraviolet photodissociation of water

Three-Body Photodissociation of Water Molecule: An Important Prebiotic Oxygen Source

Quantum state-to-state vacuum ultraviolet photodissociation dynamics of small molecules

Contact Info

Product

Resources

About