Long time scale dynamics of vibrationally excited (HBr)(n) clusters

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388955%3A_____%2F18%3A00493591" target="_blank" >RIV/61388955:_____/18:00493591 - isvavai.cz</a>

Result on the web

<a href="http://dx.doi.org/10.1063/1.5034245" target="_blank" >http://dx.doi.org/10.1063/1.5034245</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1063/1.5034245" target="_blank" >10.1063/1.5034245</a>

Result language

angličtina

Original language name

Long time scale dynamics of vibrationally excited (HBr)(n) clusters

Original language description

We investigated the photodissociation dynamics of vibrationally excited HBr molecules and clusters. The species were generated in a molecular beam and excited with an IR laser to a v = 1 vibrational state. A subsequent ultraviolet (UV)-pulse with 243 nm radiation photolysed the molecules to yield H-fragments, which were resonantly ionized by the same UV-pulse (2 + 1 REMPI) and detected in a velocity map imaging (VMI) experiment. We performed action spectroscopy to distinguish between two expansion regimes: (i) expansion leading to isolated HBr molecules and (ii) generation of large (HBr)(n) clusters. Photodissociation of isolated HBr (v = 1) molecules in particular J ro-vibrational states yielded faster H-fragments (by approximately 0.3 eV) with respect to the photodissociation of the ground state HBr (v = 0). On the contrary, the IR excitation of molecules in (HBr)(n) clusters enhanced the yield of the H-fragments UV-photodissociated from the ground-state HBr (v = 0) molecules. Our findings show that these molecules are photodissociated within clusters, and they are not free molecules evaporated from clusters after the IR excitation. Nanosecond IR-UV pump-probe experiments show that the IR-excitation enhances the H-fragment UV-photodissociation yield up to similar to 100 ns after the IR excitation. After these long IR-UV delays, excitation of HBr molecules in clusters does not originate from the IR-excitation but from the UV-photodissociation and subsequent caging of HBr molecules in v > 0 states. We show that even after similar to 100 ns the IR-excited larger (HBr)(n) clusters do not decay to individual molecules, and the excitation is still present in some form within these clusters enhancing their UV-photodissociation. Published by AIP Publishing.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10403 - Physical chemistry

Project

<a href="/en/project/GA17-04068S" target="_blank" >GA17-04068S: Molecular Clusters as Unique Nano-reactors: Controlling Chemistry with Photons and Electrons</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2018

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Journal of Chemical Physics

ISSN

0021-9606

e-ISSN

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Volume of the periodical

149

Issue of the periodical within the volume

9

Country of publishing house

US - UNITED STATES

Number of pages

8

Pages from-to

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UT code for WoS article

000444043600017

EID of the result in the Scopus database

2-s2.0-85053115296