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

Kód výsledku v 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>

Výsledek na webu

<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>

Jazyk výsledku

angličtina

Název v původním jazyce

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

Popis výsledku v původním jazyce

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.

Název v anglickém jazyce

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

Popis výsledku anglicky

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.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10403 - Physical chemistry

Projekt

<a href="/cs/project/GA17-04068S" target="_blank" >GA17-04068S: Molekulové klastry jako nano-reaktory pro chemii řízenou fotony a elektrony</a><br>

Návaznosti

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

Rok uplatnění

2018

Kód důvěrnosti údajů

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

Název periodika

Journal of Chemical Physics

ISSN

0021-9606

e-ISSN

—

Svazek periodika

149

Číslo periodika v rámci svazku

9

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

8

Strana od-do

—

Kód UT WoS článku

000444043600017

EID výsledku v databázi Scopus

2-s2.0-85053115296