Conical intersection and coherent vibrational dynamics in alkyl iodides captured by attosecond transient absorption spectroscopy
Autor: | Kristina F. Chang, Han Wang, Sonia M. Poullain, Jesús González-Vázquez, Luis Bañares, David Prendergast, Daniel M. Neumark, Stephen R. Leone |
---|---|
Přispěvatelé: | UAM. Departamento de Química |
Jazyk: | angličtina |
Rok vydání: | 2022 |
Předmět: | |
Zdroj: | Repositorio Institucional del Instituto Madrileño de Estudios Avanzados en Nanociencia instname |
DOI: | 10.1063/5.0086775 |
Popis: | The photodissociation dynamics of alkyl iodides along the C–I bond are captured by attosecond extreme-ultraviolet (XUV) transient absorption spectroscopy employing resonant ∼20 fs UV pump pulses. The methodology of previous experiments on CH3I [Chang et al., J. Chem. Phys. 154, 234301 (2021)] is extended to the investigation of a C–I bond-breaking reaction in the dissociative A-band of C2H5I, i-C3H7I, and t-C4H9I. Probing iodine 4 d core-to-valence transitions in the XUV enables one to map wave packet bifurcation at a conical intersection in the A-band as well as coherent vibrations in the ground state of the parent molecules. Analysis of spectroscopic bifurcation signatures yields conical intersection crossing times of 15 ± 4 fs for CH3I, 14 ± 5 fs for C2H5I, and 24 ± 4 fs for i-C3H7I and t-C4H9I, respectively. Observations of coherent vibrations, resulting from a projection of A-band structural dynamics onto the ground state by resonant impulsive stimulated Raman scattering, indirectly reveal multimode C–I stretch and CCI bend vibrations in the A-bands of C2H5I, i-C3H7I, and t-C4H9I. |
Databáze: | OpenAIRE |
Externí odkaz: |