title: Ultrafast evolution of imidazole after electronic excitation.
abstract: The ultrafast dynamics of the imidazole chromophore has been tracked after electronic excitation in the 250-217 nm energy region, by time delayed ionization with 800 nm laser pulses. The time-dependent signals collected at the imidazole(+) mass channel show the signature of femtosecond dynamics, originating on the πσ*- and ππ*-type states located in the explored energy region. The fitting of the transients, which due to the appearance of nonresonant coherent adiabatic excitation requires a quantum treatment based in the Bloch equations, yields two lifetimes of 18 ± 4 and 19 ± 4 fs. The first is associated with the πσ* ← ππ* internal conversion, while the second reflects the loss of ionization cross-section as the system evolves along the dissociative πσ* surface. This study provides a comprehensive picture of the photophysics of the molecule that agrees with previous experimental and theoretical findings.
authors.affiliation: Departamento de Química Física, Universidad del País Vasco (UPV/EHU), Apart. 644, 48080 Bilbao, Spain.
authors.forename: Raúl
authors.initials: R
authors.lastname: Montero
authors.forename: Álvaro
authors.initials: Á
authors.lastname: Peralta Conde
authors.forename: Virginia
authors.initials: V
authors.lastname: Ovejas
authors.forename: Marta
authors.initials: M
authors.lastname: Fernández-Fernández
authors.forename: Fernando
authors.initials: F
authors.lastname: Castaño
authors.forename: Asier
authors.initials: A
authors.lastname: Longarte
mesh_terms: D004583:Electrons; D007093:Imidazoles / Q000737:chemistry*; D011789:Quantum Theory
chemical_list: D007093:Imidazoles; C029899:imidazole