TY - JOUR

T1 - Photodissociation of van der Waals complexes of iodine X-I2 (X = I2, C2H4) via charge-transfer state

T2 - A velocity map imaging investigation

AU - Bogomolov, Alexandr S.

AU - Goldort, Veniamin G.

AU - Kochubei, Sergei A.

AU - Baklanov, Alexey V.

PY - 2017/12/21

Y1 - 2017/12/21

N2 - The photodissociation of van der Waals complexes of iodine X-I2 (X = I2, C2H4) excited via Charge-Transfer (CT) band has been studied with the velocity map imaging technique. Photodissociation of both complexes gives rise to translationally "hot" molecular iodine I2 via channels differing by kinetic energy and angular distribution of the recoil directions. These measured characteristics together with the analysis of the model potential energy surface for these complexes allow us to infer the back-electron-transfer (BET) in the CT state to be a source of observed photodissociation channels and to make conclusions on the location of conical intersections where the BET process takes place. The BET process is concluded to provide an I2 molecule in the electronic ground state with moderate vibrational excitation as well as X molecule in the electronic excited state. In the case of X = I2, the BET process converts anion I2- of the CT state into the neutral I2 in the repulsive excited electronic state which then dissociates promptly giving rise to a pair of I atoms in the fine states 2P1/2. In the case of C2H4-I2, the C2H4 molecules appear in the triplet T1 electronic state. Conical intersection for corresponding BET process becomes energetically accessible after partial twisting of C2H4+ frame in the excited CT state of complex. The C2H4(T)-I2 complex gives rise to triplet ethylene as well as singlet ethylene via the T-S conversion.

AB - The photodissociation of van der Waals complexes of iodine X-I2 (X = I2, C2H4) excited via Charge-Transfer (CT) band has been studied with the velocity map imaging technique. Photodissociation of both complexes gives rise to translationally "hot" molecular iodine I2 via channels differing by kinetic energy and angular distribution of the recoil directions. These measured characteristics together with the analysis of the model potential energy surface for these complexes allow us to infer the back-electron-transfer (BET) in the CT state to be a source of observed photodissociation channels and to make conclusions on the location of conical intersections where the BET process takes place. The BET process is concluded to provide an I2 molecule in the electronic ground state with moderate vibrational excitation as well as X molecule in the electronic excited state. In the case of X = I2, the BET process converts anion I2- of the CT state into the neutral I2 in the repulsive excited electronic state which then dissociates promptly giving rise to a pair of I atoms in the fine states 2P1/2. In the case of C2H4-I2, the C2H4 molecules appear in the triplet T1 electronic state. Conical intersection for corresponding BET process becomes energetically accessible after partial twisting of C2H4+ frame in the excited CT state of complex. The C2H4(T)-I2 complex gives rise to triplet ethylene as well as singlet ethylene via the T-S conversion.

KW - MOLECULAR-COMPLEXES

KW - GROUND-STATE

KW - DYNAMICS

KW - SPECTROSCOPY

KW - ETHYLENE

KW - PHOTOELECTRON

KW - C6H6-I-2

KW - BENZENE

KW - OXYGEN

UR - http://www.scopus.com/inward/record.url?scp=85038931508&partnerID=8YFLogxK

U2 - 10.1063/1.5001104

DO - 10.1063/1.5001104

M3 - Article

C2 - 29272931

AN - SCOPUS:85038931508

VL - 147

SP - 234304

JO - Journal of Chemical Physics

JF - Journal of Chemical Physics

SN - 0021-9606

IS - 23

M1 - 234304

ER -