6533b839fe1ef96bd12a631a
RESEARCH PRODUCT
A theoretical study of the electronic spectrum of cis-stilbene
Björn O. RoosManuela MerchánVicent Molinasubject
Valence (chemistry)Absorption spectroscopyPhotoisomerizationChemistryAtomic and Molecular Physics and OpticsAnalytical Chemistrysymbols.namesakeExcited stateSinglet fissionRydberg formulasymbolsSinglet stateAtomic physicsGround stateInstrumentationSpectroscopydescription
Abstract The valence and Rydberg electronic excited singlet states of cis -stilbene have been studied using multiconfigurational second-order perturbation theory (CASPT2). The study includes a geometry determination of the ground state. The geometry of the lowest 1 B state has also been optimized, leading to a structure where the two benzyl groups are nearly perpendicular. The calculated vertical spectrum is in agreement with the occurrence of three main bands in the observed one-photon absorption spectrum. Below the relatively intense transition to the 2 1 B (HOMO→LUMO) state at 4.61 eV, two weak transitions have been computed at 4.11–4.45 eV, which correspond to transitions to the 1 1 B and 2 1 A states, respectively. The 3 1 A state, placed at 5.56 eV above the ground state, has a pronounced doubly excited character. In addition, the lowest vertical singlet–triplet transition has been characterized. Features of some static aspects along the trans ↔ cis photoisomerization process in the singlet manifold are discussed. The lowest singlet excited state at a near-perpendicular conformation is of B symmetry with the next state (of 1 A symmetry) 0.4 eV higher.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 1999-03-01 | Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy |