DUGi

Wave Packet Dynamics at an Extended Seam of Conical Intersection: Mechanism of the Light-Induced Wolff Rearrangement

http://dugi.udg.edu/item/http:@@@@hdl.handle.net@@2072@@296737

Quantum dynamics calculations on a model surface based on CASPT(2)//CASSCF calculations are carried out to probe the traversal of a wave packet through an extended seam of conical intersection during the light-induced Wolff rearrangement of diazonaphtoquinone. The reaction is applied in the fabrication of integrated circuits. It consists of nitrogen elimination and ring rearrangement to yield a ketene. After excitation, the wave packet relaxes and reaches the extended seam. A fraction of the wave packet decays to the ground state at a region of the seam connected to a carbene intermediate, while the remaining part decays at a region leading to the ketene. The passage of the wave packet through the extended seam explains the competition between concerted ketene formation and a stepwise mechanism involving a carbene. The two primary photoproducts are formed in the first 100 fs of the simulation, in agreement with recent ultrafast spectroscopy measurements

This work has been supported by Grants CTQ2008-06696 and CTQ2011-26573 from the Spanish Ministerio de Ciencia e Innovacion (MICINN), SGR0528 from the Catalan Agencia de Gestio d’Ajuts Universitaris i de Recerca (AGAUR), and UNGI08-4E-003 from MICINN and the FEDER fund (European Fund for Regional Development). Q.L. acknowledges a Juan de la Cierva fellowship of the MICINN and A.M. a Beatriu de Pinos fellowship of the Generalitat de Catalunya (Spain)

American Chemical Society (ACS)