Banca de DEFESA: LAÍS PETRA MACHADO

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : LAÍS PETRA MACHADO
DATA : 13/03/2019
HORA: 14:00
LOCAL: Sala 50, Pavilhão de Química - ICE
TÍTULO:

Theoretical Studies of Photoisomerization of Butadiene and Substituted Butadiene 

PALAVRAS-CHAVES:

photoisomerization, butadiene, pentadienal

PÁGINAS: 88
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Química
SUBÁREA: Físico-Química
ESPECIALIDADE: Química Teórica
RESUMO:

The interaction of light with matter is present in several important processes of nature. Photons are employed by natural systems as energy donors or as information elements. And from the energy from the photons the Z-E isomerization of the C = C bond can be induced as, for example, in the butadiene molecule. Isomerization consists of a photochemical process widely explored and forms the fundamental step in many photobiological processes such as vision, light-induced ion bomb and phototaxis. The project aims to obtain stationary points from the surface of the potential energy for the butadiene molecules substituted with the Cl group, carbonyl substituted butadiene (CHO), butadiene substituted with the amine group (NH2) and butadiene. The surface description generate a model for the understanding of the influence of the groups on the geometry and the process of photoisomerization. As a starting point for the investigations in the excited state, the configurations of the molecules corresponding to the minimum energy states in the ground state were mapped by the Hartree Fock (HF) method. All the molecules were optimized (S0) in the CASSCF method, in which we chose, for the carbonyl substituted butadiene molecules, six orbitals and six electrons, for the chlorinated substituted butadienes four orbitals and four electrons were chosen, for the butadiene substituted with amine and butadiene two orbitals and two electrons were chosen. In addition to the minimum in the excited state, we found some minimums at the conic intersection (IC) for Chloro-butadiene, others for butadiene, three minimums for IC for pentadienal and still others for the amine-butadiene molecule. When comparing the results of the IC minimums with the results found in the literature it is realized that the substituents do not significantly alter the geometry of the intersection of the butadiene without substituent. An IC was also found that is possibly associated with the chlorine dissociation process, however, no other CI was found similar to it in the literature. This possible dissociation may be a third path of reaction, the other two pathways being isomerization and electrocyclization.

MEMBROS DA BANCA:
Interno - 1716351 - GLAUCO FAVILLA BAUERFELDT
Interno - 1354432 - CLARISSA OLIVEIRA DA SILVA
Interno - 1115883 - ANTONIO MARQUES DA SILVA JUNIOR
Externo ao Programa - 1808284 - MARCIO SOARES PEREIRA
Externo à Instituição - THIAGO MESSIAS CARDOZO - UFRJ
Externo à Instituição - ANDRE GUSTAVO HORTA BARBOSA - UFF