Banca de DEFESA: YSMAILYN SIQUEIRA COSTA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : YSMAILYN SIQUEIRA COSTA
DATE: 11/11/2022
TIME: 09:00
LOCAL: Auditório da Reitoria - IF UFAL
TITLE:

Geometric and charge transfer effects on linear and non-linear optical properties of organic dyes with high hyperpolarizability: Systematic study using an external electrostatic field

KEY WORDS:

 Merocyanines. DFT. Polarizability. Hyperpolarizabilities.

PAGES: 86
BIG AREA: Ciências Exatas e da Terra
AREA: Física
SUBÁREA: Física Atômica e Molecular
SPECIALTY: Estrutura Eletrônica de Átomos e Moléculas; Teoria
SUMMARY:

The systematic study of organic dye molecules' linear and non-linear electronic and optical properties was performed using the Density Functional Theory (DFT). For this, we consider a merocyanine molecule with solvatochromic properties and high hyperpolarizabilities as a prototypal molecule. A theoretical model with a static electric field applied along the molecule's dipole axis was used to analyze the structural behavior and the effect of charge transfer in cooperation and separately. This model is purposed to relate the theoretical results with those obtained experimentally for the effect of the solvent change in the considered systems. The results show that the nonlinear optical response, specifically the Brooker merocyanine (MB) Hyper-Rayleigh Scattering (HRS) response, was rationalized in terms of the structural changes and polarization effects induced by applied external electric fields. The structural change leads to large changes in the HRS response, while only slight variations were observed due to polarization effects on the fixed quinoid shape. The HRS response is dominated by the cooperative behavior of these effects for weak and intermediate electric field intensities. At the same time, the competition was a crucial factor in the region of strong electric fields. The results obtained can lead to a more straightforward process for future studies considering more realistic models of solvents where it is not simple to separate these contributions.

BANKING MEMBERS:
Interno(a) - 2318874 - FRANCISCO ANACLETO BARROS FIDELIS DE MOURA
Interno(a) - 2458049 - ITALO MARCOS NUNES DE OLIVEIRA
Interno(a) - 1120933 - MARCELO LEITE LYRA
Interno(a) - 2580000 - VINICIUS MANZONI VIEIRA
Externo(a) ao Programa - 2343745 - JULIO COSME SANTOS DA SILVA
Externo(a) à Instituição - RODRIGO DO MONTE GESTER