Multiconfigurational Calculations in the Description of Excited States Dynamics and its Correlation with Resonance Raman Spectroscopy

• Grant number: 21/07031-5
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: January 01, 2022
• End date: December 31, 2025
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal Investigator: Rômulo Augusto Ando
• Grantee: Adalberto Vasconcelos Sanches de Araújo
• Host Institution: Instituto de Química (IQ). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 22/11983-4 - Spectroscopy signal enhancement: nanomaterials, theory, and computer simulation, AP.TEM

Abstract

Despite the significant technological advancements in the last decades, the study of photophysics/photochemistry remains as a major challenge both from the experimental as the theoretical perspective, mainly for those systems that present multiple decay pathways after light absorption. The project aims the development of a robust methodology which combines ab initio multiconfigurational calculations and experimental resonance Raman (RR) spectroscopy that allows to clarify the deactivation mechanisms of the excited states. From the correlation between the paths proposed by potential surfaces calculations in high theoretical level and the experimental information concerning the dimensionless normal coordinates (delta) of the respective excited states obtained through RR spectroscopy, we can predict the main geometrical changes on the relaxation mechanism. The proposed methodology will also permit the study of solvent effects in the resonance Raman spectra and the main decay pathways of the molecules. Firstly, the photophysics of a series of 4-nitrobenzodiazoles will be investigated, molecules which present interesting spectroscopic characteristics such as low energy charge-transfer states, for which there are no detailed photophysical studies, specially concerning the deactivation mechanisms. The proposed methodology will be extended for other classes of organic and bio-inorganic molecules.

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

DE ARAUJO, ADALBERTO VASCONCELOS SANCHES; BORIN, ANTONIO CARLOS. Water Solvated Zn(II)-Guanine Complex: Structural Aspects and Luminescence Properties. Journal of Physical Chemistry A, v. 127, n. 40, p. 10-pg., 2023-09-29. (18/19454-5, 21/07031-5)

SANCHES DE ARAUJO, ADALBERTO V.; RANGEL, CLARA J.; ANDO, ROMULO A.. Multiconfigurational Calculations and Experimental Resonant Raman/SERRS of a Donor-Acceptor Thiadiazole Dye. Journal of Physical Chemistry A, v. 127, n. 51, p. 8-pg., 2023-12-18. (21/07031-5, 16/21070-5)

DE ARAUJO, ADALBERTO V. SANCHES V.; MARQUES, LEANDRO R.; BORIN, ANTONIO C.; ANDO, ROMULO A.. Simulation of charge-transfer, UV-VIS and resonance Raman spectra of push-pull systems: a TDDFT and CASPT2 comparison. Physical Chemistry Chemical Physics, v. 24, n. 46, p. 8-pg., 2022-11-07. (21/07031-5, 16/21070-5)