Triplet state quantum yield formation a two-photon absorption in Tetra-Phenyl Porfirins derivatives

• Grant number: 22/07652-2
• Support Opportunities: Scholarships in Brazil - Master
• Start date: March 01, 2023
• End date: July 31, 2024
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Leonardo de Boni
• Grantee: Júlia Akiyama da Silva
• Host Institution: Instituto de Física de São Carlos (IFSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil
• Associated research grant: 18/11283-7 - Nonlinear photonics: spectroscopy and advanced processing of materials, AP.TEM

Abstract

The research that will be developed in this project is related to an unprecedented complete spectroscopic study of a class of neutral and cationic Porphyrins, involving, for example, measurements of absorption, fluorescence, measurements of time-resolved fluorescence, determination of quantum fluorescence and triplet efficiencies. and, finally, determination of the two-photon absorption cross-sections, aiming at the therapeutic window. Therefore, the main objectives will be the determination of the quantum efficiency of triplet formation, with the double-pulse excitation technique, and the determination of the two-photon absorption cross section, by the technique of fluorescence excited via two-photon absorption. Both techniques were recently developed in our laboratory, providing different ways of obtaining such properties. For example, the double-pulse excitation technique monitors the decrease in the fluorescence signal due to the formation of non-emissive triplet states, the nature of these states. On the other hand, the two-photon-excited fluorescence technique allows the determination of the two-photon absorption cross section in molecules with low molecular concentration, by monitoring the fluorescence signal as a function of the excitation power.In addition, it is important to emphasize that this study involves an international partnership, in which the samples were provided by Prof. Maria Amparo Faustino, from the University of Aveiro, Portugal, who is very interested in the determination of these optical properties of the porphyrin derivative set provided.The strands of this project are extremely current and of great importance for basic and applied sciences, since the characterization of organic materials, such as porphyrins, can provide information on excited electronic states and how they behave in the face of interaction with optical fields.

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

SILVA, Júlia Akiyama da. Triplet state quantum yield formation and two-photon absorption in Tetra- Phenyl Porphyrins derivatives. 2024. Master's Dissertation - Universidade de São Paulo (USP). Instituto de Física de São Carlos (IFSC/BT) São Carlos.