Determination of water photochemical attenuation potential against micropollutants...
| Grant number: | 12/19823-4 |
| Support type: | Scholarships in Brazil - Post-Doctorate |
| Effective date (Start): | March 01, 2013 |
| Effective date (End): | March 05, 2017 |
| Field of knowledge: | Physical Sciences and Mathematics - Chemistry |
| Principal Investigator: | Daniel Rodrigues Cardoso |
| Grantee: | Willy Glen Santos |
| Home Institution: | Instituto de Química de São Carlos (IQSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil |
| Associated scholarship(s): | 15/13756-1 - Photochemistry and Excited-states dynamics of Tetraarylborates and Tetraarylborate-pyridinium complexes, BE.EP.PD |
Abstract The design proposed herein is intended to investigate the photochemical aromatic compound having boron atoms in the molecular structure via direct photolysis and sensitization in two component system: dye / organoborane. The presence of boron in the aromatic system is intended to facilitate the formation of free radicals which can be used in systems radical polymerization and photobiological studies. The formation of radicals in organoboranes can be obtained by photochemical means or by direct photolysis fotossensitização through dye such as riboflavin (vitamin B2). The photochemical organoborane in the presence and absence of donor / acceptor of electrons is a little explored area and that has aroused great interest in recent years. In this sense, the different photochemical interactions of flavins with organoboranes will be investigated in two main steps: (a) first, the organoboranes fotofísicamente will be characterized by electronic absorption, fluorescence, phosphorescence, transient absorption, EPR and lifetimes of singlet excited states and triplet. This stage will be determined the quantum yields of the radiative and non-radiative processes. Measurements of phosphorescence emission of singlet oxygen and will be held to determine the quantum yield of formation of singlet oxygen and triplet quantum yield calculation. (B) In the second step, the radical species formed from electron transfer reactions are characterized by the hyperfine structure of the EPR spectra and the formation of new transient absorption bands of semi-oxidized species and semirreduzidas of organoboranes and flavins (and Lumiflavina Riboflavin). Measurements of degradation of flavins be assessed by measures of fotodescoloramento degradation products and evaluated by mass spectrometry coupled to a HPLC. The results obtained by all techniques reported here will be important for the development of photochemical mechanism between flavins and organoboranes. This study has also intended to assist searches of photobiological flavins in the presence of organoboranes, since these compounds are used in the medical environment. | |