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| Author(s): |
Leandro Mitsuo Shimura Takata
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Conjunto das Químicas (IQ e FCF) (CQ/DBDCQ) |
| Defense date: | 2015-03-06 |
| Examining board members: |
Alcindo Aparecido dos Santos;
Reinaldo Camino Bazito;
Antonio Carlos Bender Burtoloso;
Maria Teresa Machini;
Kleber Thiago de Oliveira
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| Advisor: | Alcindo Aparecido dos Santos |
| Abstract | |
The studies done in this PhD thesis aimed the preparation of a material that could be used in the recognition of chiral molecules and as catalysts. Its structure was based on gold nanoparticles that was functionalized with helical polymers containing a tellurium atom as an attach point. The presentation of the results was divided in four parts and the first one was the studies about the functionalization of gold nanoparticles with organoditellurides as a model material. It was observed that the presence of various functional groups in organic tellurides does not interfere into the process. The second part was the investigation of the tolerance of the rhodium catalyst, necessary for the polymerization, to the presence of the tellurium atom. The results showed that the activity of the catalyst was inhibited in the presence of a ditelluride, however, the polymerization occured when it was linked in the nanoparticle. The third and fourth parts consisted in the synthesis of the helical polymer based on oly(phenylacetilene)s structure, which one of them was prepared in professor Dos Santos\'s laboratory (third step - Brazil) and the other part in the professor Yashima\'s laboratory (fourth step - Japan). The studies of the third step was the preparation of polymers that could be applied for the recognition of chiral molecules and assymetric catalysis, however, the obtained material was too insoluble in many organic solvents and it is necessary to modify the structure of the monomer to increase the solubility of the respective polymer. In the last step was investigated the influence of the helicity in assymetric reactions. It was prepared copolymers constituted by a chiral unit without any catalytic activity and an achiral unit containing the catalytic functional group. The results showed that the achiral unit was capable to promote assymetric transformation when embebed in a preferred-handed helical structure. In this work was determined that is possible to prepare the suggested materials raising the polymer in the nanoparticle surface. The monomer that will be anchored in the metal was successfully prepared, remaining synthetize the monomer with an appropriate structure to perform the recognition of molecules and for catalysis (AU) | |
| FAPESP's process: | 10/03256-8 - Synthesis of helical polymers for recognation of chiral molecules |
| Grantee: | Leandro Mitsuo Shimura Takata |
| Support Opportunities: | Scholarships in Brazil - Doctorate (Direct) |