Publicação
Synthesis and photochemical characterization of multiphoton absorbing chromophores
| Resumo: | Compounds with ability to absorb two or more photons have attracted the scientific community due to the need of smaller energies that allow a deeper penetration into the tissues without damaging and a higher three dimensional resolution. A structurally diversified family of oxazol-5(4H)-ones was synthesized and the influence of the substituents in their optical properties was studied,(Z)-4-(4-((E)-2-(1H-benzo[d]imidazol-2-yl)vinyl)benzylidene)-2-(4-(dimethylamino)phenyl)oxazol-5(4H)-one was found to have the best TPA properties presenting F=75% and 2=300 GM.The combinatorial aldol synthesis of TPA s-triazine derivatives from aryl-aldehydes and trimethyltriazine resulted in compounds with low TPA properties. Polymers based in the aldol condensation of dialdehydes, monoaldehydes and trimethyltriazine were prepared, providing polymers with low potential TPA properties due to their poor solubility. Nevertheless, this work inspired the production of melamines with biological applications, namely in malaria disease. Forty compounds were studied leading to the conclusion that molecules with one or two primaquine units present the best antimalarial activity. N1,N1'-(6-chloro-1,3,5-triazine-2,4-diyl)bis(N4-(6-methoxyquinolin-8-yl)pentane-1,4-diamine) was the most promising compound with IC50=598.05 nM in blood stage tests against Pasmodium Falciparum and 96% inhibition of the liver stage parasite activity.A system constituted by a standard TPA polymer (based in 2,4,6-tris(thiophen-2-yl)-1,3,5-triazine units bridged by 9,9-dihexyl-9H-fluorene) and a photochromic molecule (1,2-bis(2-methylbenzo[b]thiophen-3-yl)hexafluorocyclopentene, PC) was studied aiming the construction of two-photon activated photochromic polymers. This system showed to have efficient writing, reading and erasing processes induced by TPA irradiation. Both PC and TPA moieties revealed to be suitable for the synthesis of polymers and further application in data storage devices.The TPA properties of fluorescein based ionic liquids (ILs) with quaternary ammonium cations were studied. These ILs showed low TPA properties however, interesting linear optical properties regarding the fluorescein prototropic equilibrium were observed. For the first time the excited state deprotonation of monoanionic fluorescein was observed, resulting from residual water within ILs medium. |
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| Autores principais: | Rodrigues, Catarina |
| Assunto: | Teses de doutoramento - 2013 |
| Ano: | 2013 |
| País: | Portugal |
| Tipo de documento: | tese de doutoramento |
| Tipo de acesso: | acesso restrito |
| Instituição associada: | Universidade de Lisboa |
| Idioma: | inglês |
| Origem: | Repositório da Universidade de Lisboa |
| Resumo: | Compounds with ability to absorb two or more photons have attracted the scientific community due to the need of smaller energies that allow a deeper penetration into the tissues without damaging and a higher three dimensional resolution. A structurally diversified family of oxazol-5(4H)-ones was synthesized and the influence of the substituents in their optical properties was studied,(Z)-4-(4-((E)-2-(1H-benzo[d]imidazol-2-yl)vinyl)benzylidene)-2-(4-(dimethylamino)phenyl)oxazol-5(4H)-one was found to have the best TPA properties presenting F=75% and 2=300 GM.The combinatorial aldol synthesis of TPA s-triazine derivatives from aryl-aldehydes and trimethyltriazine resulted in compounds with low TPA properties. Polymers based in the aldol condensation of dialdehydes, monoaldehydes and trimethyltriazine were prepared, providing polymers with low potential TPA properties due to their poor solubility. Nevertheless, this work inspired the production of melamines with biological applications, namely in malaria disease. Forty compounds were studied leading to the conclusion that molecules with one or two primaquine units present the best antimalarial activity. N1,N1'-(6-chloro-1,3,5-triazine-2,4-diyl)bis(N4-(6-methoxyquinolin-8-yl)pentane-1,4-diamine) was the most promising compound with IC50=598.05 nM in blood stage tests against Pasmodium Falciparum and 96% inhibition of the liver stage parasite activity.A system constituted by a standard TPA polymer (based in 2,4,6-tris(thiophen-2-yl)-1,3,5-triazine units bridged by 9,9-dihexyl-9H-fluorene) and a photochromic molecule (1,2-bis(2-methylbenzo[b]thiophen-3-yl)hexafluorocyclopentene, PC) was studied aiming the construction of two-photon activated photochromic polymers. This system showed to have efficient writing, reading and erasing processes induced by TPA irradiation. Both PC and TPA moieties revealed to be suitable for the synthesis of polymers and further application in data storage devices.The TPA properties of fluorescein based ionic liquids (ILs) with quaternary ammonium cations were studied. These ILs showed low TPA properties however, interesting linear optical properties regarding the fluorescein prototropic equilibrium were observed. For the first time the excited state deprotonation of monoanionic fluorescein was observed, resulting from residual water within ILs medium. |
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