Navegando por Palavras-chave "Calix[4]arene"

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    Estudo e aplicação de sistemas emissores como sensores iônicos
    (Universidade Federal de São Paulo (UNIFESP), 2020-10-15) Silva, Janail Rodrigues Da [UNIFESP]; Bagatin, Izilda Aparecida [UNIFESP]; Universidade Federal de São Paulo
    The present Master thesis proposed the synthesis and characterization of new functionalized calixarene ligands aimed at the selective recognition of anionic species, such as F-, Cl-, Ac-, PO43- e H2PO4- ions, as sensors with the environmental application. In this sense, five ligands were planned and synthesized using luminescent groups and hydrogen donor groups such as NH2, namely: 5, 11, 17, 23-tetra(tert-butyl)-25, 27-bis(acetylnaphthalene)-26, 28(dihydroxy)calix[4]arene (1), 5, 11, 17, 23-tetra(tert-butyl)-25, 27-bis (butoxy)phthalimide-26, 28(dihydroxy)calix[4]arene (2), 5, 11, 17, 23–tetra(tert-butyl)-25, 27-bis(acetylnaphthalene)-(amineethoxy)-26, 28-(dihydroxy)calix[4]arene (3), 2-Bromo-N-(thiazol-2-yl)acetamide (4) and the 5, 11, 17, 23–tetra(tert-butyl)-25, 27-bis(thiazol-2-yl)-acetamide-26, 28 (dihydroxy)calix[4]arene (5). However, satisfactory results were obtained only with the ligand (4) and (5) for the proposed objectives. Spectroscopic analyzes were performed, such as UV-Vis, 1H, and 13C NMR, to characterize and understand the mechanism of interaction with the ions, confirming the interaction of such ligand aligned with the targets previously presented. The ligand (4), 2-Bromo-N-(thiazol-2-yl)acetamide, showed interaction with the fluoride anions via hydrogen bonding in the N-H group, confirmed via 1H NMR titration. This ligand had a pKa of 10.26, showing it remains protonated during the anions interaction measurements. The experiments carried out with potentially hazardous anions showed good interaction for the ligand (4) with the F-, Ac-, PO43- ions. Titrations using 1H NMR identified the functional group, NH, which participates in the interaction with the ions mentioned above. Continuous variation method (Job Plot) was performed, allowing to identify the stoichiometry of ligand: ions interaction, which is pointed to be 1: 1. The functionalization of the calix[4]arene with the ligand (4), resulted in the ligand (5), with a cone conformation, and the C2v point group, compatible with the 1H NMR results, shown by the ArCH2Ar signals, AB spin system (3.54 ppm and 4.26 ppm), as well as an m-Ar-H signal (7.06 ppm) and two tBu signals (1.18 and 1.25 ppm), two signals referring to S-CH and N-CH (7.10 ppm and 7.38 ppm), at 8.83 ppm a hydroxyl signal and 12.38 ppm referring to the NH group. The spectra obtained via two-dimensional NMR, such as COSY, HSBC, and HMBC, complemented the data for the identification of the molecules. HMBC exhibited, via proton coupling at 4.85 ppm in the hydrogen spectrum and 148.48 ppm in the carbon spectrum, a coupling of hydrogen with the phenolic ring carbons at three bonds (3JCH), confirming there was functionalization of the ligand (4) in the calix [4] arene matrix, giving the ligand (5), 5, 11, 17, 23 - tetra (tert-butyl) -25, 27-bis (thiazol-2-yl) acetamide-26,28(dihydroxy)calix[4]arene. This ligand (5) presented satisfactory interaction results for the F-, Ac- and H2PO4- ions, and through the continuous variation method, the interaction of this ligand with the proposed ions was observed having a stoichiometry 1: 1. Through the results above, it is possible to highlight two molecules with potential applications as chemical sensors for hazardous species.
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    Evaluation of the biological effects of 5-Cl-8-oxyquinolinepropoxycalix[4]arene and 8-oxyquinolinepropoxycalix[4]arene in vitro and in vivo
    (Elsevier B.V., 2014-07-01) Soares, Marcos N. [UNIFESP]; Gascon, Thais M.; Fonseca, Fernando L. A. [UNIFESP]; Ferreira, Karen S. [UNIFESP]; Bagatin, Izilda A. [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Fundacao ABC
    The development of antibacterial and antifungal drugs has been the target of several pharmaceutical and chemical industries mainly due to the lack of effective drugs with low or no side effect. in this work, studies were conducted both in vitro and in vivo with 8-oxyquinolinepropoxycalix[4]arene (A) and 5-Cl-8-oxyquinolinepropoxycalix[4]arene (B) ligands, showing fairly good results. Cytotoxicity and fungicidal actions of compounds A and B were determined in Wistar male rats and peritoneal macrophages of mice. A slight change in the total of leukocytes and erythrocytes was observed on the hematologic assays, showing almost no inflammation after using both compounds in Wistar male rats. We have also noted some, but not significant, alteration in liver enzymes representing modest hepatotoxicity. Cytotoxicity of peritoneal macrophages, in the presence of compound A or B, showed 50% of survival of macrophages. On the other hand, macrophages previously infected with Candida albicans and treated with substance A or B exhibited an increased cytokine IL-10 at 24 h incubation. By checking the effect of substance A or B on growing C. albicans, the results pointed that these substances revealed antifungal activity against C. albicans, in 24 h culture with a reduction of yeast cells. (C) 2014 Elsevier B.V. All rights reserved.
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    Photoluminescence and thermoanalytical studies of complexes based on 5-Cl-8-hydroxyquinoline and calix[4]arene ligands
    (Elsevier B.V., 2013-05-01) Soares, Marcos N. [UNIFESP]; Moscardini, Elder F. [UNIFESP]; Mercuri, Lucildes P. [UNIFESP]; Bagatin, Izilda A. [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    A innovative 5-Cl-8-oxyquinolinepropoxycalix[4]arene ligand (2) have been prepared, exhibiting, at room temperature, blue fluorescent light emission and resulting in shift band to green fluorescent light (fluorescence mode) in the presence of coordinated Eu(III) and Tb(III) ions. Terbium complex presented phosphorescence emission as noted by typical bands at 490 nm, 545 nm and 585 nm. TG/DTG data exhibited typical thermal behavior for these compounds, however DSC curves showed the melting temperature near 300 degrees C for the samples, demonstrating an unusual thermal stability when quinoline derivatives are attached to calix[4]arene matrix. This fact strongly suggests an effective approach to preparing the photoluminescent compound associating high chemical and thermal stability. (C) 2013 Elsevier B.V. All rights reserved.