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    Somente Metadadados
    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.