Since the first fluorescent chemical sensor reported in 1867 it has been frequently to find intelligent organic molecules that act as chemical sensors of high selectivity and sensitivity. In this process the colorimetric and fluorescence methods have more advantages since they are generally very sensitive, low cost, easily executable, versatile and fast-performing. Despite the great progress in recent years in this area, there are still a number of problems and challenges to be overcome. Numerous chemical and biochemical analyses (anions, cations, neutral molecules, biomolecules) can be detected by methods using fluorescence and also colorimetry. Thus, it is known that the absence or excess of some of these species of analyses in the human body can cause damage to some vital organs, but may also be related and help in the identification of diseases. Colorimetric receptors containing various chromophores with azo-compounds have been developed since the discovery of chemosensory. One of the molecules widely used is the Schiff bases, as well as the quinoline derivatives that have been showing good results and a great evolution in the researches involving their general applications. This wide applicability of the quinolinic derivatives attracts the interest of the scientific community in the synthesis and study of these compounds. Therefore, in this project we propose based on preliminary results, to use Niobium pentachloride (NbCl5) as a Lewis acid type catalyst in multicomponent reactions (MCR) that are essential tools in today's synthetic organic chemistry. The synthesized molecules will be tested for application as chemical sensors of several species. Thus, the present study aims to assist in the development of a sensitive and reliable analytical method and throughout the work, we will seek more complete answers about the behavior of these molecules in relation to different salts and solvents, but mainly to the tin that has been presented interesting results in preliminary tests. It is intended the synthesis of a series of organic receptors derived from an thrazolinic compounds having binding sites and functionalities with potential for recognition of specific anionic or cationic species. It will be carried out the structural characterization of the compounds prepared, applying different spectroscopic and spectrometric techniques and also to confirm the process of connection/interaction of the ionic species we will highlight the analysis of spectra and UV-Vis absorption and fluorescence in solution, as well as UV-Vis titration and cyclic voltammetry studies.
News published in Agência FAPESP Newsletter about the scholarship: