Estudo experimental e computacional de Solventes Eutéticos Profundos baseados no núcleo Benzalcônio

Abstract

In line with the principles of green chemistry, synthetic organic chemistry has sought to develop new environmentally safe solvents. In this context, the class of deep eutectic solvents (DES, Deep Eutectic Solvents) has been gaining prominence in the last two decades due to its potential as a “green” alternative to common organic solvents. DESs are formed by a mixture of two or more components, in appropriate molar proportions, resulting in a eutectic mixture, that is, with a lower melting point than the individual components. They are considered a very promising class of compounds due to their unique physicochemical properties and have been evaluated as a green alternative for different applications. Therefore, in this work DESs based on Benzalkonium core with glycerol and citric acid and oxalic acid as HBDs were prepared using the conventional heating method and the use of microwave irradiation as a preparation method was also investigated. The synthesized DES were obtained as liquids at room temperature and very viscous. With this, a systematic study was carried out on the structural, vibrational and physical-chemical properties of the solvents obtained and the vibrational properties were also determined through quantum calculations in DFT CAM-B3LYP/6-311++G(d,p). The characterization was performed through FTIR and NMR spectroscopic analyses, physicochemical analyzes such as Refractive Index, Conductivity, Density and Viscosity, and thermal analyzes such as TGA and DSC. The results demonstrate that the physicochemical properties of the DESs obtained are influenced by the HBD used in the preparation. They also demonstrated that the combination of spectroscopy and quantum calculations is an effective method for researching the compositions and structures of DES.