Estudio fisicoquímico de resorcin[4]arenos sulfonados en solución acuosa y su acomplejamiento con iones de interés

Abstract

In the present investigation, two novel resorcin[4]arenes were prepared and purified. The purity were evaluated by HPLC and characterization was performed by using TG, 1H-NMR, MS, IR and DRX (for Na4BRA). Physicochemicals properties such as solubilities in water, MeOH and EtOH, conductivities and viscosities in water and volumes and compressibilities in water and in DMSO, were measured. Additionally, the complexation processes with (CH3)4NBr, C12H25(CH3)3NBr, LDC, ChCl, Cu2+, Pb2+ , Cd2+ , and Hg2+ were evaluated in water by using conductivity, potentiometry, sonometry and 1H-NMR methods. The TG analysis revealed that both compounds were trihydrate in the amorphous solid state and the DRX study only showed the crown conformation for Na4BRA. In water, the crown and boat conformations were presented for both Na4RAs, while in DMSO just the crown conformation was observed by 1H-NMR. The values of solution molar properties determined by solubility were interpreted in terms of the hydrogen bonds occurrence and Van der Waals interactions. The values of BV indicated that these Na4RAs are hydrophobic solutes. The results found from volume and compressibility measurements in water and in DMSO, indicated that the solute-solvent interactions for Na4SRA are larger compared with Na4BRA. The values positives of Jones-Dole coefficient for both solutes in water, were associated to a making structure effect and were corroborates by conductivity measurements. The distribution diagram indicated that at pHs close 7, the not deprotonated species predominate in the solution. At this pH, Na4BRA is able to form host-guest complex with (CH3)4NBr, LDC, ChCl, Cu2+ y Pb2+, while Na4SRA only form complex with Hg2+.The host-guest complex formation was explicated by considering the several interaction in solution