Thiourea derivatives (46 aroylthioureas) having different substituents close to the sulfur atom were synthesized and their ionophore potential in ion selective electrodes (ISEs) was examined. Structural considerations were taken into account based on the corresponding heavy-metal ISE parameters. As ionophores, some 1-furoyl-3-substituted thioureas (series 2) gave the best results in Pb(II), Hg(II) and Cd(II) ISEs. The strong intramolecular hydrogen bond in series 2 allows ligand interaction only through the CS group. Substituents on the furan and phenyl rings give rise to low solubility in the membrane plasticizer. 3-Alkyl substituted furoylthioureas improve solubility but enhance oxidative processes with chain length. New X-ray diffraction (XRD) structures and theoretical DFT calculations were considered in the analysis of the substituent influence on the selectivity of ISEs. These new ionophores have advantages because of their stability, simple synthesis and easy modification of the sulfur binding ability resulting from substitution.
合成了46种不同取代基的
噻唑衍
生物(芳酰
噻唑),并研究了它们在离子选择电极(I
SEs)中的离子载体潜力。根据相应的重
金属I
SE参数,考虑了结构因素。作为离子载体,某些1-
呋喃酰基-3-取代
噻唑(系列2)在Pb(II)、Hg(II)和Cd(II) I
SE中表现出最佳性能。系列2中的强内氢键使得
配体只能通过CS基团进行相互作用。
呋喃和苯环上的取代基导致在膜
增塑剂中溶解度低。3-烷基取代的
呋喃酰
噻唑提高了溶解度,但随着链长的增加增强了氧化过程。在分析取代基对I
SE选择性的影响时,考虑了新的X射线衍射(XRD)结构和理论DFT计算。这些新离子载体因其稳定性、简单合成和由于取代改变
硫结合能力的易修改性而具有优势。