Microwave-assisted synthesis of aromatic thiadiazol crown ethers and determination of complexation properties with metal ions by application of Job ' s plot method to conductometry

Abstract

The microwave-assisted synthesis technique, one of the pioneers of green chemistry, was used to synthesize aromatic thiadiazole crown ethers in this study. Thiadiazole crown ethers were synthesized by the cyclization reaction of 2-amino-5-mercapto-1,3,4-thiadiazole and mono-di-tri-tetra ethylene glycol dichloride compounds using the S(N)2 reaction mechanism in acetonitrile solvent and the presence of cesium carbonate base. FT-IR, H-1-NMR, C-13-NMR, LC-MS/MS spectroscopic techniques, and elemental analysis were used to characterize the synthesized compounds after purification. Furthermore, the conductivity behaviour of the synthesized compounds against metal salts (NaCl, KCl, MgCl2, CaCl2, ZnCl2, FeSO4, AgNO3, CoCl2) was determined using Job ' s Plot technique, which was adapted to conductometry. Interactions between ligands and ions were investigated. According to conductometric data, thiadiazole crown ethers showed significant complexations; M1 and M4 with Ca2+, M2 with Fe2+, and M3 with Co2+ ions.