Potentiometric studies of complex formation of amidopyridine macrocycles bearing pendant arms with proton and heavy metal ions in aqueous solution

Synthetic Approaches to the Bifunctional Chelators for Radio­nuclides Based On Pyridine-Containing Azacrown Compounds

“…[26][27][28] In our earlier studies, the synthesis of the new derivatives of pyridine containing azacrown compounds and their complex formation with heavy metal ions have been reported. 29,30 The rigid structure of pyridine-2,6-dicarboxamide fragment provides fast kinetics of complex formation, the introduction of additional coordination groups improves the binding properties of macrocycles. These chelators have also been tested as chelating agent for radionuclides.…”

“…57 Macrocyclization gives azacrown compound 7 in 44% yield, the following hydrolysis of tert-butyl ester in boiling water without the addition of acid as catalyst results in 8 in high yield (Scheme 2). This convenient way to remove tertbutyl protection group was developed by us earlier, 30,58 it avoids the use of ion-exchange resin or other difficult methods for the purification of the target product. At the final stage, the chelating groups are introduced to obtain a bifunctional derivative 9 in 73% yield.…”

Extensive removal of thallium by graphene oxide functionalized with aza-crown ether

“…21 Because macrocyclic ligands can form complexes with different metal ions or anions, it is widely used in catalysis, metal separation, molecular recognition, sensors and other applications. [22][23][24][25] Among the various functionalities, crown ethers have a strong nucleophilic structure and rigidity that result in an affinity for alkali and alkaline earth metal ions, and aza-crown ethers have a highly nucleophilic structure and affinity for so metal ions, 26 where ligands can be customized for various metal cations. In this study, we functionalized GO with aza-crown ethers.…”

Evaluation method for heavy metal pollution control effect in rural areas of northern Anhui Province

“…Through the leaching of weathered rocks, elements, and compounds and under the action of biological microorganisms, it accumulates or dissolves in groundwater to form a soil environment of multiple vegetation nutrient elements. 3 Soil is an irreversible natural resource and a base for the growth and breeding of human beings, animals, and plants. The causes of soil pollution are complex.…”