Polymer Supported Calix[4]arene Schiff Bases: A Novel Chelating Resin for Hg²⁺and Dichromate Anions

Resorcin[4]arene Schiff base derivatives: Synthesis, characterization, and extraction studies

“…The percentage extraction of Hg 2+ found in the reported literature was nearly about 50%. 34,36,37 The best results are obtained with mercury due to its high electronegativity compared to the other tested metals.…”

“…, has potential sites to create hydrogen bonds with ligands. 34 The extraction of dichromate ions with ligands 2a-h has been studied at various pH values of the dichromate solution such as 5, 4, 3, 2, and 1. The percentage extraction of dichromate anions at different pH values shows reasonable extraction by the ligands.…”

“…33 Furthermore, the solid-liquid extraction study of calix [4]arene Schiff bases for chromate ions have been performed at different pH values. 34 In this paper, resorcin [4]arenes with an acetyl group at the ortho-position have been synthesized in excellent yields using sodium methoxide as the base under reflux conditions. Benzylamine was used to generate novel Schiff base derivatives of the resorcin [4]arene.…”

Synthesis and dichromate anion sorption of silica gel-immobilized calix[4]arenes

“…In recent years various attempts have been undertaken to incorporate calixarenes into different polymers for use as selective anion extractants [18].…”

Synthesis of Calix(aza)crown and its Oligomeric Analogue for the Extraction of Selected Metal Cations and Dichromate Anions

“…Compared to considerable interest in complexation studies of monomeric calixarenes, there are only a few studies on calixarenecontaining polymers, which may be processed into materials suitable for chemical sensor devices [7 -9, 11 -15]. Although, much work regarding the synthesis of calixarene-based crown ethers and azacrowns along with their complexation with alkali metal ions have been reported, only a small amount of work has been published on their complexation with transition metals and anions [11,12,24,25].…”