Synthesis of new anthracene‐substituted calix[4]triazacrown‐5 as highly sensitive fluorescent chemosensor and extractant against hazardous dichromate anion

Abstract

A new fluorogenic anthracene functionalized calix [4]triazacrown-5 (Ant-AzClx) was successfully synthesized using a simple Schiff's base reaction. The 1 H-NMR, 13 C-NMR, ESI-MS, and elemental analysis techniques were performed to characterize its structure. Excited at 370 nm, Ant-AzClx reveals excimer emission at 418 nm.Therefore, its anion binding properties were investigated against F À , HCO 3 À , H 2 PO 4 À , NO 3 À , Cr 2 O 7 2À , and SO 4 2À ions. When hazardous dichromate anion was introduced into medium, the fluorescence intensity of Ant-AzClx was markedly quenched. The binding constant, stoichiometry, the detection limits and Stern-Volmer equation for the complex formed between Ant-AzClx and Cr 2 O 7 2À ion were determined. Furthermore, the 1 H-NMR technique was also performed to assess the mechanism of the complex (Ant-AzClx@Cr 2 O 7 2À ). Apart from its excellent fluorescent chemosensor properties for selective and sensitive recognition of Cr 2 O 7 2À ion, Ant-AzClx was used as an efficient extractant towards dichromate anion. The extraction results indicated that Ant-AzClx exhibited high extraction capability, leading to it being a promising extractant for the removal of dichromate anions from water.

Controlled Primary Amine-Enriched SG-Bonded Papain Surface: Synthesis, Characterization, and Extraction of Protonated Dichromate

“…However, in most cases, the adsorbents need to be more selective; obviously, they may be used in removing the hexavalent chromium but suffer from selective separation for necessary the sample cleanup and preconcentration in selective detection/and quantification. 36−38 Liquid−liquid extraction 30 is brilliantly employed in selective extraction of soluble hexavalent dichromate anion Cr 2 O 7 2− using a new fluorogenic anthracene-functionalized calix [4]triazacrown-5 (Ant-AzClx) that effectively extracts 72.7% Cr 2 O 7 2− from acidic solution (at pH 2.5). However, solvent extraction is tedious and time-consuming, suffers from phase separation, and requires multiple extractions.…”

“…Nowadays, the SPE is much more applicable 21,39−41 over the tedious and time-consuming solvent extraction processes; 30 it requires a competent solid phase, usually built with efficient adsorbate-selective chelating ligands, interacting with anions selectively. 42 Chromium in hexavalent chromate anion combination CrO 4 2− /HCrO 4 − /Cr 2 O 7 2− has a great affinity toward the well-known primary amine containing sites.…”

“…42 Chromium in hexavalent chromate anion combination CrO 4 2− /HCrO 4 − /Cr 2 O 7 2− has a great affinity toward the well-known primary amine containing sites. 30,43 Thus, among the other common adsorbents, viz., biochar, activated carbon, cellulose, clays, and silica-based materials, 44,45 a lot of researchers were attracted to the biopolymer chitosan, built with primary amine groups as ligating sites to capture chromate ions from aqueous solutions effectively (Xiao et al 2021;Yang et al 2018). 34,46 The amino derivatives are the selective sorbents at pH values lower than pH PZC (around pH 7−8, where pH PZC becomes the pH value at which the surface of the sorbent has zero net charge) because, under these conditions, the protonated amino groups provide a positive surface charge, suitable for the sorption of Cr(VI) anions.…”

Preparation of Two Calix[4]arene-Functionalized Biopolymers and Evaluations of Their Extraction Abilities Against Cr(VI)/As(V) Anions

“…Therefore, the U.S. Environmental Protection Agency (EPA) listed dichromate compounds, which are extensively used in various industries such as electroplating, leather tanning, metal finishing, steels fabrication, pigments, textile etc., in as "Group A" human carcinogen [9,10]. Excessive or long-term dichromate exposure can bring out chronic chromium poisoning, and cause severe damage to human health [10][11][12]. Hereby, the World Health Organization (WHO) have recommended the allowable limit contaminant level of dichromate in natural water as 0.05 mg/L [13,14].…”

A Water-Soluble Naphthalimide-Based Fluorescent Probe for Specific Sensing of Fe3+ and $\text{C}{{\text{r}}_{2}}\text{O}_{7}^{2-}$

“…[1,9,17,20] It is well known that chromium is a heavy metal element, and its two oxidation states (Cr 3 ＋ and Cr 6 ＋ ) dominate in water and soil. [21,22] Although Cr 3 ＋ is a necessary trace ion for mammals, [21] excessive Cr 3 ＋ will bind to DNA and destroy cell structure. [23] Cr 6 ＋ is a toxic ion, and even low concentration of Cr 6 ＋ can pose a threat to life and health, [24][25] such as respiratory diseases, gastrointestinal diseases, skin damage, kidney diseases, central nervous system diseases, tumors, cancers, malformations and gene mutations.…”