Anthracene-Based Receptors with a Turn-on Fluorescence Response for Nitrate

Abstract

Herein we describe the design, synthesis, and anion binding properties of bicyclic receptors with two or three anthracenes, which show a turn-on fluorescence response in the presence of nitrate and chaotropic anions in a buffered aqueous solution. The receptor with two anthracenes binds nitrate with 10 3 M −1 affinity and stabilizes it in the inner cavity though electrostatic, hydrogen bonding, and anion−π interactions.

Advances in fluorescent and colorimetric sensors for anionic species

“…Various groups have been engaged in the development of chemosensors based around macrocyclic receptor scaffolds which include polyamines, calixarenes, calixpyrroles and porphyrins [48][49][50][51][52][53][54][55][56]. Kataev and co-workers proposed the bicyclic, anthracene-containing receptor 21 as an OFF-ON chemosensor for nitrate in buffered aqueous solution [57]. In 50 mM acetate buffer solution (5% DMSO, pH 3.6), an increase in fluorescence emission of the free chemosensor was observed upon addition of NaNO3.…”

Converting pH probes into “turn-on” fluorescent receptors for anions

“…Further studies with cryptands bearing two and three anthracene rings revealed a different sensing mechanism that appeared to be characteristic for chaotropic anions -those anions that in water solution disrupt the hydrogen bonding network inside the cavity. 42 Thus, receptors 19 and 20 in the fully protonated state show higher fluorescence intensity in the presence of such anions as NO 3 À ,ClO 4 À , PF 6 À and BF 4 À (Fig. 8).…”

Anion-Induced Intramolecular Cyclization of Urea-Based Receptors: Entrapment of Cyclic [SO4(H2O)42–]n Cluster and Encapsulation of Anions with Varied Dimensionality

“…25 Both cyclic as well as acyclic receptors have been designed by many groups for NO 3 − recognition. 26,27 Very recently, Wang et al have reported a calix [4]pyrrole strapped benzenebistriazole bis-cycle that displays strong sulfate-binding affinity of >10 6 M −1 in an aqueous medium. 28 Urea-based and squaramide-based ion pair receptors have also been designed for selective SO 4 2− anion recognition recently by many groups.…”

“…Johnson et al have designed a ditopic 3,5-bis­((2-iodophenyl)­ethynyl)­pyridinium receptor recently, which could recognize halide anions . Both cyclic as well as acyclic receptors have been designed by many groups for NO 3 – recognition. , Very recently, Wang et al have reported a calix[4]­pyrrole strapped benzenebistriazole bis -cycle that displays strong sulfate-binding affinity of >10 6 M –1 in an aqueous medium . Urea-based and squaramide-based ion pair receptors have also been designed for selective SO 4 2– anion recognition recently by many groups. − Cage-type receptors have also been developed for SO 4 2– binding by Kubik and his group, whereas, on the other hand, Kataev et al have reported an amide-based fluorescent receptor that can sense SO 4 2– in aqueous solution .…”