Multifunctional Zn(II) Coordination Polymer as Highly Selective Fluorescent Sensor and Adsorbent for Dyes

Abstract

A new Zn(II)-based coordination polymer (1) comprising the Schiff base ligand obtained by the condensation of 5-aminosalicylic acid and salicylaldehyde has been synthesized. This newly synthesized compound has been characterized by analytical and spectroscopic methods, and finally, by single-crystal X-ray diffraction technique in this study. The X-ray analysis reveals a distorted tetrahedral environment around the central Zn(II) center. This compound has been used as a sensitive and selective fluorescent sensor for acetone and Ag+ cations. The photoluminescence measurements indicate that in the presence of acetone, the emission intensity of 1 displays quenching at room temperature. However, other organic solvents caused meagre changes in the emission intensity of 1. Additionally, the fluorescence intensity of 1 has been examined in the presence of different ketones viz. cyclohexanone, 4-heptanone, and 5-nonanone, to assess the interaction between the C=O group of the ketones and the molecular framework of 1. Moreover, 1 displays a selective recognition of Ag+ in the aqueous medium by an enhancement in its fluorescence intensity, representing its high sensitivity for the detection of Ag+ ions in a water sample. Additionally, 1 displays the selective adsorption of cationic dyes (methylene blue and rhodamine B). Hence, 1 showcases its potential as an excellent luminescent probe to detect acetone, other ketones, and Ag+ with an exceptional selectivity, and displaying a selective adsorption of cationic dye molecules.

Synthesis and Experimental Structure of a Multifunctional Catechol‐Azomethinebenzoic Acid, DFT/DMol3 Calculations, and Molecular Docking with Hsp90

“…The Hirshfeld surface and fingerprint plots for 1 are very similar to those for the recently reported (E)-4-((2-hydroxy-3,5diiodobenzylidene)amino)benzoic acid (DHBA), [21] the 4-methoxybenzyl-2-dihydroxybenzalaldimine ligand in a Zn coordination polymer, [8] and the (3-((2-hydroxy-5nitrobenzylidene)amino)benzoic acid ligand in the complex [Cu 2 (L) 2 (Py) 4 ]. [9] This confirms our choice for the functional groups on 1.…”

“…DMSO (DHBA = (E)-4-((2-hydroxy-3,5-diiodobenzylidene)amino)benzoic acid; DMSO = dimethyl sulfoxide), [21] and the 4-methoxybenzyl-2-dihydroxybenzalaldimine units of a recently reported Zn coordination polymer. [8] Intramolecular OÀ H⋯N and OÀ H⋯O hydrogen bonds stabilize the molecular structure (Figure 1, Table 2). The same OÀ H⋯N hydrogen bond was observed in DHBA .…”

“…[16][17][18][19][20] When including additionally to the 2,3-dihydroxybenzaldehyde, the 4-aminobenzoic acid functionality, the total number of studies is far smaller. [8,12,[21][22][23][24][25] Some of them provide two carboxylic acid functions and vary in the location of the two phenolic OH group for building up hydrogen bonding networks. [8,9,12,14,21] The deprotonated function of such 2,3-dihydroxybenzaldehyde-4aminobenzoic acid derivatives was previously used for coordination of metals, [8,12] and contain the biologically important catechol (benzene-1,2-diol) unit.…”

“…[8,12,[21][22][23][24][25] Some of them provide two carboxylic acid functions and vary in the location of the two phenolic OH group for building up hydrogen bonding networks. [8,9,12,14,21] The deprotonated function of such 2,3-dihydroxybenzaldehyde-4aminobenzoic acid derivatives was previously used for coordination of metals, [8,12] and contain the biologically important catechol (benzene-1,2-diol) unit. [26][27][28] Heat shock proteins (Hsp) are among the most abundant intracellular proteins.…”

“…[1,6,7] Diaryl-imines formed from 2-hydroxybenzaldehyde and anilines provide a chelate N imine ^Ophenolate binding and have been extensively studied. [1,2,4,5,[7][8][9][10][11][12][13][14][15] including many examples of 2,3dihydroxybenzaldehyde derivatives. [16][17][18][19][20] When including additionally to the 2,3-dihydroxybenzaldehyde, the 4-aminobenzoic acid functionality, the total number of studies is far smaller.…”