Highly sensitive detection of nitrobenzene by a series of fluorescent 2D zinc() metal-organic frameworks with a flexible triangular ligand

• Published in: RSC advances 2021-07, Vol.11 (39), p.23975-23984
• Main Authors: Yang, Xue, Ren, Yixia, Chai, Hongmei, Hou, Xiufang, Wang, Zhixiang, Wang, Jijiang
• Format: Article
• Language: English
• Subjects: Aqueous solutions; Bimetals; Chemistry; Crystallography; Fluorescent indicators; Imidazole; Ligands; Metal-organic frameworks; Nitrobenzene; Zinc
• ISSN: 2046-2069; 2046-2069
• DOI: 10.1039/d1ra03737d

Four fluorescent zinc( ii ) metal-organic frameworks, namely [Zn(HCIA)(4,4′-bipy)] ( 1 ), [Zn 2 (CIA)(OH)(1,4-bibz) 1.5 ]·H 2 O ( 2 ), [Zn(CIA)(OH) (4,4′-bbpy)] ( 3 ), and [Zn 2 (HCIA) (4,4′-bimp)]·H 2 O ( 4 ), were prepared hydrothermally with a flexible triangular ligand (H 3 CIA) and a series of linear N-donor ligands (H 3 CIA = 5-(2-carboxybenzyloxy) isophthalic acid, 4,4′-bipy = 4,4′-bipydine, 1,4-bibz = 1,4-bis(1-imidazoly)benzene; 4,4′-bbpy = 4,4′-bis (imidazolyl) biphenyl; 4,4′-bimp = 4,4′-bis (imidazole-1-ylethyl) biphenyl). Structural analyses revealed that complex 1 exhibited a 2D brick-like network structure based on the basic bimetallic ring, 2 was also a 2D interspersed structure from the 1D tubular structure, compound 3 possessed a 2D (4,4) network with 4,4′-bbpy occupying the holes, and complex 4 displayed a 2D network from the 1D ladder-like chain. The thermal stabilities and fluorescent properties of these complexes were investigated in the solid state. The fluorescent sensing experiments revealed that all Zn-MOFs could highly sensitively detect nitrobenzene in aqueous solution, which indicated that these materials can be used as fluorescent probes for the detection of nitrobenzene. Four fluorescent 2D Zn-MOFs based on a flexible triangular ligand and linear N-donor ligands are hydrothermally prepared and used to detect nitrobenzene in aqueous solution with high sensitivity, demonstrating their potential as fluorescent sensors.