Luminescent Coordination Polymer with Conjugated Lewis Acid Sites for the Detection of Organic Amines

Abstract

A stable three-dimensional coordination polymer, [Eu3(bcbp)3(NO3)7(OH)2] n (1) (H 2 bcbp·2Cl = 1,1′-bis­(4-carboxyphenyl)-(4,4′-bipyridinium) dichloride), was prepared by the solvothermal reaction of Eu­(NO3)3·6H2O and H 2 bcbp·2Cl in methanol, which was characterized by infrared spectroscopy, single-crystal X-ray diffraction, powder X-ray diffraction, and thermogravimetric analyses. In the solid state, 1 consists of an unusual trinuclear Eu­(III) unit (Eu3(CO2)6(NO3)7(OH), Eu3–SBU), which further connects to six neighboring ones through six bcbp ligands to form a three-dimensional network. As expected, 1 exhibits a strong red-light emission at ambient temperature. Due to the presence of the electron-deficient bipyridinium moiety in the conjugation, this emission is selectively quenched by electron-rich organic amine compounds with high sensitivity and exhibits a prominent visual color change.

Space-confined indicator displacement assay inside a metal–organic framework for fluorescence turn-on sensing

“…A judicious strategy toward amine-sensing MOFs is to incorporate electron-deficient units, with which electron-rich amines can form CT complexes to induce photophysical changes. Thus, some MOFs bearing a naphthalenediimide or 4,4′-bipyridinium unit can sense amines in the turn-off mode,14 and a dynamic coordination polymer shows a turn-on response to arylamines owing to emissive π–π CT complexation 5 a . However, highly sensitive MOFs for sensing amines in aqueous media are still rare.…”

Crystal structure of poly[bis(1-methyl-[4,4′-bipyridin]-1-ium-κN)-tetrakis(μ3-sulfato-κ3 O:O′:O′′)trizinc(II)], C22H22Zn3N4O16S4

“…Structural motifs include one-dimensional chains and ladders, twodimensional grids, three-dimensional networks and interpenetrated structures [7][8][9]. Viologens (1,1-disubstituted-4,4-bipyridinium) are well known for their photoelectrochromism, electron-accepting ability and redox activity [10,11]. A series of ligands with varied coordination sites have been designed and synthesized based on 4,4-dipyridyl over the past few years [12].…”

A Porous Cadmium(II) Framework: Synthesis, Crystal Structure, Gas Adsorption, and Fluorescence Sensing Properties

“…Of particular interest is to construct porous luminescent MOFs, which can be used to detect volatile organic solvent molecules, nitroaromatic explosives, cations, anions, and temperature by luminescence sensing . So far, a large number of PMOFs with luminescent sensing functions have been realized and reported . In order to construct PMOFs, we should select appropriate organic ligands with long spacers, which can link metal ions into 3D porous frameworks with high thermal stability.…”