Four Novel d10 Metal-Organic Frameworks Incorporating Amino-Functionalized Carboxylate Ligands: Synthesis, Structures, and Fluorescence Properties.

Wang Xie,Jie Wu,Zhoulu Wang,Xiaochun Hang,Honghai Zhang,Kang Shen

doi:10.3389/fchem.2021.708314

Abstract

By employment of amino-functionalized dicarboxylate ligands to react with d10 metal ions, four novel metal-organic frameworks (MOFs) were obtained with the formula of {[Cd(BCPAB)(μ 2-H2O)]}n (1), {[Cd(BDAB)]∙2H2O∙DMF}n (2), {[Zn(BDAB)(BPD)0.5(H2O)]∙2H2O}n (3) and {[Zn(BDAB)(DBPB)0.5(H2O)]∙2H2O}n (4) (H2BCPAB = 2,5-bis(p-carbonylphenyl)-1-aminobenzene; H2BDAB = 1,2-diamino-3,6-bis(4-carboxyphenyl)benzene); BPD = (4,4′-bipyridine); DBPB = (E,E-2,5-dimethoxy-1,4-bis-[2-pyridin-vinyl]-benzene; DMF = N,N-dimethylformamide). Complex 1 is a three-dimensional (3D) framework bearing seh-3,5-Pbca nets with point symbol of {4.62}{4.67.82}. Complex 2 exhibits a 4,4-connected new topology that has never been reported before with point symbol of {42.84}. Complex 3 and 4 are quite similar in structure and both have 3D supramolecular frameworks formed by 6-fold and 8-fold interpenetrated 2D coordination layers. The structures of these complexes were characterized by single crystal X-ray diffraction (SC-XRD), thermal gravimetric analysis (TGA) and powder X-ray diffraction (PXRD) measurements. In addition, the fluorescence properties and the sensing capability of 2–4 were investigated as well and the results indicated that complex 2 could function as sensor for Cu2+ and complex 3 could detect Cu2+ and Ag+ via quenching effect.

Highlights

Metal-Organic Frameworks new absorbent materials, quantities of Metal-organic frameworks (MOFs) have been widely investigated in the capture and separation of various gases, such as CO2, SO2, H2S, NH3, hydrocarbons and so on. (Li et al, 2009; Peng et al, 2013; Zhang et al, 2014; Trickett et al, 2017; Zárate et al, 2019a; Zárate et al, 2019b; Tchalala et al, 2019; Wang et al, 2020; Han et al, 2021) Varieties of MOFs have been explored as luminescent materials in different fields, for example, sensing, nonlinear optical materials, OLED, and so forth. (Lustig et al, 2017; Medishetty et al, 2017; Gutiérrez et al, 2018) many MOFs have exhibited relatively superior performance, the majority of them do not meet the requirements of practical applications
The influence of amino groups on the structures and properties of MOFs has been intensively studied because amino groups could coordinate with metal ions and form hydrogen bonds with guest molecules, which may strengthen some performance or even endow MOFs more functionalities
Hu et al demonstrated that the supramolecular interactions of C-H···O, C···O, and O···O could distinctly enhance the adsorption capacity for CO2. (Hu et al, 2015) Dong and co-workers found that the introduction of amino groups to UiO-66 could provide sensing capability towards lysine and arginine via fluorescence turn-on effect. (Dong et al, 2020)

Summary

Introduction

Metal-organic frameworks (MOFs), which are formed by coordination bonds between metal nodes and organic linkers (Tranchemontagne et al, 2009), have been one of the most rapidly developing areas of material science, because of the tunable porosity, controlled structure, and readily chemical functionalization of these materials, and because of their wide potential applications such as heterogeneous catalysis, gas adsorption and storage, chemical sensing and explosive detection, drug delivery, and optoelectronics. (Barea et al, 2014; Canivet et al, 2014; Dhakshinamoorthy and Garcia, 2014; He et al, 2014; Hu et al, 2014; Liu et al, 2014; Van de Voorde et al, 2014; Silva et al, 2015; Zhu et al, 2015; Sheberla et al, 2017; Li et al, 2018; Park et al, 2018; Prasad et al, 2018; Wang et al, 2018; Cao et al, 2019; Mallick et al, 2019) For example, as a kind ofMetal-Organic Frameworks new absorbent materials, quantities of MOFs have been widely investigated in the capture and separation of various gases, such as CO2, SO2, H2S, NH3, hydrocarbons and so on. (Li et al, 2009; Peng et al, 2013; Zhang et al, 2014; Trickett et al, 2017; Zárate et al, 2019a; Zárate et al, 2019b; Tchalala et al, 2019; Wang et al, 2020; Han et al, 2021) Varieties of MOFs have been explored as luminescent materials in different fields, for example, sensing, nonlinear optical materials, OLED, and so forth. (Lustig et al, 2017; Medishetty et al, 2017; Gutiérrez et al, 2018) many MOFs have exhibited relatively superior performance, the majority of them do not meet the requirements of practical applications. The influence of amino groups on the structures and properties of MOFs has been intensively studied because amino groups could coordinate with metal ions and form hydrogen bonds with guest molecules, which may strengthen some performance or even endow MOFs more functionalities. In consideration of the positive effect of amino groups on the properties of MOFs, we employed amino-functionalized dicarboxylate ligands to construct MOFs in this work. For this purpose, ligands 2,5bis(p-carbonylphenyl)-1-aminobenzene (H2BCPAB) and 1,2diamino-3,6-bis(4-carboxyphenyl)benzene) (H2BDAB) were synthesized to react with d10 metal ions Zn2+ and Cd2+ in the absence and presence of auxiliary ligands and four novel MOFs with the formula of {[Cd(BCPAB)(μ2-H2O)]}n (1), {[Cd(BDAB)]· 2H2O·DMF}n (2), {[Zn(BDAB)(BPD)0.5(H2O)]·2H2O}n (3) and {[Zn(BDAB)(DBPB)0.5(H2O)]·2H2O}n (4) (BPD (4,4′-bipyridine); DBPB The fluorescence properties and the sensing capability of 2–4 were investigated as well, and the sensing experiments indicated that complex 2 could function as a sensor for Cu2+ and complex 3 could detect Cu2+ and Ag+ via quenching effect

Methods

Results

Conclusion