Gas adsorption, magnetic, and fluorescent sensing properties of four coordination polymers based on 1,3,5-tris(4-carbonylphenyloxy)benzene and bis(imidazole) linkers

Abstract

Four 3D novel coordination polymers (CPs), formulated as {[Co₃(TCPB)₂(bibp)₂(dioxane)_2.5(H₂O)₂]·(DMF)}_n (1), {[Cd₆(TCPB)₄(bibp)₄(dioxane)(H₂O)₂]·(dioxane)₃·DMF·(H₂O)_0.5}_n (2), {[Co_1.5(TCPB)(bimb)_0.5(DMF)(dioxane)]}_n (3), and {[Zn_1.5(TCPB)₂(bimb)(DMF)(dioxane)₂]·dioxane}_n (4) (H₃TCPB = 1,3,5-tris(4-carbonylphenyloxy)benzene, bibp = 4,4′-bis(imidazol-1-yl)biphenyl, and bimb = 1,4-bis(imidazol-1-ylmethyl)benzene), have been synthesized under solvothermal conditions and characterized by elemental analyses (EA), single-crystal X-ray diffraction analyses, X-ray powder diffraction analyses (PXRD), IR spectra, and thermogravimetric analyses (TGA). The structural analyses reveal that complex 1 can be simplified as a new 2-nodal (3,10)-{3·4²}₂ {3⁴·4¹⁰·5¹⁴·6¹⁴·7²·8}-3,10T3 net, complex 2 has a 3D 2-nodal (3,8)-c network with the point symbols of {4²·5}₂{4⁴·5⁹·6⁸·7³·8³·9}, complex 3 exhibits a novel 3D framework with the point symbol of {4¹⁰·6³²·7·8²}{4³}₂, and the structure of 4 is a (3,8)-connected {4³}₂{4⁶·6¹⁸·8⁴}-tfz-d net. Furthermore, gas sorption behaviors of complex 1 for N₂, H₂, CH₄, and CO₂ have been comprehensively studied at varying temperatures: the results reveal that the adsorption capacity of 1 to N₂ is stronger than those of other gases. Meanwhile, IAST calculations reveal that 1 exhibits excellent selective separation for CO₂/CH₄. Magnetic measurements indicate that both 1 and 3 have antiferromagnetic interactions within the trinuclear clusters. In addition, the fluorescent measurements showed that 2 and 4 exhibit highly selective and sensitive detection of Fe³⁺ and Cr³⁺ ions.