Two new NiII and ZnII metal–organic frameworks of glutarate and 1,4-bis[(2-methyl-1H-imidazol-1-yl)methyl]benzene ligands: syntheses, structures and luminescence sensing properties

Abstract

Two new metal–organic frameworks (MOFs), namely, three-dimensional poly[diaquabis{μ2-1,4-bis[(2-methyl-1H-imidazol-1-yl)methyl]benzene}bis(μ2-glutarato)dinickel(II)] monohydrate], {[Ni2(C5H6O4)2(C16H18N4)2(H2O)2]·H2O} n or {[Ni2(Glu)2(1,4-mbix)2(H2O)2]·H2O} n , (I), and two-dimensional poly[[{μ2-1,4-bis[(2-methyl-1H-imidazol-1-yl)methyl]benzene}(μ2-glutarato)zinc(II)] tetrahydrate], {[Zn(C5H6O4)(C16H18N4)]·4H2O} n or {[Zn(Glu)(1,4-mbix)]·4H2O} n (II), have been synthesized hydrothermally using glutarate (Glu2−) mixed with 1,4-bis[(2-methyl-1H-imidazol-1-yl)methyl]benzene (1,4-mbix), and characterized by single-crystal X-ray diffraction, IR and UV–Vis spectroscopy, powder X-ray diffraction, and thermogravimetric and photoluminescence analyses. NiII MOF (I) shows a 4-connected 3D framework with point symbol 66, but is not a typical dia network. ZnII MOF (II) displays a two-dimensional 44-sql network with one-dimensional water chains penetrating the grids along the c direction. The solid-state photoluminescence analysis of (II) was performed at room temperature and the MOF exhibits highly selective sensing toward Fe3+ and Cr2O7 2− ions in aqueous solution.