Preparation, characterization and luminescence-sensing properties of two ZnII MOFs with mixed 5-amino-2,4,6-tribromoisophthalic acid and bipyridyl-type ligands

2019 ◽  
Vol 75 (7) ◽  
pp. 859-871 ◽  
Author(s):  
Jie Xu ◽  
Kou-Lin Zhang

The bromo-substituted aromatic dicarboxylic acid 5-amino-2,4,6-tribromoisophthalic acid (H2ATBIP), in the presence of the N-donor flexible bipyridyl-type ligands 1,3-bis(pyridin-4-yl)propane (bpp) and N,N′-bis(pyridin-4-ylmethyl)oxalamide (4-bpme) and ZnII ions, was used as an O-donor ligand to assemble two novel luminescent metal–organic frameworks (MOFs), namely poly[[(μ-5-amino-2,4,6-tribromoisophthalato-κ2 O 1:O 3)[μ-1,3-bis(pyridin-4-yl)propane-κ2 N:N′]zinc(II)] dimethylformamide monosolvate], {[Zn(C8H2Br3NO4)(C13H14N2)]·C3H7NO} n , (1), and poly[[(μ-5-amino-2,4,6-tribromoisophthalato-κ2 O 1:O 3)diaqua[μ-N,N′-bis(pyridin-4-ylmethyl)oxalamide-κ2 N:N′]zinc(II)] monohydrate], {[Zn(C8H2Br3NO4)(C14H14N4O2)(H2O)2]·H2O} n , (2), using the solution evaporation method. Both (1) and (2) were characterized by FT–IR spectroscopy, elemental analysis (EA), solid-state diffuse-reflectance UV–Vis spectroscopy, and powder and single-crystal X-ray diffraction analysis. Complex (1) shows a two-dimensional (2D) corrugated layer simplified as a 2D (4,4) topological network. The supramolecular interactions (π–π stacking, hydrogen bonding and C—Br...Br halogen bonding) play significant roles in the formation of an extended three-dimensional (3D) supramolecular network of (1). Complex (2) crystallizes in the chiral space group P212121 and exhibits a novel 3D homochiral framework, showing a diamond-like topology with Schläfli symbol 66. The homochirality of (2) is further confirmed by the solid-state circular dichroism (CD) spectrum. The second harmonic generation (SHG) property of (2) was also investigated. The hydrogen and C—Br...Br/O halogen bonding further stabilize the framework of (2). The central ZnII ions in (1) and (2) show tetrahedral and octahedral coordination geometries, respectively. The coordinated and uncoordinated water molecules in (2) could be removed selectively upon heating. Most importantly, (1) and (2) show rapid and highly sensitive sensing for a large pool of nitroaromatic explosives (NAEs).

2020 ◽  
Vol 76 (11) ◽  
pp. 1024-1033
Author(s):  
Fang-Hua Zhao ◽  
Shi-Yao Li ◽  
Wen-Yu Guo ◽  
Zi-Hao Zhao ◽  
Xiao-Wen Guo ◽  
...  

Two new CdII MOFs, namely, two-dimensional (2D) poly[[[μ2-1,4-bis(1H-benzimidazol-1-yl)butane](μ2-heptanedioato)cadmium(II)] tetrahydrate], {[Cd(C7H10O4)(C18H18N4)]·4H2O} n or {[Cd(Pim)(bbimb)]·4H2O} n (1), and 2D poly[diaqua[μ2-1,4-bis(1H-benzimidazol-1-yl)butane](μ4-decanedioato)(μ2-decanedioato)dicadmium(II)], [Cd2(C10H16O4)2(C18H18N4)(H2O)2] n or [Cd(Seb)(bbimb)0.5(H2O)] n (2), have been synthesized hydrothermally based on the 1,4-bis(1H-benzimidazol-1-yl)butane (bbimb) and pimelate (Pim2−, heptanedioate) or sebacate (Seb2−, decanedioate) ligands. Both MOFs were structurally characterized by single-crystal X-ray diffraction. In 1, the CdII centres are connected by bbimb and Pim2− ligands to generate a 2D sql layer structure with an octameric (H2O)8 water cluster. The 2D layers are further connected by O—H...O hydrogen bonds, resulting in a three-dimensional (3D) supramolecular structure. In 2, the CdII centres are coordinated by Seb2− ligands to form binuclear Cd2 units which are linked by bbimb and Seb2− ligands into a 2D hxl layer. The 2D layers are further connected by O—H...O hydrogen bonds, leading to an 8-connected 3D hex supramolecular network. IR and UV–Vis spectroscopy, thermogravimetric analysis and solid-state photoluminescence analysis were carried out on both MOFs. Luminescence sensing experiments reveal that both MOFs have good selective sensing towards Fe3+ in aqueous solution.


2019 ◽  
Vol 37 (3) ◽  
pp. 304-309
Author(s):  
Azeezaa Varsha Mohammed ◽  
Suresh Sagadevan

AbstractL-cysteine hydrogen fluoride (LCHF) single crystals were grown from aqueous solution. Single crystal X-ray diffraction, FT-IR, UV-Vis-NIR, and TG-DTA were used to test the grown crystals. The specimen dielectric and mechanical behaviors were also studied. Powder X-ray diffraction of the grown crystal was recorded and indexed. The optical properties of the LCHF crystal were determined using UV-Vis spectroscopy. It was found that the optical band gap of LCHF was 4.8 eV. The crystal functional groups were identified using FT-IR. Second harmonic generation (SHG) efficiency of the LCHF was three times higher than that of KDP. The dielectric constant, dielectric loss and AC conductivity were measured at different frequencies and temperatures.


2021 ◽  
Vol 35 (1) ◽  
pp. 119-128
Author(s):  
S. Iram ◽  
T. Khurshid ◽  
S. Latif ◽  
M. Imran ◽  
F. Kanwal ◽  
...  

Metal organic frameworks are formed by the three-dimensional linkage of metal cores and organic linkers. In this work, bismuth-based metal organic framework (Bi-MOF) has been synthesized by using 5-hydroxyisophthalic acid (H2HIA) as linker via hydrothermal method. The said MOF was structurally characterized by UV/Vis, Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), 1H NMR, energy dispersive spectroscopy (EDS), thermogravimetric analysis (TGA) and X-ray diffraction technique. This MOF showed highly porous structure with surface area 1096 m2/g as determined by BET analysis. A model batch adsorption experiment was performed to evaluate the efficiency of methylene blue (MB) dye removal from aqueous media. It was found that monolayer adsorption capacity calculated from the Langmuir isotherm was 0.6240 mg/g. Bi-MOF was also screened for its antibacterial and luminescent behavior.                     KEY WORDS: Bismuth, Metal-organic Frameworks, Luminescence, Sorption   Bull. Chem. Soc. Ethiop. 2021, 35(1), 119-128. DOI: https://dx.doi.org/10.4314/bcse.v35i1.10


2020 ◽  
Vol 76 (2) ◽  
pp. 148-158
Author(s):  
Fang-Hua Zhao ◽  
Zhong-Lin Li ◽  
Shu-Fang Zhang ◽  
Jian-Hui Han ◽  
Mei Zhang ◽  
...  

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.


2020 ◽  
Vol 76 (5) ◽  
pp. 398-404
Author(s):  
Zhong-Xuan Xu ◽  
Chun-Yan Ou ◽  
Chun-Xue Zhang

Two three-dimensional cobalt-based metal–organic frameworks with 5-(hydroxymethyl)isophthalic acid (H2HIPA), namely poly[[μ2-1,4-bis(2-methyl-1H-imidazol-1-yl)benzene-κ2 N 3:N 3′][μ2-5-(hydroxymethyl)isophthalato-κ2 O 1:O 3]cobalt(II)], [Co(C9H6O5)(C14H14N4)] n (1), and poly[tris[μ2-1,4-bis(1H-imidazol-1-yl)benzene-κ2 N 3:N 3′]bis[μ3-5-(hydroxymethyl)isophthalato-κ2 O 1:O 3:O 5]dicobalt(II)], [Co2(C9H6O5)2(C12H10N4)3] n (2), were synthesized under similar hydrothermal conditions. Single-crystal X-ray diffraction analyses revealed that 5-(hydroxymethyl)isophthalate (HIPA2−) and 1,4-bis(2-methyl-1H-imidazol-1-yl)benzene (1,4-BMIB) are simple linkers connecting cobalt centres to build a fourfold interpenetration dia framework in complex 1. However, complex 2 is a pillared-layer framework with a (3,6)-connected network constructed by 1,4-bis(1H-imidazol-1-yl)benzene (1,4-DIB) linkers, 3-connected HIPA2− ligands and 6-connected CoII centres. The above significant structural differences can be ascribed to the introduction of the different auxiliary N-donor ligands. Moreover, UV–Vis spectroscopy and Mott–Schottky measurements confirmed that complexes 1 and 2 are typical n-type semiconductors.


2011 ◽  
Vol 66 (5) ◽  
pp. 533-537
Author(s):  
Can Ji ◽  
Shuang-Quan Zang ◽  
Jun-Yi Liu ◽  
Jia-Bin Li ◽  
Hong-Wei Hou

A new three-dimensional metal-organic framework {[Zn(mpda)0.5(bix)]·(H2O)1.5}n (1) (H4mpda = 1,2,3,4-benzenetetracarboxylic acid, m-bix = 1,3-bis(imidazol-1-ylmethyl)-benzene) has been synthesized and characterized by single-crystal X-ray diffraction and IR spectra. In 1, homochiral helical chains are formed in the Zn-mpda layer through spontaneous resolution by mpda4−. Such layers are further connected through the second m-bix ligand to form a 3D chiral metal-organic framework. The individual (4,4)-connected net in 1 can be specified by the Schläfli symbol (66)2(64.82). Bulk material of 1 has good second-harmonic generation (SHG) activity, approximately 0.4 times that of urea. In addition, a thermogravimetric analysis was carried out, and the photoluminescent behavior of the complex was also investigated


Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2385
Author(s):  
Vinko Nemec ◽  
Katarina Lisac ◽  
Marin Liović ◽  
Ivana Brekalo ◽  
Dominik Cinčić

In this work, we describe a novel halogen-bonded metal-organic cocrystal involving a square-planar Cu(ii) complex and 1,4-diiodotetrafluorobenzene (14tfib) by utilizing an amine ligand whose pendant acetyl group enables halogen bonding. The cocrystal was prepared by both mechanochemical synthesis (liquid-assisted grinding) and the conventional solution-based method. Crystal structure determination by single crystal X-ray diffraction revealed that the dominant supramolecular interactions are the I···O halogen bond between 14tfib and CuCl2(aap)2 building blocks, and the N–H···Cl hydrogen bonds between CuCl2(aap)2 molecules. The combination of halogen and hydrogen bonding leads to the formation of a 2D network. Overall, this work showcases an example of the possibility for extending the complexity of metal-organic crystal structures by using halogen bonding in a way that does not affect other hydrogen bonding synthons.


2017 ◽  
Vol 73 (5) ◽  
pp. 393-398 ◽  
Author(s):  
Elif Gungor

Binuclear and tetranuclear copper(II) complexes are of interest because of their structural, magnetic and photoluminescence properties. Of the several important configurations of tetranuclear copper(II) complexes, there are limited reports on the crystal structures and solid-state photoluminescence properties of `stepped' tetranuclear copper(II) complexes. A new CuII complex, namely bis{μ3-3-[(4-methoxy-2-oxidobenzylidene)amino]propanolato}bis{μ2-3-[(4-methoxy-2-oxidobenzylidene)amino]propanolato}tetracopper(II), [Cu4(C11H13NO3)4], has been synthesized and characterized using elemental analysis, FT–IR, solid-state UV–Vis spectroscopy and single-crystal X-ray diffraction. The crystal structure determination shows that the complex is a stepped tetranuclear structure consisting of two dinuclear [Cu2(L)2] units {L is 3-[(4-methoxy-2-oxidobenzylidene)amino]propanolate}. The two terminal CuII atoms are four-coordinated in square-planar environments, while the two central CuII atoms are five-coordinated in square-pyramidal environments. The solid-state photoluminescence properties of both the complex and 3-[(2-hydroxy-4-methoxybenzylidene)amino]propanol (H2 L) have been investigated at room temperature in the visible region. When the complex and H2 L are excited under UV light at 349 nm, the complex displays a strong blue emission at 469 nm and H2 L displays a green emission at 515 nm.


2020 ◽  
Vol 76 (4) ◽  
pp. 314-321
Author(s):  
Bing-Feng Li ◽  
Xi-Ting Xu ◽  
Tong-Min Dong ◽  
Wan-Ying Zhou ◽  
Yang Gu ◽  
...  

The judicious selection of suitable ligands is vitally important in the construction of novel metal–organic frameworks (MOFs) with fascinating structures and interesting properties. Recently, imidazole-containing multidentate ligands have received much attention. Two new CdII coordination frameworks, namely, poly[tris{μ-1,4-bis[(1H-imidazol-1-yl)methyl]benzene-κ2 N 3:N 3′}tetrakis(nitrato-κ2 O,O′)dicadmium], [Cd2(NO3)4(C14H14N4)3] n , (I), and poly[[bis{μ3-1,3,5-tris[(1H-imidazol-1-yl)methyl]benzene-κ3 N 3:N 3′:N 3′′}cadmium] hexafluorosilicate], {[Cd(C18H18N6)2](SiF6)} n , (II), have been synthesized and characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction. In polymer (I), the 1,4-bis[(1H-imidazol-1-yl)methyl]benzene ligand bridges Cd2+ ions with a distorted seven-coordinated pentagonal bipyramidal geometry, forming a one-dimensional ladder chain, and the nitrate anions coordinate to the Cd2+ ions in a terminal bidentate fashion. In the crystal, adjacent chains are further connected by C—H...O hydrogen bonds to generate a two-dimensional (2D) supramolecular structure. Polymer (II) exhibits a 2D layered structure in which 1,3,5-tris[(1H-imidazol-1-yl)methyl] benzene ligands join Cd2+ centres having a six-coordinated octahedral structure. The layers are connected by hexafluorosilicate anions via C—H...F hydrogen-bond interactions, giving rise to a three-dimensional supramolecular network structure in the solid state. In addition, powder X-ray diffraction (PXRD) patterns were recorded, thermogravimetric analyses (TGA) carried out and fluorescence properties investigated.


Author(s):  
Agnieszka Brozdowska ◽  
Jarosław Chojnacki

A series of diaminium thiosulfates, derivatives of diamines: NH2CH2CH(CH3)NH2(1) and NH2(CH2)nNH2,n= 3–6 [(2)–(5)] and thiosulfuric acid were prepared and their structures determined by single-crystal X-ray diffraction analysis. Compounds (1), (2) and (4) turned out to be hydrates. The crystal structure of 1,2-propylenediaminium thiosulfate is chiral and exhibits spontaneous resolution. Crystals for both enantiomers [(1a) and (1b)] were obtained with high enantiometric excess and examined. An extended network of strong, charge-assisted hydrogen bonding of the+N—H...O−type (also O—H...O and O—H...S for hydrates) is most likely the main factor defining crystal packing and the variable conformation of the cations. The formation of chiral hydrogen-bond motifs – distorted cubans – seems to induce the formation of chiral solid-state structure from achiral components in the case of (4). Diaminium thiosulfates with an odd number of C atoms in the alkyl chain [compounds (1), (2) and (4)] form three-dimensional supramolecular networks, while in the case of diaminium salts with an even number of C atoms [(3) and (5)], two-dimensional layers of hydrogen-bond domains are observed. The aminium thiosulfates were also characterized by elemental analysis, NMR and Fourier transform (FT)–IR spectroscopy. The conformations of α,ω-alkyldiaminium cations in the solid state are discussed and rationalized by DFT calculations.


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