Solvent Molecule Controlled Zinc(II) Metal‐Organic Frameworks with Different Topology

Two zinc(II) coordination polymers, namely [Zn₂(bptc)(DMF)₂(H₂O)]_n ( 1 ) and [Zn(bptc)_0.5(DMA)]_n ( 2 ) (H₄bptc = biphenyl‐3,3′,5,5′‐tetracarboxylic acid, DMF = N,N′‐dimethylformamide, DMA = N,N′‐dimethylacetamide), were obtained under solvothermal conditions by varying the reaction solvents. Single crystal X‐ray diffraction analyses revealed that compound 1 features a 3D PtS type framework based on dinuclear [Zn₂O(COO)₂] subunits and compound 2 features a 3D lvt type framework based on paddle‐wheel shaped [Zn₂(COO)₄] subunits. Moreover, the luminescent and thermal stabilities of these two compounds were investigated.     

Synthesis,Structures, and Luminescent Properties of two 3, 5‐Dimethyl‐1‐H‐1, 2,4‐triazole‐Based Zinc Metal‐Organic Frameworks with Aromatic Carboxylate as Coligand

Two metal‐organic frameworks, [Zn(dmtrz)(btrc)_1/3]_n ( 1 ) and [Zn₂(dmtrz)₂(btec)(H₂O)₂]_n ( 2 ) (dmtrz = 3, 5‐dimethyl‐1‐H‐1, 2,4‐triazole, btrc = 1, 3,5‐benzenetricarboxylate, btec = 1, 2,4, 5‐benzenetetracarboxylate), were synthesized by hydrothermal reaction. The crystal structure analysis reveals that compound 1 is a dense 3D framework with Schläfli symbols of {4³}₂{4⁶ · 6⁶ · 8³}₃, which is a loh1 structure. Compound 2 is a 2D network. In addition, the photoluminescence of two compounds were studied in solid state at room temperature, together with their thermal analysis.     

Hydrothermal Synthesis,Crystal Structure,and Luminescent Properties of Two Zinc(II) and Cadmium(II) 3D Metal‐­Organic Frameworks

Two zinc(II) and cadmium(II) metal‐organic frameworks with mixed ligands, {[Zn₂(biim‐4)₂(TDC)₂] · 2.5H₂O}_n ( 1 ) and {[Cd₂(biim‐4)₂(TDC)₂ · 2H₂O]}_n ( 2 ) [biim‐4 = 1,1′‐(1,4‐butanediyl)bis(imidazole); H₂TDC = thiophene‐2,5‐dicarboxylic acid], were hydrothermally synthesized. Both of them are characterized by elemental analysis, IR spectroscopy, and single crystal X‐ray diffraction. In 1 , the four‐connected Zn^II nodes are connected by four linear ligands extending into a 3D network, which further integrates a fivefold interpenetrating diamond 3D topological network and the free water molecules distribute in void space, whereas in 2 , the Cd^II ions are in a distorted octahedral arrangement linked by TDC^2– and biim‐4 ligands to construct a 3D framework. In topology analysis, C11 and C14 are simplified as 3‐connected nodes and the 3D framework displays a (3,5)‐connected net. Furthermore, the thermal and photoluminescent properties of 1 and 2 were also studied.     

Synthesis and Luminescent Properties of Two Zinc(II) Coordination Polymers Constructed by 4‐(Pyridin‐4‐ylmethoxy)benzolic Acid Ligand

Two coordination polymers, namely [Zn(L)Cl] ( 1 ) and [Zn(L)₂] ( 2 ) [L = 4‐(pyridin‐4‐ylmethoxy)benzolic acid] were synthesized under hydrothermal conditions and characterized by single‐crystal X‐ray diffraction analyses, powder X‐ray diffraction, and thermogravimetric analysis. Compounds 1 and 2 have a two‐dimensional square‐shaped structure (the dimensions are 15.43 × 15.43 Å for 1 and 12.064 × 15.017 Å for 2 ) with (4⁴ · 6²) topology. Moreover, compounds 1 and 2 exhibit a 3D supramolecular structure made up by strong π–π interactions from the adjacent layers. Furthermore, compounds 1 and 2 show good fluorescence properties in the solid state at room temperature.     

Pore‐Environment Engineering in Multifunctional Metal‐Organic Frameworks

As a new type of highly ordered porous crystalline material, metal‐organic frameworks (MOFs) have been extensively studied in many fields due to their high specific surface area and porosity, flexible modifiability and tailorability. After nearly 20 years of development, the synthesis of MOF materials has gradually evolved from exploration and trial to precise design. The synthesis method has also evolved from an early one‐step synthesis to the coexistence of various synthesis strategies, including functional‐oriented microstructural design optimization, pore size adjustment, and secondary structural unit modification, enabling MOF materials to expand their potential applications in many fields. In this review, we mainly discuss the pore regulation of function‐oriented MOF through different synthesis strategies, including (1) direct synthesis, (2) post‐synthesis modification (PSM), (3) building block replacement (BBR), (4) pore space partition (PSP), (5) construction of multi‐mesoporous MOF, (6) dynamic septal ligand insertion, and discuss the relationship between related performance optimization through framework structure and pore environment/size optimization.     

Syntheses,Structures, and Magnetic Properties of Two Cobalt(II) Metal‐Organic Frameworks Based on Y‐shaped 3,5,4′‐Azobenzenetricarboxylic Acid and Different N‐donor Ligands

Two metal‐organic frameworks, [Co₂(ABTC)(bimh)(OH)] · 2H₂O ( 1 ) and [Co₃(ABTC)₂(dimb)₄]_n ( 2 ) [H₃ABTC = 3,4′,5‐azobenzenetricarboxylic acid, bimh = 1,1′‐(1,4‐hexanediy)bis(imidazole), dimb = 1,4‐bis(1H‐imidazol‐1‐yl)benzene], were prepared under solvothermal conditions and structurally characterized. Complex 1 demonstrates a complicated 3D (3,8)‐connected tfz‐d net with (4³)₂(4⁶.6¹⁷.8⁵) topology. The framework of 2 can be classified as a rare 3D (3,6,6)‐connected net with the Schäfli symbol of (4.6²)₂(4².6¹⁰.8³)(4⁴.6¹⁰.8), and exhibits an intriguing self‐penetrating motif. Meanwhile, the thermal stabilities and magnetic properties for 1 and 2 were also probed.     

Hydrothermal Syntheses,Crystal Structures,and Luminescent Properties of Two Zinc(II) Coordination Polymers

Two zinc(II) compounds, namely [Zn₅(AmTAZ)₆(OH)₂]_n · 2n(NO₃) · 6n(H₂O) ( 1 ) and [Zn₃(AmTAZ)₂(mal)₂]_n ( 2 ) (HAmTAZ = 3‐amino‐1,2,4‐triazole, H₂mal = malonic acid), were hydrothermally synthesized and characterized by elemental analysis, IR spectroscopy, and X‐ray diffraction. Single crystal X‐ray diffraction analysis reveals that compound 1 features a 3D framework with dodecahedral cages occupied by free nitrate ions and lattice water molecules and can be reduced into a (4, 8)‐connected flu topological network. Compound 2 features a 3D framework based on two different 1D chains. Moreover, the thermal stabilities and luminescent properties of compounds 1 and 2 were investigated.     

One‐dimensional Europium(III) Coordination Polymer Based on 3‐Pyridylacrylic Acid

Under hydrothermal conditions, the reaction of racemic 3‐pyridyl‐3‐aminopropionic acid (rac‐HPAPA) with Eu(ClO₄)₃· 6H₂O affords a 1‐D chain complex, [Eu(3‐PYA)₃(H₂O)]_n ( 1 ) (3‐PYA=3‐pyridylacrylate), which represents an example of neutral 1‐D coordination polymeric material based on 3‐HPYA (HPYA= pyridylacrylic acid) ligand with strong red fluorescent emission in the solid state.     

Transition‐Metal Dependent Cation Disorder in the Chiral Cubic AB(HCO2)3 Metal‐Organic Frameworks (A = Li or Na,B = Mn or Co)

This study examines the crystal structures of the AB(HCO₂)₃ (A = Li or Na and B = Mn or Co) metal‐organic frameworks, which we find to adopt a chiral cubic P2₁3 structure. This shows that the Li containing formates are isostructural with their Na analogues, extending the phase stability of this chiral architecture. The Mn containing compounds have a magnetic sublattice similar to β‐Mn, long of interest due to its highly frustrated antiferromagnetic coupling. In contrast the Co formates appear to have partially disordered alkali and transition metal cations, which prevents the formation of a clean β‐Mn‐like magnetic sublattice. We have also re‐examined the magnetic properties of NaMn(HCO₂)₃ finding it to be a simple paramagnet down to 2 K with only weak antiferromagnetic coupling.     

Synthesis,Structure, and Magnetic Properties of a Copper(II) Metal‐Organic Framework with Biphenyl‐2,2′,4,4′‐tetracarboxylic Acid

The 2D Cu^II metal‐organic framework [Cu₂(bptc)(H₂O)₄]_n · 4nH₂O ( 1 ) (H₄bptc = biphenyl‐2,2′,4,4′‐tetracarboxylic acid) was hydrothermally synthesized and characterized by single‐crystal X‐ray diffraction and magnetic measurements. In the structure, bptc^4– serves as a twisted Π‐shaped organic building block to connect paddlewheel [Cu₂(COO)₄] dinuclear units and mononuclear units through 2‐/2′‐carboxylate and 4‐/4′‐carboxylate, respectively. According to the magnetic analysis using a dimer‐plus‐monomer model, strong antiferromagnetic coupling is operative within the dinuclear unit (J = –311 cm^–1 based on H = –J S ₁ S ₂), and the compound behaves like a mononuclear molecule at low temperature.     

Two Three‐Dimensional Metal‐Organic Frameworks Constructed from Alkaline Earth Metal Cations (Sr and Ba) and 5‐Nitroisophthalicacid – Synthesis,Charaterization, and Thermochemistry

Two MOFs of [Sr^II(5‐NO₂‐BDC)(H₂O)₆] ( 1 ) and [Ba^II(5‐NO₂‐BDC)(H₂O)₆] ( 2 ) have been synthesized in water using alkaline earth metal salts and the rigid organic ligand 5‐NO₂‐H₂BDC. The compounds were characterized by elemental analysis, infrared spectrum, thermal analysis, and X‐ray crystallography. Crystal structure analyses have shown that the two complexes are isostructural as evidenced by IR spectra and TG‐DTA. Both compounds present three‐dimensional frameworks built up from infinite chains of edge‐sharing twelve‐membered rings through O–H···O hydrogen bonds. The specific heat capacities of the title complexes have been determined by an improved RD496‐III microcalorimeter with the values of (109.29 ± 0.693) J mol⁻¹ K⁻¹ and (81.162 ± 0.858) J mol⁻¹ K⁻¹ at 298.15 K, and the molar enthalpy changes of the formation reactions of complexes at 298.15 K were calculated as (4.897 ± 0.008) kJ mol⁻¹ and (2.617 ± 0.009) kJ mol⁻¹, respectively.     

Synthesis,Structure and High Thermal Stability of a Novel Three‐dimensional Zinc(II) Complex with an Unsymmetrical Rigid‐flexible Ligand

A novel metal‐organic framework, [Zn(C₁₀H₈O₅)]_n ( 1 ) (C₁₀H₈O₅ = 2‐(4‐carboxylatophenoxy)propionate), was synthesized and characterized by elemental analysis, IR spectroscopy, X‐ray crystallography and thermogravimetric analysis. The crystal structure study reveals that each zinc atom is coordinated by four oxygen atoms from four different ligands to obtain a distorted tetrahedron. The rigid carboxyl group bridges two adjacent zinc atoms to form a dimer of eight‐membered rings, whereas the flexible carboxyl group bridges two adjacent dimers to form 1D chains along the a axis. Two adjacent 1D chains are interconnected by the ligands to produce 2D layers. These layers are further stabilized by intermolecular hydrogen bonds to construct a 3D framework showing high thermal stability (445 °C).     

Synthesis,Structure, Photoluminescence,and Theoretical ­Calculation of an rtl‐type Zinc(II) Compound with Linear Trinuclear [Zn3(COO)4(μ2‐H2O)2] Subunits

The zinc(II) coordination polymer [Zn₃(BPT)₂(μ₂‐H₂O)₂(H₂O)₂]_n · n(DMA) ( 1 ) (H₃BPT = biphenyl‐3,4′,5‐tricarboxylic acid, DMA = N,N′‐dimethylactamide) was obtained by the solvothermal reaction of H₃BPT with Zn(NO₃)₂ in DMA/H₂O mixed solvent. Single crystal X‐ray analysis reveals that compound 1 has a complicated 3D framework containing linear trinuclear [Zn₃(COO)₄(μ₂‐H₂O)₂] clusters as building subunits, which can be simplified into a (3,6)‐connected rtl topological network with the Schläfli symbol {4.6²}₂{4².6¹⁰.8³}. The calculated results of total and partial density of states (DOS) indicate that the luminescence of 1 mainly originates from intraligand charge transfer.     

柔性金属—有机骨架材料中已烷的扩散研究

本工作将MM3力场进行了扩展,使其可用于描述其它IRMOF材料的柔韧性;在此基础上,我们采用分子动力学模拟研究了柔性IRMOF-1和-16材料中已烷的扩散。 本文重点研究了温度和分子数对己烷自扩散系数、扩散机理,以及骨架柔性的影响。结果表明,分子数是影响扩散路径的重要因素。其次,IRMOF-16的柔性强于IRMOF-1。 工作的结论有助于进一步研究链状分子在柔性MOF材料中的扩散。     

Template Syntheses of Two Open‐framework Zinc Phosphites

Two new open‐framework zincophosphites, Zn(H₆C₄N₂S)(HPO₃) (TJPU‐4) and [C₆N₂H₁₄]·[Zn₃(HPO₃)₄] (TJPU‐5) have been hydrothermally synthesized by using 2‐mercapto‐1‐methylimidazole [MMI] and 1,4‐diazabicyclo[2.2.2]octane [DABCO] as templates. TJPU‐4 crystallizes in monoclinic space group P2₁/c with the cell parameters a = 8.787(4) Å, b = 9.732(4) Å, c = 10.515(4) Å, β = 105.316(6)°, V = 867.3(6) ų. The structure of TJPU‐4 is constructed by ZnO₃S tetrahedron and HPO₃ pseudo‐pyramid to generate a layer of 4, 8‐network in bc plane. The organic template locates on the both sides of the 8‐membered rings and bonds to zinc atom through Zn–S bond. TJPU‐5 crystallizes in the triclinic space group with cell parameters a = 9.294 (5) Å, b = 9.976 (5) Å, c = 9.986 (5) Å, α = 85.692 (7)°, β = 82.010 (7)° and γ = 80.184 (7)°, V = 902.1 (8) ų. A novel 4⁴8⁸ cage is found in TJPU‐5. The connections of Zn(1)O₄, Zn(3)O₄ and HPO₃ groups give rise to an infinite corner‐shared four‐ring chain. Using Zn(2)O₄ as four connected bridges, linkages of these chains produce a 3‐D framework with intersecting 8‐ring channels running along [100], [010], [001], [011] and [111] directions.     

Substituent Dependent Dimensionality in Luminescent Zinc Isophthalate Coordination Polymers Containing Bis(3‐pyridylmethyl)piperazine

Divalent zinc coordination polymers containing bis(3‐pyridylmethyl)piperazine (3‐bpmp) and isophthalate ligands have been hydrothermally synthesized and structurally characterized by single‐crystal X‐ray diffraction. {[Zn(ip)(H3‐bpmp)]ClO₄·4H₂O}_n ( 1 , ip = isophthalate) has twofold parallel interpenetrated (4,4) grid cationic coordination polymer nets, with unligated perchlorate ions and intriguing infinite water molecule chains. {[Zn₂(NO₂ip)₃(H₂3‐bpmp)(H₂O)₅]·3H₂O}_n ( 2 , NO₂ip = 5‐nitroisophthalate) exhibits a supramolecular lattice built from 1D chain motifs, revealing a significant dependence of topology on the steric bulk of the dicarboxylate ligand. Luminescent properties for 1 and 2 are also reported.     

Urothermal Syntheses of two New Luminescent Zinc(II) Compounds via Dual-ligand Strategy

Urothermal reaction of Zn(NO₃)₂ · 6H₂O, Htrz and NH₂H₂pdc or H₂pdc affords two new compounds, namely [Zn₂(NH₂bdc)(trz)₂]_n · 2n(e-urea) ( 1 ) and [Zn₄(bdc)₂(trz)₄(H₂O)(e-urea)]_n · n(e-urea) ( 2 ) (Htrz = 1,2,4-triazole, NH₂H₂bdc = 2-aminoterephthalic acid, H₂bdc = terephthalic acid, e-urea = 1,3-ethyleneurea). X-ray structural analyses revealed that both compounds 1 and 2 feature e-urea-templated 3D pillar-layer framework with 2D Zn^II-triazole layer and 6-connected pcu topological network. These two compounds not only have high thermal stabilities but also show intense luminescence at room temperature.