An Effective Method to Construct Cluster‐based Frameworks with Multifarious Structures,Luminescence, and Sorption Properties

An effective method was developed for the synthesis of three cluster‐based frameworks with multifarious secondary building units (SBUs) and various structures, which were formulated as [Me₂NH₂]₂[Zn₁₀(BTC)₆(μ₃‐O)(μ₄‐O)(H₂O)₅] · 3DMA · 9H₂O ( FJI ‐ 3 ), [Me₂NH₂]₂[Zn₉(μ₃‐OH)₂(BTC)₆(H₂O)₃] · 5DMA · 6H₂O ( FJI ‐ 4 ) and [Me₂NH₂][Zn₃(μ₃‐OH)(BTC)₂DMF] · H₂O ( FJI ‐ 5 ) (H₃BTC = 1,3,5‐benzenetricarboxylic acid, DMA = N,N′‐dimethyl acetamide and DMF = N,N′‐dimethyl formamide), respectively. X‐ray structural analysis reveals that FJI ‐ 3 displays 3D highly porous metal‐organic framework with four kinds of microporous cages constructed by two paddle‐wheel Zn₂(CO₂)₄, trimeric Zn₃O(CO₂)₆, and tetrameric Zn₄O(CO₂)₆ SBUs. FJI ‐ 4 exhibits 3D microporous MOFs with a dodecahedral cavities built by paddle‐wheel Zn₂(CO₂)₄ and trimeric Zn₃O(CO₂)₆. FJI ‐ 5 shows 3D microporous MOFs with an 1D channel assembled by the Zn₃O(CO₂)₆ SBUs. In addition, the fluorescence and sorption properties in these cluster‐based frameworks were also investigated. Furthermore, the method employed in this work may provide an useful approach to the design and synthesis of novel cluster‐based frameworks.     

3D Coordination Polymers with Chiral Structures, [Ln2(tda)2(H2O)3]·5H2O: Hydrothermal Synthesis,Structural Characterization,and Luminescent Properties

Reactions of H₃tda (H₃tda = 1H‐1, 2, 3‐triazole‐4, 5‐dicarboxylic acid) with Sm(NO₃)₃ · 6H₂O, Eu(NO₃)₃ · 6H₂O, and Tb(NO₃)₃ · 6H₂O, in the presence of NaOH under hydrothermal conditions, produced three new coordination polymers, [Ln₂(tda)₂(H₂O)₃] · 5H₂O [Ln = Sm ( 1 ), Eu ( 2 ), Tb ( 3 )]. These compounds were structurally characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis (TGA), PXRD and single‐crystal X‐ray diffraction. The single‐crystal X‐ray diffraction studies of compounds 1 – 3 reveal that all compounds are three‐dimensional porous structures with chiral frameworks. Furthermore, the luminescence studies of compound 2 and 3 in the solid state reveal that they are potential luminescent materials at room temperature.     

A Novel d-f Heterometallic CdII-EuIII Metal-organic Framework as a Sensitive Luminescent Sensor for the Dual Detection of Ronidazole and 4-Nitrophenol

A novel three-dimensional (3D) d-f heterometallic metal-organic framework (MOF) formulated as [EuCd_1.5L₂(H₂O)₃] · 2H₂O ( 1 ) [H₃L = 5-(4-(tetrazol-5-yl)phenyl)isophthalic acid] was successfully synthesized and characterized. Structural analysis displays that 1 features a 3D (3, 12)-connected framework constructed by [Eu₂Cd₃(tetrazole)₄(COO)₈] units. The powder X-ray diffraction measurement of 1 immersed in different solvents reveals that 1 possess good solvent stability. It is worth noting that 1 displays highly selective detection for ronidazole (RDZ) and 4-nitrophenol (4-NP) through luminescence quenching. The possible mechanism of luminescent sensing is also well discussed.     

Hydrothermal Preparation of a Series of Luminescent Cadmium(II) and Zinc(II) Coordination Complexes and Enhanced Real‐time Photo‐luminescent Sensing for Benzaldehyde

Two cadmium(II) and two zinc(II) coordination complexes with diverse structural motifs, [Cd₂(HL)I₃H₂O] · H₂O ( 1 ), [Cd₂(H₂L)₂(H₂O)₄] · 2SO₄ · 14H₂O ( 2 ), [Zn₃(L′)₂(H₂O)₆] · 4H₂O · 2(NO₃) ( 3 ), and [Zn₃L'₂(H₂O)₂Cl₂] · H₂O ( 4 ) [H₂L = 1,1‐bis(5‐(pyrid‐2‐yl)‐1,2,4‐triazol‐3‐yl)methane; H₂L′ = 1,1‐bis(5‐(pyrid‐2‐yl)‐1,2,4‐triazol‐3‐yl)methanone] were synthesized through a hydrothermal method. These coordination complexes were characterized by single‐crystal X‐ray diffraction, powder X‐ray diffraction (PXRD), FT‐IR spectroscopy, and photo‐luminescent experiments. Single crystal structural analysis revealed that 1 – 4 belong to polynuclear coordination compounds. PXRD analysis of 1 – 4 unambiguously confirmed the purity of the as‐synthesized coordination compounds. It is the first time to synthesize coordination compounds based on H₂L′, which reacted from the original material H₂L through in‐situ hydrothermal conditions. In addition, photo‐luminescent experiments revealed that 1 – 4 have real‐time sensing effects for benzaldehyde through fluorescence quenching. For 1 – 4 , the photo‐luminescent quenching effect for benzaldehyde was also compared and the coordination complexes 3 and 4 based on H₂L′ have higher photo‐luminescent quenching effect than compounds 1 and 2 .     

Solvothermal Syntheses,Crystal Structures,and Luminescent Properties of Two New Cadmium(II) Coordination Polymers Based on Rigid / Flexible Dicarboxylate and N,N′‐Bis(4‐pyridyl)‐1,4,5,8‐naphthalenetetracarboxydiimide

In order to investigate the effect of the organic ligands on the structures of coordination polymers, two new cadmium(II) coordination polymers based on the different dicarboxylate ligands, namely [Cd₂(bpdc)₂(DPNDI)₂] · 3H₂O · NMF ( 1 ) and [Cd(obb)(DPNDI)] ( 2 ) [H₂bpdc = biphenyl‐4,4′‐dicarboxylate, H₂obb = 4,4′‐oxybis(benzoic acid), DPNDI = N,N′‐bis(4‐pyridyl)‐1,4,5,8‐naphthalene tetracarboxydiimide, and NMF = N‐methylformamide), were synthesized under solvothermal condition and further characterized. Complex 1 shows a twofold interpenetrated pcu topology. Complex 2 possesses a two‐dimensional (2D) layer structure with –ABCD– stacking sequence. Furthermore, the luminescent properties of complexes 1 and 2 are investigated.     

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.     

4,4’－二(磷酸二甲酯甲基)联苯连接的具有互穿结构的二维锰(II)配位聚合物的合成与结构研究

在常规条件下,合成了具有新颖结构的配位聚合物[Mn(bdpbp)2(NO3)2]n (1) [bdpbp =4,4’-二(磷酸二甲酯甲基)联苯]。配合物1由单晶x-射线衍射确定结构,并用元素分析、红外光谱、荧光光谱和热重进行了表征和性质研究。配合物1具有二维无限的网格状结构,形成双重互穿,并由弱的C-H···O氢键进一步连接成三维超分子网络。     

Solvent‐Dependent Synthesis from Layer to Microporous Pillared‐Layer Framework for Selective Sorption of Gas Light Hydrocarbons

Three metal‐organic frameworks, [Zn₃(bdc)₃(DMA)₂] ( 1 ) (H₂bdc = terephthalic acid; DMA = N,N‐dimethylacetamide), [Zn₃(bdc)₃(DMA)(DMPU)] ( 2 ) (DMPU = 1,3‐dimethylpropyleneurea), and [Zn₃(bdc)₄(Hdma)₂] ( 3 ) [Hdma = protonated dimethylamine (Me₂NH₂)] were synthesized by using different solvents. The solvents determine the framework architectures range from layer to microporous pillared‐layer framework. The microporous framework has 8‐connected bcg topology and shows selective sorption ability for gas light hydrocarbons.     

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,Characterization and Photoluminescence of Lanthanide Metal‐organic Frameworks,Constructed from Triangular 4,4′,4″‐s‐triazine‐1,3,5‐triyl‐p‐aminobenzoate Ligands

Eight isomorphous metal‐organic frameworks: [Ln₂(TATAB)₂(H₂O)(DMA)₆]·5H₂O (Ln = Sm ( 1 ), Eu ( 2 ), Gd ( 3 ), Tb ( 4 ), Dy ( 5 ), Er ( 6 ), Tm ( 7 ), Yb ( 8 )); TATAB = 4,4′,4″‐s‐triazine‐1,3,5‐triyl‐p‐aminobenzoate, DMA = N,N‐dimethylacetamide), were synthesized by the self‐assembly of lanthanide ions, TATAB, DMA and H₂O. Single‐crystal X‐ray crystallography reveals they are three dimensional frameworks with 2‐fold interpenetration. Solid‐state photoluminescence studies indicate ligand‐to‐metal energy transfer is more efficient for compounds 2 and 4 which exhibit intense characteristic lanthanide emissions at room temperature.     

Synthesis,crystal structure,and luminescent properties of metal complexes bearing 2,6-pyridine-diacylhydrazide ligands: supramolecular assemblies via intermolecular interactions

Four metal complexes of N,N′-bis(salicyl)-2,6-pyridine-dicarbohydrazide ligand (H₆L), [Co^II(H₄L)(H₂O)₂]·2DMF (1), [Zn^II(H₄L)(H₂O)₂]·2DMF (2), [Cd^II(H₄L)(Py)₂]·DMF·Py (3), and [Co^IICo₂^III(H₄L)₄(H₂O)₄]·DMF·H₂O (4), were synthesized and characterized by elemental analysis, IR, and single-crystal X-ray diffraction analysis. Structural studies revealed that complexes 1–3 present discrete mononuclear structures and complex 4 displays a centrosymmetric mixed-valence trinuclear structure. All four complexes are further extended into interesting two- or three-dimensional supramolecular frameworks. The luminescent properties of 2 and 3 were studied, which show emissions with maxima at 485 nm upon excitation at 396 nm for 2 and 476 nm upon excitation at 397 nm for 3, respectively.     

Synthesis,crystal structure,and luminescence of a new zinc(II) coordination polymer based on 2-naphthol-5-carboxylate and 4,4′-bipyridine

To further explore the coordination possibilities of naphthalene-based carboxylic acids, a Zn^II coordination polymer, [Zn₃(L)₆(bipy)₂] _n (1), with bulky 2-naphthol-5-carboxylate (L) and bridging 4,4′-bipyridine (bipy), was synthesized and characterized. Structural analysis reveals that 1 is a 1-D polymeric chain with trinuclear units as nodes, which are further extended via interchain secondary interactions, such as O–H ··· O hydrogen-bonding and aromatic π ··· π stacking interactions, to form an overall 3-D framework. Complex 1 exhibits strong solid-state luminescence emission at room temperature, mainly originating from intraligand π→π* transition of L.     

Hydrothermal Synthesis of Two High‐dimensional Architectures Based on Bridging Ligand Pyridine‐2,3‐dicarboxylic Acid

Two novel metal‐organic coordination polymers [Zn₂(PDC)₂·H₂O]_n ( 1 ) and [Zn₂La₂(OH)(NO₃)(PDC)₄‐ (H₂O)₆·2H₂O]_n ( 2 ) (PDC??pyridine‐2,3‐dicarboxylic acid) have been synthesized by hydrothermal pretreatment and cooling‐down crystallization. X‐ray diffraction analyses reveal that they posses the 3D frameworks. Frame work 1 has been accomplished by using building blocks Zn‐PDC with beautiful undulances. Frame work 2 is a new 3d‐4f heterometallic polymer with a distinctive mono‐ and dinuclear mixed one sinusoidal‐like wave viewed along the b axis.     

Synthesis,Structures, and Properties of Four Novel Coordination Compounds based on a Flexible Tetrakis(imidazol‐1‐ylmethyl)methane Ligand

Four coordination polymers, namely, [Zn₂(TIYM)(2,6‐PYDC)₂]_n · n(CH₃OH) · 3n(H₂O) ( 1 ), [Cu(TIYM)(2,6‐PYDC)]_n · 3n(H₂O) ( 2 ), [Co(TIYM)(2,6‐PYDC)]_n · n(CH₃OH) · 3n(H₂O) ( 3 ), and [Cd₂(TIYM)(2,6‐PYDC)₂(H₂O)]_n · n(H₂O) ( 4 ) with the flexible N‐containing ligand [tetrakis(imidazol‐1‐ylmethyl)methane (TIYM)] and the N‐containing dicarboxylic acid [2,6‐pyridinedicarboxylic acid (2,6‐PYDC)] were prepared. Compounds 1 – 4 show various structures because of different N–C_center–N angles (θ) of TIYM ligands and changing coordination modes of 2,6‐PYDC. Compounds 1 , 2 , and 3 display a similar 1D ladder‐like chain, whereas 4 gives a 1D quad‐core lifting platform shaped belt. The structural diversities in 1 – 4 suggest that the multiple coordination modes or the different freely twist angles of ligands and the presence of different metal atoms play important roles in the resulting structures of the coordination polymers. Furthermore, the solid‐state luminescence properties of 1 and 4 , and the magnetic properties of 3 were investigated.     

基于二-吡嗪-(2, 3-f: 2′3′-h)-喹喔啉和吡啶-2，5-二羧酸混合配体的两个新奇金属有机超分子骨架的水热合成、晶体结构与光致发光

以二-吡嗪-(2, 3-f: 2′3′-h)-喹喔啉(Dpq)和吡啶-2,5-二羧酸(2,5-H2pda)两种混合配体与不同金属硝酸盐为原料,通过水热反应得到了两个新奇的金属有机骨架[Zn2(Dpq)2(2,5-pda)2(H2O)2]·2H2O(1)和[Cd2(Dpq)2(2,5-pda)2]·2H2O(2),并经元素分析、TG、IR、X-射线单晶衍射分析进行了表征。结构分析表明,2,5-pda采取不同的配位方式桥连金属离子分别形成了二聚物1和2D菱形网络2。在化合物1中,相邻的二聚物通过氢键和π-π堆积作用形成扭曲的a-Po超分子结构。在化合物2中,相邻的配位聚合物层通过氢键拓展成扭曲的a-Po超分子骨架,而π-π堆积起到巩固骨架的作用。化合物1和2的结构差异表明了金属离子和配体在配位聚合物自组装过程中对结构的影响。此外固态标题化合物在室温下表现出蓝色的发光性质。     

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.     

Syntheses,Structures, and Thermal Reactivity of New ZnII and CdII Thio‐ and Selenocyanato Coordination Compounds

Reaction of Zn^II and Cd^II thiocyanate or selenocyanate with pyrazine leads to the formation of new Zn^II and Cd^II coordination compounds. The structures of [Zn(NCSe)₂(pyrazine)₂]_n ( 1A ), [Cd(NCS)₂(pyrazine)₂]_n ( 2A ) and [Cd(NCSe)₂(pyrazine)₂]_n ( 3A ) consist of octahedrally coordinated metal cations which are surrounded by two terminal N‐bonded anions and two μ₂‐bridging pyrazine molecules. The metal cations are connected via the pyrazine ligands into layers, which are further linked by weak intermolecular S···S respectively Se···Se interactions. Investigations on the thermal degradation behavior of 1A , 2A , and 3A using simultaneous differential thermoanalysis and thermogravimetry as well as X‐ray powder diffraction, IR‐ and Raman spectroscopy prove that on heating, the pyrazine‐rich compound 1A decomposes in one step into zinc selenocyanate without the formation of a pyrazine‐deficient intermediate. In contrast, for compounds 2A and 3A a stepwise decomposition is observed, leading to the formation of the pyrazine‐deficient compounds [Cd(NCS)₂(pyrazine)]_n ( 2B‐I and 2B‐II ) and [Cd(NCSe)₂(pyrazine)]_n ( 3B ) as intermediates. The structures and the thermal reactivity are discussed and compared with that of related transition metal thiocyanates and selenocyanates with pyridine as N‐donor ligand.     

Synthesis,Structure and Luminescence of Cd3Cu2 and Cd2Ni4 Heteronuclear Complexes with Macrocyclic Oxamide and 5‐Sulfosalicylicate

Two novel heteronuclear complexes [Cd₃(SSAL)₂(CuL)₂(H₂O)₄]_n ( 1 ) and [Cd₂(HSSAL)₂(NiL)₄] · 4H₂O ( 2 ) were synthesized and structurally determined, where SSAL is the fully deprotonated 5‐sulfosalicylic ion (CuL and NiL, H₂L = 2,3‐dioxo‐5,6,14,15‐dibenzo‐1,4,8,12‐tetraazacyclopentadeca‐7,13‐diene). Compound 1 displays a 1D ladder‐like chain and all these chains are further interlinked through hydrogen bonds resulting in a 2D architecture. The structure of 2 consists of 5‐sulfosalicylates and an oxamido‐bridge and is arranged in butterfly‐like hexanuclear molecules. The luminescent properties of compounds 1 and 2 are also discussed.     

X-ray diffraction study of Al-Si melts

New layered metal-organic coordination polymers [Zn₃(bpdc)₃(DMA)₂]·3DMA (1) (H₂bpdc = 4,4′-biphenyldicaboxylic acid, DMA = N,N′-dimethylacetamide) and [Zn₃(bdc)₃(im)₂]·1.5H₂O (2) (H₂bdc = terephtalic acid, im = imidazole) are synthesized and characterized by X-ray crystallography.     

Poly[[tetraaquabis(μ2‐2‐nitroterephthalato‐κ3O1:O4,O4′)(μ2‐piperazine‐κ3N:N′)dicadmium(II)] dihydrate]

In the title complex, {[Cd₂(C₈H₃NO₆)₂(C₄H₁₀N₂)(H₂O)₄]·2H₂O}_n, the Cd^II atoms show distorted octahedral coordination. The two carboxylate groups of the dianionic 2‐nitroterephthalate ligand adopt monodentate and 1,2‐bridging modes. The piperazine molecule is in a chair conformation and lies on a crystallographic inversion centre. The Cd^II atoms are connected via three O atoms from two carboxylate groups and two N atoms from piperazine molecules to form a two‐dimensional macro‐ring layer structure. These layers are further aggregated to form a three‐dimensional structure via rich intra‐ and interlayer hydrogen‐bonding networks. This study illustrates that, by using the labile Cd^II salt and a combination of 2‐nitroterephthalate and piperazine as ligands, it is possible to generate interesting metal–organic frameworks with rich intra‐ and interlayer O—H...O hydrogen‐bonding networks.