超分子化合物[M(4，4′-bipy)2(H2O)4·(4，4′-bipy)2·(3，5-diaba)2·8H2O](M=Co，Ni，Cd)的合成及晶体结构

合成了3个超分子化合物[M(4，4′-bipy)₂(H₂O)₄]·(4，4′-bipy)₂·(3，5-diaba)₂·8H₂O(M=Co (1)，Ni (2)，Cd (3)；4，4′-bipy=4，4′-联吡啶；3，5-diaba=3，5-二氨基苯甲酸阴离子)，用红外光谱、元素分析及X-射线单晶衍射进行了表征。3个化合物的晶体都属于单斜晶系，空间群为P2/c。晶体学参数：化合物1：a=0.938 9(2) nm，b=0.775 1(1) nm，c=3.928 4(6) nm，β=90.14(2)°，V= 2.858 80(69) nm³，Z=4，D_c=1.397 g·cm^-3，F(000)=1 266，μ=0.380 mm^-1，R₁=0.034 9,wR₂=0.082 9;化合物2:a=0.938 3(2) nm,b=0.775 3(1) nm，c= 3.921 8(6) nm，β=90.09(1)°，V=2.852 80(68) nm³，Z=2，D_c=1.399 g·cm^-3，F(000)=1 268，μ=0.420 mm^-1，R₁=0.036 6，wR₂=0.080 5；化合物3：a=0.940 91(13) nm，b=0.778 85(11) nm，c=3.971 2(5) nm，β=90.10°，V=2.910 2(7) nm³，Z=2，D_c=1.433 g·cm^-3，F(000)=1 308，μ=0.454 mm^-1，R₁=0.046 8，wR₂=0.096 4。3，5-diaba未参与配位，在配位阳离子[M(4，4′-bipy)₂(H₂O)₄]²⁺中，金属离子M(II)与来自2个4，4′-bipy的2个氮原子和4个水分子的氧原子配位，呈八面体的几何构型。分子中还存在未配位的4，4′-bipy。通过配位阳离子、游离4，4′-bipy及未配位的3，5-diaba间的丰富氢键，构建成具有三维结构的超分子化合物。     

超分子化合物{[8-hydroxyquinolineH]44+·[SiW12O40]4-·2H2O}的水热合成、晶体结构及热稳定性

A supermolecular compound, {[8-hydroxyquinolineH]₄⁴⁺·[SiW₁₂O₄₀]^4-·2H₂O} was synthesized by hydrothermal reaction with silico-tungstic acid and 8-hydroxyquinoline. The crystal of the compound belongs to monoclinic system, space group P2₁/n, with a=1.282 6(6) nm, b=2.292 7(4) nm, c=2.092 0(6) nm, β=95.495(2)°, Z=4, V=6.124 1(7) nm³, D_c=3.791 g·cm^-3, μ=22.568 mm^-1, F(000)=6 200, R₁=0.029 3, wR₂=0.069 3, GOF=1.079. Su-permolecular compound is composed of one SiW₁₂O₄₀^4- with Keggin structure, four protonated cations of 8-hydroxyquinoline, two hydrones. Thermal analysis results showed that the anionic skeleton construction of heteropoly acid in compound decomposed approximately at 349.0 ℃. CCDC: 622142.     

一个新颖敞开结构硼磷酸盐的合成、结构、热和磁学性质：NH4Mn(H2O)2BP2O8· H2O

利用新的模板剂在水热条件下合成结构新颖的硼磷酸盐化合物NH₄Mn(H₂O)₂BP₂O₈·H₂O,单晶X射线衍射分析证明化合物属六方晶系,空间群为P6₁22,a = 0.9652(2) nm,c = 1.5792(5) nm,V = 1.2740(5) nm³,Z = 6．化合物所具有的三维敞开结构由硼磷酸盐螺旋带{[BP₂O₈]^3-和八面体MnO₄(H₂O)₂所构成．突出的结构特点是,化合物结构中的氨离子位于螺纹的外侧并与周围的氧原子形成较强的氢键．实验结果表明,顺磁性的标题化合物在较低的温度下表现出微弱的反铁磁性（Ө = -7.3 K）．此外,化合物的IR、元素分析和热分析在文中也被讨论．     

双核铜(Ⅱ)配合物在H2O2存在下对DNA的氧化切割活性

A novel dinuclear copper(Ⅱ) complex, [Cu₂(phen)(dipic)₂(H₂O)₂]·2H₂O (phen=1,10-phenanthroline, dipicH₂=2,6-pyridinedicarboxylic acid), has been prepared and structurally characterized. The complex crystallizes in the triclinic system, space group P1 with cell parameters a=0.846 0(17) nm, b=1.289 5(3) nm, c=1.452 7(3) nm, α=77.42(3)°, β=79.11(3)°, γ=87.08(3)°, and V=1.518 8(6) nm³. The dinuclear complex shows potential DNA cleavage activity at micromolar concentration in the presence of H₂O₂ and exhibits higher nuclease efficiency than mononuclear complex [Cu(dipic)(H₂dipic)]·H₂O. Without external reductants, the added H₂O₂ may contribute to the generation of hydroxyl radicals that result in DNA strand scission.CCDC:291786.     

锗钨酸分子间化合物的合成和结构研究

以锗钨酸和4-甲基吡啶为原料合成了分子间化合物H₄GeW₁₂O₄₀·5C₆H₇N·CH₃CN。单晶X-射线分析表明，属正交晶系，空间群P2₁2₁2₁, 晶胞参数a=13.533(5),b=20.835(5), c=21.859(7)?，V=6164(3)?³。Dc=3.650 Mg/m³, Z=4。对3934个可观察到的衍射点进行全矩阵最小二乘法修正后，可靠性因子R=0.0534。     

苯并咪唑-5，6-二甲酸-锰配合物的合成，晶体结构和磁性质

采用水热法将MnCl₂与苯并咪唑-5,6-二甲酸混合反应合成出一个新的具有二维层状结构的锰金属配位聚合物{[Mn(Hbim)(H₂O)₂]·(H₂O)₂}_n (1),并分别用元素分析,红外谱图,差热分析和X-射线单晶衍射表征该结构。X-射线单晶衍射分析表明,晶体属于正交晶系,Pbca空间群,晶胞参数a=0.728 2(14) nm,b=1.804 5(4) nm,c=1.915 5(4) nm,V=2.429 3(8) nm³,Z=8,C₉H₁₂MnN₂O₈,M_r=331.15,D_c=1.811 g·cm^-3,F(000)=1 352,μ(Mo Kα)=1.130 mm^-1,最终R=0.037 1,wR=0.085 8。在配位聚合物中,锰-羧基Z字形链相互连接成具有尺寸为0.57 nm×0.75 nm一维通道的二维网络结构,并进一步被分子间的氢键作用构筑成三维超分子结构。磁性质测试表明该化合物为反铁磁。     

钴镍取代杂多酸盐甘氨酸超分子化合物的合成及性质

Supermolecular compounds of glycine monosubstituted heteropolytungstates isomer with Keggin structure β_i-K_6-n(HGly)_n[SiW₁₁M(H₂O)O₃₉]·xH₂O (M=Co²⁺, Ni²⁺； β_i=β₂, β₃) were synthesized and characterized by means of elementary analysis, IR, UV, TG-DTA, X-ray diffraction, polarography and CV. The results indicate that glycin combines the electrostatic effect with heteropolytungstates isomer. The heteropoly anion still remains its Keggin structure in supermolecular compounds. The electrochemical behavior of the compound in 1 mol·L^-1 HAc-NaAc shows that two redox waves correspond to two two-electron processes attributing to the reduction of [SiW₁₁Co(H₂O)O₃₉]^6-. Steady-state fluorescence spectrum shows two intenser fluorescence emission peaks in 447 nm and 486 nm appeared after the supermolecular compound being excited by the excitation wavelength in 274 nm.     

四种Keggin型多酸纳米材料的制备及其吸附有机染料的性能

以4种Keggin型多酸作为原料(分别为H₃PW₁₂O₄₀·36H₂O(简写为PW₁₂^a)、H₃PMo₁₂O₄₀·34H₂O(简写为PMo₁₂^a)、H₄SiW₁₂O₄₀·35H₂O(简写为SiW₁₂^a)和H₄GeW₁₂O₄₀·40H₂O(简写为GeW₁₂^a)),采用表面活性剂智能化控制的软化学法制备了相应的4种Keggin型多酸纳米材料,分别为Ag₃PW₁₂O₄₀·36H₂O(简写为PW₁₂^b)、Ag₃PMo₁₂O₄₀·34H₂O(简写为PMo₁₂^b)、Ag₄SiW₁₂O₄₀·35H₂O(简写为SiW₁₂^b)和Ag₄GeW₁₂O₄₀·40H₂O(简写为GeW₁₂^b)。采用IR、UV-Vis、XRD和SEM表征多酸的结构和纳米粒子的形貌。在室内黑暗条件下,100 mg样品可在5 min内把20 mg·L^-1的100 mL亚甲基蓝(MB)染料溶液脱色,使其变为接近无色,吸附效率最高可达96.3%,吸附效率大小为PMo₁₂^b > PW₁₂^b > GeW₁₂^b > SiW₁₂^b。相同条件下,100 mg样品使20 mg·L^-1的100 mL罗丹明B(RhB)染料溶液30 min内脱色完全,脱色效率最高可达96.1%,吸附效率大小为PW₁₂^b > PMo₁₂^b > SiW₁₂^b > GeW₁₂^b。说明该4种多酸纳米材料具有较高的吸附有机染料性能。     

超分子配合物[Co(H2O)6]·(Hnip)2·(H2nip)2·(CH3NHCH3)2·(H2O)8的直接合成，晶体结构和热分解反应动力学(nip=5-nitroisophthalate)

用直接法培养了配合物[Co(H₂O)₆]·(Hnip)₂·(H₂nip)₂·(DMA)₂·(H₂O)₈(DMA=CH₃NHCH₃)的晶体并用X射线单晶衍射，元素分析和傅里叶变换红外光谱进行了表征。该晶体属于三斜晶系，P-1空间群，晶胞参数为a=0.7012(1)nm, b=1.1378(2) nm, c=1.6612(3) nm, α=84.92(3)º, β=85.19(3)º,γ=85.91(3)º。晶胞体积V=1.3128(5) nm³, Z=1, 理论密度D_c=1.573 g/cm³. 最终R因子[I>2σ(I)]为: R₁=0.0279,wR₂=0.0765; 所有衍射点的R因子为: R₁=0.0327, wR₂=0.0806.衍射结果表明，在晶体结构中两个Hnip分子，两个H₂nip分子，两个DMA分子和八个水分子通过氢键和π-π堆积作用连接到每个Co配位八面体中心上。对配合物进行了DSC和TG-DTG热分析，根据热分析结果推测得到配合物的热分解机理，并且用Kissinger,Ozawa，积分法和微分法确定了最可能的动力学模型函数。     

柔性多羧酸配体锶配合物的合成、晶体结构及拓扑学分析

利用水热合成制备了一个新颖的基于柔性多羧酸配体的碱土金属配合物Sr(BuTA)_0.5(H₂O)₂(1)(H₄BuTA=1,2,3,4-丁四酸)。利用元素分析及X-射线单晶衍射对其进行了表征。结构分析结果表明标题化合物1属于单斜晶系,P2₁/c空间群,晶胞参数为a=0.870 03(5) nm,b=0.793 03(5) nm,c=1.268 07(5) nm,β=127.689(3)°,晶胞体积V=0.692 36(7) nm³,Z=4,D_calc=2.290 g·cm^-3,F(000)=468,μ=7.768 cm^-1,R=0.015 8,wR=0.037 7。在化合物1中,每个Sr(Ⅱ)的配位环境为八配位的反四棱柱配位构型。在配合物中金属和配体互相连接形成一个三维的框架结构,其拓扑为(4⁶)₂(4¹².6¹².8⁴)。在其结构中配体是少见的八连接点。对配合物1的热稳定性也做了测试。     

Supramolecular Networks Extended by N–H···O Interactions between Cu‐Benzimidazole Subunits and Keggin Anions

Three new 2D/3D supramolecular architectures derived from Cu‐organic subunits and Keggin anions, [Cu^II₂(biz)₈(HPMo^VI₁₀Mo^V₂O₄₀)(H₂O)₂] · 2H₂O ( 1 ), [Cu^I₄(biz)₈(SiW₁₂O₄₀)] · 2H₂O ( 2 ) and [Cu^I₂(dmbiz)₄(Hdmbiz)₂(SiW₁₂O₄₀)] ( 3 ) (biz = benzimidazole, dmbiz = 5, 6‐dimethyl benzimidazole), were obtained under hydrothermal conditions. Single crystal X‐ray diffraction analysis reveals that compound 1 has two kinds of [Cu^II(biz)₂]²⁺ cations, which are further extended by Keggin anions into a 2D (4, 8)‐connected supramolecular network by hydrogen bonding interactions. In compound 2 , four types of [Cu^I(biz)₂]⁺ subunits link the [SiW₁₂O₄₀]^4– anions to form a 3D (2, 6)‐connected supramolecular structure. Compound 3 shows a 3D supramolecular network with a NaCl‐type topology constructed by [Cu^I(dmbiz)₂]⁺ subunits, anions, and discrete [Hdmbiz]⁺ cations. Moreover, the electrochemical and photocatalytic properties of compounds 1 and 2 were investigated.     

A series of new organic–inorganic compounds templated by the [SiW12O40]4− polyanion

Two couples of new compounds templated by the polyanion [SiW₁₂O₄₀]^4?,[Hbix][Cu^I(bix)]₃[SiW₁₂O₄₀]·4H₂O (1) and [Cu^II(H₂O)(Hbix)₂(bix)]₂[Cu^II(H₂O)₂(Hbix)₂(bix)][SiW₁₂O₄₀]₃·4H₂O (2) (bix = 1,4-Bis(imidazol-1-ylmethyl)benzene), [Cu^I(bbi)]₄[SiW₁₂O₄₀]·2H₂O (3) and [Cu^II(bbi₂)]₂[SiW₁₂O₄₀] (4) (bbi = 1,1′-(1,4-butanediyl)bis(imidazole)) were hydrothermally synthesized, and characterized by elemental analyses, IR spectroscopy, thermogravimetric analyses and single X-ray diffraction. Compounds 1 and 2 were synthesized from the same reactants but exhibited distinct structures which could be ascribed to the different ratios of the reactant bix to Cu^II. In compound 1, the higher ratio of bix results in the transformation of the Cu^II to Cu^I, the [SiW₁₂O₄₀]^4? templates direct the Cu^I–bix coordination polymers to form a 3D supramolecular framework with grid-like channels along two directions. The [SiW₁₂O₄₀]^4? templates in compound 2 locate in the voids of the 3D supramolecular network constructed by Cu^II–bix coordination polymers, which exhibits the interdigitation fashion in both the formation of the 2D layer and the 3D framework. Compounds 3 and 4 were synthesized similar to 1 and 2, except for the change of bix to bbi. In compound 3, the Cu^I–bbi polymers form a supramolecular metal–organic host framework with rhombic channels in which the SiW₁₂ templates reside. Compound 4 shows a framework with hexagonal channels constructed by Cu^II–bbi coordination polymers which accommodated the SiW₁₂ templates.     

Solvent-dependent assembly of porous coordination polymers based on Keggin-type [SiW12O40]4–

Two coordination polymers (CPs) based on Keggin-type [SiW₁₂O₄₀]^4– (SiW₁₂), [Zn₂(bpy)₂(SiW₁₂O₄₀)(DMF)₈]·solvent (1) and [Zn₂(bpy)(SiW₁₂O₄₀)(DMA)₈]·2DMA (2) (bpy = 4,4′-bipyridine, DMF?=?N,N′-dimethylformamide; DMA?=?N,N′-dimethylacetamide), have been solvo-thermally synthesized and characterized by single crystal X-ray diffraction, powder X-ray diffraction, IR spectra, elemental analyses and thermogravimetric analyses. Both 1 and 2 are synthesized under similar conditions except DMF and DMA were used as the solvents for 1 and 2, respectively. Structural studies reveal that the supramolecular framework of 1 contains pumpkin-like voids, while 2 has a non-porous supramolecular framework. These results show that solvents play an important role in construction of the POM-based CPs. The luminescent properties for 1 and 2 have also been investigated.     

Assembly of a Supramolecular Architecture Based on Keggin POMs and Lanthanide Coordination Cations

Two new compounds based on Keggin polyoxometalates (POMs) [SiW₁₂O₄₀]⁴⁻ (SiW₁₂), [Na(H₂O)₃(H₂L)SiW₁₂O₄₀](H₂L)₂   6H₂O (1), and [Ce(H₂O)₃(HL)₂(H₂L)]₂[SiW₁₂O₄₀]₂ 10H₂O (2) (HL = C₆H₅NO₂ = isonicotinic acid), have been conventionally synthesized and characterized by routine methods. Compound 1 possesses a 1D right-handed helical structure constructed by SiW₁₂O₄₀ ⁴⁻ {SiW₁₂} and [Na(H₂O)₃(HL)] complexes. Interestingly, these right-handed helical chains are linked together via H-bonds forming a novel chiral layer. By using the similar synthesis method to that for compound 1, except for employing Ce³⁺ cations in instead of La³⁺ cations, a 3D supramolecular compound 2 based on SiW₁₂ and Ce³⁺ coordination cations has been obtained, which contains 1D channels along a axis. Additionally, the luminescence properties of 2 were studied. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Synthesis,properties and photochromism of novel charge transfer compounds with Keggin anions and protonated 2,2′-biquinoline

Several novel compounds with protonated 2,2′-biquinoline (biqui) and Keggin polyoxoanions (α-isomers), having the general formula (Hbiqui)_m[XM₁₂O₄₀]·nsolv, X=P (m=3), Si (m=4); M=Mo, W; n=0, 3; solv=H₂O, N,N-dimethylformamide (dmf), were synthesized and characterized by analytical, spectroscopic and X-ray diffraction techniques. Electronic spectroscopy (visible/UV) indicated the presence of intermolecular charge transfer between the organic and inorganic moieties in the solid state. Evidence for the existence of intermolecular electronic interaction in solution was found for compounds with the [SiW₁₂O₄₀]⁴⁻ anion, a fact quite uncommon for charge transfer compounds based on Keggin anions. A single crystal X-ray diffraction study could be performed on (Hbiqui)₄[SiW₁₂O₄₀]·3dmf crystals, but the refinements revealed the presence of highly disordered 2,2′-biquinoline molecules and α-[SiW₁₂O₄₀]⁴⁻ anions. Photosensitivity to sunlight and to W-lamp visible light was assessed for all compounds. Photochromic properties were found for solids with [XMo₁₂O₄₀]^m− Keggin anions. Reduction of these anions upon irradiation was observed by diffuse reflectance and EPR spectroscopy. After a minimum of 5 h under sunlight, the extent of anion reduction followed the order (Hbiqui)₃[PMo₁₂O₄₀]·3dmf>(Hbiqui)₄[SiMo₁₂O₄₀]·3dmf>(Hbiqui)₃[PMo₁₂O₄₀]>(Hbiqui)₄[SiMo₁₂O₄₀]·4H₂O. The Kurtz powder test was used to evaluate the second-order non-linear optical properties of the prepared compounds. (Hbiqui)₄[SiW₁₂O₄₀]·3H₂O originated a second harmonic generation signal with intensity about 15% that of urea for 1064 nm radiation.     

Assembly of two new polyoxometalate-templated supramolecular compounds by utilizing flexible 1,4-bis(pyrazol-1-ylmethyl)benzene ligand

Two new polyoxometalate-templated supramolecular compounds, [Cu^I₄(bpmb)₄][PMo^VI₁₁Mo^VO₄₀] (1) and [Cu^I₄(bpmb)₄SiW₁₂O₄₀] (2) (bpmb = 1,4-bis(pyrazol-1-ylmethyl)benzene), have been synthesized under hydrothermal conditions and characterized by routine methods. Structural analysis shows that in 1, there exist crown-like [Cu^I₄(bpmb)₄] coordination macrocycles, and the Keggin polyanions [PMo ^VI₁₁Mo^VO₄₀]^4? (abbr. as PMo₁₂), which direct the crown-like macrocycle to form a 3-D supramolecular framework. In 2, there exist unusual meso-helix chains, and these chains are mutually interlaced in a wave–trough pattern, but without intersection resulting in a multi-cavity layer, in which the [SiW₁₂O₄₀]^4? (abbr. as SiW₁₂) clusters as guest molecules occupy the cavities of the layers. The distinct structural features of the two compounds suggest that Keggin polyanions should play a significant role in the process of assembly. Electrocatalytic properties of 1 and 2 were investigated.     

Hydrothermal syntheses and structural characterization of two new supramolecular compounds: (H2bbi)2[Mo8O26] and (H2bbi)2[SiW12O40]·2H2O [bbi = 1,1′-(1,4-butanediyl)bis(imidazole)]

Two new inorganic–organic hybrid supramolecular compounds based on imidazolium and POMs formulated as (H₂bbi)₂[Mo₈O₂₆] (1) and (H₂bbi)₂[SiW₁₂O₄₀]·2H₂O (2) [bbi = 1,1′-(1,4-butanediyl)bis(imidazole)] have been prepared under hydrothermal conditions and characterized by elemental analyses, IR and single-crystal X-ray diffraction analyses. The two compounds consist of protonated bbis together with POMs. [Mo₈O₂₆]^4? and [SiW₁₂O₄₀]^4? are linked through H₂bbi into a three-dimensional (3D) network via hydrogen bonds, respectively. Compound 1 is the first example of 3D two-fold interpenetrating hydrogen bond-supported supramolecular assembly from octamolybdate one-dimensional (1D) chain and imidazolium. The fascinating structural feature of compound 2 is that the anions and the protonated bbi ligands formed a 3D (4, 8) supramolecular network by hydrogen bonds. Compound 2 has been used as a solid bulk-modifier to fabricate three-dimensional bulk-modified carbon paste electrode (CPE) by direct mixing. The electrochemical behavior and electrocatalysis of compound 2 modified CPE (2-CPE) have been studied.     

Synthesis,Crystal Structure,Fluorescence and Photocatalytic Properties of a Copper Compound with 2‐Phenyl‐1H‐1,3,7,8‐tetraazacyclopenta[l]phenanthrene and Silicotungstic Acid

The polyoxometalate compound [CuPTCP(H₂O)_2.5]₂[SiW₁₂O₄₀] · 10.5H₂O ( 1 ) was synthesized under hydrothermal conditions using 2‐phenyl‐1H‐1,3,7,8‐tetraazacyclopenta[l]phenanthrene (PTCP) and Keggin‐type silicotungstic acid (H₄SiW₁₂O₄) as neutral ligands. Compound 1 was characterized by single‐crystal X‐ray diffraction, elemental analysis, as well as IR and UV/Vis spectroscopy. It crystallizes in the orthorhombic space group Cmcm with a = 15.490(8) nm, b = 25.263(8) nm, c = 20.988(8) nm, α = 90°, β = 90°, γ = 90°, V = 8213(6) nm³, Z = 2. Compared with the ligand PTCP, the fluorescent spectra of compound 1 are different. Furthermore, the Rhodamine B (RhB) photodegration process by compound 1 as catalyst was studied. It could be shown that the DR% of compound 1 is more than twice that of pure silicotungstic acid.     

Synthesis, structure, and characterization of a silicotungstate anion-supported organic-inorganic hybrid complex [Zn(2,2′-Bipy)3]1.5[SiW12O40Zn(2,2′-Bipy)2(OH)] · 0.25H2O

A new Keggin-type silicotungstate anion-supported organic-inorganic hybrid transition metal complex, [Zn(Bipy)₃]_1.5[SiW₁₂O₄₀Zn(Bipy)₂(OH)] · 0.25H₂O (I) (Bipy = 2,2′-bipyridine), has been synthesized by the hydrothermal method and characterized by elemental analysis, IR, UV, and EPR spectra, TG-DTA analysis, and single crystal X-ray diffraction. The structural analysis indicates that each structural unit of I consists of one [SiW₁₂O₄₀Zn(Bipy)₂(OH)]³⁻ heteropolyanion, one and a half isolated [Zn(Bipy)₃]²⁺ cations, and a quarter of crystal water molecule. The [Zn(Bipy)₂(OH)]⁺ unit is covalently bonded to one Keggin polyoxoanion [SiW₁₂O₄₀]⁴⁻ in the [SiW₁₂O₄₀Zn(Bipy)₂(OH)]³⁻ cluster. The EPR spectrum indicates the existence of Zn²⁺ with the high-spin state, and TG-DTA analysis exhibits that I has two steps of weight loss and the polyoxoanion framework is collapsed at 618°C.     

Syntheses, structures and properties of 3D inorganic-organic hybrid frameworks constructed from lanthanide polymer and Keggin-type tungstosilicate

Inorganic-organic hybrid frameworks, namely [Ce(H₂O)₃(pdc)]₄[SiW₁₂O₄₀]·6H₂O 1, [M(H₂O)₄(pdc)]₄[SiW₁₂O₄₀]·2H₂O (M=Ce for 2a, La for 2b, Nd for 2c; H₂pdc=pyridine-2,6-dicarboxylic acid) were assembled through incorporation of Keggin-type heteropolyanion [SiW₁₂O₄₀]⁴⁻ within the voids of lanthanides-pdc network as pillars or guests under hydrothermal condition. Single-crystal X-ray analyses of these crystals reveal that compound 1 presents 3D pillar-layered framework with the [SiW₁₂O₄₀]⁴⁻ anions located on the square voids of the two-dimensional Ce-pdc bilayer. Compounds 2a-c are isostructural and constructed from 3D Ln-pdc-based metal-organic framework (MOF) incorporating noncoordinating guests Keggin structure [SiW₁₂O₄₀]⁴⁻. Solid-state properties of compounds 1 and 2a-c such as thermal stability and photoluminescence have been further investigated.