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.     

Synthesis,structure, and photoluminescence of a series of lanthanide coordination polymers constructed from nitrogen containing organic ligands

We have synthesized four coordination polymers with two different nitrogen containing organic ligands and different lanthanide metal ions, under hydrothermal condition. [{Ln₂(bpdc)₃(H₂O)₂}] _n (Ln = Dy (1), Sm (2)) (bpdc = 2,2-bipyridine-3,3-dicarboxylic acid) are isostructural, with 2-D supramolecular layer structure composed from 1-D chains. Like 1 and 2, [{Ln(pzda)₂(H₂O)₂} · 4H₂O] _n (Ln = Dy (3), Nd (4)) (pzda = pyrazine-2,6-dicarboxylic acid) are also isostructural with 1-D chain-like structures. The photoluminescence of 2 is studied.     

Syntheses,crystal structures,and photoluminescence of two new coordination polymers derived from dicarboxylate and N-donor ligands

Two metal-organic coordination polymers, [Co(tda)(ip)(H₂O)₂] _n (1) and [Mn(tda)(ip)(H₂O)] _n (2) [H₂tda?=?thiophene-2,5-dicarboxylic acid, ip?=?1H-imidazo[4,5-f][1,10]-phenanthroline], have been synthesized and characterized by elemental analyses, IR, PXRD, and X-ray diffraction. Single-crystal X-ray analyses reveal that 2,5-tda is a bridging ligand, exhibiting two coordination modes to link metal ions: μ₁-η¹?:?η⁰/μ₁-η¹?:?η⁰ and μ₂-η¹?:?η¹/μ₁-η¹?:?η⁰. Compound 1 demonstrates a 1-D structure in which Co²⁺ centers are connected via tda anions into 1-D chains; the chains are further connected via hydrogen-bonding and π?···?π interactions. Compound 2 displays a 2-D structure in which tda connects two Mn ions forming a dinuclear molecule. In 2 the 3-D supramolecular structure arrays through hydrogen-bonding and π?···?π interactions. In addition, photoluminescence for 1 and 2 is also investigated in the solid state at room temperature.     

Syntheses, structures and photoluminescence of a series of lanthanide-organic frameworks involving in situ ligand formation

A series of lanthanide-organic frameworks with aromatic pyridinecarboxylate ligand, generally formulated as [Ln(PYDC)(C₂O₄)_0.5(H₂O)₂]·H₂O (LnPr(1), Nd(2), Eu(3), Gd(4), Tb(5), Er(6); H₂PYDC3,4-pyridinedicarboxylic acid) have been successfully synthesized and characterized. Their isostructures are built up from one-dimensional (1D) infinite chains cross-linked via the tri-connected PYDC ligands, leading to the two-dimensional (2D) layer structure. The adjacent layers are further extended into three-dimensional (3D) supramolecular frameworks through hydrogen bonding and π-π stacking interactions. Interestingly, the oxalate bridging ligand is believed to form via in situ ligand synthesis through decarboxylation of the organic precursor, H₂PYDC. Complexes 3 and 5 exhibit strong fluorescent emissions in the visible region at room temperature.     

Syntheses,crystal structures,and photoluminescence of two Cd(II) complexes with simple ligands

Two cadmium complexes, {[Cd₂(2,5-tda)₂(ip)₄]·4H₂O}_n (1) and {[Cd₂(4,4′-obb)₂(ip)₂·H₂O]·H₂O}_n (2) (2,5-tda?=?thiophene-2,5-dicarboxylic acid, 4,4′-obb?=?4,4′-oxybisbenzoic acid, ip?=?1H-imidazo[4,5-f][1, 10]-phenanthroline), were synthesized and characterized by IR, elemental analysis, powder X-ray diffraction, and single-crystal X-ray diffraction. X-ray analysis revealed that 1 is a dinuclear complex with the 2,5-tda anion connecting two Cd ions in a μ₁-η¹:η⁰/μ₁-η¹:η⁰ coordination mode. Each dinuclear complex is further connected with neighboring complexes via hydrogen-bonding interactions. Compound 2 displays a 2-D layer structure with opened windows occupied by crystallographic water molecules. The layers are further packed via hydrogen-bonding interactions. Luminescent properties for 1 and 2 are also investigated in the solid state at room temperature.     

Syntheses, structures, near-infrared and visible luminescence, and magnetic properties of lanthanide-organic frameworks with an imidazole-containing flexible ligand

Reactions of tripodal ligand 1,3,5-tris(imidazole-1-ylmethyl)-2,4,6-trimethylbenzene (L) with lanthanide metal salts and triethyl orthoformate led to the formation of six bowl-like dinuclear compounds [Ln2(L)(HL)(NO3)6(HCOO)].3CH3OH (Ln = Gd 1, Tb 2, Dy 3, Er 4, Yb 5, and Eu 6). The single-crystal X-ray diffraction analysis revealed that six complexes are isomorphous and isostructural and that the dinuclear molecules are further connected by hydrogen bonds and pi-pi interactions, resulting in 3D channel-like structures. The luminescence properties have been studied, and the results showed that the Tb(III) (2) and Eu(III) (6) complexes exhibited sensitized luminescence in the visible region and their luminescence lifetimes in powder and DMSO-d6 solution are in the range of milliseconds. The Yb(III) complex (5) emits typical near-infrared luminescence in DMSO-d6 solution. Variable-temperature magnetic susceptibility measurements of 1-6 showed that complex 1 (Gd) is nearly a paramagnet and complexes 2 (Tb), 3 (Dy), and 4 (Er) show the ferromagnetic coupling between magnetic centers, whereas the depopulation of the Stark levels in complexes 5 (Yb) and 6 (Eu) leads to a continuous decrease in (chi M)T when the sample is cooled from 300 to 1.8 K.     

Lanthanide-organic frameworks based on terphenyl-tetracarboxylate ligands: syntheses,structures, optical properties and selective sensing of nitro explosives

Three isostructural three-dimensional(3D) lanthanide-based metal-organic frameworks [Ln_2L(H_2L)(NMP)_2].H_2O(Ln=Sm(1), Eu(2), Gd(3); H_4L=1,1′:4′,1″-terphenyl-2′,4,4″,5′-tetracarboxylic acid; NMP=N-methyl-2-pyrrolidone) have been synthesized and structurally characterized. In 1–3, two Ln3+ ions are doubly-bridged by two oxygen atoms of two carboxylate groups to form the dinuclear Ln_2(OCOO–)_2 unit. Each Ln_2(OCOO–)_2 unit links with four H_2L~(2-) ligands and four L4. ligands to lead to the 3D framework,which can be rationalized as a new trinodal 4,4,8-connected(44.62)(45.6)(412.616) topological network by considering the dinuclear Ln_2(OCOO–)_2 units as 8-connected nodes and L~4./H_2L~(2-) ligands as planar 4-connected nodes, respectively. 1 and 3 exhibit blue emission originated from the ligand with the emission maximum at 384 nm, while 2 shows intense characteristic red emission of Eu~(3+) ions and weak ligand-centered emission. Moreover, 2 has fluorescent quenching response towards the aromatic nitro compounds, especially for the 3,4-dinitrotoluene(3,4-DNT) with the linear Stern-Volmer relationship in the concentration range of 0–1 mM and the quenching constant(Ksv) of 2.084×10~3 M~(-1).     

Synthesis, structures, and photoluminescence properties of novel lanthanide tetracyanoplatinates lacking Pt-Pt interactions

The synthesis of a series of lanthanide tetracyanoplatinates all incorporating 2,2′:6′,2″-terpyridine (terpy) have been carried out by reaction of Ln³⁺ nitrate salts with terpy and potassium tetracyanoplatinate. The incorporation of different Ln³⁺ cations results in the isolation of [Ln(DMF)₂(C₁₅H₁₁N₃)(H₂O)₂(NO₃)]Pt(CN)₄ (Ln=La-Nd, Sm-Yb) under otherwise identical reaction conditions. These compounds have been isolated as single crystals and X-ray diffraction has been used to investigate their structural features. All of the reported compounds are isostructural. Crystallographic data for the representative Eu³⁺ compound (EuPt) are (MoKα, λ=0.71073 Å): monoclinic, space group P2₁/c, a=10.1234(4) Å, b=18.7060(7) Å, c=17.1642(5) Å, β=97.249(3)°, V=3224.4(2), Z=4, R(F)=2.78% for 426 parameters with 7724 reflections with I>2σ(I). The structure consists of a zero-dimensional, ionic salt containing complex [Eu(DMF)₂(C₁₅H₁₁N₃)(H₂O)₂(NO₃)]²⁺ cations and anions. The complex cations contain the Eu³⁺ ions in a tri-capped trigonal prismatic coordination environment with one terdentate 2,2′:6′,2″-terpyridine molecule, one bidentate nitrate anion, two O-bound dimethylformamide molecules, and two coordinated water molecules. Photoluminescence data illustrate that EuPt displays intramolecular energy transfer from the coordinated terpy molecule to the Eu³⁺ cation. The uncoordinated tetracyanoplatinate anion also exhibits visible emission.     

Syntheses, structures and properties of silver-organic frameworks constructed with 1,2,3,4-benzenetetracarboxylic acid

The reactions of 1,2,3,4-benzenetetracarboxylic acid (H(4)mpda) and different silver(I) salts under hydrothermal or solvent evaporation conditions yielded four unusual coordination complexes with interesting frameworks: [Ag(4)(mpda)](n) (1), {[Ag(2.5)(mpda)(bpy)(2)]·[Ag(bpy)]·[Ag(bpy)(H(2)O)]·(NO(3))(0.5)·(H(2)O)(9)}(n) (2), {[Ag(5)(mpda)(2)(bpy)(4)]·[Ag(bpy)]·[Ag(bpy)(H(2)O)]·[Ag(bpy)(H(2)O)]·(H(2)O)(16)}(n) (3), {[Ag(2)(mpda)(H(2)O)]·[Ag(bpy)]·[Ag(bpy)]}(n) (4) (bpy = 4,4'-bipyridine). Complex 1 displays a novel (3,4,7)-connected {4.6(2)}{4.6(5)}{4(2).6(13).8(5).10} topology, in which the carboxylic groups of the mpda(4-) ligand adopt variable coordination modes. In 1, besides Ag-O coordination bonding, AgAg and Agaromatic intermolecular interactions also make their appearance. In complexes 2-4, rare architectures comprising three or four isolated coordination polymers within the same crystalline structure have been obtained, respectively. In 2 and 3, neighboring layers are linked together through water tapes into a three-dimensional supramolecular architecture, which is also consolidated by π···π stacking, while independent infinite rod-like polymer chains fill the void space between layers. Interestingly, an anionic (H(2)O-NO(3)(-))(n) layer, built from water tapes and nitrate anions as well as consolidated by the mpda(4-) ligands, has been structurally identified in compound 2. A new water tape constructed from alternating tetramers and decamers has been obtained in compound 3. In compound 4, a right-handed helical chain and two rod-like polymeric chains are interconnected through host-guest molecular recognition to generate a three-dimensional chiral supramolecular architecture. Bulk materials for 1 and 4 have second-harmonic generation activity, being approximately 0.6 and 0.4 times that of urea. The IR spectra, thermogravimetric analysis and luminescent properties of all compounds were also investigated.     

Syntheses, structures and physical properties of transition metal-organic frameworks assembled from trigonal heterofunctional ligands

Six novel metal-organic frameworks (MOFs), {Mn(bpydb)(bpyHdbH)}(n) (1) {[Co(2)(bpydb)(2)](H(2)O)(0.5)}(n) (2), {[Ni(0.5)(bpydbH)(H(2)O)](DMF)(2)}(n) (3), {[Cu(2)(bpydb)(2)](H(2)O)(0.5)}(n) (4), {Zn(bpyHdb)(2)}(n) (5) and {[Cd(0.5)(bpydb)(0.5)(DMF)](H(2)O)}(n) (6), were successfully synthesized by assembling transition metal salts with trigonal heterofunctional ligand 4,4'-(4,4'-bipyridine-2,6-diyl) dibenzoic acid (bpydbH(2)) under hydrothermal and/or solvothermal conditions. Compound 1 features a rare 4-fold interpenetrating (3,5)-connected framework with hms-type topology. Isostructural compounds 2 and 4, constructed by M(2)(COO)(4) secondary building units, exhibit a robust 3D framework with alb topological type in 2-fold interpenetrating mode. Compound 3 consists of 2D (4,4) networks, which are further assembled into the new topological framework with the symbol (5(3)·6(2)·8)(5(3)·6(3))(2) through O-HO interactions. Compound 5 manifests a novel 4-connected interpenetrating framework, constructed by 2D (4,4) layers and interbedded N-HO interactions. Non-interpenetrating honeycomb networks are observed in compound 6, and further packed into a 3D framework featuring 1D channels. The magnetic susceptibility of compound 2 indicates antiferromagnetic interactions between cobalt ions. The photoluminescent properties of 5 and 6 were investigated in the solid state at room temperature.     

A series of lanthanide-organic frameworks constructed by 2-methyl imidazole dicarboxylate and oxalate: synthesis,structures, and properties

Five lanthanide(III) coordination polymers with 2-methyl-1H-imidazole-4,5-dicarboxylic acid (H₃MIDC) and ammonium oxalate, {[(Ln1)₂(HMIDC)₂(C₂O₄)(H₂O)₃]?·?3H₂O} _n (Ln1?=?Nd (1), Sm (2)), {[Eu₂(HMIDC)₂(C₂O₄)(H₂O)₃]?·?0.5EtOH?·?3H₂O} _n (3), {[Ce₂(HMIDC)₂(C₂O₄)(H₂O)₃]?·?EtOH?·?3H₂O} _n (4), and {[Gd₂(HMIDC)₂(C₂O₄)(H₂O)₃]?·?MeOH?·?3H₂O} _n (5), have been prepared and structurally characterized. Single-crystal X-ray diffraction analyses reveal that 1 and 2 are isostructural, as are 3, 4, and 5. Each exhibits a 3-D open framework, which is built by a regular 2-D grid connected by HMIDC^2? and Ln(III). The luminescence and thermal properties of these complexes have been investigated as well.     

Syntheses,structures, and characterizations of three Ag(I) complexes constructed by length-modulated pyrazole-based ligands

Three coordination complexes with N-donor ligands, Ag₂(L1)_1.5(NO₃)₂ (1), Ag₃(L2)₂(NO₃)₃ (2), and Ag(L1)₂NO₃ (3) {L1?=?1,4-bis(pyrazole-1-ylmethyl)benzene, L2 = 4,4′-bis(pyrazole-1-ylmethyl)biphenyl}, have been synthesized and structurally characterized by elemental analysis, IR spectroscopy, TGA, and X-ray single crystal diffraction. Complex 1 shows a 3-D fsh-3,4-P2₁/c structure with brevity code {8³}²{8⁵·10}. Complex 2 has a 3-D framework with a 2-D layer penetrated by an infinite 1-D zigzag chain. Complex 3 exhibits a (4,4)-net racemizing layer structure with nitrate anions filling the cavity. The results indicate that L1 and L2 can adopt varied conformations in formation of the complexes, and the length of the ligands plays a key role in configuring and directing the corresponding structure of the complexes.     

不同V型辅助配体构筑的两个镉配位聚合物的合成、结构和荧光性质

在溶剂热条件下,合成了2个基于V型辅助配体（bipmo、bppmo）的镉配位聚合物{[Cd （bipmo）（NDC）]·1.75H₂O}_n（1）和{[Cd （bppmo）（NDC）（H₂O）]·H₂O}_n（2）,其中H₂NDC=2,6-萘二羧酸,bipmo=双（4-（1H-咪唑-1-基）苯基）甲酮,bppmo=双（4-（吡啶-4-基）苯基）甲酮。利用单晶X射线衍射、键价和分析、红外光谱和元素分析对其结构进行了表征。研究发现,配合物1具有二重互穿的{6³}拓扑结构。配合物2同样是3-连接的{6³}拓扑,却存在三重穿插结构。分析表明,V型配体对最终结构的形成有很大影响。此外,对配合物1和2的发光性质也进行了详细研究。     

不同V型辅助配体构筑的两个镉配位聚合物的合成、结构和荧光性质

在溶剂热条件下,合成了 2 个基于 V 型辅助配体(bipmo、bppmo)的镉配位聚合物{[Cd(bipmo)(NDC)]·1.75H₂O}_n (1)和{[Cd(bppmo)(NDC)(H₂O)]·H₂O}_n (2),其中 H2NDC=2,6 萘二羧酸,bipmo=双(4 (1H 咪唑 1 基)苯基)甲酮,bppmo=双(4 (吡啶 4 基)苯基)甲酮。利用单晶X射线衍射、键价和分析、红外光谱和元素分析对其结构进行了表征。研究发现,配合物1具有二重互穿的{63}拓扑结构。配合物2同样是 3 连接的{6³}拓扑,却存在三重穿插结构。分析表明,V型配体对最终结构的形成有很大影响。此外,对配合物1和2的发光性质也进行了详细研究。     

Two d 10-metal coordination polymers constructed from flexible ligands: Syntheses, crystal structures, and luminescent properties

Two new complexes, Zn(Glut)(Bix) · 2H₂O (I) and Cd(Pda)(Bimb) (II) (H₂Glut = glutaric acid, H₂Pda = 1,3-phenylenediacetic acid, Bix = 1,4-bis(imidazol-1-ylmethyl)benzene and Bimb = 1,4-di(1H-imidazol-1-yl)butane) were obtained under hydrothermal conditions by employing mixed ligands with metal salts and characterized by elemental analysis, IR, TGA, and Single crystal X-ray diffraction. Complex I presents a two-dimensional 2-fold interpenetrating layer structure. Whereas complex II is a two-dimensional layer network and exhibits a typical (4,4) topological net. The infrared spectra, thermogravimetric and luminescent properties were also investigated in detail for two complexes.     

A 2-D dysprosium-organic complex constructed from 6,7-dihydropyrido(2,3-d)pyridazine-5,8-dione and oxalic acid: synthesis,characterization and photoluminescence

A pyridine derivative 6,7-dihydropyrido(2,3-d)pyridazine-5,8-dione (H₂PDH) and oxalic acid (H₂ox) are reacted with dysprosium oxide to develop a new 2-D dysprosium–organic complex [Dy(PDH)(ox)_0.5(H₂O)₂]. The single-crystal structure reveals that acylamino oxygens and coordinated waters develop a 3-D supramolecular network, which is composed of 2-D layers, and each 2-D layer is formed by 1-D Dy–H₂O–ox chains linked by tridentate PDH^2? ligands. The complex exhibits metal-centered luminescence with yellowish blue emission. The energy transfer mechanism and photoluminescence are also investigated.     

Syntheses, structures, and photoluminescence of three-dimensional lanthanide coordination polymers with 2,5-pyridinedicarboxylic acid

Four new open-framework coordination polymers of lanthanide 2,5-pyridinedicarboxylates, with the formulas Pr2(pydc)₃(H₂O)₂ (1), Ln(pydc)(Hpydc) (Ln=Tb (2), Er (3), Eu (5)), and Gd(pydc)(nic)(H₂O) (4) (H₂pydc=2,5-pyridinedicarboxylic acid, Hnic=nicotinic acid), have been hydrothermally synthesized and four of them (except Eu (5)) have been structurally characterized. Complex 1 consists of two types of ligand-binding modes contributing to link the PrO₇N(H₂O) polyhedral chains to three-dimensional (3D) open-framework architecture. Complexes 2 and 3 are isostructural and feature unique 3D cage-like supramolecular frameworks remarkably different from that of 1, owing to the different ligand-bridging pattern. Complex 4, however, has the distinct 3D open-framework architecture due to the presence of unexpected nicotinate ligands, which may be derived from pydc ligands via in-situ decarboxylation under the hydrothermal condition.     

Syntheses,crystal structures and properties of four metal coordination complexes constructed from aromatic carboxylate and benzimidazole-based ligands

Transition Metal Chemistry - Four metal–organic coordination complexes, namely {[Zn(SIP)(mbi)2]·(Hmbi)·(H2O)2}n (1), {[Cd3(SIP)2(bbhb)3(H2O)4]·(H2O)2}n (2),...     

Syntheses,structures and luminescent properties of a series of ladder-shaped [Ln2Sr3] heterometal-organic frameworks

A series of Ln^III–Sr^II heterometallic coordination polymers formulated as [Ln₂Sr₃(pda)₆(H₂O)₁₈]·nH₂O (Ln = Pr-1, n = 14; Nd-2, n = 12; Sm-3, n = 11; Eu-4, n = 11; Gd-5, n = 16; Tb-6, n = 13; Dy-7, n = 13) were synthesized via assembly of Ln(NO₃)₃·6H₂O, SrCl₂·6H₂O, pyridine-2,6-dicarboxylic acid (H₂pda) and imidazole (im) in H₂O/C₂H₅OH solution. Single crystal X-ray diffraction revealed that they are isostructural. All of these complexes possess ladder-shaped 1-D chain structures. The luminescent properties of Sm-3, Eu-4, Gd-5, Tb-6 and Dy-7 have been investigated. The solid-state quantum yields and the lifetimes of Eu-4 and Tb-6 are also studied.     

Tetrazoleacetic acid templated 3d-4f heterometallic-organic frameworks constructed from different ligands: structures,luminescence, magnetism and photocatalytic properties

A series of 3-D lanthanide-transition 3d-4f heterometallic complexes have been synthesized by hydrothermal route from mixtures of 2,2′-bipyridyl-5,5′-dicarboxylic acid (H₂bpdc) and acetic acid (HAc) with tetrazoleacetic acid as template. The single-crystal X-ray analysis shows that nine CdLn(H₂O)₂Cl₂(bpdc)Ac complexes (Ln = La for 1, Pr for 2, Nd for 3, Sm for 4, Eu for 5, Gd for 6, Dy for 7, Ho for 8, Er for 9) crystallized in the space group P-1 and featured three-nodal (3, 4, 6)-three connected topological frameworks. The photocatalytic behaviors imply that 1–9 have significant photocatalytic activities for degradation of RhB.