1D Ladder-Like Structure Motif Assembled from Edge-Sharing Rhombic Squares of Sm2Mo2 Based on [Mo(CN)8]4− and Sm3+ Ions as Building Blocks

Novel bimetallic 4d–4f complex, {Cs[Sm(MeOH)₃(DMF)(H₂O)Mo(CN)₈] · H₂O} _n (1) (DMF = N,N′-dimethylformamide) has been synthesized and structurally characterized. The crystal analyses shown that 1 exhibit a one-dimension (1D) infinite chain structure, which adopts a 1D ladder-like structure motif assembled from edge-sharing rhombic squares of Sm₂Mo₂, and that is the first structurally characterized example of a 1D ladder structure based on the [Mo(CN)₈]^4? and Sm³⁺ building blocks. The complex 1 crystallizes in triclinic, space group P-1, with a = 9.905(2), b = 10.333(2), c = 13.562(3) Å, α = 82.00(3)°, β = 86.62(3)°, γ = 65.76(3)°, V = 1253.5(4) Å³ and Z = 2. The magnetic behavior of 1 has also been studied in this paper.     

A Flexible Hexacarboxylate-Samarium(III) Metal–Organic Framework: Synthesis, Structure and Spectroscopic Properties

A new flexible triazine-based polycarboxylate metal–organic framework, [Sm₂(TTHA)(H₂O)₄]·9H₂O (I) (TTHA = 1,3,5-triazine-2,4,6-triamine hexaacetate), has been synthesized under hydrothermal conditions and characterized by single crystal X-ray diffraction, elemental analysis and FT-IR spectroscopy. Crystal data for I are monoclinic C2/c, a = 12.6974(13) Å, b = 16.7309(12) Å, c = 14.8076(15) Å, β = 91.452(8)°, V = 3,144.7(5) Å³. Each Sm^III ion is 9-coordinate in a distorted tri-capped trigonal prismatic geometry; but, the principal inorganic building block is {Sm₂O₁₆}, which comprises two of these polyhedra that share an edge. The complex exhibits a three-dimensional open-framework structure of approximately 31 % void volume, which comprises two types of channels oriented in three directions; [0 0 1], [1 1 0] and [?1 1 0]. The network can be simplified into either the cooperite (pts) or anatase (ant) topologies depending on the choice of nodes. The UV–Vis spectra of the compound are dominated by the absorption of the TTHA ligand. Thermogravimetric analysis shows that the loss of channel and coordinated water upon heating occurs in two distinct steps.     

Metal–Organic Framework Based on Pyridine-2,3-Dicarboxylate and a Flexible Bis-imidazole Ligand: Synthesis, Structure, and Photoluminescence

A novel metal–organic framework {[Zn(2,3-pydc)(bbi)]·0.5CH₃CN·2H₂O} _n (2,3-pydc = pyridine-2,3-dicarboxylate, bbi = 1,1′-(1,4-butanediyl)bis(imidazole)) (1), was prepared under hydrothermal conditions and characterized by elemental analyses, IR and X-ray diffraction. Crystal data for 1 are monoclinic, space group C2/c, a = 19.685(2) Å, b = 14.332(1) Å, c = 16.930(2) Å, β = 121.205(2)°, U = 4085.3(6) Å³, Z = 4. The results reveal that the Zn(II)-atom is five-coordinated with two O-atoms and three N-atoms forming a distorted trigonal bipyramidal geometry. The Zn(II) atoms are bridged by 2,3-pydc and bbi ligands, leading to a three-dimensional network. The Zn···Zn separations are 8.277 Å [through the 2,3-pydc bridge] and 12.638 Å [through the bbi bridge]. Additionally, 1 shows strong fluorescence in the solid state at room temperature.     

Crystal Structures and Luminescent Properties of Two Lanthanide(III) Complexes Featuring Double-Stranded Helical Chains of Based on 2-Sulfoterephthalate

Hydrothermal reaction of Eu³⁺ and Dy³⁺ salts with monosodium 2-sulfoterephthalate (NaH₂stp) gives two 2D lanthanide coordination polymers, [Ln(stp)(H₂O)₂] _n (Ln = Eu (1) and Dy (2)). Single-crystal X-ray diffraction of the complexes reveal that both 1 and 2 crystallize in the triclinic crystal system of Pī space group. For 1, each Eu³⁺ ion lies in a 9-coordinated slightly distorted tri-capped triangle pyramidal configuration. The stp ligands adopt a μ ₄-type link to the metal ions to form a 2D layer-like structure, of which there exist the left- and right-handed double-stranded helical chains. For 2, each Dy³⁺ ion is in a 8-coordinated distorted bi-capped triangle pyramidal geometry. The double-stranded helical chains in 2 differ from those in 1. The thermal stabilities of the two compounds are studied by TGA. The solid state photoluminescence of 1 and 2 are reported. The fluorescent decay curves of the ligand and compounds indicate that 1 has the lifetime of 286.7 μs, τ ₁ = 0.51 ns and τ ₂ = 3.07 ns for the ligand, and for 2, τ ₁ = 0.53 ns and τ ₂ = 2.71 ns.     

Syntheses, Structures and Properties of Two 2D Transition Metal Coordination Polymers Based on Oxalate and Two Types of N-donor Auxiliary Ligands

Two new two-dimensional (2D) metal–organic coordination polymers [Co(ox)(bbbm)]·H₂O (1) and [Cu(ox)(bppdca)]·2H₂O (2) (H₂ox = oxalic acid, bbbm = 1,1-(1,4-butanediyl)bis-1H-benzimidazole and bppdca = N,N′-bis(pyridin-3-yl)-2,6-pyridinedicarboxamide) were synthesized under hydrothermal conditions and structurally characterized. Both 1 and 2 exhibit a 2D four-connected network formed by the Co^II/Cu^II ions as four-connected nodes; and, the ox anions and bbbm/bppdca ligands as linkers with a (4⁴.6²) topology as determined by single crystal X-ray diffraction. In addition, the thermal stability, electrochemical and luminescent properties for 1 and 2 were investigated.     

Simultaneous Growing of Two New Cd(II) Metal–Organic Frameworks with 2,6-Naphthalendicarboxylic Acid as New Precursors for Cadmium(II) Oxide Nanoparticles: Thermal, Topology and Structural Studies

Crystal structure and thermal stability of two new 3D Cd(II) metal–organic frameworks (MOF) containing 2,6-naphthalenedicarboxylate, [Cd(NDC)(DMF)], 1, and [Cd₃(NDC)₄], 2 (H₂NDC = 2,6-naphthalenedicarboxylic acid; DMF = N,N-dimethylformamide) have been studied. These two MOFs grow simultaneously within the same solution to give multiple crystals that are due to the general lability of Cd(II) complexes. Structure 1 shows a 3D neutral metal–organic framework with PtS topology and crystallizes in the triclinic system, space group P-1 (No. 2), whilst 2 crystallizes in the orthorhombic system, space group Fdd2 (No. 43) with body-centered cubic bcu-(4²⁴.6⁴) topology. The elongated nature of NDC results in large cavities in both compounds; however, the pores are filled by coordinated DMF molecules in 1. The thermal stability of 1 and 2 were studied by thermogravimetry and show stability to 400 °C for 1 and continuous weight loss for 2. CdO nanoparticles were prepared by direct calcination of 1 and 2 at 600 °C. The CdO nanoparticles were characterized by X-ray powder diffraction and its morphology were studied by scanning electron microscopy. The results show that the CdO is pure and has a uniform morphology.     

The First Two Examples of (R)-2-Chloromandelato Coordination Polymers: Synthesis,Structure, Magnetic and Ferroelectric Properties

Both (R)-2-Chloromandelato coordination polymers, [Cu(Clma)₂] _n 1 and [Mn(H₂O)(Clma)₂] _n 2, crystallizing in the polar chiral monoclinic space group P2₁ represent the first two examples of metal complexes with (R)-2-Chloromandelic acid (HClma) ligand. Through the (R)-2-Chloromandelate Clma^? ions, the penta- and hexa-coordinated metal atoms in 1 and 2 are linked into chains, _∞ ¹ {[Cu(Clma)](Clma)_2/2} _n and _∞ ¹ {[Mn(H₂O)(Clma)](Clma)_2/2} _n , respectively, and further assembled into 3D supramolecular architectures via hydrogen bonding and close packing interactions. They exhibit ferroelectricity (Pr = 0.03 and 0.01 μC cm^?2, Ec = 5.09 and 0.52 kV cm^?1, Ps = 0.10 and 0.17 μC cm^?2, respectively). The magnetic behaviors of 1 and 2 can be interpreted by means of a 1D chain model, where the magnetic exchanges are transmitted via carboxylate groups between metal atoms, and the best fit results in J = 2.97, ?0.15 cm^?1 for 1 and 2, suggesting ferromagnetic and antiferromagnetic interactions, respectively.     

A Bimetallic Chain Based on [Mo(CN)8]3− and Er3+ Ions as Building Blocks: Synthesis and Magnetic Properties

A novel bimetallic 4d-4f complex, [Er^III(DMF)₄(H₂O)₂][Mo^V(CN)₈]·i-C₃H₇OH·4H₂O (1) (DMF = N,N′-dimethylformamide), has been synthesized and structurally characterized. The crystalline analysis shows that the build up of 1D zigzag-like chains produces complex 1, which is the first structurally characterized example of 1D structure based on the [Mo(CN)₈]^3? and Er³⁺ ions as building blocks. Complex 1 crystallizes in monoclinic system of space group P2₁/n, with a = 12.031(6), b = 16.027(7), c = 20.263(9) Å, β = 105.711(6)º and Z = 4. Magnetic measurements confirm that 1 presents probably a ferromagnetic interaction between the Mo^V and Er^III ions.     

Preparation, Crystal Structure and Magnetic Properties of Two 1,2-Di(4-pyridyl)ethylene-Bridged Manganese(II) Complexes

Two polymeric carboxylato-bridged manganese(II) complexes, $ {}_{\infty }^{1} $ ∞ 1 [Mn(bpe)(NBA)₂] (1) and $ {}_{\infty }^{1} $ ∞ 1 [Mn(bpe)(MBA)₂] (2) (bpe = 1,2-di(4-pyridyl)ethylene; HNBA = m-nitrobenzoic acid; HMBA = m-methyl-benzoic acid), were synthesized and characterized. Compounds 1 and 2 are isostructural. X-ray diffraction studies show that the title compounds possess a double chain structure. The chains in 1 and 2 are assembled into 2-D layers via C–H···O hydrogen bonds interactions. Furthermore, owing to the offset face-to-face π–π stacking interactions, the adjacent 2-D layers embed into each other to form a 3-D supramolecular framework. Variable-temperature (2–300 K) magnetic susceptibility measurements show the presence of weak antiferromagnetic interactions between the high-spin Mn(II) (S = 5/2) ions through a carboxylato bridge with the best fit parameters for 1 being J = ?0.13 cm^?1, zJ′ = ?0.098 cm^?1 and for 2, J = ?0.33 cm^?1, zJ′ = ?0.001 cm^?1.     

A Series of Luminescent Lanthanide–Organic Complexes Constructed from In Situ Generated Dithiobenzoic Acid

Two types of lanthanide thiolato-carboxylate complexes, [Type I: [Yb(dtba) (Hdtba)] _n (1), Type II: [Ln(dtba)_1.5(biim)] _n (Ln = Pr (2a), Nd (2b), Sm (2c), Eu (2d), Gd (2e), Tb (2f), Dy (2g), H₂dtba = 2,2′-dithiodibenzoic acid, bimm = diimidazole)] have been obtained by hydrothermal method and characterized by the single-crystal X-ray diffraction, IR, 2D-COS IR, TG and the luminescence analysis. The H₂dtba ligand came from the in situ S–S function reaction of 2-mercaptobenzoic acid (H₂mba) under the hydrothermal condition. Complex 1 is a 2D bamboo-like sqr-topology layered structure, and the 3D (4, 4, 6)-connected supramolecular frameworks is produced by the hydrogen bonds of O–H···O. Complexes of type II (from 2a to 2g) are isostructural and they are assigned to 1D rope-like chains by introducing the chelating ligand of diimidazole. These 1D rope-like chains are further linked by N–H···O hydrogen bonds into a 3D supramolecular framework with CdSO₄-type topology. Photoluminescence studies reveal that complexes 2b, 2c, 2d, 2f, 2g exhibit strong lanthanide characteristic emission bands in the solid state at room temperature.     

Two New Luminescent Cadmium Thiolato-carboxylates with 2,2′-Bipyridine

Two new cadmium thiolato-carboxylate complexes, [Cd₂(mba)₂(2,2′-bpy)₂] (1), [Cd₂(dtba)₂(2,2′-bpy)₄]·4H₂O (2) (H₂mba = 2-mercaptobenzoic acid, H₂dtba = 2,2′-dithiodibenzoic acid, 2,2′-bpy = 2,2′-bipyridine) were obtained by reacting Cd(II) salts and the ligands of H₂mba and 2,2′-bpy, and were characterized by the single-crystal X-ray diffraction, IR, 2D-COS IR, solid UV, TG and XRD. In complex 2, the H₂dtba ligand came from the in situ S–S function reaction of H₂mba under the hydrothermal conditions. Complexes 1 and 2 are both 1D chains, but the difference lies in the linkage of the ligands. The 3D super-molecular frameworks of 1 and 2 are produced by π–π stacking interaction between the 2,2′-bpy ligands and the hydrogen bonds of O–H…O with ths-type and dia-type topology, respectively. The fluorescent emissions are observed in 1 and 2 with λ _em = 533 nm and λ _em = 436 nm, due to the ligand-to-metal charge transfer (LMCT) and π* → π transitions, respectively.     

Three New Coordination Polymers Constructed from Mixed Ligands: Syntheses,Luminescence and Magnetism

Three new coordination polymers, namely, {[Cd(H₂bptc)(IP)(H₂O)]·2H₂O} _n (1), {[Mn₂(IP)₂(dstc)]·6H₂O} _n (2) and {[Zn₂(IP)₂(dstc)]·3H₂O} _n (3) (IP = 1H-imidazo[4,5-f][1,10]-phenanthroline, H₄bptc = 3,3′,4,4′-benzophenonetetracarboxylic acid, and H₄dstc = 3,3′,4,4′-diphenylsulfonetetracarboxylic acid) have rationally designed and characterized by single crystal X-ray diffraction. Polymer 1 shows a 1D ribbon-like structure. Although compounds 2 and 3 feature 2D grid networks, the coordinative modes of dstc ligand and the arrangements of IP ligand are very different. Furthermore, the luminescence properties for 1 and 3, as well as the magnetism of 2 are explored in detail.     

Syntheses,Crystal Structures and Physical Properties of Four Zinc/Cadmium Coordination Polymers Based on 4-Nitrophthalic Acid and N-donor Auxiliary Ligands

Four new d¹⁰ metal coordination polymers, [Zn(4-NPA)(2,2-bipy)] _n (1), [Zn(4-NPA)(1,3-bimb)·H₂O] _n (2), [Cd(4-NPA)(2,2-bipy)] _n (3) and [Cd(4-NPA)(1,3-bimb)·H₂O] _n (4) (4-NPAH₂ = 4-nitrophthalic acid, 2,2-bipy = 2,2-bipyridine, 1,3-bimb = 1,3-bis(imidazol-1-ylmethyl)-benzene), have been hydrothermally synthesized and characterized by elemental analyses, IR spectra, and X-ray single crystal diffractions. Compounds 1?3 possess different one-dimensional (1D) chain structures. Compound 4 shows a two-dimensional (2D) layered structure. Moreover, the luminescent and thermal stabilities properties of compounds 1–4 were investigated in the solid state.     

Ancillary Ligand-Mediated Syntheses,Structures and Fluorescence of Three Zn/Cd(II) Coordination Polymers Based on Nitrobenzene Dicarboxylate

The Zn/Cd(II)-nbdc carboxylate motifs mediated by various dipyridyl-typed ligands afforded three new coordination compounds, namely, [Zn(nbdc)(bpa)_0.5(H₂O)]·H₂O (1), [Zn₂(nbdc)₂(bpp)₂]·H₂O (2), and [Cd(nbdc)(bpe)_0.5(H₂O)₂] (3) (H₂nbdc = 4-nitrobenzene-1,2-dicarboxylic acid, bpa = 1,2-bi(4-pyridyl)ethane, bpe = 1,2-di(4-pyridyl)ethylene, and bpp = 1,3-bis(4-pyridyl)propane), which were synthesized by hydrothermal reaction and characterized by elemental analysis, IR, thermal analysis (TGA), and fluorescent analysis. The single-crystal X-ray diffractions reveal that three complexes display a diverse range of connectivity topology from 1D to 3D, which is dependent on the type of dipyridyl-typed ligands and metal centers. Complex 1 is the 1D chain featuring Zn-carboxylate binuclears extended further by bpa coligands. Complex 2 is the 2D thick-layer containing double-stranded chains cross-linked further by bpp coligands. Complex 3 is the 3D framework with (6³)(6⁵.8) ins topology featuring Cd-carboxylate chiral layers pillared by bpe coligands. The thermal stabilities and fluorescence properties for complexes 1–3 are investigated.     

Synthesis, Crystal Structures and Properties of Two Metal–Organic Frameworks Constructed from Pyridine Dicarboxylate and Flexible Bis(imidazole) Ligand

Two novel interesting metal–organic frameworks, [Zn(PDA)(bbi)] _n (1) and [Cd₂(PDA)₂(bbi)₂(H₂O)₂·10H₂O] _n (2) [H₂PDA = pyridine-2,6-dicarboxylic acid, bbi = 1,1′-(1,4-butanediyl)bis(imidazole)] have been isolated under hydrothermal conditions and structurally characterized. X-ray single crystal structure analysis reveals that complex 1 crystallize in monoclinic P2₁/c space group, while complex 2 crystallize in triclinic P-1 space group. The PDA^2? anions act in two different coordination modes: terminal chelating for 1 and chelating and bis-monoatomic bridging for 2. Polymeric chains of 1 and 2 are composed of Zn(II) and Cd(II) ions bridged by bbi ligands. The fluorescent properties of 1 and 2 were also investigated.     

1D Hydrogen-Bonded Polymers Assembled by Tetraaza Macrocyclic Metal(II) Complexes and Inorganic Salts

The self-assembly of [M(L)]Cl₂·2H₂O (M = Ni²⁺ and Cu²⁺, L = 3,14-dimethyl-2,6,13,17-tetraazatricyclo[14,4,0^1.18,0^7.12]docosane) with sodium 1,2,4-benzenetricarboxylate (Na₃btcb) and KNO₃ generates the 1D hydrogen-bonded polymers with formulas [Ni(L)(H₂btcb^?)₂] (1) and [Cu(L)(NO₃)₂] (2). These polymer complexes have been characterized by X-ray crystallography, spectroscopy and cyclic voltammetry. The crystal structure of 1 shows a distorted octahedral coordination geometry around the nickel(II) ion, with the four secondary amines of the macrocycle and two carboxylate oxygen atoms of the H₂btcb^? ligand in the trans position. In 2, the coordination environment around the central copper(II) ion reveals an axially elongated octahedron with four Cu–N bonds and two oxygen atoms of the nitrate ligand in the trans position. The cyclic voltammograms of the complexes undergo two one-electron waves corresponding to M^II/M^III and M^II/M^I processes. The electronic spectra and electrochemical behavior of the complexes are significantly affected by the nature of the axial ligands.     

Synthesis and Structural Characterization of Triorganotin(IV) Derivatives with 2,2′-Thiodiglycolic Acid and 3,3′-Thiodipropionic Acid

The synthesis and structural characterization of four novel triorganotin(IV) complexes, {(R₃Sn)₂[C₂H₄S(COO)₂]} _n (R = Me: 1), {(R₃Sn)₄[C₂H₄S(COO)₂]₂} _n (R = nBu: 2), {(R₃Sn)₂[C₄H₈S(COO)₂]} _n (R = Me: 3; nBu: 4) were obtained by the reaction of 2,2′-thiodiglycolic acid, 3,3′-thiodipropionic acid and the corresponding R₃SnCl (R = Me, nBu) with potassium hydroxide in methanol. All the complexes were characterized by elemental analysis, Fourier transform infrared and nuclear magnetic resonance (¹H, ¹³C, ¹¹⁹Sn) spectroscopies, X-ray crystallography and thermogravimetric analyses. The crystal structures show that 1 has 2D network structure in which 2,2′-thiodiglycolic acid acts as a tetradentate ligand coordinating to the trimethyltin(IV) ions. Complexes 2, 3, and 4 are 3D metal-organic framework structures in which the deprotoned acids act as a tetradentate ligand afforded by four oxygen atoms.     

Direct Synthesis and Crystal Structure of Dehydrated State in Vapochromic MMX-type Quasi-One-Dimensional Iodide-Bridged Platinum Complexes

The dehydrated vapochromic 1D coordination polymer, (H₃NC₄H₈NH₃)₂[Pt₂(pop)₄I] (1) was synthesized directly from methanol solution. Although vapochromic 1 · 4H ₂ O has been synthesized, dehydrated high-temperature structure has never been determined because of lowering the quality of crystal by dehydration. The crystal structure of 1 was determined by X-ray crystal structure analysis, and we confirmed that it was identical to the dehydrated high-temperature structure of 1 · 4H ₂ O by comparing the powder X-ray diffraction (XRD) patterns. The Pt–I–Pt distance (d(Pt–I–Pt)) of compound 1 · 4H ₂ O was shortened for approximately 1.1 Å by desorption of water to form compound 1, accompanied with phase transition in electronic states. The other crystal including methanol molecule as lattice solvent, 1 · 2MeOH, was also obtained as by-product. The synthesis from various kinds of organic solvent has the great potential to develop the field of vapochromism accompanying phase transition of electronic state.     

A Facile Access to New Polymethylmethacrylate-Anchored Ferrocene Substituted Nickel(II) Unsymmetrical Schiff Base Complexes: Synthesis and Characterization

This paper discloses two new side-chain metallopolymers containing an unsymmetrical organometallic Schiff base complex of Ni(II) linked to a polymethylmethacrylate (PMMA) matrix. The neutral ferrocene substituted Schiff base complex 1, Ni{CpFe(η⁵-C₅H₄)-C(O)CH=C(CH₃)N–o-C₆H₄N=CH-(2-O,5-OH-C₆H₃)} where (Cp = η⁵-C₅H₅), was synthesized via template reaction by condensation of the tridentate half-unit metalloligand Fc-C(O)CH=C(CH₃)-N(H)-o-C₆H₄NH₂ (Fc = ferrocenyl = CpFe(η⁵-C₅H₄)) with 2,5-dihydroxybenzaldehyde in the presence of nickel(II) acetate tetrahydrate. The binuclear Schiff base complex of Ni(II) containing an aromatic free hydroxyl group was reacted under basic conditions with PMMA to afford, upon trans-esterification reaction, metallopolymers 2 (complex 1 monomeric unit/PMMA = 1/5) and 3 (complex 1 monomeric unit/PMMA = 1/3). Elemental analysis, FT-IR, ¹H and ¹³C NMR spectroscopies, and cyclic voltammetry were utilized to characterize the newly synthetized compounds. Surface morphology of the metallopolymer film of 2 was studied using atomic force microscopy.