Syntheses,crystal structures,and properties of three two-dimensional complexes constructed by flexible (2,3-pyridylmethyl)amine

Three two-dimensional coordination polymers [Cd(2,3-Pyma)Cl₂] _n (I), {[Cd(2,3-Pyma)(1,4-Chdc)] · 4H₂O}n (II) and {[Zn₂(2,3-Pyma)(1,2,4,5-Bttc)(H₂O)₄] · 6H₂O} _n (III) (2,3-Pyma = (2,3-pyridylmethyl) amine, H₂-1,4-Chdc = 1,4-cyclohexanedicarboxylic acid, and H₄-1,2,4,5-Bttc = 1,2,4,5-benzenetetracarboxylic acid) have been synthesized and structurally characterized by single crystal X-ray crystallography (CIF files CCDC nos. 989461 (I), 1055685 (II) and 1055686 (III)). Three complexes are all twodimensional layer networks bridged by the flexible 2,3-Pyma ligands or the carboxylate ligands. It is noted that the flexible 1,4-Chdc ligands bind the Cd²⁺ ions into a helical chain structure in complex II. The photoluminescence and thermal properties are investigated.     

Structure and photoluminescence of Zn(II) and Сd(II) complexes with chiral bis-pyridine containing fragments of natural (–)-α-pinene

Complexes ZnLCl₂ (I) and [CdLCl₂] _n (IV), where L is chiral bis-pyridine containing fragments of natural monoterpenoide (–)-α-pinene are synthesized. Single crystals of [ZnLCl₂]·CH₂Cl₂ (II), [ZnLCl₂]·i-PrOH (III), and IV compounds are grown. The crystal structures of II and III are composed of mononuclear ZnLCl₂ complex molecules and solvate CH₂Cl₂ and i-PrOH molecules; the coordination polyhedron of the zinc atom Cl₂N₂ is a distorted tetrahedron. According to the single crystal XRD data, complex IV is a 1D coordination polymer; the coordination core CdN₂Cl₄ is a distorted octahedron and Cl atoms are bridging ligands. In the structures of II, III, and IV the L molecule functions as a bidentate chelate ligand. In the solid phase, complexes I and IV exhibit photoluminescence in the visible range (λ_max 505 nm and 460 nm respectively). The band intensity in the photoluminescence spectra of I and IV complexes considerably exceeds the band intensity in the spectrum of free L.     

Synthesis and structure of mononuclear zinc complexes with pyridine-2-aldoxime

Three mononuclear different-ligand Zn(II) complexes, [Zn(CH₃COO)₂(PaoH)₂] (I), [Zn(PaoH)₂(DMSO)₂][BF₄]₂ (II), and [Zn(NCS)₂(PaoH)₂] (III) (DMSO = dimethylsulfoxide) were prepared by the reaction of zinc acetate and tetrafluoroborate with pyridine-2-aldoxime (PaoH). The composition and structure of the complexes were confirmed by IR spectroscopy and X-ray diffraction. All compounds crystallize in the monoclinic system, compounds I and II have space group P2₁/n, while compound III has space group C2/c. In all compounds, the Zn coordination polyhedron is a distorted octahedron, which is formed by the N₄O₂ sets of donor atoms in I and II and by N₆ in III. Complex I in the optimal concentration of 5–10 mg/L was found to stimulate the biosynthesis of standard (pH 4.7) amylases by the micromycete Aspergillus niger CNMN FD 06.     

Copper(II) and cobalt(II) complexes with a chiral 5-pyrazolone derivative obtained from the terpene (+)-3-carene: Synthesis and properties

The complexes [CuLCl₂] (I), [CoLCl₂] (II), and CuLBr₂ (III) (where L is the derivative of optically active 5-pyrazolone prepared from the terpene (+)-3-carene) were obtained and characterized. According to X-ray diffraction data, crystal structures I and II (orthorhombic crystal system) are built from mononuclear acentric molecules. In the resulting complexes, the Cu²⁺ or Co²⁺ ion coordinates two N atoms of the chelating bidentate ligand L and two Cl atoms, thus making a distorted tetrahedron. Intermolecular contacts and the hydrogen bonds Cl(1)…H-O(1) give rise to columns parallel to axis y. For complexes I and III, μ_eff = 1.83 and 1.81 μB, respectively; these values correspond to the electronic configuration d ⁹ . For complex II, μ_eff = 4.42 μB, which suggests the tetrahedral structure of the coordination entity CoCl₂N₂. Complexes I and III were studied by EPR spectroscopy.     

Three metal complexes based on tetrazolyl ligands: Hydrothermal syntheses,crystal structures,and fluorescence properties

Three new complexes based on 1-tetrazole-4-imidazole-benzene (Tibz), namely, [Cd(Tibz)₂(H₂O)₂] _n (I), [Mn(Tibz)₂(H₂O)₄] · 2H₂O (II) and [Co(Tibz)₂(H₂O)₄] · 2H₂O (III) have been synthesized through hydrothermal method and structurally characterized by element analyses, IR spectroscopy and single-crystal X-ray diffraction analyses (CIF files CCDC nos. 1443867 (I), 1443868 (II), 1443869 (III)). Single-crystal X-ray diffraction reveals that complex I is a 1D double-chain architecture, II and III are both mononuclear complexes. The results of single-crystal X-ray diffraction analyses indicate that the hydrogen bond and π··· π stacking exist in the complexes, which make great contribution to the stabilities of complexes I–III. The fluorescent properties of these complexes have also been studied in the solid state at room temperature.     

Syntheses and luminescence of three lanthanide complexes constructed by flexible carboxylate ligand

Three new complexes, namely {[Ln(L)₃(2,2′-Bipy)] _n · H₂O} (Ln = Pr (I), Sm (II), and Nd (III)) (HL = 3-(2-hydroxyphenyl)propanoic acid), have been synthesized and structurally characterized. The structural determinations indicated (CIF files CCDC nos. 1472729 (I), 1472730 (II), 1472734 (III)) that I–III have similar dinuclear structures, which can be further linked into 2D sheet via the hydrogen bond interactions. Furthermore, the luminescent properties of I–III show the strong emissive power and feature.     

Hydrothermal Synthesis,Crystal Structures,and Fluorescence Properties of Ni(II)–Ln(III) Complexes (Ln = Sm,Pr, Eu)

Three novel 3d–4f heterometal complexes [Ln(NiL)₃(Btca)(NO₃)] · xH₂O (Ln = Sm(III) (I), Pr(III) (II), Eu(III) (III) (H₂L = 2,3-dioxo-5,6,14,15-dibenzo-1,4,8,12-tetraazacyclo-pentadeca-7,13-dien, H₂Btca = benzotriazole-5-carboxylic acid) were solvothermally synthesized and characterized by singlecrystal X-ray diffraction (CIF files CCDC nos. 1555557 (I), 1555555 (II), 1555556 (III)). They crystallized in the monoclinic space group P2₁/n for I (x = 1.5) and C2/c for (II) and (III) (x = 1), respectively. In these complexes, the central Ln(III) and external nickel ions are bridged by macrocyclic oxamide groups. The metal center of Ln(III) resides in a distorted bicapped square antiprism surrounding with six oxygen atoms of three oxamide groups, two oxygen atoms of Btca^2– ion and two oxygen atoms of NO₃^-. Furthermore, there are C–H···O and/or C–H···N hydrogen bond interactions among nitrate, benzotriazole-5-carboxylate, macrocyclic oxamide and water to form three-dimensional superamolecular architecture. The fluorescence properties of the compounds I and II are also discussed.     

Two novel 2D cadmium compounds with noncentrosymmetric or symmetric network dependent on different pH values

Hydrothermal reaction of cadmium chloride and 2-carboxyethyl(phenyl)phosphinic acid (H₂L) under pH 2.69 or 5.00 afforded two novel Cd(II) compounds with the formula of [Cd(HL)₂] _n (I) and [Cd₃(L)₂(OH)₂] _n (II), respectively. Both compounds were well characterized by elemental analysis, IR spectroscopy, power X-ray diffraction, fluorescence and single-crystal X-ray diffraction (CIF files CCDC nos. 1049809 (I), 1049810 (II)). Compound I crystallizes in a Pca2₁ space group and presents a two-dimensional (2D) layered noncentrosymmetric structure, in which slight difference of the two Cd–O(phosphinico) distances leads to the formation of the chiral phosphorus atom in HL^– ligand. Compound II adopts a centrosymmetric P2 ₁/c space group and exhibits a 2D network. Both compounds show violet fluorescence, assigned as an intraligand emission.     

μ<Subscript>2</Subscript>-Oxobis[(aroxo)tris(<Emphasis Type="Italic">para</Emphasis>-tolyl)antimony]: Synthesis and Structure

µ₂-Oxobis[(2,4,6-tribromophenoxo)tris(para-tolyl)antimony] (I), µ₂-oxobis[(2,3,4,5,6-pentachlorophenoxo) tris(para-tolyl)antimony] (II), and µ₂-oxobis(2,4-dinitrophenoxo)tris(para-tolyl)antimony] (III) have been synthesized with high yields by the reaction of tris(para-tolyl)antimony with 2,4,6-tribromo-, 2,3,4,5,6-pentachloro-, and 2,4-dinitrophenol, respectively, in ether in the presence of tert-butylhydroperoxide. The Sb atoms in complexes I, II, and III have a distorted trigonal bipyramidal coordination with the aroxyl ligands and the bridging oxygen atom in axial positions. The central Sb–O–Sb moiety in molecules of complexes I–III has an angular structure.     

Bis(citrato)germanates of bivalent 3<Emphasis Type="Italic">d</Emphasis> metals (Fe,Co, Ni,Cu, Zn): Crystal and molecular structure of [Fe(H<Subscript>2</Subscript>O)<Subscript>6</Subscript>][Ge(HCit)<Subscript>2</Subscript>] · 4H<Subscript>2</Subscript>O

In continuation of a systematic study of bis(citrate)germanates, we synthesized a number of heterometallic germanium(IV) and 3d metal complexes based in citric acid (H₄Cit) with the molecular formula [M(H₂O)₆][Ge(HCit)₂] · nH₂O, where M = Fe, n = 4 (I); Co, n = 2 (II); Ni, n = 2 (III); Cu, n = 1 (IV); Zn, n = 3 (V). The complexes were characterized by elemental analysis, X-ray diffraction, thermogravimetry, and IR spectroscopy. The X-ray diffraction analysis of compound I was performed. Crystals are monoclinic, a = 10.091(4) Å, b = 11.126(4) Å, c = 10.996(4) Å, β = 100.966(6)°, V = 1212.1(8) ų, Z = 4, space group P2₁/n, R1 = 0.0561 for 2266 reflections with I > 2σ(I). Compound I is composed of centrosymmetric octahedral complexes-[Ge(HCit)₂]^2? anions and [Fe(H₂O)₆]²⁺ cations—and crystallization water molecules. Structural units in compound I are combined by a hydrogen bond system.     

Anion-assisted two group IIB metallic coordination architecture and luminescence performance

React of cadmium salts with 4,4'-bis((2-(pyridin-2-yl)-1H-benzo[d]imidazol-1-yl)methyl)biphenyl (Bpbib) yields two one-dimensional (1D) coordination architectures of two new complexes—{[Cd₂(Bpbib)₂(NO₃)₄] ? CH₃OH} _n (I) and {[Cd(Bpbib)Cl₂] ? 2CH₃OH} _n (II). Complexes I and II were characterized by the elemental analyses, photoluminescence and emission spectra and single-crystal X-ray diffraction (CIF files CCDC nos. 1046021 (I), 1046022 (II)). Complex I is a helical array, whereas II features a zigzag pattern, depending upon the type of their associated anions. In addition to the primary organic linker, the counter anions also have a dominant influence on the overall structures, and even arouse the luminescence performance diversity.     

Crystal structure,fluorescence spectroscopy,and electrochemical property of two neodymium coordination polymers with phenoxy acids

Two nine-coordination coordination polymers of neodymium, [Nd₂(p-C₈H₄O₄)(o-C₈H₄O₄)₂ ? 4H₂O] _n (I), [Nd₂(C₁₀H₄O₈)(C₁₀H₂O₈) ? 2H₂O] _n (II), have been prepared by hydrothermal reaction of Nd(NO₃)₃ ? 6H₂O with terephthalic acid and phthalic acid, or benzenetetracarboxylic anhydride and determined by means of IR, UV, fluorescence, TG-DTA, cyclic voltammetry (CV) and X-ray single-crystal diffraction methods (CIF files CCDC nos. 1006206 (I), 979309 (II)). Yellow-green luminescence could been observed at 391 nm (λ_ex = 305 nm) for complex I and 370 nm (λ_ex = 331 nm) for the complex II. The emission of complexes I and II may be due to the π* → n transition, which may be assigned to the ligand-to-metal charge-transfer bands. Compared with complex II, the complex I exhibits a stronger fluorescence intensity for the different coordinated environment. Cyclic voltammetric measurement of the two compounds reveal that the compounds both have a couple of irreversible redox peak, indicating that the two polymers were both corresponded to the unusual Nd(III)/Nd(V).     

Synthesis and physicochemical properties of the <Emphasis Type="Italic">d</Emphasis> metal complexes with 2-phenyl-4-(piperidyl-1)-pyrido[2,3-a]anthraquinone. The molecular and crystal structures of 2-phenyl-4-(piperidyl-1)-pyrido[2,3-a]anthraquinonium-7,12 tetranitrozincate

Two types of complexes of 2-phenyl-4-(piperidyl-1)-pyrido[2,3-a]anthraquinone (L) with transition metals were isolated from neutral acetonitrile and acidified acetonitrile and ethanol solutions and characterized. Metal complexes synthesized at pH = 7 had the composition MCl₂L · (CH₃CN) _n (M = Cu, Co, Ni). The complexes (HL)₂[Cu₂Cl₆] (I), (HL)₂[CoCl₄] (II), (HL)₂[Zn(NO₃)₄] (III) were obtained at pH = 1–2. The molecular and crystal structure of complex III was determined. Some spectral parameters of L and its complexes were measured.     

Hybrid nanocomposites: Poly(chloromethyl-), poly(methyl-), poly(phenylsilsesquioxane)-nitrogen polybase

Formation of nanocomposites in the sol-gel systems RSiX₃ [R = CH₃ (I), C₆H₅ (II), X = Cl; R = ClCH₂ (III), X = OC₂H₅]-polyvinylazole [(-CH₂-C(Y)H-) _n , Y = pyrazolyl, imidazolyl, 4-pyridinyl, 2-methyl-5-pyridinyl], and also I-1-vinyl-4,5,6,7,-tetrahydroindole using was studied. The composition and structure of the resulting nanocomposites were analyzed.     

Copper(II) coordination compounds with 8-quinolinaldehyde semicarbazone: Synthesis and structure

A series of compounds of the general formula Cu(HL)X₂ · nH₂O (compound I, X = ClO₄, n = 3; compound II, X = NO₃, n = 2; compound III, X = Cl, n = 0.5; compound IV, X = 1/2SO₄, n = 0) is isolated by the reactions of the copper(II) salts with quinolinaldehyde semicarbazone (HL). Regardless of the reactant ratio, only the compounds with a metal to ligand mole ratio of 1: 1 are formed, where the organic reactant is coordinated in the molecular form. The X-ray diffraction analyses of the [Cu(HL)(NO₃)(H₂O)](NO₃) · H₂O (II) and [Cu(HL)Cl₂] · 0.5H₂O(III) compounds show their substantially different organizations of the molecular structures depending on the specifics of the acido ligand. An ionic structure with one NO ₃ ^? anion incorporated into the inner coordination sphere of the metal as a bidentate chelate ligand is observed in compound II. Molecular tetragonal pyramidal complexes associated into a dimer due to the bridging function of one coordinated Cl^? anion are formed in structure III. The coordination polyhedron of the copper atom in structures II and III is an asymmetrically extended tetragonal bipyramid. The CuClCu angle equal to 90° and the distance between two planes in compound III equal to 2.978 Å determine the insignificant antiferromagnetic interaction in this compound (g = 2.1, J = ?2.5 cm^?1).     

Four novel metal–organic frameworks based on 3,4,7,8-tetramethyl-1,10-phenanthroline: Syntheses,structures, and thermal properties

Four novel metal–organic frameworks, [Cu(Tmp)₂(H₂O)] · NO₃ (I) (Tmp = 3,4,7,8-tetramethyl-1,10-phenanthroline), [Mn(Tmp)₂(H₂O)₂] · 2NO₃ · H₂O (II), [Pb(Tmp)(CH₃COO)₂] · 3H₂O (III) and [Zn(Tmp)₂(H₂O)₂] · 2NO₃ · 2H₂O (IV), have been synthesized and characterized by single crystal X-ray diffraction (CIF files CCDC nos. 88362–88365 for I–IV, respectively), IR spectroscopy, elemental analysis and thermogravimetric analysis. Both I and II complexes are crystallized in monoclinic system with space groups C2/c, P2₁/c, respectively, while III and IV complexes are crystallized in triclinic system with space groups \(P\overline 1 \). Generally, these crystal structures are stabilized by O–H···O hydrogen bonds and π–π interactions between the phenanthroline rings of neighboring molecules. Thermogravimetric analyses of compounds I–IV display considerable thermal stability.     

Effect of solvent on the crystal structures of copper(II) complexes based on 4′-(4-methoxyphenyl)-2,2′:6′,2″-terpyridine and 4′-(3-chlorophenyl)-2,2′:6′,2″-terpyridine

Four homoleptic copper(II) complexes, [Cu(Meophtpy)₂](ClO₄)₂ (Meophtpy = 4′-(4-methoxylphenyl)- 2,2′:6′,2″-terpyridine) (I), [Cu(Meophtpy)₂](ClO₄)₂ · 2H₂O (II), [Cu₂(m-Clphtpy)₄](ClO₄)₄ (m-ClPhtpy = 4′-(3-chlorophenyl)-2,2′:6′,2″-terpyridine) (III), and [Cu₂(m-ClPhtpy)₄](ClO₄)₄ (IV) have been synthesized by hydrothermal methods and characterized by IR, elemental analysis and single crystal X-ray diffraction (CIF files CCDC nos. 963375 (I), 885457 (II), 963377 (III), and 963376 (IV)). Complex II is a polymorph of I and complex IV is a polymorph of III. All these complexes are obtained with 95% ethanol solution or 50% ethanol solution and the solvent control on the crystallization are obviously found. In all complexes, the face-to-face interactions between pyridyl rings or phenyl rings facilitate the construction of 3D network in the crystal in addition to hydrogen bonds. The fluorescence properties of these complexes have been investigated.     

Synthesis,structures, and magnetic properties of two closely-related manganese(II) coordination polymers

The reactions of Mn²⁺ ion with 4-nitrobenzene-1,2-bicarboxylic acid in the presence of bipyridyl-type coligands gave two new manganese(II) coordination polymers, [Mn₂(Nbdc)₂(Bipyp)(H₂O)₄] _n (I) and [Mn₂(Nbdc)₂(Bipye)(H₂O)₄] _n (II) (H₂Nbdc = 4-nitrobenzene-1,2-bicarboxylic acid, Bipyp = 1,3-bi(4-pyridyl)propane, and Bipye = 1,2-bi(4-pyridyl)ethane). Both two complexes contain uniform carboxyl-bridged manganese chains with the composition of [Mn₂(Nbdc)₂(H₂O)₄] _n , which are interlinked by interchain Bipyp/Bipye spacers to afford two closely-related layers (CIF files CCDC nos. 1008182 (I) and 1008183 (II)). Magnetic studies for two compounds show the presence of similar antiferromagnetic couplings between the adjacent Mn²⁺ ions through the carboxyl bridges, the best fittings to the experimental magnetic susceptibilities gave J =–0.20 cm^–1 and g = 1.96 for I, and J =–0.24 cm^–1 and g = 1.98 for II. Similar magnetic parameters and thermal behaviors further verify that two compounds possess closely-related structures.     

Syntheses,crystal structures,and properties of various one- dimensional coordination polymers based on macrocyclic metallic tectons and dicarboxylic acid ligand

The reaction of different macrocyclic metallic tectons and dicarboxylic acid ligand yielded six new coordination polymers, namely, {[(NiL¹)(4,4'-Bpdc)] ? DMF ? 2.5H₂O} _n (I), {[(NiL²)(4,4'-Bpdc)] ? DMF ? 2.5H₂O} _n (II), [(NiL³)₂(4,4'-Bpdc)_1.5][(NiL³)(4,4'-Bpdc)] ? ClO₄ ? 28H₂O (III), {[(NiL⁴)(4,4'-Bpdc)] ? 4H₂O} _n (IV), {[(NiL⁵)(4,4'-Tpdc)] ? 5H₂O} _n (V), {[(NiL³)(4,4'-Tpdc)]} _n (VI) (L¹ = 1,4,7,9,12,14-hexaaza-tricyclo[12.2.1.1^4.7]octadecane, L² = 1,3,10,12,15,18-hexaazatetracyclo[16.2.1.1^12.15.0^4.9]docosane, L³ = 11-methyl-1,4,8,10,13,15-hexaaza-tricyclo[13.3.1.1^4.8]icosane, L⁴ = 1,3,10,12,16,19-hexaazate-tracyclo[17.3.1.1.^12.16,0^4.9]tetracosane, L⁵ = 1,4,8,10,13,15-hexaaza-tricyclo[13.3.1.1^4.8]icosane, 4,4'-Bpdc = 4,4'-biphenyldicarboxylic acid and 4,4'-Tpdc = 4,4'-terphenyldicarboxylic acid) (CIF files CCDC nos. 1055545–1055550 for I–VI, respectively). Except for the different conformations of the macrocyclic metallic tectons or dicarboxylic acid ligands, complexes I–VI crystallized under the same environment, however, they exhibit diverse packing mode of infinite 1D coordination polymers, showing macrocyle or dicarboxylic acid ligand regulated self-assemble. The solid states UV-Vis for complexes I–VI also have been investigated.     

Syntheses and crystal structures of hydrated complexes of strontium and barium bromides with 18-crown-6

Two complexes, namely, triaqua(18-crown-6)strontium dibromide monohydrate (I) and diaquabromo(18-crown-6)barium bromide (II), are synthesized. Their crystal structures are determined by X-ray diffraction analyses. For complex I, space group C2/c, a = 17.547 Å, b = 10.246 Å, c = 14.786 Å, β = 123.08°, Z = 4. For complex II, space group Pnma, a = 17.753 Å, b = 17.465 Å, c = 6.629 Å, Z = 4. The structures are solved by a direct method and refined by the full-matrix least-squares method in the anisotropic approximation to R = 0.056 (I) and 0.042 (II) for 2696 (I) and 2440 (II) independent reflections (CAD-4 automated diffractometer, λMoK _α radiation). Both complex cations—randomly disordered [Sr(18C6)(H₂O)₃]²⁺ in complex I and [BaBr(18C6)(H₂O)₂]⁺ in complex II—are of the host-guest type. The Sr²⁺ (Ba²⁺) cation resides in the cavity of the 18-crown-6 ligand and coordinated by all six O atoms. In the structures complexes I and II, the coordination polyhedra of the Sr²⁺ and Ba²⁺ cations (coordination number 9) can be described as distorted hexagonal bipyramids with one apex at the O atom of the water molecule in complex I or at the Br^? ligand in complex II and the other split apex at the O atoms of two water molecules.