Hetero‐metallic Lanthanide CPs Involving Sodium: Synthesis,Crystal Structure,and Luminescence Properties

[TbNa(4‐msal)₄(phen)₂]_n ( 1 ) (4‐msal = 4‐methyl salicylic acid), a new hetero‐metallic lanthanide coordination polymer (CP) involving sodium was synthesized. It crystallizes in the monoclinic space group P2₁/n, with a = 20.4809(9) Å, b = 9.8183(2) Å, c = 26.1987(11) Å, α = 90.00°, β = 112.922(5)°, γ = 90.00°, V = 4852.2(3) ų, and Z = 4. The complex was characterized by single crystal and powder X‐ray diffraction, elemental analysis (EA), and Fourier transform infrared (FT‐IR) and luminescence spectroscopy. The luminescence properties of a powder sample of 1 were studied at room temperature and the luminescence lifetime and total quantum yield (QY) were determined.     

Hydrothermal synthesis, crystal structural, and thermal properties of a 1D zinc coordination polymer based on benzoate and flexible bis(benzimidazole) ligands

A new coordination polymer, [Zn(PhCOO)₂(Bbbm)] _n (I), where Bbbm = 1,1′-(1,4-butanediyl)bis-1H-benzimidazole, has been synthesized under hydrothermal conditions and characterized by elemental analysis, IR, TG and X-ray single-crystal diffraction. The complex crystallizes in the monoclinic system with space group P2₁/n, the unit cell parameters: a = 10.815(3), b = 20.516(6), c = 12.802(4) Å, β = 102.025(3)°, V = 2778.2(14) ų, Z = 4. In this structure, the Zn²⁺ ion is in a distorted tetrahedral geometry, one-dimensional linear chain is constructed by Bbbm ligand with bis(monodentate) coordination mode.     

A Novel Two‐dimensional Coordination Polymer based on Rhombic Tetrameric Subunit Zn4O4 as Building Block

Hydrothermal reaction of olsalazine sodium, phenanthroline and Zn(ClO₄)₂·6H₂O in the presence of water and ethanol affords a two‐dimensional coordination polymer [Zn₄(OSA)₃(Phen)₂(H₂O)₂]_n ( 1 ) (OSA = olsalazine) which is characterized by single X‐ray determination, IR and UV spectrum. The local coordination around all zinc ions can be best described as a slightly distorted triangle bipyramid. Complex 1 consists of a tetrameric subunit, which is made up of four Zn atoms bridged by four O atoms. Two types of osalazine ligands can be found in the complex according to their different coordination modes of carboxyl groups. Crystal data for 1 : , a = 10.087(7), b = 12.830(9), c = 14.545(11) Å, α =114.598(10)°, β = 92.552(10)°, γ = 108.515(10)°, V = 1588(2) ų, Z = 2, R1 = 0.0818, wR2 = 0.1855. In comparison with the free ligand, the UV spectrum of 1 in solution (H₂O: EtOH = 1:1) shows a small Einstein shift probably due to the formation of coordination polymer and supramoleculer hydrogen‐bonding interactions.     

Hydrothermal synthesis and structural characterization of a one-dimensional coordination polymer [Zn(Pydc)(Dppz)] n (H2Pydc = 2,6-pyridinedicarboxylic acid, Dppz = dipyrido[3,2-a:2′,3′-c]phenazine)

A new metal-organic coordination polymer [Zn(Pydc)(Dppz)] _n (I) (H₂Pydc = 2,6-pyridinedicarboxylic acid, Dppz = dipyrido[3,2-a:2′,3′-c]phenazine) was hydrothermally synthesized and characterized by elemental analysis, IR and X-ray single-crystal diffraction. The X-ray diffraction analysis reveals that I crystallizes in the monoclinic system, space group P2₁/c. The Pydc^2? ligands adopt O,N,O′-tridentate chelating and monodentate bridging coordination mode to link two adjacent Zn2+ ions to form a one-dimensional (1D) zigzag chain. The adjacent chains are further linked through hydrogen bonds and π-π stacking interactions, forming a three-dimensional (3D) supramolecular framework. The unit cell parameters for I: a = 7.332(3) Å, b = 36.023(9) Å, c = 7.8838(13) Å, β = 105.65(3)^○, V = 2005.1(10) ų, Z = 4.     

Three Ternary Rare Earth(III) Complexes Based on 3‐[(4,6‐Dimethyl‐2‐pyrimidinyl)thio]‐propanoic Acid and 1,10‐Phenanthroline: Synthesis,Crystal Structure and Antioxidant Activity

Three ternary rare earth [Nd^III ( 1 ), Sm^III ( 2 ) and Y^III ( 3 )] complexes based on 3‐[(4,6‐dimethyl‐2‐pyrimidinyl)thio]‐propanoic acid (HL) and 1,10‐phenanthroline (Phen) were synthesized and characterized by IR and UV/Vis spectroscopy, TGA, and single‐crystal X‐ray diffraction. The crystal structures showed that complexes 1 – 3 contain dinuclear rare earth units bridged by four propionate groups and are of general formula [REL₃(Phen)]₂ · nH₂O (for 1 and 2 : n = 2; for 3 : n = 0). All rare earth ions are nine‐coordinate with distorted mono‐capped square antiprismatic coordination polyhedra. Complex 1 crystallizes in the monoclinic system, space group P2₁/c with a = 16.241(7) Å, b = 16.095(7) Å, c = 19.169(6) Å, β = 121.48(2)°. Complex 2 crystallizes in the monoclinic system, space group P2₁/c with a = 16.187(5) Å, b = 16.045(4) Å, c = 19.001(4) Å, β = 120.956(18)°. Complex 3 crystallizes in the triclinic system, space group P1 with a = 11.390(6) Å, b = 13.636(6) Å, c = 15.958(7) Å, α = 72.310(17)°, β = 77.548(15)°, γ = 78.288(16)°. The antioxidant activity test shows that all complexes own higher antioxidant activity than free ligands.     

Cadmium(II) complex with 2-methyl-1H-4,5-imidazoledicarboxylic acid ligand: synthesis,characterization, and biological activity

A coordination polymer, [Cd(L)₂(H₂O)₂]_n (HL = 2-methyl-1H-4,5-imidazoledicarboxylic acid), was prepared from reactions of Cd(NO₃)₂ with L at room temperature. It was characterized by IR spectra and elemental analysis. The complex was structurally characterized by X-ray single-crystal diffraction revealing that the complex crystallizes in monoclinic with P2(1)/c space group, a = 12.203(10)?Å, b = 9.332(8)?Å, c = 7.554(7)?Å, β = 100.894(2)?Å, V = 844.7(13)?ų, Z = 2. Fluorescence and UV absorption spectroscopy indicated that the complex can bind to fish sperm DNA. Gel electrophoresis assay demonstrated the ability to cleave the HL-60 plasmid DNA. Apoptotic study showed that the complex exhibited significant cancer cell (JEKO and KB) inhibitory rate.     

Synthesis,Characterization, and Crystal Structure of Complexes of Lanthanide Picrates with N,N,N′,N′-tetraphenyl-3,6-dioxaoctanediamide

Lanthanide picrate complexes with the ligand N,N,N′,N′-tetraphenyl-3,6-dioxaactanediamide (tdd): [Ln(Pic)₃(tdd)] (Ln = La, Nd, Eu, Tb, Er) have been prepared in a nonaqueous medium and characterized by elemental analysis, conductivity measurements, IR, and ¹H-NMR spectra. The crystal structures of the complexes for Ln = Nd and Er were determined. The early lanthanide, Nd^III, crystallizes as the nona-coordinate complex [Nd(Pic)₃(tdd)]. 2 CH₃CN in the monoclinic space group P2₁n with a = 11.384(2), b = 18.805(4), c = 27.526(5) Å, β = 99.41(1)°, V = 5832(2) ų, and D_c = 1.58 gcm^?3 for Z = 4. The structure was refined to R = 0.0505, based on 4772 observed Deflections. The late lanthanide, Er^III, forms an octa-coordinate complex [Er(Pic)₃(tdd)]; crystals are triclinic, P1, with a = 12.449(2), b = 17.065(2), c = 26.243(4) Å, α = 72.12(1), β = 87.86(1), γ = 84.60(1)°, V = 5282(1) ų, and D_c = 1.68 g cm^?3 for Z, = 4. The structure was refined to R = 0.0469, based on 10666 observed reflections, The results reveal that tdd forms a ring-like structure with its four O-atoms, coordinating to the metal ions as multidentate ligand, together with one O-atom of the bidentate picrate. The structure of the complexes is greatly affected by the ionic radius due to participation of the picrates in coordination.     

Synthesis and Structure of a One-Dimensional Coordination Polymer Based Upon Tetracyanocalix[4]arene in the Cone Conformation

Abstract

Tetracyanocalix[4]arene has been synthesized in a cone conformation and crystallized from solution in an orthorhombic system, space group P2₁2₁2₁, with a = 13.7999(9) Å, b = 16.820(1) Å, c = 21.754(1) Å, D_c = 1.218 g/cm³, Z = 4 (C₆₂H₄₇N₅O₄). Refinement based on 11008 observed reflections yielded R1 = 0.042. Further crystallographic studies have revealed that this compound self-assembles into a one-dimensional coordination polymer in the presence of Ag⁺ cation. This extended structure also crystallizes in an orthorhombic system, space group Cmca, with a = 17.770(1) Å, b = 31.498(2) Å, c = 23.107(2) Å, D_c = 1.319 g/cm³, Z = 8 (C₆₃H₅₂AgCl₂F₆N₄O₆P). Refinement based on 7391 observed reflections yielded R1 = 0.109.     

The synthesis and structural studies of mixed ligand complex,tris(1-phenyl-3-methyl-4-trifluoroacetyl-pyrazol-5-one)mono(1-phenyl-3-methyl-pyrazol-5-one)neodymium(III) monohydrate

A mixed ligand neodymium complex containing 1-phenyl-3-methyl-4-trifluoroacetyl-pyrazol-5-one (HPMTFP) and 1-phenyl-3-methyl-pyrazol-5-one (PMP), with molecular formula Nd (PMTFP)₃·PMP·H₂O was synthesized. Its crystal and molecular structure has been determined by single crystal X-ray diffraction method. The complex crystallizes in monoclinic system with space group C⁵₂-P2₁/n. There are four formula units in a cell of dimensions a = 12.837(3), b = 23.763(5), c = 16.810(4) Å, β = 109.58(2)°. The structure has been refined by full-matrix least-squares techniques to a final R value of 0.0487 and R_w value of 0.432. The neodymium atom is coordinated to eight oxygen atoms with the average Nd—O bond length 2.439Å. Its thermostability, and mass spectrum have been discussed.     

Cobalt(II) Complexes with Dicyanamide — from Binuclear Entities to Chains

One binuclear complex [Co(bpm*)₂(dca)]₂(ClO₄)₂ ( 1 ) and two 1D chain Co^II complexes, {[Co(bpm)₂(dca)](ClO₄)}_n ( 2 ) and [Co(dmf)₂(dca)₂]_n ( 3 ), (bpm*: bis[(3, 5‐dimethyl)pyrazolyl]methane; bpm: bis(pyrazolyl)methane; dca: dicyanamide; dmf: N, N‐dimethyl formamide) have been prepared and structurally characterized. The cobalt atoms are hexa‐coordinated forming a slightly distorted octahedral coordination. Compound 1 crystallizes in the monoclinic system, space group P2₁/c, a = 9.849(3)Å, b = 21.944(7)Å, c = 13.814(5)Å, β = 94.824(6), Z = 4, R₁ = 0.0672, wR₂ = 0.1395. 1 is a binuclear complex linked by two dca ligands, and each Co^II ion is coordinated by two terminal bpm* ligands. Compound 2 crystallizes in the orthorhombic system, space group Cmcm, a = 10.377(4)Å, b = 13.594(5)Å, c = 15.999(6)Å, Z = 4, R₁ = 0.0609, wR₂ = 0.1328. The structure of 2 can be described as a one‐dimensional zigzag chain of Co^II ions bridged by one dca ligand. Each Co^II ion in the chain is coordinated by two bpm ligands. Compound 3 crystallizes in the monoclinic system, space group C₂, a = 13.559(15)Å, b = 7.393(8)Å, c = 8.110(9)Å, β = 112.228(15), Z = 2, R₁ = 0.0260, wR₂ = 0.0760. 3 has a one‐dimensional linear chain of Co^II ions bridged by two dca ligands, in which each Co^II ion is coordinated with two dmf molecules.     

Synthesis, crystal structure, and thermal stability of 1D coordination polymer [Zn(BDOA)(Py)2(H2O)] n

A new coordination polymer, [Zn(BDOA)(Py)₂(H₂O)] _n (I) (BDOA = benzene-1,4-dioxylacetate, Py = pyridine), has been prepared via self-assembly of benzene-1,4-dioxylacetate with zinc nitrate under mild conditions and characterized by IR spectra, elemental analysis and X-ray diffraction single-crystal analysis. The complex crystallizes in the monoclinic system, space group C2/c with a = 15.5751(9), b = 6.0898(4), c = 21.7133(13) Å, V = 1991.9(2) ų, β = 104.719(1)°, Z = 4. The zinc atoms are bridged by BDOA ligand, forming a one-dimensional chain along the z axis. A two-dimensional layer structure is formed by the intermolecular hydrogen bonds. The thermal decomposition profile of the complex is reported as well.     

Synthesis,crystal structure and fluorescence of a two-dimensional coordination polymer with 1-(pyrazin-2-yl)pyridine-2(1H)-one and thiocyanate as mixed bridge ligands

A two-dimensional sheet coordination polymer, [Cd(μ-C₉H₇N₃O)(μ-NCS)₂] _n , (C₉H₇N₃O=1-(pyrazin-2-yl)pyridin-2(1H)-one), has been synthesized with 1-(pyrazin-2-yl)pyridin-2(1H)-one and thiocyanate anion as bridging ligands, and its crystal structure determined by X-ray crystallography. The crystal belongs to monoclinic system with space group P2₁ /c, and its relevant crystal parameters are: a?=?7.5392(16) Å, b?=?18.343(4) Å, c?=?10.155(2) Å, β?=?106.362(3)°, Z?=?4, V?=?1347.4(5) ų, C₁₁H₇CdN₅OS₂, D _Calcd?=?1.980, R?=?0.0516. The crystal structure reveals that both 1-(pyrazin-2-yl)pyridin-2(1H)-one and thiocyanate anion connect adjacent Cd(II) ions resulting in a two-dimensional sheet structure in the bc plane. There are weak π–π stacking interactions between adjacent pyridine rings. The coordination polymer has weaker fluorescent emission in the solid state than 1-(pyrazin-2-yl)pyridin-2(1H)-one compound, attributed to the π–π stacking interaction and the coordination effect.     

Synthesis,Crystal Structures,and Characterization of Two 3d‐3d Heterometallic Coordination Frameworks: [ZnCo(Hcit)Cl] and [ZnCo(Hcit)Br]

Reactions between CoO, ZnCl₂ (or ZnBr₂), and molten citric acid (Hcit) led to the formation of two 3d‐3d heterometallic coordination frameworks: [ZnCo(Hcit)Cl] ( 1 ) and [ZnCo(Hcit)Br] ( 2 ). X‐ray structure analyses show that both compounds 1 and 2 crystallize in the monoclinic space group P2₁/n [ 1 : a = 5.8699(5) Å, b = 17.7963(13) Å, c = 9.2152(8) Å, β = 106.806(4) °, Z = 4, V = 921.53(13) Å³; 2 : a = 5.909(3) Å, b = 17.798(8) Å, c = 9.302(5) Å, β = 106.374(7) °, Z = 4, V = 938.6(8) Å³]. The structures of the two compounds are almost the same except for the terminal halogen ligand. Both of them are 3D frameworks based on citric acid bridging ligands and a 1D backbone chain built of corner‐shared {CoO₆} and {ZnO₃Cl} polyhedra. Photoluminescence and thermal stabilities of the compounds were studied.     

Three Copper(II) Coordination Polymers Constructed by Both Rigid and Flexible Ligands

Three new Copper(II) polymers coordinated by both rigid and flexible ligands, [Cu(bpy)(C₅H₆O₄)]_n ( 1 ), [Cu(bpy)(C₆H₈O₄)]_n ( 2 ), and [Cu₂(bpy)₂(C₆H₈O₄)₂]_n ( 3 ) (bpy = 4,4′‐bipyridine), have been hydrothermally synthesized and structurally characterized. Complex 1 features a box‐like bilayer motif of (4, 4) net. It crystallizes in triclinic space group with cell parameters: a = 8.1395(6) Å, b = 9.43 12(8) Å, c = 10.5473(8) Å, α = 112.1830(1)°, β = 92.423(2)°, γ = 104.752(2)°, V = 716.31(1) ų, Z = 2. Complex 2 crystallizes in triclinic space group with a = 8.8652(4) Å, b = 8.9429(4) Å, c = 10.6390(4) Å, α = 89.520(2)°, β = 69.123(2)°, γ = 75.2440(1)°, V = 758.92(6) ų, Z = 2. Complex 3 crystallizes in monoclinic space group Cc with a = 11.1521(1) Å, b = 15.3961(1) Å, c = 17.7419(1) Å, β = 105.715(3)°, V = 2932.4(5) ų, Z = 4. Complexes 2 and 3 are isomeric with different coordination modes of adipato ligand. Both of them possess the two‐fold interpenetrated 3‐D pcu topological net.     

A 3-D cobalt(II)-coordination polymer with mixed-connected network topology constructed from 4-pyridin-3-yl-benzoic acid

A new coordination polymer, [Co₂(μ-H₂O)(4,3-pybz)₄] _n (1), has been hydrothermally synthesized from Co(NO₃)₂ · 6H₂O and an unsymmetrical 4-pyridin-3-yl-benzoic acid (4,3-Hpybz), which is characterized by IR, elemental analysis, thermogravimetric analysis, and single crystal X-ray diffraction. This compound crystallizes in monoclinic, space group C2/c with a = 11.876(3) Å, b = 15.462(3) Å, c = 21.545(4) Å, β = 94.873(5)°, V = 3942.0(15) ų, Z = 4, Dc = 1.565 g cm^?3, F(000) = 1904, GOF = 1.025, μ = 0.910 mm^?1, R ₁ = 0.0456, wR ₂ = 0.0983. Compound 1 shows a 3-D (3,6)-connected coordination framework with (3.4.5)(3².4⁴.5⁵.6².7²) topology, in which cobalt is a six-connected node, and the 4,3-Hpybz ligands serve as two-connected spacers and three-connected nodes. In addition, the magnetic and thermal properties of 1 have also been investigated.     

Alkoholyse von [Fe2(OtBu)6] als einfacher Weg zu neuen Eisen(III)‐Alkoxo‐Verbindungen: Synthesen und Kristallstrukturen von [Fe2(OtAmyl)6], [Fe5OCl(OiPr)12], [Fe5O(OiPr)13], [Fe5O(OiBu)13], [Fe5O(OCH2CF3)13], [Fe5O(OnPr)13] und [Fe9O3(OnPr)21] · iPrOH

Alcoholysis of [Fe₂(O^tBu)₆] as a Simple Route to New Iron(III)‐Alkoxo Compounds: Synthesis and Crystal Structures of [Fe₂(O^tAmyl)₆], [Fe₅OCl(OⁱPr)₁₂], [Fe₅O(OⁱPr)₁₃], [Fe₅O(OⁱBu)₁₃], [Fe₅O(OCH₂CF₃)₁₃], [Fe₅O(OⁿPr)₁₃], and [Fe₉O₃(OⁿPr)₂₁] · ⁿPrOH New alkoxo‐iron compounds can be synthesized easily by alcoholysis of [Fe₂(O^tBu)₆] ( 1 ). Due to different bulkyness of the alcohols used, three different structure types are formed: [Fe₂(OR)₆], [Fe₅O(OR)₁₃] and [Fe₉O₃(OR)₂₁] · ROH. We report synthesis and crystal structures of the compounds [Fe₅OCl(OⁱPr)₁₂] ( 2 ), [Fe₂(O^tAmyl)₆] ( 3 ), [Fe₅O(OⁱPr)₁₃] ( 4 ), [Fe₅O(OⁱBu)₁₃] ( 5 ), [Fe₅O(OCH₂CF₃)₁₃] ( 6 ), [Fe₉O₃(OⁿPr)₂₁] · ⁿPrOH ( 7 ) and [Fe₅O(OⁿPr)₁₃] ( 8 ). Crystallographic Data: 2 , tetragonal, P 4/n, a = 16.070(5) Å, c = 9.831(5) Å, V = 2539(2) ų, Z = 2, d_c = 1.360 gcm^?3, R₁ = 0.0636; 3 , monoclinic, P 2₁/c, a = 10.591(5) Å, b = 10.654(4) Å, c = 16.740(7) Å, β = 104.87(2)°, V = 1826(2) ų, Z = 2, d_c = 1.154 gcm^?3, R₁ = 0.0756; 4 , triclinic, , a = 20.640(3) Å, b = 21.383(3) Å, c = 21.537(3) Å, α = 82.37(1)°, β = 73.15(1)°, γ = 61.75(1)°, V = 8013(2) ų, Z = 6, d_c = 1.322 gcm^?3, R₁ = 0.0412; 5 , tetragonal, P 4cc, a = 13.612(5) Å, c = 36.853(5) Å, V = 6828(4) ų, Z = 4, d_c = 1.079 gcm^?3, R₁ = 0.0609; 6 , triclinic, , a = 12.039(2) Å, b = 12.673(3) Å, c = 19.600(4) Å, α = 93.60(1)°, β = 97.02(1)°, γ = 117.83(1)°, V = 2600(2) ų, Z = 2, d_c = 2.022 gcm^?3, R₁ = 0.0585; 7 , triclinic, , a = 12.989(3) Å, b = 16.750(4) Å, c = 21.644(5) Å, α = 84.69(1)°, β = 86.20(1)°, γ = 77.68(1)°, V = 4576(2) ų, Z = 2, d_c = 1.344 gcm^?3, R₁ = 0.0778; 8 , triclinic, , a = 12.597(5) Å, b = 12.764(5) Å, c = 16.727(7) Å, α = 91.94(1)°, β = 95.61(1)°, γ = 93.24(2)°, V = 2670(2) ų, Z = 2, d_c = 1.323 gcm^?3, R₁ = 0.0594.     

A blue luminescent binuclear cadmium-orotate coordination polymer: synthesis,crystal structure,and thermogravimetric analysis

Assembly of orotic acid (H₃Or, 1,2,3,6-tetrahydro-2,6-dioxo-4-pyrimidinecarboxylic) and Cd(NO₃)·6H₂O yielded a coordination polymer, [(Cd(Hor)·2.5H₂O)₂]_n (1), which has been characterized by X-ray single-crystal diffraction, TGA, and ?uorescence spectra. Single-crystal X-ray structural analyses reveal that 1 is a hydrogen-bonded binuclear Cd-orotate coordination polymer in which both Cd²⁺ ions have different coordination environments with identical distorted octahedral geometry. Crystal data for 1: monoclinic, space group P2₁/n, a = 7.0209(10) Å, b = 13.974(2) Å, c = 17.541(3) Å, β = 98.842(2)°, V = 1700.5(4) Å, Z = 4, R1 = 0.0269, wR2 = 0.0612, θ_max = 25.960. The emission spectrum of the Cd-complex recorded with 265 nm excitation wavelength reveals the complex has strong blue luminescence with the peak maximum 420 nm (2.95 eV) as a result of the n–π* and π–π* transitions on the H₃Or ligand.     

A 1D coordination polymer {Pb[C6H4(COO)2][phen]} n with strong blue fluorescent emission

The hydrothermal reaction of 1,3-dicyanobenzene, 1,10-phenanthroline (phen) and Pb(CH₃COO)₂ yields a new 1D coordination polymer, {Pb[C₆H₄(COO)₂][phen]} _n . The 1,3-benzenecarboxylate anion found in the final product was generated in situ during the synthesis by hydrolysis of 1,3-dicyanobenzene. X-ray diffraction shows that complex 1 crystallizes in the triclinic system, space group P 1, a?=?7.5442(2)?Å, b?=?9.7962(3)?Å, c?=?13.1505(4)?Å, α?=?69.739(2)?Å, β?=?80.597(2)?Å, γ?=?71.377(2)?Å, v?=?862.48(4)?ų, Z?=?2, D _c?=?2.124 Mg?m^?3. Complex 1 emits strong blue fluorescent light (λem(max)?=?482.4?nm) when excited by UV light in the solid state at room temperature.     

Seltenerdhalogenide Ln4X5Z. Teil 1: C und/oder C2 in Ln4X5Z

Rare Earth Halides Ln₄X₅Z. Part 1: C and/or C₂ in Ln₄X₅Z The compounds Ln₄X₅C_n (Ln = La, Ce, Pr; X = Br, I and 1.0 < n < 2.0) are prepared by the reaction of LnX₃, Ln metal and graphite in sealed Ta‐ampoules at temperatures 850 °C < T < 1050 °C. They crystallize in the monoclinic space group C2/m. La₄I₅C_1.5: a = 19.849(4) Å, b = 4.1410(8) Å, c = 8.956(2) Å, β = 103.86(3)°, La₄I₅C_2.0: a = 19.907(4) Å, b = 4.1482(8) Å, c = 8.963(2) Å, β = 104.36(3)°, Ce₄Br₅C_1.0: a = 18.306(5) Å, b = 3.9735(6) Å, c = 8.378(2) Å, β=104.91(2)°, Ce₄Br₅C_1.5: a = 18.996(2) Å, b = 3.9310(3) Å, c = 8.282(7) Å, β = 106.74(1)°, Pr₄Br₅C_1.3: a = 18.467(2) Å, b = 3.911(1) Å, c = 8.258(7) Å, β = 105.25(1)° and Pr₄Br₅C_1.5: a = 19.044(2) Å, b = 3.9368(1) Å, c = 8.254(7) Å, β = 106.48(1)°. In the crystal structure the lanthanide metals are connected to Ln₆‐octahedra centered by carbon atoms or C₂‐groups. The Ln₆‐octahedra are condensed via opposite edges to chains and surrounded by X atoms which interconnect the chains. A part n of isolated C‐atoms is substituted by 1‐n C₂‐groups. The C‐C distances range between 1.26 and 1.40Å. In the ionic formulation (Ln³⁺)₄(X^?)₅(C^4?)_n(C₂^m?)_1?n·e^? with 0 < n < 1 and m = 2, 4, 6 (C₂^2?, C₂^4? C₂^6?), there are 1 < e^? < 5 electrons centered in metal‐metal bonds.     

Synthesis,crystal structure and luminescence of a 3-D coordination polymer based on 4-(1H-tetrazol-5-yl) benzoic acid

A cobalt(II) coordination polymer [Co(4-TZBA^2?)(H₂O)₂] (1) was obtained by treatment of Co(ClO₄)₂ · 6H₂O with 4-(1H-tetrazol-5-yl)benzoic acid [H₂(4-TZBA)] under hydrothermal conditions. The X-ray single crystal diffraction analysis reveals that 1 crystallizes in monoclinic P2₁/c, with a = 10.503(2) Å, b = 9.0860(18) Å, c = 10.179(2) Å, β = 96.75(3)° and Z = 4. In 1, adjacent cobalt(II) atoms are bridged by two 4-TZBA^2? ligands to form a dimer, which is linked with six dimers to result in a 3-D structure. 1 exhibits strong luminescence at room temperature in the solid state.