One‐dimensional zinc‐based coord­in­ation polymers incorporating cyanate anions

Two one‐dimensional zinc‐based coordination polymers containing cyanate anions are reported. catena‐Poly[sodium [[tricyanato­zinc(II)]‐μ‐1,4‐diaza­bicyclo­[2.2.2]octane‐κ²N:N′]], {Na[Zn(NCO)₃(C₆H₁₂N₂)]}_n, consists of linear [tricyanato­zinc(II)]‐μ‐1,4‐diaza­bicyclo­[2.2.2]octane strands in which the Zn²⁺ cations adopt trigonal–bipyramidal coordination on sites of m2 point symmetry. Na⁺ cations lie between the strands on sites of m point symmetry, coordinated in a distorted octa­hedral geometry by six O atoms of the cyanate anions. catena‐Poly[[dicyanato­zinc(II)]‐μ‐4,4′‐bipyridine‐κ²N:N′], [Zn(NCO)₂(C₁₀H₈N₂)]_n, crystallizes in the space group P2₁/n with Z′ = 5. The structure consists of zigzag strands formed by Zn²⁺ cations linked via 4,4′‐bipyridine. Each Zn²⁺ cation adopts a tetra­hedral coordination, with two sites occupied by 4,4′‐bipyridine and two cyanate anions completing the coordination sphere. The structure is closely comparable with the thio­cyanate and halide analogues [ZnX₂(C₁₀H₈N₂)] (X = NCS, Cl or Br).     

Two alkali metal chlorites,LiClO2 and KClO2

The structures of tetragonal (P4₂/ncm) lithium chlorite, LiClO₂, and orthorhombic (Cmcm) potassium chlorite, KClO₂, have been determined by single‐crystal X‐ray analyses. In LiClO₂, the Li atom is at a site of symmetry, while in KClO₂, the K atom is at a site with 2/m symmetry. In both compounds, the unique Cl and O atoms are at sites with mm and m symmetry, respectively. The structure of LiClO₂ consists of layers of Li⁺ cations coordinated by ClO₂⁻ anions. In contrast, the structure of KClO₂ contains pseudo‐layers of K⁺ and ClO₂⁻ ions containing four short K—O distances. The Li⁺ and K⁺ cations are surrounded by four and eight chlorite O atoms in tetrahedral and distorted cubic coordination environments, respectively.     

Poly[[[diaqua­zinc(II)]‐bis(μ2‐3‐cyano‐4‐dicyano­methyl­ene‐5‐oxo‐4,5‐dihydro‐1H‐pyrrol‐2‐olato‐κ2N3:N3′)] dihydrate]

The coordination of the 3‐cyano‐4‐dicyano­methyl­ene‐5‐oxo‐4,5‐dihydro‐1H‐pyrrol‐2‐olate anion to Zn^II, the apical sites of which are occupied by two water mol­ecules, results in the formation of two‐dimensional layers of the title coordination polymer, {[Zn(C₈HN₄O₂)₂(H₂O)₂]·2H₂O}_n, in which the Zn^II cations lie on inversion centres in space group C2/c, with water ligands in the apical sites of octa­hedral geometry. Hydrogen bonds between coordinated and lattice water mol­ecules, and π–π stacking inter­actions between the anions link adjacent layers into a continuous framework.     

Li6+2x[B10Se18]Sex (x ≈ 2), ein ionenleitendes Doppelsalz

Li_6+2x[B₁₀Se₁₈]Se_x (x ≈ 2), an Ion‐conducting Double Salt Li_6+2x[B₁₀Se₁₈]Se_x (x ≈ 2) was prepared in a solid state reaction from lithium selenide, amorphous boron and selenium in evacuated carbon coated silica tubes at a temperature of 800 °C. Subsequent cooling from 600 °C to 300 °C gave amber colored crystals with the following lattice parameters: space group I2/a (at 173 K); a = 17.411(1) Å, b = 21.900(1) Å, c = 17.820(1) Å, β = 101.6(1)°. The crystal structure contains a well‐defined polymeric selenoborate network of composition ([B₁₀Se₁₆Se_4/2]^6?)_n consisting of a system of edge‐sharing [B₁₀Se₁₆Se_4/2] adamantanoid macro‐tetrahedra forming large channels in which a strongly disorderd system of partial occupied Li⁺ cations and additional disordered Se^2? anions is observed. The crystal structure of the novel selenoborate is isotypic to Li_6+2x[B₁₀S₁₈]S_x (x ≈ 2) [1]. X‐ray and ⁷Li magic‐angle spinning NMR data suggest that the site occupancies of the three crystallographically distinct lithium ions exhibit a significant temperature dependence. The lithium ion mobility has been characterized by detailed temperature dependent NMR lineshape and spin‐lattice relaxation measurements.     

Anhydrous polymeric zinc(II) octanoate

The structure of the title compound, poly­[zinc(II)‐bis(μ‐octanoato‐O:O′)], [Zn(C₈H₁₅O₂)₂]_n, consists of polymeric sheets parallel to (100) in which tetrahedrally coordinated Zn²⁺ cations are connected by carboxyl­ate bridges in a syn–anti arrangement.     

Li+ cation coordination in [Li2(CF3SO3)2(diglyme)] and [Li3(C2F3O2)3(diglyme)]

The title compounds, poly­[[[bis(2‐methoxy­ethyl) ether]­lithium(I)]‐di‐μ₃‐tri­fluoro­methanesulfonato‐lithium(I)], [Li₂(CF₃SO₃)₂(C₆H₁₄O₃)]_n, and poly­[[[bis(2‐methoxy­ethyl) ether]­lithium(I)]‐di‐μ₃‐tri­fluoro­acetato‐dilithium(I)‐μ₃‐tri­fluoro­acetato], [Li₃(C₂F₃O₂)₃(C₆H₁₄O₃)]_n, consist of one‐dimensional polymer chains. Both structures contain five‐coordinate Li⁺ cations coordinated by a tridentate diglyme [bis(2‐methoxy­ethyl) ether] mol­ecule and two O atoms, each from separate anions. In both structures, the [Li(diglyme)X₂]^? (X is CF₃SO₃ or CF₃CO₂) fragments are further connected by other Li⁺ cations and anions, creating one‐dimensional chains. These connecting Li⁺ cations are coordinated by four separate anions in both compounds. The CF₃SO₃^? and CF₃CO₂^? anions, however, adopt different forms of cation coordination, resulting in differences in the connectivity of the structures and solvate stoichiometries.     

Interaction of thiamine with anions in the triclinic form of thiamine iodide: 3‐[(4‐amino‐2‐methylpyrimidin‐5‐yl)methyl]‐5‐(2‐hydroxyethyl)‐4‐methyl‐1,3‐thiazol‐3‐ium iodide 1.25‐hydrate

The asymmetric unit of the title compound, C₁₂H₁₇N₄OS⁺·I⁻·1.25H₂O, contains two crystallographically independent molecules. Both formula units assume the usual F conformation and have the hydroxyethyl group disordered over two sites, each with half occupation. Two thiamine cations are linked by hydrogen bonds into a cyclic dimer. These dimers are further connected by base‐pairing hydrogen bonds into a chain along [010]. The stacked dimers form channels, which are occupied by iodide anions. The cations and anions are associated by N—H...I hydrogen bonds, C—H...I interactions and I...thiazolium ring close contacts. The interactions between thiamine and the iodide anions are similar to those observed in monoclinic thiamine iodide 1.5‐hydrate [Hu & Zhang (1993). J. Inclusion Phenom. Mol. Recognit. Chem. 16 , 273–281].     

Tris[2‐(1,3‐thiazol‐2‐yl‐κN)‐1H‐benzimidazole‐κN3]zinc(II) dinitrate ethanol hemisolvate monohydrate at 100 K

The Zn^II center in the dicationic complex of the title compound, [Zn(C₁₀H₇N₃S)₃](NO₃)₂·0.5C₂H₅OH·H₂O, is in a distorted octahedral environment with imperfect noncrystallographic C₃ symmetry. Each 2‐(1,3‐thiazol‐2‐yl)‐1H‐benzimidazole ligand coordinates in a bidentate manner, with the Zn—N(imidazole) bond lengths approximately 0.14 Å shorter than the Zn—N(thiazole) bond lengths. Charge‐assisted hydrogen bonds connect cations, anions and water molecules. A lattice void is occupied by an ethanol solvent molecule disordered about a crystallographic inversion center and π‐stacking is observed between one type of symmetry‐related benzene rings.     

THE CRYSTAL AND MOLECULAR STRUCTURE OF A FURAN-2-CARBOXYLATE HETEROBIMETALLIC COMPLEX [Zn(H2O)6]2+[Zn8Na2(C5H3O3)18(OH)2]2-

Abstract

The crystals of a zinc-sodium complex with furan-2-carboxylate (FCA) as a ligand, n[Zn(H₂O)₆]²⁺[Zn₈Na₂(FCA)₁₈(OH]₂]^2- _n , contain hexahydrated zinc cations and polyanions in which four differently coordinated zinc(II) cations are bridged by bidentate and monodentate (FCA) ligands. In addition, a number of carboxylate and furan ring oxygen atoms are coordinated to sodium(I) atoms which constitute the backbone of the polyanion. [Zn(H₂O)₆]²⁺ cations are located in cavities formed by adjacent polyanions and interact with them via a system of hydrogen bonds. The resulting molecular layers are stacked in the crystal along the [100] direction.     

Site Preference of Cations and Structural Variation in MgAl2–xGaxO4 (0 ≤ x ≤ 2) Spinel Solid Solution

The crystal structures of MgAl_2–xGa_xO₄ (0 ≤ x ≤ 2) spinel solid solutions (x = 0.00, 0.38, 0.76, 0.96, 1.52, 2.00) were refined using ²⁷Al MAS NMR measurements and single crystal X‐ray diffraction technique. Site preferences of cations were investigated. The inversion parameter (i) of MgAl₂O₄ (i = 0.206) is slightly larger than given in previous studies. It is considered that the difference of inversion parameter is caused by not only the difference of heat treatment time but also some influence of melting with a flux. The distribution of Ga³⁺ is little affected by a change of the temperature from 1473 K to 973 K. The degree of order‐disorder of Mg²⁺ or Al³⁺ between the fourfold‐ and sixfold‐coordinated sites is almost constant against Ga³⁺ content (x) in the solid solution. A compositional variable of the Ga/(Mg + Ga) ratio in the sixfold‐coordinated site has a constant value through the whole compositional range: the ratio is not influenced by the occupancy of Al³⁺. The occupancy of Al³⁺ is independent of the occupancy of Ga³⁺, though it depends on the occupancy of Mg²⁺ according to thermal history. The local bond lengths were estimated from the refined data of solid solutions. The local bond length between specific cation and oxygen corresponds with that expected from the effective ionic radii except local Al–O bond length in the fourfold‐coordinated site and local Mg–O bond length in the sixfold‐coordinated site. The local Al–O bond length in the fourfold‐coordinated site (1.92 Å) is about 0.15 Å longer than the expected bond length. This difference is induced by a difference in site symmetry of the fourfold‐coordinated site. The nature that Al³⁺ in spinel structure occupies mainly the sixfold‐coordinated site arises from the character of Al³⁺ itself. The local Mg–O bond length in the sixfold‐coordinated site (2.03 Å) is about 0.07 Å shorter than the expected one. Difference Fourier synthesis for MgGa₂O₄ shows a residual electron density peak of about 0.17 e/ų in height on the center of (Ga_0.59 Mg_0.41)–O bond. This peak indicates the covalent bonding nature of Ga–O bond on the sixfold‐coordinated site in the spinel structure.     

Bridging behaviour of the 2‐thiobarbiturate anion in its complexes with LiI and NaI

The structures of the Li^I and Na^I salts of 2‐thiobarbituric acid (2‐sulfanylidene‐1‐3‐diazinane‐4,6‐dione, H₂TBA) have been studied. μ‐Aqua‐octaaquabis(μ‐2‐thiobarbiturato‐κ²O:O′)bis(2‐thiobarbiturato‐κO)tetralithium(I) dihydrate, [Li₄(C₄H₃N₂O₂S)₄(H₂O)₉]·2H₂O, (I), crystallizes with four symmetry‐independent four‐coordinated Li^I cations and four independent HTBA⁻ anions. The structure contains two structurally non‐equivalent Li^I cations and two non‐equivalent HTBA⁻ anions (bridging and terminal). Eight of the coordinated water ligands are terminal and the ninth acts as a bridge between Li^I cations. Discrete [Li₄(HTBA)₄(H₂O)₉]·2H₂O complexes form two‐dimensional layers. Neighbouring layers are connected via hydrogen‐bonding interactions, resulting in a three‐dimensional network. Poly[μ₂‐aqua‐tetraaqua(μ₄‐2‐thiobarbiturato‐κ⁴O:O:S:S)(μ₂‐thiobarbiturato‐κ²O:S)disodium(I)], [Na₂(C₄H₃N₂O₂S)₂(H₂O)₅]_n, (II), crystallizes with six‐coordinated Na^I cations. The octahedra are pairwise connected through edge‐sharing by a water O atom and an O atom from the μ₄‐HTBA⁻ ligand, and these pairs are further top‐shared by the S atoms to form continuous chains along the a direction. Two independent HTBA⁻ ligands integrate the chains to give a three‐dimensional network.     

A zinc–lithium complex of 4,7‐bis(2‐aminoethyl)‐1,4,7‐triazacyclononane‐1‐acetate

The asymmetric unit of {[4,7‐bis(2‐amino­ethyl)‐1,4,7‐tri­aza­cyclo­nonan‐1‐yl]acetato}zinc(II) triaqua{μ‐[4,7‐bis(2‐amino­ethyl)‐1,4,7‐tri­aza­cyclo­nonan‐1‐yl]acetato}lithium(I)zinc(II) chloride diperchlorate, [Zn(C₁₂H₂₆N₅O₂)][LiZn(C₁₂H₂₆N₅O₂)(H₂O)₃]Cl(ClO₄)₂, obtained from the reaction between the lithium salt of 4,7‐bis(2‐amino­ethyl)‐1,4,7‐tri­aza­cyclo­nonane‐1‐acetate and Zn(ClO₄)₂, contains two Zn^II complexes in which each Zn^II ion is six‐coordinated by five N‐atom donors and one O‐­atom donor from the ligand. One carboxyl­ate O‐atom donor is not involved in coordination to a Zn^II atom, but coordinates to an Li⁺ ion, the tetrahedral geometry of Li⁺ being completed by three water mol­ecules. The two complexes are linked via a hydrogen bond between a primary amine N—H group and the carboxyl­ate‐O atom not involved in coordination to a metal.     

The novel arsenate Na4Co7−xAl2/3x(AsO4)6 (x = 1.37): crystal structure,charge‐distribution and bond‐valence‐sum investigations

The title compound, tetrasodium cobalt aluminium hexaarsenate, Na₄Co_7−xAl_2/3x(AsO₄)₆ (x = 1.37), is isostructural with K₄Ni₇(AsO₄)₆; however, in its crystal structure, some of the Co²⁺ ions are substituted by Al³⁺ in a fully occupied octahedral site (site symmetry 2/m) and a partially occupied tetrahedral site (site symmetry 2). A third octahedral site is fully occupied by Co²⁺ ions only. One of the two independent tetrahedral As atoms and two of its attached O atoms reside on a mirror plane, as do two of the three independent Na⁺ cations, all of which are present at half‐occupancy. The proposed structural model based on a careful investigation of the crystal data is supported by charge‐distribution (CHARDI) analysis and bond‐valence‐sum (BVS) calculations. The correlation between the X‐ray refinement and the validation results is discussed.     

Multiscale Computational Study on the Adsorption and Separation of CO2/CH4 and CO2/H2 on Li+‐Doped Mixed‐Ligand Metal–Organic Framework Zn2(NDC)2(diPyNI)

The quantum mechanics (QM) method and grand canonical Monte Carlo (GCMC) simulations are used to study the effect of lithium cation doping on the adsorption and separation of CO₂, CH₄, and H₂ on a twofold interwoven metal–organic framework (MOF), Zn₂(NDC)₂(diPyNI) (NDC=2,6‐naphthalenedicarboxylate; diPyNI=N,N′‐di‐(4‐pyridyl)‐1,4,5,8‐naphthalenetetracarboxydiimide). Second‐order Moller–Plesset (MP2) calculations on the (Li⁺–diPyNI) cluster model show that the energetically most favorable lithium binding site is above the pyridine ring side at a distance of 1.817 Å from the oxygen atom. The results reveal that the adsorption capacity of Zn₂(NDC)₂(diPyNI) for carbon dioxide is higher than those of hydrogen and methane at room temperature. Furthermore, GCMC simulations on the structures obtained from QM calculations predict that the Li⁺‐doped MOF has higher adsorption capacities than the nondoped MOF, especially at low pressures. In addition, the probability density distribution plots reveal that CO₂, CH₄, and H₂ molecules accumulate close to the Li cation site. The selectivity results indicate that CO₂/H₂ selectivity values in Zn₂(NDC)₂(diPyNI) are higher than those of CO₂/CH₄. The selectivity of CO₂ over CH₄ on Li⁺‐doped Zn₂(NDC)₂(diPyNI) is improved relative to the nondoped MOF.     

Selective Metal‐Cation Recognition by [2.2]Ferrocenophanes: The Cases of Zinc‐ and Lithium‐Sensing

The synthesis, electrochemical, optical, and cation‐sensing properties of [2.2]ferrocenophanes, in which the two ferrocene subunits are linked through two aldiminic or iminophosphorane moieties, are reported. The new compounds show remarkably selective cation‐sensing properties due to the presence of redox‐active units (ferrocene) and aza‐unsaturated functionalities that are able to act as putative cation‐binding sites. In this structural motif, the aldimine groups act as a highly selective binding site for Zn²⁺ cations, whereas the iminophosphorane bridges display an unusually strong binding affinity towards Li⁺ cations, which could be explained by an additional Li???Fe interaction. The X‐ray structure of the complex 4? Li⁺ as well as detailed NMR spectroscopic studies, both in solution and in the solid state, support this assessment. Experimental data and conclusions about the cation‐sensing capabilities of this family of compounds are supported by DFT calculations.     

Synthesis,Structural Characterization and Physical Properties of a New Member of Ternary Lithium Layered Compounds – Li2RhO3

Li₂RhO₃ was synthesized by solid state reaction and its crystal structure was refined from X‐ray powder data by the Rietveld‐method. The compound was obtained as a black powder and crystallizes in the monoclinic space group C2/m, with unit cell parameters a = 5.1198(1), b = 8.8497(1), c = 5.1030(1) Å, β = 109.61(2) °, V = 217.80(1), and Z = 4. The structure determination shows that the oxygen atoms in Li₂RhO₃ form an approximate cubic close packing, where all octahedral voids are occupied by Rh⁴⁺ and Li⁺ cations. The structure is closely related to the α‐NaFeO₂ and Li₂MnO₃ layered structure types (layered variants of the NaCl‐type), but in Li₂RhO₃ the lithium and rhodium atoms are partially disordered. Li₂RhO₃ behaves as a semiconductor with rather small activation energy of 7.68 kJ · mol^–1 and is thermally stable up to 1273 K in argon atmosphere. According to measurements of the magnetic susceptibility in the temperature range from 2 to 330 K, Li₂RhO₃ is paramagnetic, obeys the Curie–Weiss law at temperatures above 150 K, and has an effective magnetic moment of 1.97 μ_B at 300 K.     

Synthesis,Spectral, Thermal Studies of Co(II), Ni(II), Cu(II) and Zn(II)‐arginato Complexes. Crystal Structure of Monoaquabis(arginato‐κO,κN)copper(II). [Cu(arg)2(H2O)].NaNO3

Transition metal complexes of arginine (using Co(II), Ni(II), Cu(II) and Zn(II) cations separately) were synthesized and characterized by FTIR, TG/DTA‐DrTG, UV‐Vis spectroscopy and elemental analysis methods. Cu(II)‐Arg complex crystals was found suitable for x‐ray diffraction studies. It was contained, one mole Cu^II and Na⁺ ions, two arginate ligands, one coordinated aqua ligand and one solvent NO₃^? group in the asymmetric unit. The principle coordination sites of metal atom have been occupied by two N atoms of arginate ligands, two carboxylate O atoms, while the apical site was occupied by one O atom for Cu^II cation and two O atoms for Co^II, Ni^II, Zn^II atoms of aqua ligands. Although Cu^II ion adopts a square pyramidal geometry of the structure. Co^II, Ni^II, Zn^II cations have octahedral due to coordination number of these metals. Neighbouring chains were linked together to form a three‐dimensional network via hydrogen‐bonding between coordinated water molecule, amino atoms and O atoms of the bridging carboxylate groups. Cu^II complex was crystallized in the monoclinic space group P2₁, a = 8.4407(5) Å, b = 12.0976(5) Å, c = 10.2448(6) Å, V = 1041.03(10) ų, Z = 2. Structures of the other metal complexes were similar to CuII complex, because of their spectroscopic studies have in agreement with each other. Copper complex has shown DNA like helix chain structure. Lastly, anti‐bacterial, anti‐microbial and anti‐fungal biological activities of complexes were investigated.     

Ba3Li2V2O7Cl4, a new vanadate with a channel structure

The tribarium dilithium divanadate tetrachloride Ba₃Li₂V₂O₇Cl₄ is a new vanadate with a channel structure and the first known vanadate containing both Ba and Li atoms. The structure contains four non‐equivalent Ba²⁺ sites (two with m and two with 2/m site symmetry), two Li⁺ sites, two nonmagnetic V⁵⁺ sites, five O²⁻ sites (three with m site symmetry) and four Cl⁻ sites (m site symmetry). One type of Li atom lies in LiO₄ tetrahedra (m site symmetry) and shares corners with VO₄ tetrahedra to form eight‐tetrahedron Li₃V₅O₂₄ rings and six‐tetrahedron Li₂V₄O₁₈ rings; these rings are linked within porous layers parallel to the ab plane and contain Ba²⁺ and Cl⁻ ions. The other Li atoms are located on inversion centres and form isolated chains of face‐sharing LiCl₆ octahedra.     

Le phosphate de cobalt et de lithium à valence mixte Li4+xCo2−x(P2O7)2 (x = 0,03): étude structurale et analyse de distribution de charge

The title compound, namely lithium cobalt(II/III) bis(diphosphate), Li_4.03Co_1.97(P₂O₇)₂, is a new mixed‐valent lithium/cobalt(II/III) phosphate. Three metal sites out of seven are occupied simultaneously by Li⁺ and Co^II/III ions. This disorder was established both from an analysis of the atomic displacement ellipsoids and Li/Co—O bond distances, and by means of a charge‐distribution (CHARDI) model, which provides satisfactory agreement on the computed charges (Q) for all the cations.     

A two‐dimensional coordination polymer containing a two‐dimensional zinc–carboxylate layer constructed from helical chains: poly[(μ4‐benzene‐1,2‐dicarboxylato)zinc(II)]

The title compound, [Zn(C₈H₄O₄)]_n, consists of one Zn^II cation and one benzene‐1,2‐dicarboxylate dianion (BDC²⁻) as the building unit. The Zn^II cation is four‐coordinated by four carboxylate O atoms from four dianionic BDC²⁻ ligands in a distorted tetrahedral geometry. The Zn^II cations are linked by the BDC²⁻ ligands to generate a structure featuring two‐dimensional zinc–carboxylate layers containing left‐ and right‐handed helical chains. The two‐dimensional layers are stacked along the a direction. The thermal stability of the title compound has been studied.