Syntheses and crystal structures of three cesium salts: Cesium 5-sulfosalicylate, cesium 3,5-dinitrosalicylate and cesium 2,4-dinitrophenoxide monohydrate

In an attempt to probe a potential template role of the large alkali-metal cation cesium in organization of biorelevant ligands, 5-sulfosalicylate, 3,5-dinitrosalicylate and 2,4-dinitrophenol complexes of cesium were prepared and structurally investigated. The structures of cesium 5-sulfosalicylate, cesium 3,5-dinitrosalicylate and cesium 2,4-dinitrophenoxide monohydrate have been determined through X-ray diffraction analysis. The 5-sulfosalicylate anion has lost the proton at the −SO₃H group while the 3,5-dinitrosalicylate anion at −COOH group but both retains the usual intermolecular hydrogen bond between phenolic and carboxylic oxygen. In cesium 2,4-dinitrophenoxide monohydrate, the Cs⁺ cation is 12-coordinate by O atoms in anions and water molecules while the metal atoms in cesium 5-sulfosalicylate and cesium 3,5-dinitrosalicylate have coordination numbers 10 and 11, respectively, with an irregular coordination sphere made up exclusively of oxygen atoms. Even more in cesium 2,4-dinitrophenoxide monohydrate, the water molecules are in rare triply bridging positions between these cations. Both complexes have layer structures containing the cations and polar groups of the ligands in core domains sandwiched by the aromatic rings above and below. The organization of all layer structures appears to be governed mainly by steric effects and electrostatic forces with very little directional influence of the cations.     

Synthesis and crystal structure of Ni(II) complexes of 2′-(3,5-dibromo-2-hydroxybenzylidene)-3,5-dihydroxybenzoylhydrazide

A new mononuclear nickel(II) complex incorporating a Schiff-base ligand, [NiL₂](DMF)₄ (HL = 2′-(3,5-dibromo-2-hydroxybenzylidene)-3,5-dihydroxybenzoylhydrazide), has been synthesized and characterized by IR, UV-Vis, elemental analysis and X-ray crystal structure analysis. HL is an anionic tridentate ligand. The nickel atom is hexacoordinated with two oxygen atoms from keto group and two oxygen atoms from hydroxy group and two nitrogen atoms from amide, with the two nitrogen atoms occupying the axial positions forming a distorted octahedral coordination sphere.     

Crystal structures of rubidium and cesium anthranilates and salicylates

In an attempt to probe a potential template role of the large alkali-metal cations rubidium and cesium in the organization of biorelevant ligands, salicylate and anthranilate complexes of the two elements were prepared and structurally investigated. The studies were also expected to show the marked structural differences compared to the corresponding thallium(I) compounds. Rubidium anthranilate and cesium salicylate could be crystallized as the monohydrates Rb(Anth)(H(2)O) and Cs(Sal)(H(2)O). Both have layer structures containing the cations and the polar groups of the ligands in core domains sandwiched by the aromatic rings above and below. The metal atoms have coordination numbers 7 and 8, respectively, with an irregular coordination sphere made up exclusively of oxygen atoms. Crystalline material with a 1:2 stoichiometry, Cs[H(Anth)(2)], is obtained from aqueous solutions of Cs(Anth) upon absorption of carbon dioxide with concomitant formation of cesium bicarbonate, Cs(HCO(3)). The crystal structure of Cs(HCO(3)) was redetermined to obtain precise benchmark data for cesium carbonates and carboxylates. The cesium hydrogen bisanthranilate also has a layer structure with eight-coordinate cesium atoms. The coordination sphere includes one nitrogen donor atom. The organization of all layer structures appears to be governed mainly by steric effects and electrostatic forces with very little directional influence of the cations. This result suggests that the large alkali metals have no efficient template effect for the organization of biological substrates and can explain the low toxicity of rubidium and cesium salts.     

Tetradentate nitrogen-containing ligands bis-5-(2-pyridylmethylidene)-3,5-dihydro-4<Emphasis Type="Italic">H</Emphasis>-imidazol-4-ones and their coordination compounds with Cu<Superscript>I</Superscript> and Cu<Superscript>II</Superscript>

Tetradentate N₄-type organic ligands containing two 5-(2-pyridylmethylidene)-2-thio-3,5-dihydro-4H-imidazol-4-one fragments linked by two-, four-, or six-carbon polymethylene bridges between the sulfur atoms were synthesized. Mono- and dinuclear complexes of these ligands with copper(II) chloride, as well as with copper(I) and copper(II) perchlorates, were prepared. The structure of the coordination compound (5Z,5′Z)-2,2′-(butane-1,2-diyl-disulfanyldiyl)bis-5-(2-pyridylmethylidene)-3-phenyl-3,5-dihydro-4H-imidazol-4-one with copper(I) perchlorate was established by X-ray diffraction. The copper atom in this complex is in a distorted tetrahedral coordination formed by four nitrogen atoms of two imidazole and two pyridine rings. The perchlorate anion is located in the outer sphere of the complex and is not involved in the coordination with the copper ion. The electrochemical study of the ligands and the complexes was carried out by cyclic voltammetry and rotating disk electrode voltammetry. The initial reduction of the complexes under study occurs at the metal atom. The length of the polymethylene bridge in the ligand has only a slight effect on the redox properties of the ligands and the complexes.     

3，5-二羟基-2，4，6-三硝基苯酚铷的晶体结构和热行为

0IntroductionSom e nitrogen鄄rich alkaline and alkali鄄earth m et鄄als com pounds of polynitro hydroxybenzenes can beused environm entally friendly prim ary explosives[1￣5].2,4,6鄄Trinitro鄄1,3,5鄄trihydroxybenzene(trinitrophloroglu鄄cinol,TNPG)belongs to a polynitro hydroxybenzeneand has been used in chem icalindustry as an ingredi鄄entfor prim ing com position,percussion caps and deto鄄nator form ulations[6].Therefore,in recent years,ithasbeen exploited to prepare a num ber of salts of ba…     

Structural Diversity in the Self‐assembly of Cd(II) Complexes Containing 2,6‐Dimethyl‐3,5‐dicyano‐4‐(4‐pyridyl)‐1,4‐dihydropyridine

The syntheses, structures and properties of the complexes [CdBr₂( L )₂·4H₂O]_n [ L = 2,6‐dimethyl‐3,5‐dicyano‐4‐(4‐pyridyl)‐1,4‐dihydropyridine], 1 and [Cd(SCN)₂( L )₂(H₂O)]_n, 2 , are reported. In polymeric complexes 1 — 2 , the L ligands bridge the metal centers through the pyrimidyl and cyano nitrogen atoms forming 1‐D double‐stranded chain and zigzag chain, respectively. The L ligands in complex 1 act as κ1, κ1‐bidentate bridging ligand, whereas the L ligands in complex 2 act as κ1‐monodentae and κ1, κ1‐bidentate bridging ligand. The molecules of these complexes are interlinked through various weak interactions that form the packed structure. All the complexes exhibit emissions which may be tentatively assigned as intraligand (IL) π→π* transitions.     

Syntheses and Characterization of Two Coordination Polymers Constructed by the Ligand 3,5‐Bis(pyridin‐4‐ylmethoxy)benzoic Acid

Two coordination polymers, namely [Zn(L1)(OAc)]·H₂O ( 1 ) and [Cd(L1)₂] ( 2 ), where L1 = 3,5‐bis(pyridin‐4‐ylmethoxy)benzoic acid, have been synthesized under hydrothermal conditions and characterized by single‐crystal X‐ray diffraction analysis. Complex 1 has a 2D layer structure in which the hydrogen bonds between lattice water molecules and uncoordinated carboxylate oxygen atoms of the ligand L1 in the adjacent layers extend the 2D layer into a 3D supramolecular architecture. The structure of 2 is a 2D (3,5)‐connected net with (3·5²)(3²·5³·6⁴·7) topology. In addition, the luminescent properties of complexes 1 and 2 have been studied in the solid state at room temperature.     

Corrigendum

Three neodymium compounds, Nd(4DNP)₃(C₂H₅OH)₃ (1), Nd(4DNPO)₃ · 7H₂O (2), and {[Nd(μ-ox)(4DNPO)(H₂O)₄] · 4H₂O} _n (3) (4HDNP, 3,5-dinitropyrid-4-one; 4HDNPO, 3,5-dinitropyrid-4-one-N-hydroxide; ox, oxalate), were synthesized and characterized by FT-IR, elemental analysis, thermogravimetry–differential scanning calorimetry (TG–DSC), and two of them by single-crystal X-ray diffraction analyses. The results revealed that in 1, the Nd(III) is surrounded by three chelating ligands and three ethanol solvent molecules. The structure of 3 could be described as 1-D chains in which Nd is bis-bidentately bridged by oxalates, together with a monodentate 3,5-dinitropyrid-4-onate N-oxide 4DNPO ligand and four water molecules as well as four uncoordinated water molecules in the crystal lattice. The origin of the oxalate anions in 3 is probably due to decomposition of the 4DNPO or its oxidation of other species. The TG–DTG (DTG, derivative thermogravimetry) and DSC analyses showed that 1 underwent a three-stage decomposition process. A kinetic equation for decomposition reaction of 2 was also obtained. The apparent activation energy (E _a) and pre-exponential factor (A) of the main decomposition reaction are 157.70 kJ mol^?1 and 10^11.97 s^?1, respectively. The kinetic equation can thus be expressed as dα/dt = 10^11.97(1 ? α)e^{?1.90 × 104/ T} .     

Synthesis and Crystal Structures of Alkali and Alkaline Earth Metal Complexes of 3,5-Dinitropyrazolyl-4-carboxylate

The synthesis and crystal structures of 3,5-dinitro-1H-pyrazolyl-4-carboxylic acid (H₂dnpzc) and its four complexes with Ca²⁺, Ba²⁺, Na⁺ and K⁺ are reported in this paper. Ca(dnpzc) · 5H₂O exhibits a 1D polymeric structure, whereas Ba(dnpzc) · 4H₂O possesses a 2D structure. The structure of Na₂(dnpzc) · 4H₂O consists of 2D layers of [Na(dnpzc)]^–_n and 1D chains of [Na(H₂O)₃]⁺_n. K₂(dnpzc) · H₂O has a true 3D structure. It was observed that the doubly deprotonated ligand (dnpzc^2–) can act as a versatile bridge to form polymeric structures by varying combinations of its 8 potential donor atoms (two carboxy O atoms, two pyrazolyl N atoms and four nitro O atoms). Particularly in the structure of K₂(dnpzc) · H₂O, all the 8 donor atoms of dnpzc^2– take part in the coordination and as many as 10 potassium atoms are connected by one ligand.     

两个含双(3,5－二甲吡唑基)甲烷配体的铅(II)配合物的合成与结构表征

Reactions of lead（Ⅱ） nitrate or perchlorate with bis（3,5-dimethylpyrazolyl）methane （dmpzm）, produced two new Pb（Ⅱ） chelated complexes [Pb（dmpzm）2X2] （X=NO3^- 1, ClO4^- 2）. Both compounds were structurally characterized by elemental analysis, IR spectroscopy, thermal analysis, and single crystal X-ray diffraction. Both compounds are mononuclear with a distorted square antiprismatic PbN4O4 coordination geometry incorporating a pair of O,O＇-bidentate anions and N,N＇-bidentate dmpzm ligands. In the crystals of 1 or 2, the methyl or methylene groups of dmpzm ligand interact with the oxygen atoms of nitrates or perchlorates to afford intra- and intermolecular hydrogen bonding, thereby forming a two-dimensional network 1 or a three-dimensional structure 2.     

Syntheses,crystal structures and thermoanalyses of alkaline earth metal complexes derived from dinitropyridone

Six new alkaline-earth metal compounds derived from dinitropyridone ligands (3,5-dinitropyrid-2-one, 2HDNP; 3,5-dinitropyrid-4-one, 4HDNP and 3,5-dinitropyrid-4-one-N-hydroxide, 4HDNPO) were synthesized and characterized by elemental analysis, FT-IR and partly by powder XRD, TG-DSC and X-ray single-crystal diffraction analysis. The structural determination revealed that one molecule of both magnesium salts (Mg(2DNP)₂ ·?8H₂O, (1), and Mg(4DNP)₂ ·?6H₂O (4)) comprise one cation [Mg(H₂O)₆]²⁺ and two anions displaying centro-symmetry with the Mg atom located at the center. Two anions (and crystalline water molecules) are joined by hydrogen bonds. The barium salt Ba(4DNP)₂ ·?4H₂O (5), is a centro-symmetric dimer with each Ba(II) being coordinated by one monodentate ligand anion, two bidentate ligand anions (different coordination pattern) and five water molecules. Another barium salt, Ba(4DNPO)₂ ·?6H₂O (6), is a coordination polymer, the ten-coordinate (BaO₁₀) barium environment comprising four water molecules, a pair of 4DNPOs via the pyridine-N-oxide oxygen, and one 4DNPOs from an adjacent metal atom offering chelating nitro group oxygen, bridging adjacent bariums. Abundant intermolecular hydrogen bonds link the molecules of each complex into multi-dimensional chains. The X-ray powder diffraction analysis confirmed the phase homogeneity of the polycrystalline samples. The TG-DSC results revealed that Mg(2DNP)₂ ·?8H₂O and Ba(4DNP)₂ ·?6H₂O each has three main weight-loss stages. The first step is the loss of all water molecules and the last step is the loss of the nitro groups and/or decomposition of the pyridine rings with the release of heat.     

3,5-吡啶二羧酸镍配位聚合物的合成与晶体结构

采用水热法合成了3个新的3,5-吡啶二羧酸镍配位聚合物[Ni(3,5-Pydc)(H₂O)₄·H₂O]_n(1), [Ni₂(3,5-Pydc)₂(H₂O)₈·(H₂O)₂]_n(2)和[Ni(3,5-Pydc)(H₂O)₂]_n(3), 并通过X射线单晶衍射、FTIR及热重分析对其结构和组成进行了表征. 单晶衍射结果表明, 化合物1和2是一维折线型链状结构, 而化合物3是二维层状结构. 化合物1是由3,5-Pydc配体将中心镍离子连接起来形成的折线型一维链. 在化合物2中存在着两条各自独立的折线型一维链, 但它们的配位方式却完全相同, 每一条链都是由3,5-Pydc配体将镍离子连接而成. 而化合物3则是由3个镍离子和3个3,5-Pydc配体形成的二十元环构成的二维网格. 3个化合物分别通过链间或层间氢键作用(O-H…O)形成三维超分子结构, 化合物1和2中的客体水分子被氢键限域在超分子结构之中.     

Molecular Chains in the Crystals of a Calcium(II) Complex with Pyridine-3,5-Dicarboxylate (Dinicotinate) and Water Ligands

The crystal of pentaqua (catena-pyridine-3,5-dicarboxylato-O,O) calcium(II) contain zigzag molecular chains composed of Ca ions linked by two bridging oxygen atoms, each donated by one carboxylate group [Ca-O1 2.353(2) Å, Ca-O3^III 2.334(1) Å]. The Ca ions, the ligand molecules and one water oxygen atom coordinated by each metal ion [Ca-O5 2.410(2) Å] are coplanar. The coordination of the Ca ion is completed by four other water oxygen atoms situated above and below the plane of the chain [Ca-O6 2.475(1) Å, Ca-O7 2.371(2) Å]. The coordination number of the calcium(II) ion is seven. The water molecules act as donors in a system of hydrogen bonds.     

Syntheses and characterizations of four metal coordination polymers constructed by the pyridine-3,5-dicarboxylate ligand

A series of metal-organic frameworks, namely [Ni(PDB)(H₂O)]_n (1), [Pb(PDB)(H₂O)] · (H₂O) (2), [Co₂(PDB)₂(bpy)₂(H₂O)₄] · 4H₂O (3) and [Co₂(PDB)₂(phen)₂]_n (4) (H₂PDB = pyridine-3,5-dicarboxylic acid, bpy = 2,2′-bipyridine, phen = 1,10-phenanthroline), have been synthesized based on pyridine-3,5-dicarboxylate acid and two neutral chelate ligands, with different metal ions such as Ni^II, Co^II and Pb^II, under hydrothermal conditions. The framework structures of these polymeric complexes have been determined by the X-ray single crystal diffraction technique. In the four complexes, the pyridine-3,5-dicarboxylate acid ligand exhibits diverse coordination modes, which play an important role in the construction of metal-organic frameworks. The thermal analyses of these four complexes have been measured and discussed. In addition, complex 2 shows strong phosphorescent emission at room temperature and the magnetic measurement of the polymer of 4 reveals a typical antiferromagnetic exchange.     

Synthesis,characterization, and crystal structures of two coordination polymers from 3,5-bis(pyridin-4-ylmethyl) aminobenzoic acid

Aqueous medium reactions of transition metal salts with HL under hydrothermal conditions at 90°C led to two new coordination polymers, [M(L)₂(H₂O)₂]?·?H₂O [M?=?Co(1) and Mn(2); HL?=?3,5-bis(pyridin-4-ylmethyl)aminobenzoic acid]. HL contains both flexible N-donor groups [(pyridin-4-ylmethyl)amino] and carboxylate. The flexibility of (pyridin-4-ylmethyl)amino endows HL the ability to adopt varied conformations and coordination modes. Due to the presence of nitrogen and oxygen of HL and water in the reaction system, hydrogen-bonding interactions are available to assemble donor and acceptor building blocks. The two complexes are structurally similar to L^? doubly interconnecting M(II) to form 1-D chains. The extension of the 1-D chain through hydrogen-bonding forms fascinating 3-D supramolecular frameworks. FT-IR spectroscopy and thermal stability have been studied. The two compounds represent the first complexes containing 3,5-bis(pyridin-4-ylmethyl)amino benzoate.     

A three‐dimensional coordination polymer of 3‐(3,5‐dicarboxybenzyloxy)benzoic acid with zinc

The synthesis is reported of the tricarboxylic acid 3‐(3,5‐dicarboxybenzyloxy)benzoic acid (H₃L) and the product of its reaction under solvothermal conditions with Zn^II cations, namely poly[[μ₆‐3‐(3,5‐dicarboxylatobenzyloxy)benzoato](dimethylformamide)‐μ₃‐hydroxido‐dizinc(II)], [Zn₂(C₁₆H₉O₇)(OH)(C₃H₇NO)]_n, the formation of which is associated with complete deprotonation of H₃L. Its crystal structure consists of a single‐framework coordination polymer of the organic L³⁻ ligand with Zn^II cations in a 1:2 ratio, with additional hydroxide and dimethylformamide (DMF) ligands coordinated to the Zn^II centres. The Zn^II cations are characterized by coordination numbers of 5 and 6, being bridged to each other by hydroxide ligands. In the polymeric framework, the carboxylate‐ and hydroxy‐bridged Zn^II cations are arranged in coordination‐tessellated columns, which propagate along the a axis of the crystal structure, and each L³⁻ ligand links to seven different Zn^II centres via Zn—O bonds of two different columns. The coordination framework, composed of [Zn₂(L)(OH)(DMF)]_n units, forms an open architecture, the channel voids within it being filled by the zinc‐coordinating DMF ligands. This report provides the first structural evidence for the formation of coordination polymers with H₃L via multiple metal–ligand bonds through its carboxylate groups.<!?tpb=21.5pt>     

Synthesis,Crystal Structure,and Properties of Energetic Copper(II) Complex based on 3,5‐Dinitrobenzoic Acid and 1,5‐Diaminotetrazole

Energetic copper(II) complexes based on 3,5‐dinitrobenzoic acid (HDNBA) and 1,5‐diaminotetrazole (DAT), Cu(DNBA)₂(H₂O)₂ ( 1 ) and Cu(DAT)₂(DNBA)₂ ( 2 ) were synthesized and characterized by elemental analysis, IR spectroscopy, single‐crystal and powder X‐ray diffraction. In both complexes, Cu^II was coordinated to a plane tetragon, by four oxygen atoms from two DNBA^– ions and two coordinated H₂O molecules for 1 , and by two oxygen atoms and two nitrogen atoms from different DNBA^– ions and DAT ligands for 2 . Differential scanning calorimetry (DSC) and thermogravimetry (TG) analyses were employed to measure the thermal decomposition processes and non‐isothermal kinetics parameters of the complexes. The thermal decomposition onset temperatures of 1 and 2 are 321 and 177 °C. The apparent activation energies of the first exothermic decomposition peaks of 1 and 2 are 247.2 and 185.2 kJ · mol^–1. Both 1 (35 J, > 360 N) and 2 (12.5 J, > 360 N) are less sensitive than RDX. The catalytic effects on the decomposition of ammonium perchlorate (AP) of 1 and 2 were studied by DSC. All results supported the potential applications of the energetic complexes as additives of solid rocket propellants.     

Divalent transition metal complexes of 3,5-pyrazoledicarboxylate

New divalent transition metal 3,5-pyrazoledicarboxylate hydrates of empirical formula Mpz(COO)₂(H₂O)₂, where M=Mn, Co, Ni, Cu, Zn and Cd (pz(COO)₂=3,5-pyrazoledicarboxylate), metal hydrazine complexes of the type Mpz(COO)₂N₂H₄ where M=Co, Zn or Cd and Mpz(COO)₂nN₂H₄·H₂O, where n=1 for M=Ni and n=0.5 for M=Cu have been prepared and characterized by physico-chemical methods. Electronic spectroscopic data suggest that Co and Ni complexes adopt an octahedral geometry. The IR spectra confirm the presence of unidentate carboxylate anion (Δν=ν_asy(COO^–)–ν_sym(COO^–)>215 cm^–1) in all the complexes and bidentate bridging hydrazine (ν_N–N=985–950 cm^–1) in the metal hydrazine complexes. Both metal carboxylate and metal hydrazine carboxylate complexes undergo endothermic dehydration and/or dehydrazination followed by exothermic decomposition of organic moiety to give the respective metal oxides as the end products except manganese pyrazoledicarboxylate hydrate, which leaves manganese carbonate. X-ray powder diffraction patterns reveal that the metal carboxylate hydrates are isomorphous as are those of metal hydrazine complexes of cobalt, zinc and cadmium.     

Two lanthanide luminescent coordination compounds based on 3,5-pyrazoledicarboxylate and oxalic acid

Two isostructural 3-D complexes [Ln(pdc)(ox)_0.5(H₂O)₂]?H₂O (Ln = Tb(1), Eu(2); pdc = 3,5-pyrazoledicarboxylate; ox = oxalate) have been synthesized under hydrothermal conditions. Both are characterized by single crystal X-ray diffraction, elemental analysis, and IR. Compounds 1 and 2 possess a 3-D framework with 1-D rectangular channels built from 2-D, brick-like networks, and pdc ligands. The photoluminescence and lifetimes of 1 and 2 in the solid state have been studied.     

基于3,5-二((4'-羧基苄基)氧)苯甲酸和4'-(4-吡啶基)-2,2':6',2"-三联吡啶为混合配体的两个配合物的水热合成与晶体结构

在水热条件下,以3,5-二（（4''-羧基苄基）氧）苯甲酸（H3bcb）和4''-（4-吡啶基）-2,2''：6'',2"-三联吡啶（PYTPY）为混合配体构筑了2个过渡金属配合物[Co（H₂bcb）₂（PYTPY）]_n （1）和[Mn（H₂bcb）₂（PYTPY）]_n （2）,利用元素分析、红外光谱以及单晶X射线衍射表征其结构。分析表明配合物1和2为一维链状结构。此外,2个配合物展示了优良的热稳定性。磁化率的测试结果表明,配合物1和2在2 K和8 K以下时展示了反铁磁相互作用。