Heterovalent trinuclear Co(III)-Co(II)-Co(III) complexes with N-(2-Carboxyethyl)salicylaldimines

The heterovalent trinuclear cobalt complexes [Co₂^IIIL₄ ⁱ · Co^II(H₂O)₄] · nXmY (L ⁱ are deprotonated Schiff bases derived from substituted salicylaldehydes and β-alanine; i = 1–3) were obtained and characterized. An X-ray diffraction study of the trinuclear cobalt complex with N-(2-carboxyethyl)salicylaldimine showed that the central Co(II) ion and the terminal Co(III) ions are linked by bridging carboxylate groups. Either terminal Co(III) atom is coordinated to two ligand molecules. They form an octahedral environment consisting of two azomethine N atoms, two phenolate O atoms, and two O atoms of two carboxylate groups. The central Co(II) atom is coordinated to four water molecules and to two O atoms of two bridging carboxylate ligands involved in the coordination sphere of the terminal Co(III) atoms.     

μ3-ethylidyne-triphenylphosphine-octacarbonyltricobalt: a re-determination from diffractometer data

The structure of the title compound was originally reported from film data (Brice et al., Inorg Chem 9:362, 1970) and comprises a triangle of cobalt atoms capped by an ethylidyne substituent to form an approximately tetrahedral cluster unit. The triphenylphosphine ligand lies in an equatorial position with respect to the plane of the cobalt triangle. Two carbonyl groups, one axial the other equatorial, complete the coordination sphere of the cobalt atom bound to phosphorus. The other two cobalt atoms each carry two equatorial and one axial carbonyl ligand. The Co–Co bond cis to the phosphine substituent is significantly longer than the other two Co–Co distances. The crystal structure is stabilised by C—H···π interactions and C—H···O hydrogen bonds. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Synthesis, spectral and thermal properties, and crystal structure of catena-poly-μ-ethylenediamine(dipicolinato)zinc(II) trihydrate, {[Zn(dipic)(μ-en)]·3H2O}n

A novel metal–organic coordination polymer framework formulated as {[Zn(dipic)(μ-en)]·3H₂O} _n (1) (catena-poly-μ-ethylenediamine(dipicolinato)zinc(II) trihydrate) has been synthesized and characterized by spectral method (IR), elemental analysis, thermal analysis (TG, DTG, DTA) and single crystal X-ray diffraction techniques. It crystallizes in the triclinic system, space group P−1. The asymmetric unit contains three hydrogen-bonded water molecules and the Zn atom is five-coordinated by three N and two O atoms. In fact, it is a new one-dimensional zinc complex with the peculiarity of having the ethylenediamine ligand very unusually acting as bridge to form polymeric chains. In the crystal structure, intramolecular O–H···O and intermolecular O–H···O and N–H···O hydrogen bonds result in the formation of a supramolecular structure, in which they seem to be effective in the stabilization of the structure.     

Electronic structure and hydrogen bond in the crystal of paracetamol drugs

We study the density of state (DOS), band structure (BS), and atomic orbit projected density of state (PDOS) of paracetamol crystal adopting the density functional theory (DFT) technique in the local density approximation (LDA). The band structure around the Fermi level and the contributions from p-type orbit of C, N, O, and s-type orbit of H to the total density of state (TDOS) are addressed, and we find that the electronic characteristic is the key to form the hydrogen bond between O and H atoms. We show that the structure of paracetamol crystal consists of the –OH···O=C and –NH···OH hydrogen-bonding cycle by studying a single paracetamol molecule as well as the PDOS graph of O and H atoms in the crystal.     

Structure and hydrogen bonding in polyhydrated complexes of guanine

Abstract Molecular structure of complexes of guanine with 12, 13, 16, and 17 water molecules were calculated using B3LYP/6-311G(d,p) level of theory. Interaction with water results in some deformation of geometrical parameters of guanine, which can be described as contribution of zwitter-ionic resonant form into the structure of DNA base. Saturation of water binding sites within guanine creates possibilities for the formation of the N···H–O hydrogen bond where the nitrogen atom of amino group acts as proton acceptor. The NBO analysis of guanine–water interactions reveals that hydrogen bonds involving the N(3) and N(7) atoms of guanine represent a case of mixed N···H–O/π···H–O hydrogen bonds where contribution of π-system into total energy of interaction varies from 3% to 41%. This contribution significantly depends on orientation of the hydrogen atom of water molecule with respect to plane of purine bicycle and influence of neighboring water molecules. Graphical Abstract      

Synthesis and Characterization of [Hg(sulfamethoxazolato)2]·2DMSO and[Cu2(μ‐CH3CO2)4(sulfamethoxazole)2]

[Hg(sulfamethoxazolato)₂]·2DMSO ( 1 ) and [Cu₂(CH₃COO)₄(sulfa‐methoxazole)₂] ( 2 ) can be obtained by the reaction of sulfamethoxazole with mercury acetate or copper acetate in methanol. The structures of the two complexes were characterized by single crystal X—ray diffractometry. Compound 1 consists of sulfamethoxazolato ligands bridging the metal ions building an unidimensional chain. Two solvent dimethylsulfoxide molecules are involved via N‐H···O hydrogen bridges. The mercury atom shows a linear primary coordination arrangement formed by two trans deprotonated sulfonamidic nitrogen atoms. The overall coordination around the metal atom may be regarded as a strongly distorted octahedron when the interactions of mercury with four sulfonamidic oxygen atoms [bond distances of 2.761(4) Å—2.971(4) Å] are also considered to build an equatorial plane and the N1 and N1′ atoms [bond distance of 2.037(5) Å] occupy the apical positions. Compound 2 is a dinuclear complex in which the copper ions are bridged by four syn‐syn acetate ligands which are related by a symmetry centre located in the centre of the complex. Each copper atom presents a nearly octahedral coordination where the equatorial plane is formed by four oxygen atoms and an isoxazolic nitrogen atom and the second copper atom occupy the apical positions.     

Synthesis,IR spectrum,thermal property and crystal structure of cyano-bridged heteronuclear polymeric complex, [Cd(teta)Ni(μ-CN)<Subscript>2</Subscript>(CN)<Subscript>2</Subscript>] · 2H<Subscript>2</Subscript>O

The cyano-bridged heteronuclear polymeric complex, [Cd(teta)Ni(μ-CN)₂(CN)₂] · 2H₂O (1), (teta = triethylenetetraamine) was synthesized and characterized by FT-IR spectroscopy, thermal analysis and single crystal X-ray diffraction techniques. It crystallizes in the orthorhombic system, space group Pccn. The asymmetric unit also contains two uncoordinated water molecules. The coordination geometry around the Cd(II) centre is a highly distorted octahedral. In the crystal structure, intramolecular N–H···O and intermolecular N–H···O, O–H···O and O–H···N hydrogen bonds, beside the cyano-bridged chains made up of tetracyanonickelate ions coordinated to Cd(II) ions, where the Ni(II) ion is coordinated by four cyanoligands in a square-planar arrangement, link the molecules into polymeric networks parallel to (001) plane, where the hydrogen bonded water molecules occupy the cavities between the layers. The FT-IR spectrum was reported in the 4,000–400 cm⁻¹ region. Vibration assignments were given for all the observed bands and the spectral feature also supported the structure of the polymeric complex. The decomposition reaction takes place in the temperature range 20–1,000 °C in the static air atmosphere.     

Synthesis and Crystal Structure of 1D Coordination Polymer of N,N＇-Bis（3-pyridylmethyl）-1,4-benzenedicarboxamide and Cobalt（Ⅱ） Nitrate

A noval cobalt(II) coordination polymer, {[Co(bpmb)(H₂O)₂(C₂H₅OH)₂]·(NO₃)₂}‐ (1). where bpmb=N,N′‐bis(3‐pyridylmethyl)‐1,4‐benzenedicarboxamide, was synthesized by self‐assembly of the two topic ligands with cobalt nitrate in ethanol solution, and characterized structurally by X‐ray crystallography analysis. The crystal data belong to triclinic, space group P1 with cell parameters a=0.8911(3) nm, b=0.9042(3) nm, c= 1.0068(3) nm, α= 73.083(5)°, β=81.069(5)°, γ=76.210(5)°, R₁=0.0518, wR₂=0.0947. The results of structure analysis indicate that each bpmb ligand coordinates two Co(II) atoms and each metal atom is in octahedral coordination geometry with four oxygen atoms of two ethanol and two water molecules, two nitrogen atoms from two different bpmb ligands in trans position forming an infinite 1D chain‐like structure. There BTC hydrogen bonding and π‐π stacking interaction among these chains, leading to supramolecular formation with 3D net structure.     

Synthesis and spectroscopic studies of the cobalt(II) complex with methyl 2-pyridylmethylidenehydrazinecarbodithioate (HNNS)

A new cobalt(II) complex with the Schiff base methyl 2-pyridylmethylidenehydrazinecarbodithioate (HNNS), Co(NNS)₂, has been synthesized and characterized using single-crystal X-ray diffraction and spectroscopy (IR, UV–Vis, MS and EA). Complex [Co(NNS)₂] crystallizes in the orthorhombic, space group Pna2(1). The coordination geometry around Co(II) in the complex is distorted octahedral and the two ligands in the mer-configuration (S and tertiary N atom cis to each other and the iminic N atoms trans). Furthermore, the neutral molecule unit Co^II(NNS)₂ is connected by hydrogen bonds C–H ··· S and forms a three dimensional ordered network structure.     

Crystal structures of calcium and barium oxalato(ethylenediamine-N,N′-diacetato)× chromates(III) M[Cr(Edda)(C2O4)]2·5H2O (M = Ca, Ba)

The crystal structure of Ca[Cr(Edda)(C₂O₄)]₂·5H₂O and Ba[Cr(Edda)(C₂O₄)]₂·5H₂O (H₂Edda — ethylenediamine-N,N′-diacetic acid) was determined by X-ray diffraction analysis. The nearest environment of alkaline earth ions consists of the oxygen atoms of the neighboring [Cr(Edda)(C₂O₄)]^? complex ions (five for Ca and four for Ba) and the water molecules that complete the coordination number to eight. Two atoms and two complex ions are linked into a ring; each Ca atom in the ring is bonded by the oxalate ion bridge to another anion. This results in a centrosymmetric hexanuclear supramolecular assembly. The atoms and the complex anions alternate to form an infinite chain, in which each Ba atom is additionally linked via the oxalate ion bridge with one anion.     

Synthesis,crystal structure and other properties of the complexes of Er(III), Yb(III) and Lu(III) with 4,4′-bipyridine and dichloroacetates

A novel mixed-ligand complexes of Er(III), Yb(III) and Lu(III) with title ligands were prepared and characterized by chemical and elemental analysis and IR spectroscopy, conductivity (in methanol, dimethyloformamide and dimethylsulphoxide). The thermal properties of complexes in the solid state were studied. The mode of metal–ligand coordination was discussed. The title compounds are isomorphic and isostructural in solid state. All atoms in studied compounds lie in general positions but occurrence of inversion on the midpoint of the bond linking two pyridine rings leads to existence in asymmetric unit one complex molecule and half of outer coordination sphere 4-bpy molecule. All chelating carboxylate groups are symmetrically bonded to the metal cations. The molecules of studied compounds are connected to the three dimensional network via O–H···O and O–H···N intermolecular hydrogen bonds. In the structures also exist C–H···O, C–H···Cl weak hydrogen bonds and π····π stacking interactions.     

The structure and thermal behaviour of sodium and potassium multinuclear compounds with hexamethylenetetramine

Sodium and potassium thiocyanate complex compounds of formulae [Na(hmta)(H₂O)₄]₂²⁺·2SCN⁻ (1) and [K₂(hmta)(SCN)₂] _n (2) have been synthesized and characterised by IR spectroscopy, thermogravimetry coupled with differential thermal analysis, elemental analysis and X-ray crystallography. Each sodium and potassium cation is six co-ordinated, the sodium by one monofunctional hmta molecule, three terminal water molecules and two bridging water molecules, and the potassium by two bridging tetrafunctional hmta molecules and four bridging tetrafunctional thiocyanate ions. The coordination polyhedra of the central atoms can be described as distorted tetragonal bipyramids. The complex cations and anions of (1) are interconnected by multiple intramolecular O(water)—H···N(hmta/NCS) and O(water)—H···S hydrogen bonds to the three dimensional net. In each complex cation the intramolecular O–H···O hydrogen bonds link two terminal water molecules bonded to two metal cations. The compound (2) forms the three dimensional hybrid network in which the classical two-dimensional coordination polymers are linked by inorganic SCN⁻ spacers to the third-dimension. Thermal analyses show that the compounds decompose gradually in three (for 1) and two (for 2) steps with formation of Na₂SO₄ and K₂S as the final products, respectively, for 1 and 2.     

Synthesis, Crystal Structure and Electrochemical Properties of One-dimensional Chain Coordination Polymer [Co(II)(C_6H_5CH=CHCOOH)_2(4,4′-bipy)(H_2O)_5]_n

A one-dimensional chain coordination polymer [Co(II)(C6H5CH=CHCOOH)2(4,4′- bipy)(H2O)5]n has been synthesized with cinnamylic acid, 4,4′-bipy and cobaltous chloride as raw materials. Crystal data for this complex: monoclinic, space group P21/c, a = 1.1481(3), b = 1.1230(2), c = 1.1759(3) nm, β = 97.054(4)o, V = 1.5046(6) nm3, Mr= 617.50, Dc = 1.363 g/cm3, Z = 2, μ(MoKα) = 0.627 mm-1, F(000) = 646, S = 1.062, R 0.0443 and wR = 0.1178. The crystal structure shows that two neighboring cobalt(II) ions are linked together by one 4,4′-bipy, and the whole complex molecule adopts a one-dimensional chain structure. Each cobalt(II) ion is coordinated with two nitrogen atoms from two 4,4′-bipy molecules and four oxygen atoms from four water molecules, giving a distorted octahedral coordination geometry. The electrochemical properties were analyzed by combining with the crystal structure.     

Synthesis and Crystal Structure of a One-dimensional Azido-bridged Manganese (II) Compound [Mn(N_3)_2(H_2O)_3·C_6H_(12)N_4]_n

1 INTRODUCTION The azide anion is a good bridging ligand for di- valent metal ions to form discrete, one-dimensional, two-dimensional or three-dimensional complexes. In recent years, these complexes have drawn consider- able attentions for their interesting magnetic charace- ristics which attribute to the efficient magnetic coup- ling ability of the azido bridges[1]. When the azide anion acts as a bridging ligand, two typical modes are adopted: end-to-end (EE, μ1, 3) or end-on (EO, μ1…     

一种锰的超分子化合物的制备、结构及非线性光学 性质研究

用MnSO4·H2O,KSCN,六次甲基四胺(HMTA)制备出超分子化合物[Mn(NCS)2(H2O)2(HMTA)2][Mn(NCS)2(H2O)4](H2O)2,并测定了其晶体结构。该化合物由[Mn(NCS)2(H2O)2(HMTA)2],[Mn(NCS)2(H2O)4]和H2O三部分组成,每一个HMTA配体中仅有一个N原子与Mn原子配位,剩余的3个N分别与[Mn(NCS)2(H2O)4]中的H2O及结晶H2O之间形成氢键。[Mn(NCS)2(H2O)2(HMTA)2]和[Mn(NCS)2(H2O)4]之间通过N…H—O氢键边接成无限延伸的线性长链,链与链、以及链和结晶H2O之间通过七种形式的氢键构成三维结构的超分子。用Z-扫描法测定该化合物在DMF溶液中的三阶非线性光学性质,发现它具有自聚焦效应,三阶非线性折射系数n2=9.52×10^-9m^2·W^-1,非线性极化率χ^(3)=3.41×10^-12esu.     

Synthesis, Crystal Structure and Electrochemical Properties of One-dimensional Chain Coordination Polymer [Co(Ⅱ)(C6H5CH=CHCOOH)2(4,4''-bipy)(H2O)5]n

A one-dimensional chain coordination polymer [Co(Ⅱ)(C6H5CH=CHCOOH)2(4,4'-bipy)(H2O)5]n has been synthesized with cinnamylic acid, 4,4'-bipy and cobaltous chloride as raw materials. Crystal data for this complex: monoclinic, space group P21/c, a - 1.1481(3), b =1.1230(2), c = 1.1759(3) nm, β = 97.054(4)°, V = 1.5046(6) nm3, Mr= 617.50, Dc = 1.363 g/cm3, Z= 2, μ(MoKα) = 0.627 mm-1, F(000) = 646, S = 1.062, R 0.0443 and wR = 0.1178. The crystal structure shows that two neighboring cobalt(Ⅱ) ions are linked together by one 4,4'-bipy, and the whole complex molecule adopts a one-dimensional chain structure. Each cobalt(Ⅱ) ion is coordinated with two nitrogen atoms from two 4,4'-bipy molecules and four oxygen atoms from four water molecules, giving a distorted octahedral coordination geometry. The electrochemical properties were analyzed by combining with the crystal structure.     

2,6‐Bis[bis(2‐pyridiniomethyl)aminomethyl]‐4‐tert‐butylphenol dichloride diperchlorate hydrate

The title compound, C₃₆H₄₄N₆O⁴⁺·2Cl^?·2ClO₄^?·0.132H₂O, is shown to be protonated at all the pyridine N atoms; the two chloride ions are hydrogen bonded to three pyridine N atoms and to the phenolic O atom of the same cation [Cl?N = 3.045 (2)–3.131 (2) Å and Cl?O = 2.938 (2) Å], and the remaining pyridine N atom is hydrogen bonded to the phenolic O atom [N?O = 2.861 (2) Å]. The mean value of the C—N—C angle of the protonated pyridine rings is 123.4 (1)°, which is significantly larger than that found for unprotonated pyridine rings.     

Über die Struktur von Bis-(dihydroxoboroxalendiamiddioximato)-nickel(II)-tetrahydrat

The space group of the sparingly soluble brown coloured bis-(dihydroxobor-oxalene-diamide-dioximato)-nickel(II)-tetrahydrate (C₄H₁₂N₈O₈B₂Ni · 4 H₂O) is P21/c with a = 9.25, b = 13.27, c = 6.61 Å and β = 92.7°. The structure was solved on single crystals. There are two molecules in the unit cell. Within the square planar complex the nickel atom is bonded to the four nitrogen atoms of the plane system of the two dioximato ligands (Ni? N = 1.84 ± 0.02 Å). Each of the boron atoms is tetrahedrally surrounded by two oxygen atoms belonging to the oxime groups and two hydroxyl groups (B? O = 1.50 ± 0.06 Å). Thus the complex has the conformation of a chair form. The water molecules participate in intermolecular hydrogen bonds. There is no interaction between Ni atoms.     

Synthesis and Crystal Structure of a One-dimensional Azido-bridged Manganese (II) Compound [Mn(N3)2(H2O)3·C6H12N4]n

A new one-dimensional azido-bridged manganese compound has been prepared and structurally characterized by X-ray diffraction. The complex [Mn(N3)2(H2O)3·C6H12N4]n crystallizes in space group Pnma with a = 6.5252 (5), b = 9.3226(7), c = 22.2070(15)(A), V = 1350.89(17)(A)3, Z = 4, Mr = 333.24, Dc = 1.639 g/cm3, μ= 1.005 mm-1 and F(000) = 692. The final refinement gave R = 0.0328 and wR = 0.0777 for 1085 observed reflections with I > 2σ(I). The structure contains [Mn- (N3)2(H2O)3]n polymeric chains and uncoordinated hexamethylenetetramine (HMTA) molecules with Mn/HMTA molar ratio of 1:1. The Mn atoms are bridged by end-to-end azido ligands to construct one-dimensional zig-zag infinite chains. Each Mn atom is six-coordinated by three N atoms of three azido ligands and three water O atoms, resulting in an octahedral geometry. Extending hydrogen- bonding interactions involving water O atoms, azido and HMTA N atoms link the chains and HMTA molecules into a three-dimensional network.     

Self‐Assembly and Structure of Cobalt(II) Complexes Using Diaminodiamide Ligands

The self‐assembly of Co(II) with two diaminodiamide ligands, 4,7‐diazadecanediamide and 4,8‐diazaundecanediamide, gave two different crystals, [(C₈H₁₈N₄O₂)Co(OH)₂Co(C₈H₁₈N₄O₂)]Cl₂ ( 1 ) [Co(C₉H₂₀N₄O₂)(Cl)(H₂O)]·Cl·2H₂O ( 2 ). Structures of 1 and 2 were characterized by single‐crystal X‐ray diffraction analysis. Structural data for 1 shows a novel type of binuclear complex with distorted octahederal coordination geometry around the Co atoms through the hydroxo bridges. By using inter‐connector N‐H···N hydrogen bonding interactions as building forces, each cationic moiety [(C₈H₁₈N₄O₂)Co(OH)₂Co(C₈H₁₈N₄O₂)]²⁺ is linked to neighboring ones, producing a charged hydrogen‐bonded 1D chain‐like structure. The chains are further connected into a 2D layer in a (4,4)‐topology via N‐H···Cl_free hydrogen‐bonding interactions. Structural data for 2 indicate that the cobalt atom adopts a six‐coordinated N₂O₄ environment, giving a distorted octahedral geometry, where two N‐ and two O‐donor sets of ligand located at equatorial positions and one water and one chloride occupied at axial positions. Through NH···Cl‐Co and OH···Cl‐Co contacts, each cationic moiety [Co(C₉H₂₀N₄O₂)(Cl)(H₂O)]⁺ in 2 is linked to neighboring ones, producing a charged hydrogen‐bonded 1D chainlike structure. Thus, the crystal‐engineering approach has proved successful in the solid‐state packing due to steric strain effect of the diaminodiamide ligand.