Self-assemblies of Ni(II) with phenanthroline and maleate anions: [Ni(H2O)3(phen)L] ⋅ H2O (1) and [Ni(H2O)2(phen)L] ⋅ 2H2O (2) with H2L = maleic acid

The complex [Ni(H₂O)₃(phen)(C₄H₂O₄)] H₂O (1), which was obtained by reaction of phenanthroline, Ni(NO₃)₂ 6H₂O, and maleic acid in CH₃OH/H₂O at pH = 7.05, crystallized in the monoclinic space group P2₁ (no. 4) with cell dimensions: a = 9.350(1) Å, b = 7.631(1) Å, c = 12.821(1) Å, = 106.25(1), and D _calc = 1.607 g/cm³ for Z = 2. The Ni atoms are each octahe drally coordinated by one chelating phen ligand, three H₂O molecules and one monodentate maleato ligand to form [Ni(H₂O)₃(phen)(C₄H₂O₄)] complex molecules with d(Ni–O) = 2.038–2.090 Å, d(Ni–N) = 2.066, 2.089 Å. The formed complex molecules are, via the intermolecular hydrogen bonds, assembled into columnar 1D chains. Interdigitation of the chelating phen ligands of the neighboring chains leads to 2D layers and the crystal H₂O molecules are hydrogen bonded to the oxygen atoms of the maleate not coordinated to the Ni atom. However, reaction of NiCO₃, phen, and maleic acid in CH₃OH/H₂O at pH = 6.33 afforded [Ni(H₂O)₂(phen)(C₄H₂O₄)] 2H₂O (2), which crystallized in the triclinic space group (no. 2) with cell dimensions: a = 7.971(1) Å, b = 8.237(1) Å, c = 13.304(1) Å, = 81.005(6)°, = 87.877(8)°, = 78.322(8)°, and D _calc = 1.671 g/cm³ for Z = 2. The Ni atoms are each octahedrally coordinated by two N atoms of one phen ligand and four O atoms of two H₂O molecules and two bis–monodentate maleato ligands with d(Ni–O) = 2.041–2.120 Å and d(Ni–N) = 2.095 Å. The Ni atoms are bridged by the maleato ligands to generate 1D ¹ [Ni(H₂O)₂(phen)(C₄H₂O₄)_2/2] chains along [100]. The supramolecular assemblies of the 1D chains via – stacking inter- actions result in thick 2D layers parallel to (001), between which the noncoordinating H₂O molecules are sandwiched. The paramagnetic [Ni(H₂O)₂(phen)(C₄H₂O₄)_2/2] 2H₂O (2) obeys the Curie–Weiss law _m(T-) = 1.139cm³ mol^–1 K with the Weiss constant = –0.95 K.     

An unusual function of the anion of 1-hydroxyethane-1,1-diphosphonic acid (H4 L): Crystal structure of [Ni(Phen)3](H7 L 2)0.5(H5 L 2)0.5 ⋅ 2H2O

Crystals of [Ni(Phen)₃](H₃ L)₂ ? 2H₂O (H₄ L is 1-hydroxyethane-1,1-diphosphonic acid) have been synthesized, and their structure has been determined by X-ray diffraction analysis. The cationic complexes [Ni(Phen)₃]²⁺, the centrosymmetric dimeric anions H₇ L ₂ ^? and H₅ L ₂ ^3? , and the molecules of crystallization water are the structural units of the crystal. The outer-sphere function of the H4 L anions in transition metal compounds and also the presence of differently charged dimeric anions are revealed for the first time. The structural units are joined together by an extended system of hydrogen bonds, including symmetric (or pseudosymmetric) hydrogen bonds in dimeric anions (O?O, 2.436 and 2.466 Å). The Ni-N(Phen) bond lengths fall in the range 2.074–2.107 Å. The compound has the structural formula [Ni(Phen)₃](H₇ L ₂)_0.5(H₅ L ₂)_0.5 ? 2H₂O.     

Crystal structures of acid ethylenediaminetetraacetates [Cd(H2 Edta)(H2O)] · 2H2O and [Mn(H2O)4][Mn(HEdta)(H2O)]2 · 4H2O

The crystal structures of [Cd(H₂ Edta)(H₂O)] · 2H₂O (I) and [Mn(H₂O)₄][Mn(HEdta)(H₂O)]₂ · 4H₂O (II) are studied by X-ray diffraction [R ₁ = 0.0209 (0.0272), wR ₂ = 0.0571 (0.0730) for 2551 (4025) reflections with I > 2σ(I) in I (II), respectively]. Structure I contains mononuclear [Cd(H₂ Edta)(H₂O)] complexes with the C ₂ symmetry, and structure II contains centrosymmetric trinuclear [Mn(H₂O)₄][Mn(HEdta)(H₂O)]₂ complexes. In I and II, the protonated ligands are hexadentate (2N + 4O), and the water molecule increases the coordination number of the metal atom to seven. The acid protons participate in short intermolecular hydrogen bonds, which are symmetric in II and asymmetric in I.     

Synthesis and crystal structure of [Ni(H2O)6](C19H17O9S)2·2H2O

A water soluble flavonoid sulfate, [Ni(H₂O)₆](C₁₉H₁₇O₉S)₂·2H₂O was synthesized and its structure was determined by single-crystal X-ray diffraction analysis. The crystal of it belongs to triclinic crystal system, space group P–1. The results show that the title compound consists of [Ni(H₂O)₆]²⁺, C₁₉H₁₇O₆SO₃ ⁻ and H₂O. Ni(II) is located on the symmetry center and octahedrally coordinated by six water molecules. A variety of hydrogen bonds among [Ni(H₂O)₆]²⁺, C₁₉H₁₇O₆SO₃ ⁻ and the lattice water molecules build a hydrophilic region. Aromatic π–π stacking interactions assemble isoflavone skeletons into a column and the columns form a hydrophobic region of the title compound. The sulfo-groups bridge the hydrophilic regions and the hydrophobic regions as well as the inorganic components and organic components. Hydrogen bonds, stacking interactions and the electrostatic interactions between cation [Ni(H₂O)₆]²⁺ and anion sulfonate C₁₉H₁₇O₆SO₃ ⁻ lead the moieties to a three-dimensional structure.     

Synthesis and crystal structure of [Co(phen)(H2O)4](SO4)⋅2(H2O)

The title complex, [Co(phen)(H₂O)₄](SO₄)2(H₂O) (phen = 1,10-phenanthroline) was prepared in aqua tert-butylperoxohydrogen solution. X-ray single crystal structure determination reveals that the complex consists of a phenanthrolinatocobalt(II)tetrahydrate dication, two uncoordinated water molecules and a sulfate anion. It crystallizes in the orthorhombic space group Pbca with a = 8.856(1), b = 18.318(3), c =21.918(5) Å, V = 3555.6(11) ų. The coordination geometry at each cobalt(II) atom is a slightly distorted octahedron.     

Structure and conformation of the monohydrate of N-t-boctyrosyl-proline (Boc-Tyr-Pro·H2O)

The structure and conformation of the monohydrate of N-t-boc-tyrosyl-proline (Boc-Tyr-Pro·H₂O) (C₁₉H₂₆O₆N₂·H₂O) has been investigated with X-ray crystallographic and spectroscopic methods. Boc-Tyr-Pro crystallized in an extendedtrans conformation in the space group P2₁2₁2₁ with cell dimensionsa=8.566(1),b=9.996(1),c=24.734(1). The conformation of Boc-Tyr-Pro reflex -helix type prolines. Three intermolecular hydrogen bonds are observed. Crystal water is involved in two hydrogen bonds (to the hydroxyl group of the C-terminal of the proline residue; to the carbonyl group of the t-Boc functionality) while the hydroxyl group of the tyrosyl residue (to the carbonyl group of the amide bond) is involved in one hydrogen bond. The puckering mode of the pyrrolidine ring of the proline residue is similar to what has been previously observed for other proline-containing peptides.Cis-trans isomerism is observed in the NMR spectra of Boc-Tyr-Pro with a predominance for the extended side chain for the tyrosyl residue.     

Crystal structure of aqua[S-prolinato-N-monoacetato)copper(II) dihydrate [Cu(Proma)H2O] ⋅ 2H2O

The crystal structure of [Cu(C₇H₉NO₄)H₂O] ? 2H₂O is determined by X-ray diffraction (λMo, R = 0.0316 for 857 reflections). The crystals are tetragonal, a = 8.219(1) Å, c = 17.449(3) Å, Z = 4, ρ_calcd = 1.627 g cm^?3, and space group P4₃. The coordination polyhedron of the Cu atom is a tetragonal pyramid with the O atom of the acetate arm of the prolinatomonoacetate ion (Proma) in the apical position [Cu-O 2.312(6) Å]. The O atom of the water molecule and the N and O atoms of the prolinate group of the Proma ligand lie in the basal plane. The Cu-N bond length is 2.044(6) Å, and the Cu-O bond lengths are 1.932(7) and 1.927(6) Å. The O atom of the acetate arm of the neighboring Proma ion completes the basal plane [Cu-O 1.951(6) Å], thus linking the copper complexes into infinite chains.     

Synthesis and structure of (NH4)3[UO2(C3H2O4)2(NCS)] · 2H2O

Malonate-thiocyanate complex (NH₄)₃[UO₂(C₃H₂O₄)₂(NCS)] · 2H₂O is synthesized and studied by X-ray diffraction. The compound crystallizes in the monoclinic system: a = 13.9983(4) Å, b = 8.1947(2) Å, c = 16.4678(4) Å, β = 100.846(1)°, space group Cc, Z = 4, and R = 0.0158. The main structural units of the crystal are mononuclear [UO₂(C₃H₂O₄)₂(NCS)]^3? groups belonging to the AB ₂ ⁰¹ M ₁ crystal chemical group of uranyl complexes (A = UO ₂ ²⁺ , B ⁰¹ = C₃H₂O ₄ ^2? , M ¹ = NCS^?). Discrete uranium-containing groups are connected by electrostatic interactions with ammonium ions and by hydrogen bonds. Some specific structural features of crystals containing [UO₂(L)₂(NCS)]^3? complexes, where L is the oxalate or malonate ion, are discussed.     

Synthesis and structure of [Ca(triethyleneglycol)2](NO3)2·H2O

Crystallization of calcium nitrate from a toluene solution of triethyleneglycol (= 2,2-[1,2-ethanediylbis(oxy)]-bisethanol) resulted in the formation of the 1:2 solvate [Ca(triethyleneglycol)₂](NO₃)₂·H₂O. [Ca(C₆H₁₄O₄)₂](NO₃)₂·H₂O is monoclinic, P2₁/c, a = 15.775(1), b = 8.660(2), c = 16.342(1) Å, = 91.239(7)°, V = 2232.1(6) ų, Z = 4, and D _c = 1.429 g cm^–3. The eight-coordinate calcium has square antiprismatic geometry with two triethyleneglycol molecules straddling the metal center. The nitrate anions and water of crystallization are involved in hydrogen bonding with the alcoholic hydrogen atoms.     

Crystal structures of mixed ligand complexes containing saccharinate and nicotinamide: [Cu(saccharinato)2 (nicotinamide) (H2O)]⋅(H2O) and [M(nicotinamide)2 (H2O)4]⋅(saccharinate)2 (M = Ni2+, Co2+)

[M(saccharinato)₂(H₂O)₄] (M = Cu²⁺, Ni²⁺, Co²⁺) react with nicotinamide to form mixed ligand complexes, [Cu(saccharinato)₂(nicotinamide)(H₂O)](H₂O) (1) and [M(nicotinamide)₂(H₂O)₄](saccharinate)₂ (2: M = Ni²⁺; 3: M = Co²⁺), and their crystal structures have been determined by X-ray diffraction. In 1, the Cu²⁺ atom in an octahedral configuration is coordinated by two monodentate saccharinato ligands in the trans arrangement through the deprotonated ring nitrogens, by two bidentate nicotinamide ligands, one through the pyridyl ring nitrogen and the other through the amide oxygen, and by a water molecule, thus forming a nicotinamide-bridged one-dimensional extended structure. In the isomorphous complexes 2 and 3, the octahedral metal atom, which rides on a crystallographic center of symmetry, is coordinated by two monodentate nicotinamide ligands through the ring nitrogens and four water molecules to form a discrete [M(nicotinamide)₂(H₂O)₄]^{2 +} structural unit, which captures up and down two saccharinate ions, each through three hydrogen bonds: two hydrogen bonds between two water ligands and the ring N and the carbonyl O atoms and one between the amide N of the nicotinamide ligand and the carbonyl O.     

Crystal and molecular structure of complex compound [Fe3O(CH3COO)6(H2O)3]2[ZnCl4] ⋅ 2H2O

The X-ray crystal structure of trinuclear iron acetate [Fe₃O(CH₃COO)₆(H₂O)₃]₂ [ZnCl₄] ? 2H₂O was determined. The crystal has a ionic structure. It is monoclinic, a = 25.363(7), b = 14.533(4), c = 15.692(4) Å, β = 103.11(2)°, space group _C2/c, and R = 0.0685. The structure of the cationic complex [Fe₃O(CH₃COO)₆(H₂O)₃]⁺ is typical of trinuclear iron(III) compounds containing a μ₃-O bridge: the iron atoms are situated at the vertices of an almost equilateral triangle with the O atom at the center. Each Fe atom is coordinated by four O atoms of bridging carboxy groups, the μ₃-bridging O atom, and the water molecule in the trans position to the latter O atom. Mössbauer spectroscopy evidence indicates the high-spin state (_S = 5/2) of the iron(III) ions.     

Metal-hydroxycarboxylate interactions: syntheses and structures of K2[VO2(C6H6O7)]2·4H2O and (NH4)2[VO2(C6H6O7)]2·2H2O

Potassium and ammonium dimeric (citrato)dioxovanadium(V) hydrate K₂[VO₂(H₂cit)]₂·4H₂O1 and (NH₄)₂[VO₂(H₂cit)]₂·2H₂O2 (H₄cit=citric acid) have been prepared and characterized by X-ray structure analyses. Vanadate1 crystallizes in the monoclinic space groupP2₁/n (No. 14) with unit cell parameters:a=9.304(2),b=11.756(2),c=11.911(2)Å, =111.72(3)°, andD _c=1.911 g/cm³,Z=2; Vanadate2 also crystallizes in the monoclinic space groupP2₁/n with unit cell parameters:a=9.719(2),b=11.111(3),c=11.294(2)Å, =109.03(2)°, andD _c=1.781 g/cm³,Z=2. Each dimer contains a centro-symmetric planar four-member V₂O₂ ring with two exocyclic citrate entities coordinated by the oxygen atoms of the hydroxy-and -carboxylate ligands, while the other two -carboxylate groups remain uncomplexed. Principal dimensions of the V–O bonds are 1.986(4)_av (hydroxy) and 1.980(3)Å(-carboxyl) for vanadate1, 1.988(2)_av (hydroxy) and 1.974(3)Å(-carboxyl) for vanadate2.     

Crystal structure and characterization of [Co(saccharinate)2(L1)(H2O)2] n solvate: A new microporous coordination polymer generated from 1,4-bis(3-pyridyl)-2,3-diaza-1,3-butadiene (L1) and [Co(saccharinate)2·4H2O]·2H2O

A new microporous coordination polymer, [Co(saccharinate)₂(L1)(H₂O)₂] _n solvate, has been prepared from the reaction of the N,N bidentate ligand 1,4-bis(3-pyridyl)-2,3-diaza-1,3-butadiene (L1) with [Co(saccharinate)₂·4H₂O]·2H₂O in a methylene chloride/ethanol solvent mixture. The compound crystallizes in the triclinic system, space group P-1, with lattice parameters a = 7.6893(5) Å, b = 11.0169(7) Å, c = 11.2369(7) Å, = 66.2610(10)°, = 74.4160(10)°, = 74.6740(10)°. The structure consists of one-dimensional chains composed of octahedrally coordinated Co(II) centers linked by L1. The packing of these chains, along with intrachain and interchain hydrogen bonds, generates a 3-D framework with infinite channels that are occupied by disordered guest molecules. The compound was further characterized by IR spectroscopy and DTA/TGA.     

Crystal and molecular structures of the 4-(1H)-pyridone (=L) lanthanide complexes {[GdL(NO3)3(H2O)]·CH3OH}2 and [DyL4(NO3)2](NO3) and of L2HNO3

The crystal structures of the title compounds have been determined by single crystal diffraction methods. Crystals of the dysprosium compound are monoclinic, space groupP2₁/c witha=14.133(4),b=13.438(5),c=14.401 (4)Å,=103.98(2)°,V=2654(1)ų,Z=4,D _c =1.82 g cm^–3, finalR=0.035. The Dy atom is eight-coordinate with a distorted dodecahedral coordination geometry involving two bidentate nitrate groups and four pyridone oxygen atoms. An erbium complex with analogous stoichiometry was also prepared but not structurally characterized. Crystals of the Gd compound are monoclinic, space groupP2₁/n, witha=11.226(2),b=9.075(2),c=16.737(3)Å,=93.88(3)°,V=1701(1)ų,Z=2,D _c =1.91 g cm^–3, finalR=0.042. Each Gd atom is bonded to one pyridone oxygen atom, a water molecule and three bidentate nitrate groups. An oxygen atom of one of the bidentate nitrates additionally serves to bridge pairs of Gd atoms so as to form a dinuclear complex in which each Gd atom is nine-coordinate with a tricapped trigonal prismatic geometry. Crystals of L₂HNO₃ are monoclinic, space groupI2/a witha=12.479(4),b=6.535(2),c=14.297(6)Å,=96.07(3)°,V=1159(1)ų,Z=4,D _c =1.45 g cm^–3, finalR=0.057. The pyridones are linked in pairs by very short (2.44 Å) symmetrical OHO hydrogen bonds. Each pair is further linked via a nitrate ion by means of N-HO(nitrate)H-N hydrogen bonds, so as to form an extended chevron-like pyridone-pyridone-nitrate-pyridone-pyridone array. Adjacent chains are linked via weak C-HO(NO₃) interactions.     

Synthesis of [Mn(O2CCH2CH2CO2)(2,2′-bipyridyl) (H2O)2]n·H2O

The title compound exists as a 1D coordination polymer consisting of succinate anions, manganese cations and 2,2-bipyridyl molecules. Twelve water molecules are present in the unit cell and are part of a hydrogen bonding system. Some of these waters are binding to manganese cations while others are only participating in hydrogen bonding. The structure has a monoclinic space group P2₁/c with a = 8.2750(3) Å, b = 11.5104(3) Å and c = 16.9113(6) Å, = 95.2727(16); V = 1603.96(9) ų and Z = 4.     

Structural and spectroscopic characterization of the macrocyclic complex: [Tb(CrO4)(H2O)(C22H26N6)] ·0.5(Cr2O7)·(H2O)

The title complex was obtained by anion metathesis from [Tb(CH₃COO)₂(C₂₂H₂₆N₆)] (CH₃COO)·4H₂O and K₂CrO₄ in aqueous solution. The compound crystallizes in the triclinic space group witha=8.384(2),b=10.425(2)c=15.752(2)Å, =98.82(2), =93.52(2), =97.22(2)°, andZ=2. The structure is ionic and consists of a (+1) complex cation balanced in a 21 ratio by a disordered dichromate ion. The 9-coordinate Tb(III) is linked to the six nitrogen atoms of the macrocyclic ligand L=C₂₂H₂₆N₆, as well as to a water molecule and a bidentate chelating chromate situated on opposite sides of the macrocycle. The infrared spectrum shows, in addition to the pattern of the macrocyclic ligand, the absorptions arising from the stretching modes of the bidentate chelating CrO₄ ^2– ligand and of the Cr₂O₇ ^2– counterion.     

Synthesis and crystal structure of a tetranuclear manganese(IV) cluster [L4Mn4O6](ClO4)4·2H2O (L = 1,4,7-triazacyclononane)

A tetranuclear manganese (IV) complex, [L₄Mn₄O₆](ClO₄)₄·2H₂O (1), with 1,4,7-triazacyclononane (L) as the capping ligands, has been synthesized and characterized by X-ray diffraction; monoclinic, space group P2₁/n with a = 21.335(6) Å, b = 11.387(3) Å, c = 21.788 (6) Å, = 111.410 (6)°, V = 4928 (2) Å, Z = 4. Each manganese atom has a distorted octahedral environment comprised of three facially coordinated amine nitrogen atoms and three oxygen atoms, and the cation is an idealized tetrahedron. The Mn₄O₆ ⁴⁺ cation corresponds to an adamantane skeleton.     

Crystal and molecular structure of [Cu2(3,5-dihydroxybenzoate)4 (acetonitrile)2] ⋅ 8H2O

The crystal and molecular structure of the title compound, [Cu₂(3,5-dihydroxybenzoate)₄ (acetonitrile)₂] 8H₂O 1, is reported. Crystal data for 1: tetragonal, space group I 4/m, a = 11.720(2) Å, c = 15.304(3) Å, V = 2102.4(6), and D _c = 1.53 g/cm³, for Z = 2. The metal and organic components crystallize to form a Cu paddle-wheel complex, of idealized D_4h symmetry, that assembles in the solid-state, along with eight equivalents of water, to form a 3D hydrogen-bonded network held together by O–H O hydrogens bonds. The metal complexes pack to form a 2D layered structure.     

Molecular structure and hydrogen bonding of 4-dimethylaminopyridinioacetate in its crystalline dihydrate and hydrochloride trihydrate,L·2H2O and [L2H]Cl·3H2O (L=p-Me2NC5H4N+CH2CO2 −)

The crystalline dihydrate and hydrochloride trihydrate of a new betaine, namely, L·2H₂O (1) and [L₂H]Cl·3H₂O(2) (L=p-Me₂NC₅H₄N⁺CH₂CO₂), have been synthesized and characterized by X-ray crystallography. Molecule L in compound1 [space groupPbcn, witha=15.732(3),b=7.894(2),c=18.304(4) Å, andZ=8] possesses approximateC _s symmetry. The formation of hydrogen bonds by water molecules bridging neighboring carboxy oxygen atoms leads to an infinite two-dimensional network composed of a packing of two different kinds of 12-membered rings. In compound2 [space group PT witha=7.341(2),b=9.543(2),c=17.010(4) Å, =82.43(2)°, =80.34(2)°, =74.05(2)°, andZ=2], the carboxylate groups of a pair of betaine molecules are bridged by a proton to form a dimeric cation L₂H⁺ with a very strong asymmetric hydrogen bond of length 2.464(7) Å. The crystal structure features a hydrogen-bonded corrugated ribbon comprising an alternate arrangement of edge-sharing centrosymmetric (H₂O)₄(Cl^–)₂ and (H₂O)₄ rings running parallel to thea axis.     

A comparison of the crystal structures of (dabcoH2)CuCl4 and (dabcoH2)CuCl4⋅H2O

The crystal structures of the anhydrous and monohydrated (dabcoH₂)CuCl₄nH₂O salts (n = 0,1) have been determined and a comparison of their crystal structures has been reported. The anhydrous salt is monoclinic P2₁/c with a = 9.045(2) Å, b = 6.9270(10) Å, c = 18.767(4) Å and = 90.07(3)° with V = 1175.8(4) ų. The hydrated salt is also monoclinic P2₁/c with a = 9.266(2) Å, b = 9.395(2) Å, c = 14.386(3) Å and = 93.32(3)° with V = 1250.3(5) ų. The structures of the two salts are closely related. Both compounds contain isolated distorted (compressed) tetrahedral CuCl₄ ^2– anions, diprotonated dabco cations, and in the case of the hydrated salt, lattice H₂O molecules. In the anhydrous salt, each of the two N–H⁺ groups of the dabcoH₂ ²⁺ dications form bifurcated hydrogen bonds to chloride ions on adjacent CuCl₄ ^2– anions along the c axis, thus forming chains running parallel to the c axis. In the hydrated salt, a water molecule is inserted into one of the pair of bifurcated hydrogen bonds, forming instead N–H O–H CuCl₄ ^2– linkages. The chains thus formed are cross-linked by O–H Cl hydrogen bonds between the chains. Because of this additional hydrogen bonding, the CuCl₄ ^2– anions in the hydrated salt are distorted further from tetrahedral geometry.