A new polyoxovanadium supramolecular complex [(N(CH2CH2NH3)3)2(V6O18)]·3H2O: Synthesis, structure, and thermal properties

A new polyoxovanadium supramolecular complex, [(N(CH₂CH₂NH₃)₃)₂(V₆O₁₈)]·3H₂O (1), was synthesized as a crystalline product from aqueous solution at room temperature. From single crystal X-ray structural analysis, the complex is monoclinic, space group P2₁/n, with a = 15.878(2) ?,b = 11.3309(15) ?, c = 19.469(3) ?, β = 102.244(2)°, V = 3423.0(8) ?³, Z = 4, final R = 0.0469. The crystal structure comprises 1D spiral vanadate chain as the oxide moiety, doubly protonated cations of tris(2-aminoethyl)amine (tren) and three lattice molecules of water. There are numerous H bonds in the structure connecting the polyoxovanadium anion moiety, protonated tren cation and lattice water molecules; the average O...O and N...O distances are 2.753 ? for O-H...O and 2.879 ? for N-H...O, respectively. Original Russian Text Copyright ? 2009 by J. Li, Y. H. Xing, M. F. Ge, C. G. Wang, Z. P. Li, and S. Y. Niu The text was submitted by the authors in English. Zhurnal Strukturnoi Khimii, Vol. 50, No. 3, pp. 553–559, May–June, 2009.     

Crystal structure of Li(H<Subscript>2</Subscript>O)<Subscript>3</Subscript>[GaEdta]

The ethylenediaminetetraacetate complex Li(H₂O)₃[Ga(Edta)] was synthesized and its crystal structure composed of octahedral (Ga(Edta)⁻ anions connected to the Li(H₂O)₃⁺ ion through the oxygen atom was studied. Five of the six hydrogen atoms of water molecules are involved in weak hydrogen bonds with the oxygen atoms of four Ga(Edta)⁻ complexes, the complex anion is hydrogen-bonded to five water molecules. In addition, shortened contacts C(221)–H(22A)…O(112) between the Ga(Edta)⁻ anions were found. As a result, the molecular packing in the crystal is determined by the three-dimensional lace of hydrogen bonds. The results are compared with published data for the lithium salts of Bi(III), Sb(III), Fe(III), Ni(II), and Hg(II) ethylenediaminetetraacetates.     

Local dipole interactions induce helicity of (<Emphasis Type="Italic">S</Emphasis>)-2-butyl-<Emphasis Type="Italic">N</Emphasis>-(1,8-naphthaloyl)-2-aminobenzoate molecules containing 1,8-naphthalimide rings utilized as a column building blocks: X-ray and quantum mechanical studies

In the crystal of triclinic symmetry the title compound contains four independent molecules, which differ in the conformation of the aliphatic carbon chain (T, G ⁺and G ⁻) and in the helicity (M or P) of the N-(1,8-naphthaloyl)-2-aminobenzoate (NAB) unit. Quantum chemical MP2 calculations showed that isolated molecules favor helicity of NAB bichromophores most likely due to attractive interactions between local dipoles formed along carbonyl bonds, such that the helical arrangement of O=C–C–C–N–C=O fragments is stabilized by intramolecular interactions between terminal anti-parallel local carbonyl dipoles. In the crystal structure, columnar stacking of the anti-parallel 1,8-naphalimide rings is observed. In a column the neighboring NAB units display opposite helicity.     

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.     

Structures of an infinite helical water chain and discrete lattice water in metal–organic framework structures

Two supramolecular complexes Ni[(Py)₂C(OH)₂]₂·(CH₃COO)₂·4H₂O 1 and Co[(Py)₂C(OH)₂]₂·(CH₃COO)₂·2H₂O 2 have been synthesized under hydrothermal conditions and structurally characterized by elemental analysis, IR spectra, and X-ray single-crystal diffraction. The X-ray diffraction analysis indicates that the center metal (Ni²⁺ and Co²⁺) ions having the same coordination environments are chelated by two pyridyl N atoms and a hydroxyl O atom of the gem-diol ligand in an octahedral geometry. In 1, the lattice water molecules form infinite single helical chains, while in 2, two lattice water molecules are discrete. In their crystal structures, intermolecular O–H···O and C–H···O hydrogen bonds form an extensive three-dimensional network, which consolidates the crystal packing.     

Crystal and Molecular Structure of (trans-3,4-Diamino-2,2,6,6-tetramethylpiperidine-1-oxyl-N3, N4)(oxalato-O,O′)platinum(II) Dihydrate

The crystal and molecular structure of (trans-3,4-diamino-2,2,6,6-tetramethylpiperidine-1-oxyl-N ³, N ⁴)(oxalato-O,O′)platinum(II) dihydrate was studied by single crystal X-ray diffraction. The crystals belong to the monoclinic system; a 8.261, b 13.129, c 15.224 Å; β 104.29°, Z 4, space group P2₁/n. The structure was solved by the direct method and refined by the full-matrix least-squares method in the anisotropic approximation to R 0.026 for all the 3660 measured unique reflections. The structure consists of individual mononuclear bischelate molecules containing two different bidentate ligands. The Pt²⁺ coordination is distorted square-planar. The complex molecules and water molecules in the crystal of I are linked by hydrogen bonds forming an infinite 3D network. __________ Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 11, 2005, pp. 1893–1897. Original Russian Text Copyright ? 2005 by Chekhlov.     

Synthesis and structure of layered fluorine-containing crystal hydrates based on aquacomplexes of noble metals

Crystal hydrates were synthesized based on aquaions of noble metals [M(H₂O)₆]F₃·nH₂O, where n = 3–8 and M = Ir, Rh. The structure of the resulting crystal hydrates with three aqueous molecules is characterized by the space group P3, Z = 1 and has a layered form. The positively charged layers [M(H₂O)₆F ₂ ⁺ which alter with negatively charged layers of the composition ∼_-·3H₂O, are located perpendicular to the c axis. According to X-ray structural and nuclear magnetic resonance data, the water molecules and the F_- ions in the negatively charged layers are disordered. Translated fromZhurnal Strukturnoi Khimii, Vol.40, No. 2, pp. 259–264, March–April, 1999.     

Structure of associates in tetramethylurea aqueous solutions from the data of Raman scattering spectroscopy

The results from investigating interactions between tetramethylurea (TMU) and water molecules by means of Raman light scattering spectroscopy (RS) are presented. It is established that spectroscopic manifestations of association of TMU and H₂O molecules are observed for the TMU molecule valence vibration band ν(CO) 1638 cm⁻¹. By means of quantum-chemical calculations, it is shown that the band sensitivity to molecular environment is defined by the number of 5–6 H₂O molecules. It is found that in a pure TMU medium, chain dimers are formed due to the interactions of molecular dipoles arranged in parallel and hydrogen bonds of the C-H…O type. Ground state geometries of TMU, TMU-TMU, H₂O molecules and TMU · (H₂O) _n complexes (n = 1−14) are optimized by the density functional B3LYP procedure, using the 6–31++G(d, p) basis set. The main vibration frequencies are calculated in the harmonic approximation. Associate formation energies are calculated with allowance for the basis set superposition error (BSSE).     

Syntheses, characterization, and structure determination of nine-coordinate Na[YIII(edta)(H2O)3]· 5H2O and eight-coordinate Na[YIII(cydta)(H2O)2]·5H2O complexes

Syntheses and structure determination of the Y^III complexes with ethylenediaminetetraacetic acid (H₄edta) and trans-1,2-cyclohexanediaminetetraacetic acid (H₄cydta) are reported. The crystal and molecular structures of the complexes, as well as their molecular formulas and compositions, were determined by single-crystal X-ray structure analyses, NMR, IR, thermogravimetric measurements, and elementary analyses. The crystal of the Na[Y^III(edta)(H₂O)₃]·5H₂O complex belongs to the orthorhombic crystal system and space group Fdd2. The crystal data are as follows: a = 19.355(5) Å, b = 35.431(11) Å, c = 12.122(3) Å, V = 8313(4) ų, Z = 16, M = 544.23, D_c = 1.739 g·cm⁻³, μ = 2.908 mm⁻¹ and F(000) = 4480. The final R and Rw are 0.0483 and 0.1172 for 3284 (I > 2σ(I)) unique reflections, R and Rw are 0.0678 and 0.1440 for all 8499 reflections, respectively. The Y^IIIN₂O₇ part in the [Y^III(edta)(H₂O)₃]⁻ complex anion has a pseudo-monocapped square antiprismatic nine-coordinate structure, in which the six coordinated atoms (two N and four O) from the edta ligand and three water molecules are coordinated to the central Y^III ion directly. The crystal of the Na[Y^III(cydta)(H₂O)₂]·5H₂O complex belongs to the triclinic crystal system and space group. The crystal data are as follows: a = 8.405(2) Å, b = 9.970(2) Å, c = 14.763(4) Å, α = 88.538(4)°, β = 76.193(4)°, γ = 88.100(4)°, V = 1200.6(5) Å ³, Z = 2, M = 580.31, D_c = 1.605 g·cm⁻³, μ = 2.519 mm⁻¹ and F(000) = 600. The final R and Rw are 0.0381 and 0.0911 for 4198 (I > 2σ(I)) unique reflections, R and Rw are 0.0530 and 0.1041 for all 6186 reflections, respectively. The Y^IIIN₂O₆ part in the [Y^III(cydta)(H₂O)₂]⁻ complex anion has a pseudo square antiprismatic eight-coordinate structure in which the six coordinated atoms (two N and four O) from the cydta ligand and two water molecules are coordinated to the central YIII ion directly. Original Russian Text Copyright ? 2005 by J. Wang, Y. Wang, Zh. H. Zhang, X. D. Zhang, J. Tong, X. Zh. Liu, X. Y. Liu, Y. Zhang, and Zh. J. Pan __________ Translated from Zhurnal Strukturnoi Khimii, Vol. 46, No. 5, pp. 928–938, September–October, 2005.     

1，4-二氮杂二环[2.2.2]辛烷-氰基合钴(Ⅲ)三维框架氢键型晶体的合成、相变及介电性质

室温下以1,4-二氮杂二环[2.2.2]辛烷（Dabco）和钴氰酸为原料、水和甲醇为混合溶剂,以缓慢蒸发的方式获得Dabco-氰基合钴氢键型框架晶体材料（H₃O）（H₂Dabco）[Co （CN）₆]·H₂O （1）。并通过单晶X射线衍射、红外光谱、元素分析、粉末X射线衍射、热重分析、差示扫描量热、变温-变频介电常数测试对其结构、热性能与电性能进行表征。在低温（100 K）与室温（296 K）下,化合物均为单斜晶系P2₁/c空间群。单晶结构显示氰基合钴阴离子、水分子与水合质子在晶体内部通过氢键的相互作用形成三维网状框架,质子化的（H₂Dabco）²⁺阳离子镶嵌在其中构成分子马达型囊状结构。随着温度的升高（H₂Dabco）²⁺阳离子发生弹簧式扭转,从而引发晶体在254 K附近相变,在相同温度下沿着晶体的3个轴向发生介电异常,呈现明显的介电各向异性。     

The effect of the oxidative properties of [Mg(H2O)6] in the triplet and singlet states on the energetics of adenosine triphosphate cleavage

The interaction of the adenosine triphosphate (ATP) molecule (the ATP subsystem) with the magnesium complex [Mg(H₂O)₆]²⁺ (the Mg subsystem) in the singlet (S) and triplet (T) states in an aqueous medium mimicked by 78 water molecules was studied by the molecular dynamics (density functional theory) method MD DFT:B3LYP with the 6–31G** basis set at T = 310 K. Potential energy surfaces for the S (lowest-lying) and T (highest-lying) states are significantly separated in space. The Mg complex moves along these surfaces to approach either oxygen atoms of the γ-β phosphate groups (O1–O2) (S PES) or oxygen atoms of β-α phosphate groups (O2–O3) (T PES). Chelation of the γ-β β-α and phosphates yields, respectively, a stable low-energy complex ([Mg(H₂O)₄-(O1–O2)ATP]²⁻) and a metastable high-energy complex ([Mg(H₂O)₂-(O2–O3)ATP]²⁻), which differ in the number of water molecules surrounding the Mg atom. Crossing of two triplet PESs is accompanied by the formation of an unstable state characterized by redistribution of spins between the Mg and ATP subsystems. This state, sensitive to interaction with the ²⁵Mg nuclear spin, induces an unpaired electron spin, which initiates the ATP cleavage by the ion-radical mechanism, yielding a reactive radical ion of adenosine monophosphate (•AMP⁻), which was earlier found experimentally by the of chemically induced dynamic nuclear polarization (CIDNP) method. Biological aspects of the results obtained are discussed. Original Russian Text ? A.A. Tulub, V.E. Stefanov, 2009, published in Zhurnal Neorganicheskoi Khimii, 2009, Vol. 54, No. 7, pp. 1188–1195.     

catena‐Poly[[[pentaaquathulium(III)]‐μ‐5‐sulfonatobenzene‐1,3‐dicarboxylato] 4,4′‐bipyridyl 1.5‐solvate hemihydrate]

The crystal structure of the title compound, {[Tm(C₈H₃O₇S)(H₂O)₅]·1.5C₁₀H₈N₂·0.5H₂O}_n, is built up from two [Tm(SIP)(H₂O)₅] molecules (SIP³⁻ is 5‐sulfonatobenzene‐1,3‐dicarboxylate), three 4,4′‐bipyridyl (bpy) molecules and one solvent water molecule. One of the bpy molecules and the solvent water molecule are located on an inversion centre and a twofold rotation axis, respectively. The Tm^III ion coordination is composed of four carboxylate O atoms from two trianionic SIP³⁻ ligands and five coordinated water molecules. The Tm³⁺ ions are linked by the SIP³⁻ ligands to form a one‐dimensional zigzag chain propagating along the c axis. The chains are linked by interchain O—H...O hydrogen bonds to generate a two‐dimensional layered structure. The bpy molecules are not involved in coordination but are linked by O—H...N hydrogen bonds to form two‐dimensional layers. The two‐dimensional layers are further bridged by the bpy molecules as pillars and the solvent water molecules through hydrogen bonds, giving a three‐dimensional supramolecular structure. π–π stacking interactions between the parallel aromatic rings, arranged in an offset fashion with a face‐to‐face distance of 3.566 (1) Å, are observed in the crystal packing.     

Specific features of the structures of iron(II) α-benzyl dioxymate solvates with pyridine

Coordination compounds [Fe(DfgH)₂Py₂] (I) and [Fe(DfgH)₂Py₂] · A, where DfgH is the α-benzyldioxime monoanion and A = Py (II), DMF (III), and methyl ethyl ketone (IV), have been synthesized and studied by X-ray diffraction analysis. Diamagnetism and the gamma-resonance (GR) spectral parameters confirm that iron exists in the oxidation state +2 in the low-spin state. The octahedral trans configuration of the iron polyhedra is a common feature of all complexes. The equatorial plane of the octahedron contains two intramolecular hydrogen bonds O-H...O between two organic anions DfgH⁻ affording a pseudomacrocycle. The axial coordinate of the octahedron is occupied by the pyridine molecules, which are almost perpendicular to the equatorial plane N₄(oxime) in complexes I–IV. The structure of the compounds is a framework with allowance for weak interactions C-H...O and C-H...C. The manner of inclusion of solvents into the crystal and their functioning in structure formation of compounds II–IV are discussed.     

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.     

Study of the NpO

A new neptunium(VI) complex [(NpO₂)(CrO₄)(H₂O)] ⋅ 4H₂O (I) was synthesized, its crystal structure was determined, and the IR and near-IR absorption spectra were measured. The unit cell parameters are: a = 8.634(4) Å, b = 11.119(4) Å, c = 9.410(3) Å, β = 92.40(3)°, space group P2₁/c, Z = 4, V = 902.6(6) ų, R = 0.048, wR(F ²) = 0.054. The crystal structure of the compound is composed of the [(NpO₂)(CrO₄)(H₂O)] _n layers and the crystal water molecules located between the layers. The coordination polyhedron of neptunium is a pentagonal bipyramid whose equatorial plane is formed by the oxygen atoms of two bridging water molecules and three chromate ions. The Np(VI) complexation with the chromate ions in an aqueous solution at μ = 1 was studied by spectrophotometry. The stability constants for 1 : 1 and 1 : 2 complexes were calculated, logβ₁ = 3.19(2), logβ₂ = 3.93(2), respectively. __________ Translated from Koordinatsionnaya Khimiya, Vol. 31, No. 11, 2005, pp. 848–852. Original Russian Text Copyright ? 2005 by Budantseva, Andreev, Fedoseev, Astafurova, Antipin.     

A New Inclusion Compound between 2,4,5,7,9,10-hexachloro-1,3,6,8-tetrakis (4-methoxyphenylthio)pyrene Host and Cyclohexane Guest Stabilized by C–H···π and C–H···Cl Interaction

Crystal structure analysis shows the 2,4,5,7,9,10-hexachloro-1,3,6,8-tetrakis-(4-methoxyphenylthio) pyrene host and its cyclohexane guest in the Pnma crystal lattice. The crystal data and refinement parameter for the title compound are: a = 15.864(3), b = 30.455(6), c = 9.231(5) Å, V = 4459.2 (14) ų. For Z = 4 and M _w = 1045.76, the calculate density Dcal = 1.558 g/cm³. The C–H···π interaction and C–H Cl interaction stabilized the inclusion of cyclohexane molecules. The S···Cl weak interaction assembled the host molecules into a two-dimensional layer structure, and a three-dimensional structure was obtained by connecting the layers with C–H···O hydrogen bonding.Electronic Supplementary Material Supplementary material is available for this article at ^*Supplementary data: crystallographic data (atomic coordinates, anisotropic displacement parameters, selected bond distance and angles) for the structures in this paper have been deposited with the Cambridge Crystallographic Data Center with CCDC 270603 as supplementary publication.     

Dehydration-induced changes in the vibrational states of dioptase Cu6Si6O18·6H2O

This paper reports on the results of temperature studies (20–880°C) of the IR absorption spectra of dioptase crystals in the range 50–4000 cm⁻¹. During the dehydration of dioptase the state of water changes as follows: (1) initial state, (2) intermediate state with damped external vibrations of H₂O, (3) isolated water molecules with new hydrogen bonds, (4) formation of hydroxyls. The bands of the external virations of H₂O (1) vanish in state (2) because of the formation of vacancies in the six-membered water rings. The frequencies of the translation vibrations of 6H₂O in initial dioptase are close to those in liquid water: 169–170 and 277–290 cm⁻¹. A factor-group analysis of the dioptase vibrations in the space group C _3i ² is performed. All IR active vibrations 23A_u+23E_u are described. The thirty five bands observed in the IR spectra are assigned. The dehydration-induced deformations of the silicate rings are determined from the shifts of the vibrational bands of Si₆O₁₈. Institute of Mineralogy and Petrography, Siberian Branch, Russian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 37, No. 1, pp. 68–74, January–February, 1996. Translated by I. Izvekova     

Interaction of O+ ion with water molecules: A quantum-chemical study

The interaction of O⁺ ion with several (from one to four) water molecules was studied by theab initio (UMP4/4-31G^*) and semiempirical (AM1) quantum-chemical methods. It was found that the energy of binding the O⁺ ion to the first water molecule is appreciably higher than those of binding to the subsequent water molecules. In the complex with a water molecule, whose structure corresponds to that of water oxide, the O⁺ ion retains high reactivity. The barrier to the transfer of O⁺ ion to another water molecule is much lower than the barrier to analogous transfer of O atom from the molecule of water oxide, despite the lower dissociation energy of the H₂O−O bond. Consideration of subsequent interactions with water molecules leads to an increase in the barrier to the transfer of O⁺ ion. The doublet and quadruplet excited states of the O⁺+2 H₂O system were also studied. In these cases, the formation energies are well described by the ion-dipole model. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 981–988, June, 2000.     

Processes of dissociative electron capture by 20-hydroxyecdysone molecules

The peculiarities of dissociative electron capture by 20-hydroxyecdysone molecules with the formation of fragment negative ions were studied. In the region of high electron energies (5–10 eV), processes of skeleton bond rupture are accompanied by the elimination of H₂O and H₂ molecules. In the region of thermal energies of electrons (≈0 eV), the mass spectrum is formed mainly by the [M−nH₂O]^.− (n=1–3) and [M−H₂−nH₂O]^.− (n=0−3) ions that are generated exclusively by the rearrangement. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 709–712, April, 2000.     

Diaquabis(quinoxaline‐2‐carboxylato‐κ2N1,O)copper(II)

In the title compound, [Cu(C₉H₅N₂O₂)₂(H₂O)₂], the Cu^II ion lies on an inversion centre and has an elongated centrosymmetric octahedral environment, equatorially trans‐coordinated by two N,O‐bidentate quinoxaline‐2‐carboxylate ligands and axially coordinated by two water O atoms. Symmetry‐related molecules are linked by strong O—H...O hydrogen bonds, involving the uncoordinated carboxyl O atom of the carboxylate group and the coordinated water molecules, to form a two‐dimensional network. Weak intermolecular C—H...N interactions also stabilize the crystal structure.