Syntheses,structural determination,and binding studies of binuclear eight-coordinate (enH2)[GdIII 2(pdta)2(H2O)2] · 8H2O and mononuclear nine-coordinate (enH2)[GdIII(egta)(H2O)]2 · 6H2O

The (enH₂)[Gd^III ₂(pdta)₂(H₂O)₂]?·?8H₂O (1) (en?=?ethylenediamine and H₄pdta?=?propylenediamine-N,?N,?N′,?N′-tetraacetic acid) and (enH₂)[Gd^III(egta)(H₂O)]₂?·?6H₂O (2) (H₄egta?=?ethyleneglycol-bis-(2-aminoethylether)-N,?N,?N′,?N′-tetraacetic acid) complexes were synthesized and characterized by infrared spectrum, thermal analysis, and single-crystal X-ray diffraction. The complex (enH₂)[Gd^III ₂(pdta)₂(H₂O)₂]?·?8H₂O has a binuclear eight-coordinate structure with pseudo square antiprism and crystallizes in the monoclinic crystal system with C2/c space group. Through a carboxylate bridge, an infinite 1-D zigzag polymeric binuclear [Gd^III ₂(pdta)₂(H₂O)₂]^2? complex anion is formed. All infinite zigzag polymeric complex anions link through hydrogen bonds, yielding a layer structure. (enH₂)[Gd^III(egta)(H₂O)]₂?·?6H₂O has a mononuclear nine-coordinate structure with pseudo monocapped square antiprism and crystallizes in the monoclinic crystal system with P2₁/n space group. Each enH₂ ²⁺ cation, through hydrogen bonds, connects two adjacent [Gd^III(egta)(H₂O)]^? complex anions.     

Crystal Structure and Interaction with DNA of [Ni(phen)(mal)(H2O)2]·3H2O

A new complex [Ni(phen)(mal)(H2O)2]·3H2O (phen = 1,10-phenanthroline,mal2-= malonic acid) has been synthesized by the reaction of nickel nitrate,phen and malonic acid.EA,IR spectra and X-ray single-crystal diffraction were carried out to determine the composition and crystal structure of the title complex.Crystal data:monoclinic system,space group P2/c,a =8.937(3),b = 12.163(5),c = 9.725(3)(A),β = 119.36°,C15H19N2O9Ni,Mr= 430.03,Z = 2,F(000) =446,V = 921.3 (A)3,Dc = 1.550 g/cm3,μ = 1.104 mm-1,-10≤h≤ 10,-12≤k≤ 14,-11 ≤l≤7,R =0.0261 and wR = 0.0609 for 4376 (Rint = 0.0203) independent reflections and 1631 observed ones (I＞ 2σ(I)).Ni(Ⅱ) exhibits an octahedral coordination geometry,with hydrogen bonds and π-π interactions stabilizing the whole structure.UV spectrum of the complex interacting with protamine DNA indicates that the title compound interacts with DNA via insertion mode with bonding constant Kb of 1.11 × 104.     

X-ray crystal structure of [VO(DPA)(H2O)2]·2H2O (DPA=Dipicolinate dianion)

The X-ray crystal structure of the trans-diaqua complex [VO(DPA)(H2O2)]·2H2O (1) (DPA=dipicolinate dianion) has been determined. Comparison with the known structure of [VO(DPA)(o-phen)]·3H2O (2), obtained from (1) by displacement of the two coordinated aqua molecules, shows that the coordination sphere around vanadium is reorganised during this reaction.     

Synthesis and Structure of a Novel Compound [Cu2(EDTA)(Py)2(H2O)2]·2H2O

A novel compound [Cu2(EDTA)(Py)2(H2O)2]·2H2O was synthesized by the reaction of CuSO4(5H2O with H4EDTA in pyridine/water (V/V = 1/4) solvent, and characterized by elemental analysis, IR spectrum and X-ray single-crystal diffraction. It crystallizes in the monoclinic system, space group P21/n with a = 1.26974(6), b = 0.67949(3), c = 1.48548(3) nm, β = 91.454(2)o, V = 1.28122(9) nm3, Z = 2, Dc = 1.673 g/cm3, Mr = 645.56, F(000) = 664, μ(MoKα) = 1.729 mm-1, the final R = 0.0353 and wR = 0.0832 for 1920 observed reflections (I > 2((I)). The compound is a centrosymmetric binuclear molecule with bridged EDTA group. Each Cu(II) atom is linked to two oxygen atoms and one nitrogen atom of EDTA, one oxygen atom of water and one nitrogen atom of pyridine to form a distorted square pyramidal environment. There exist face-to-face π-π stacking interactions between pyridine rings from neighboring molecule with the interplanar distance of 0.3670 nm and hydrogen bonding between EDTA and water molecules.     

Synthesis and Crystal Structure of {Cu2(pdc)2(4,4′-bipy)(H2O)·(3H2O}2

The title compound {Cu2(pdc)2(4,4′-bipy)(H2O)(3H2O}2 1 (H2pdc = pyridine-2,6- dicarboxylic acid, also known as dipicolinic acid; 4,4′-bipy = 4,4′-bipyridine) has been synthesized by the hydrothermal reaction and its structure was determined by single-crystal X-ray diffraction. The crystal is of triclinic, space group Pī with a = 7.2278(3), b = 10.6259(4), c = 17.7614(6)A, α= 79.5990(10), β = 83.6300(10), γ = 71.8280(10)o, V = 1272.60(8)A3, C48H44Cu4N8O24, Mr = 1371.07, Z = 1, Dc = 1.789 g/cm3, μ = 1.747 mm-1, F(000) = 696, R = 0.0397 and wR = 0.1137 for 3938 observed reflections (I > 2σ(I)). There are two kinds of Cu coordination environments, and each central copper(II) atom is five-coordinated in a distorted square-based pyramidal coordination geo- metry. Four copper(II) atoms are linked by four pdc and two 4,4′-bipy ligands to form an annular rectangle structure. Extensive hydrogen-bonding interactions involving carboxylate O atoms as well as coordinated and free water molecules lead to the formation of a three-dimensional network struc- ture.     

Synthesis and Crystal Structure of [Zn(FcCOO)2(2,2′-bipy)(H2O)]2·H2O

A novel complex [Zn(FcCOO)2(2,2′-bipy)(H2O)]2·H2O (Fc = (η5-C5H5)Fe(η5-C5H4), 2,2′-bipy = 2,2′-bipyridine) has been synthesized and characterized by elemental analysis, IR and X-ray diffraction. It crystallizes in monoclinic system, space group P21/c with a = 6.8187(4), b = 21.7155(13), c = 19.7411(12) (A), α = 90, β = 97.7420(10), γ = 90°, C64H58Fe4Zn2N4O11, Mr = 1413.28, V = 2896.4(3) (A)3, Dc = 1.620 g/cm3, Z = 2, F(000) = 1444, μ(MoKα) = 1.857 mm-1, R = 0.0523 and wR = 0.0982 for 3219 observed reflections (I ＞ 2σ(I)). Structural analysis shows that the zinc atom is coordinated with three oxygen atoms from two ferrocenemonocarboxylates and one water molecule together with two nitrogen atoms from 2,2′-bipyridine, giving a distorted square-pyramidal coordination geometry. The complex molecules are linked to form an infinite one-dimensional chain by both intermolecular hydrogen bonds and π-π stacking interactions of the bipyridine rings.     

Synthesis and Crystal Structure of [Zn(FcCOO)2(2,2′-bipy)(H2O)]2·H2O

A novel complex [Zn(FcCOO)2(2,2′-bipy)(H2O)]2·H2O (Fc = (η5-C5H5)Fe(η5-C5H4), 2,2′-bipy = 2,2′-bipyridine) has been synthesized and characterized by elemental analysis, IR and X-ray diffraction. It crystallizes in monoclinic system, space group P21/c with a = 6.8187(4), b = 21.7155(13), c = 19.7411(12) (A), α = 90, β = 97.7420(10), γ = 90°, C64H58Fe4Zn2N4O11, Mr = 1413.28, V = 2896.4(3) (A)3, Dc = 1.620 g/cm3, Z = 2, F(000) = 1444, μ(MoKα) = 1.857 mm-1, R = 0.0523 and wR = 0.0982 for 3219 observed reflections (I ＞ 2σ(I)). Structural analysis shows that the zinc atom is coordinated with three oxygen atoms from two ferrocenemonocarboxylates and one water molecule together with two nitrogen atoms from 2,2′-bipyridine, giving a distorted square-pyramidal coordination geometry. The complex molecules are linked to form an infinite one-dimensional chain by both intermolecular hydrogen bonds and π-π stacking interactions of the bipyridine rings.     

Synthesis and Crystal Structure of a Macrocycle [Cu(dadm)(mal)(H2O)]2·2H2O

The reaction of 4,4′-diaminodiphenylmethane (dadm), malonic acid (H2mal) and Cu(NO3)2 in aqueous solution results in a discrete binuclear Cu(II) macrocycle: [Cu(dadm)(mal)- (H2O)]2(2H2O. It crystallizes in monoclinic, space group P21/c with a = 15.231(3), b = 11.847(2), c = 9.801(2)A,Z= 106.75(3)o, V = 1693.5(6)A3, Z = 2, C32H40Cu2N4O12, Mr = 799.76, Dc = 1.568 g/cm3, λ(MoK() = 0.71073A, μ = 1.325 mm-1, F(000) = 828, the final R = 0.0531 and Wr = 0.1244 for 3421 observed reflections with I > 2σ(I). Each Cu(II) is coordinated by two oxygen atoms from a mal ligand, two nitrogen atoms from two dadm ligands and a water oxygen atom to form a triangle bipyramidal motif. The title compound possesses a distorted macrocycle enclosed by dadm with approximate dimensions of 8.3A× 5.9A.     

Syntheses and structures of seven-coordinate K3[Cd(Dtpa)], K2[Cd(H2O)4][Cd(Edta)(H2O)]2 · 2H2O, and Na2[Cd(H2O)4][Cd(Edta)(H2O)]2 · 2H2O complexes

The title complexes, K₃[Cd(Dtpa)] (H₅Dtpa = diethylenetriamine-N,N,N,N′,N′-pentaacetic acid, (I)), K₂[Cd(H₂O)₄][Cd(Edta)(H₂O)]₂ · 2H₂O (H₄Edta = ethylenediamine-N,N,N′,N′-tetraacetic acid, (II)), and Na₂[Cd(H₂O)₄][Cd(Edta)(H₂O)]₂ · 2H₂O (III), were prepared, and their compositions and structures were determined by elemental analyses, IR spectra, and single-crystal X-ray diffraction techniques, respectively. In complex I, the Cd is seven-coordinated by one Dtpa ligand yielding a pseudo-monocapped trigonal prism conformation, and the complex crystallizes in the triclinic crystal system with the Pi space group. The crystal data are as follows: a = 8.7300(17), b = 9.1200(18), c = 15.110(3) Å, α = 95.52(3)°, β = 96.59(3)°, γ = 99.63(3)°, V = 1170.0(4) ų, Z = 2, ρ = 1.754 g/cm³, μ = 1.519 mm^?1, F(000) = 616, R = 0.0644 and wR = 0.1712 for 3842 observed reflections with I ≥ 2σ(I). For complex II, in the [Cd(Edta)(H₂O)]^2? complex anion the Cd²⁺ ion is seven-coordinated by one Edta ligand and one water molecule, yielding a pseudo-pentagonal bipyramid conformation. In the [Cd(H₂O)₄]²⁺ cation, the bridged Cd is six-coordinated, yielding an almost standard octahedral conformation. The complex crystallizes in the monoclinic system with P2₁/n space group. The crystal data are as follows: a = 9.098(3), b = 16.442(6), c = 12.023(4) Å, β = 91.053(6)°, V = 1798.3(12) ų, Z = 2, ρ = 2.098 g/cm³, μ = 2.086 mm^?1, F(000) =1124, R = 0.0406 and wR = 0.1152 for 3680 observed reflections with I ≥ 2σ(I). In complex III, the conformations of Cd²⁺ ions are similar to those of the potassium salt complex, and the complex also crystallizes in the monoclinic crystal system with the P2₁/n space group. The crystal data are as follows: a = 9.134(7), b = 16.500(13), c = 12.075(10) Å, β = 91.054(12)°, V = 1820(2) ų, Z = 2, ρ = 2.015 g/cm³, μ = 1.856 mm^?1, F(000) = 1092, R = 0.0363 and wR = 0.0879 for 3707 observed reflections with I ≥ 2σ(I).     

Ab initio electron correlated studies on the intracluster reaction of NO+ (H2O)(n) → H3O+ (H2O)(n-2) (HONO) (n = 4 and 5)

Hydrated nitrosonium ion clusters NO(+)(H(2)O)(n) (n = 4 and 5) were investigated by using MP2/aug-cc-pVTZ level of theory to clarify isomeric reaction pathways for formation of HONO and fully hydrated hydride ions. We found some new isomers and transition state structures in each hydration number, whose lowest activation energies of the intracluster reactions were found to be 4.1 and 3.4 kcal mol(-1) for n = 4 and n = 5, respectively. These thermodynamic properties and full quantum mechanical molecular dynamics simulation suggest that product isomers with HONO and fully hydrated hydride ions can be obtained at n = 4 and n = 5 in terms of excess hydration binding energies which can overcome these activation barriers.     

Keggin polyoxoanion supported organic-inorganic trinuclear lutetium cluster, {Na(H(2)O)(3)[Lu(pydc)(H(2)O)(3)](3)}[SiW(12)O(40)]·26.5H(2)O

A novel strawberry-like organic-inorganic hybrid, {Na(H(2)O)(3)[Lu(pydc)(H(2)O)(3)](3)}[SiW(12)O(40)]·26.5H(2)O (H(2)pydc = pyridine-2,6-dicarboxylate) containing an intriguing trinuclear lutetium cluster {Na(H(2)O)(3)[Lu(pydc)(H(2)O)(3)](3)}(4+) has been synthesized and its luminescent properties, IR, UV, TG, PXRD analyses and single crystal X-ray diffraction were investigated.     

Synthesis,structure, and Mössbauer study of [Fe(H2O)(2)(C(9)O(6)H4)].H2O: a two-dimensional iron(II) trimellitate (MIL-67)

The two-dimensional (2D) iron trimellitate [Fe(H(2)O)(2)(C(9)O(6)H(4))].H(2)O, labeled MIL-67, has been obtained under hydrothermal conditions (473 K, 48 h). In the 2D structure of MIL-67, the Fe(2+) ions display two different octahedral environments: [FeO(4)(H(2)O)(2)] and [FeO(2)(H(2)O)(4)]. These octahedra share an apical water molecule to form infinite chains. The chains are linked by partly deprotonated C(9)O(6)H(4)(2-) anions to give hybrid organic-inorganic layers; the remaining acidic-CO(2)H group is dangling in the interlayer space. Below 8(1) K, MIL-67 displays a canted antiferromagnetic behavior, according to analyses via magnetic measurements and M?ssbauer spectroscopy. Crystal data for MIL-67 are as follows: triclinic; space group P1 (No. 2), with a = 6.9671(2) A, b = 7.3089(3) A, c = 12.5097(3) A, alpha = 78.758(1) degrees, beta = 89.542(2) degrees, and gamma = 65.197(1) degrees; volume V = 565.21(3) A(3); and Z = 2.     

Physical Characterization and Reactivity of the Uranyl Peroxide [UO(2)(η(2)-O(2))(H(2)O)(2)]·2H(2)O: Implications for Storage of Spent Nuclear Fuels

The unusual uranyl peroxide studtite, [UO(2)(η(2)-O(2))(H(2)O)(2)]·2H(2)O, is a phase alteration product of spent nuclear fuel and has been characterized by solid-state cyclic voltammetry. The voltammogram exhibits two reduction waves that have been assigned to the U(VI/V) redox couple at -0.74 V and to the U(V/IV) redox couple at -1.10 V. This potential shows some dependence upon the identity of the cation of the supporting electrolyte, where cations with larger ionic radii exhibit more cathodic reduction potentials. Raman spectroelectrochemistry indicated that exhaustive reduction at either potential result in a product that does not contain peroxide linkers and is likely to be UO(2). On the basis of the reduction potentials, the unusual behavior of neptunium in the presence of studtite can be rationalized. Furthermore, the oxidation of other species relevant to the long-term storage of nuclear fuel, namely, iodine and iodide, has been explored. The phase altered product should therefore be considered as electrochemically noninnocent. Radiotracer studies with (241)Am show that it does not interact with studtite so mobility will not be retarded in repositories. Finally, a large difference in band gap energies between studtite and its dehydrated congener metastudtite has been determined from the electronic absorption spectra.     

Syntheses and crystal structures of two Cd(II) coordination polymers: one-dimensional chain [Cd(C4H6N2)2(C4H2O4)(H2O)2] n and two-dimensional sheet [Cd(C4H6N2)(H2O)(C4H4O4)] n · n H2O

Two new Cd(II) coordination polymers, [Cd(C₄H₆N₂)₂(C₄H₂O₄)(H₂O)₂] _n (1) (where C₄H₆N₂?=?2-methylimidazole, C₄H₂O₄?=?fumarate), and [Cd(C₄H₆N₂)(H₂O)(C₄H₄O₄)] _n ?·?nH₂O (2), (where C₄H₄O₄?=?succinates), have been prepared and structurally characterized by single crystal X-ray diffraction. Complex 1 crystallizes in the triclinic space group P 1 in a one-dimensional chain structure, in which carboxy is monodentate; a three-dimensional supermolecular network structure was formed through hydrogen bonding. In complex 2, the coordination geometry of the Cd atoms is a pentagonal bipyramid, and a two-dimensional sheet is formed though carboxyl group bridging. In 1 and 2, IR spectra indicate the presence of bridging carboxyl groups, confirmed by structure analyses.     

Synthesis and Crystal Structure of Diaqua(2,2"-Dipyridyl)isothiocyanatoneptunoyl Monohydrate [NpO2(C10H8N2)(NCS)(H2O)2] · H2O

The crystal structure of the complex [NpO₂(C₁₀H₈N₂)(NCS)(H₂O)₂] · H₂O is determined. The unit cell parameters are a= 7.406, b= 9.517, c= 11.518 Å, = 103.65°, = 92.68°, = 96.53°, V= 781.6 ų, space group , Z= 2, (calcd) = 2.257 g/cm³, R= 0.046, R _w= 0.122. The coordination polyhedron of the Np atom is a pentagonal bipyramid with two nitrogen atoms of dipyridyl, a nitrogen atom of isothiocyanate ion, two oxygen atoms of water molecules lying in the equatorial plane, and oxygen atoms of the neptunoyl group lying in the axial positions.     

Synthesis of calcium titanate from [Ca(H2O)3]2[Ti2(O2)2O(NC6H6O6)2]·2H2O as a cheap single-source precursor

Calcium titanate (CaTiO₃) was conveniently synthesized by thermal decomposition of a single-source precursor [Ca(H₂O)₃]₂[Ti₂(O₂)₂O(NC₆H₆O₆)₂]·2H₂O at low temperature. This single-source precursor was characterized by elemental analysis, IR spectrum, thermal gravimetric analysis and X-ray single crystal diffraction. The calcined products at different temperature were further characterized by powder X-ray diffractions and IR spectra. The morphology, microstructure, and crystallinity of the resulting CaTiO₃ materials have been characterized by SEM and TEM. The BET measurement revealed that the CaTiO₃ powders had a surface area of 14.0 m²/g. In addition, the microwave dielectric properties of the resulting CaTiO₃ material have been measured.     

Synthesis and structural determination of the first eight-coordinate rare earth metal complex with a six-member ring, (NH4)[EuIII(pdta)(H2O)] · H2O

(NH₄)[Eu^III(pdta)(H₂O)]?·?H₂O has been synthesized and characterized by infrared spectrum, fluorescence spectrum, elemental analyses and single-crystal X-ray diffraction techniques. It crystallizes in the monoclinic system with space group P2₁/n, a?=?12.7700(15)?Å, b?=?9.3885(11)?Å, c?=?14.4070(18)?Å, α?=?90°, β?=?95.950(2)°, γ?=?90°, V?=?1718.0(4)?ų, Z?=?4, M?=?508.28, D _c?=?1.965?g?cm^?3, μ?=?3.708?mm^?1, F(000)?=?1108. The structure was refined to R ₁?=?0.0238 for 3469 observed reflections (I?>?2σ(I)). The Eu^IIIN₂O₆ part in the [Eu^III(pdta)(H₂O)]^? complex anion has an eight-coordinate structure with a distorted square anti-prismatic conformation, in which six coordination positions, two nitrogen atoms and four oxygen atoms are from one pdta (=propylenediaminetetraacetic acid) ligand, the seventh position is an oxygen (O(8A)) from another pdta and the eighth coordination site is occupied by a water molecule. (NH₄)[Eu^III(pdta)(H₂O)]?·?H₂O is the first eight-coordinate complex with a six-member ring in the rare earth metal complexes with aminopolycarboxylic acid ligands.     

Synthesis and Crystal Structure of [{Cd(hmbdc)(H2O)3}·2H2O]n

A novel coordination polymer [{Cd(hmbdc)(H2O)3}·2H2O]n (hmbdc=5-hydroxy- isophthalic acid) has been synthesized and characterized by elemental analysis, IR spectra and single-crystal X-ray diffraction. The crystal belongs to monoclinic, space group P21/c, with a=9.599(3), b=18.699(5), c=7.557(2) (A), β= 108.198(4)°, V=1288.6(6) (A)3, Z=4, Mr=382.60, Dc=1.972 g/cm3, F(000)=760, μ=1.740, the final R=0.0555 and wR=0.0995 for 1732 observed reflections with Ⅰ ＞ 2σ(Ⅰ). The structural analysis shows that the intermolecular hydrogen bonds and π-π interactions result in a three-dimensional supramolecular framework.     

[Ni(bpy)(mal)(H2O)3]·H2O and [Ni(4,4′-dmbpy)(mal)(H2O)3]·1.5H2O: syntheses,crystal structures,magnetic properties,and computational study of stacking interactions

[Ni(bpy)(mal)(H₂O)₃]·H₂O and [Ni(4,4′-dmbpy)(mal)(H₂O)₃]·1.5H₂O (mal = maleato; bpy = 2,2′-bipyridine; 4,4′-dmbpy = 4,4′-dimethyl-2,2′-bipyridine) exhibit molecular crystal structures. The Ni(II) central ions in both complexes are six-coordinate by one chelate bonded L–L ligand, three aqua ligands, and one position is occupied by a maleato oxygen donor atom. Hydrogen bonded ribbon-like supramolecular structural motifs are present in both studied complexes; these are linked by weaker C–H?O hydrogen bonds in [Ni(bpy)(mal)(H₂O)₃]·H₂O, whereas in [Ni(4,4′-dmbpy)(mal)(H₂O)₃]·1,5H₂O the hydrogen bonded ribbons are linked by O?H-O-H?O hydrogen bonds with the participation of the additional water solvate molecule positioned on the twofold axis. In both structures, π–π stacking interactions with different patterns in respective structures were found. The role of dispersion energy and many-body effects in the stabilization of bpy and 4,4′-dmbpy stacking interactions were investigated using methods of computational chemistry. Those confirm the dispersion-dominated stabilization of the 4,4′-dmbpy supramolecular chain-like structure, with only marginal impact of cooperativity effects. Thermal decompositions of both complexes start with dehydration. Magnetic susceptibility studies performed from 2 to 300 K revealed a dominant effect of the zero-field splitting of the Ni(II) ion, governing the low-temperature magnetic properties of both compounds.