Highly efficient phosphate diester hydrolysis and DNA interaction by a new unsymmetrical FeIIINiII model complex

A new heterodinuclear mixed valence complex [Fe^IIINi^II(BPBPMP)(OAc)₂]ClO₄ 1 with the unsymmetrical N₅O₂ donor ligand 2-bis[{(2-pyridylmethyl)-aminomethyl}-6-{(2-hydroxybenzyl)(2-pyridylmethyl)}-aminomethyl]-4-methylphenol (H₂BPBPMP) has been synthesized and characterized. 1 crystallizes in the monoclinic system, space group P2₁/n, a=12.497(2), b=18.194(4), c=16.929(3) Å, β=94.11(3)°, V=3839.3(12) ų and has an Fe^IIINi^II(μ-phenoxo)-bis(μ-carboxylato) core. Solution studies of 1 indicate that a pH-induced change in the bridging acetate occurs and the formation of an active [(OH)Fe^III(μ-OH)Ni^II(OH₂)]⁺ species as the catalyst for phosphate diester hydrolysis and DNA interaction is proposed. In addition, the results presented here suggest that Ni^II would be a good candidate as a substitute of M^II in purple acid phosphatases.     

Synthesis,structure and electronic calculation of alkali metals borate Li2Na[B5O8(OH)2]

A new alkali metals borate complex, Li₂Na[B₅O₈(OH)₂], has been successfully synthesized by a facile hydrothermal method. Single-crystal X-ray diffraction analysis reveals that it crystallizes in orthorhombic space group Pbcn with a = 8.919(3) Å, b = 9.181(3) Å, c = 8.416(2) Å, Z = 4. The crystal structure is constructed of two dimensional (2D) [(B₅O₈)(OH)₂]_∞ layers, while stacking along b axis and then connected by Li⁺ and Na⁺ cations to extend to 3D framework Li₂Na[B₅O₈(OH)₂]. UV-vis-NIR spectrum shows that Li₂Na[B₅O₈(OH)₂] possesses a wide range of transparency and a UV cut-off edge below 190 nm which indicates that it may be applied in the deep ultraviolet region. The calculated band structures and the density of states indicate that Li₂Na[B₅O₈(OH)₂] is a direct band gap compound with a band gap of 5.68 eV. In addition, IR spectroscopy, thermal stability and theoretical calculations of Li₂Na[B₅O₈(OH)₂] are also reported in this work.     

LiBa1.5[B5O8(OH)3]: A new 1-D metal borate chain constructed from B5O9(OH)36 − cluster units

A new mixed metal borate LiBa_1.5[B₅O₈(OH)₃] (1) has been hydrothermally synthesized and structurally characterized by FT-IR spectroscopy, powder X-ray diffraction, single crystal X-ray diffraction, and thermogravimetric analysis, respectively. 1 crystallizes in the monoclinic system, space group C2/c, a = 11.2839(7) Å, b = 7.3974(4) Å, c = 20.7151(13) Å, β = 103.392(6)°, V = 1682.10(17) ų and Z = 8. The structure consists of infinite one-dimensional (1-D) borate chains constructed from B₅O₉(OH)₃^6 − cluster units. These BO chains are further linked by the Ba^2 + and Li⁺ cations to form a 3-D framework.     

A three-dimensional zincic molybdenum (V) phosphate with helical channel: Synthesis,structure, and electrochemical properties

A new reduced zincic molybdophosphate, (H₂bpp)₃[Zn₃Mo₁₂^VO₂₄(OH)₆(H₂O)₂(HPO₄)₆(PO₄)₂]·2H₂O 1 (bpp = 1,3-bis(4-pyridyl)propane) has been hydrothermally synthesized and characterized by elemental analysis, IR, TG, and single-crystal X-ray diffraction. Compound 1 crystallizes in the tetragonal space group I 41/a c d with a = 31.8033(4) Å, b = 31.8033(4) Å, c = 34.5593(8) Å, V = 34955.0(10) ų, and Z = 16 and exhibits a 4,6-connected 3-D framework with (3².8⁴)(3⁴.4².8³.9⁵.10) topology. The basic building blocks of [Zn(2)(Mo₆P₄)₂] are linked through [Zn(3)O₆] octahedra and [Zn(1)O₄] tetrahedra to construct 1-D chains along four different directions. Such 1-D chains are further connected by [Zn(1)O₄]²⁺ linkers to form a 3-D intricate framework with helical channels occupied by protonated bpp and water molecules. Additionally, the electrochemical property of the 1-CPE has been studied in detail.     

An organic–inorganic hybrid nickel-substituted arsenotungstate consisting of three types of polyoxotungstate units

A new organic–inorganic hybrid nickel-substituted arsenotungstate [Na(H₂O)₃]₂[Ni(H₂O)₆]₂[Ni(H₂O)₅]{[Ni₃(dap)(H₂O)₂]₂(H₂W₄O₁₆)}{(α-H₂AsW₆O₂₆)[Ni₆(OH)₂(H₂O)(dap)₂](B-α-HAsW₉O₃₄)}₂·7H₂O (1) (dap = 1,2-diaminopropane) has been hydrothermally synthesized and structurally characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction. Crystal data for 1: C₁₈H₁₄₄As₄N₁₂Na₂Ni₂₁O₁₇₆W₃₄, Mr = 11174.92, triclinic, space group P-1, a = 15.004(4) Å, b = 16.357(5) Å, c = 22.070(6) Å, α = 80.458(5)°, β = 79.291(5)°, γ = 72.074(5)°, V = 5030(3) Å³, Z = 1, GOOF = 1.007, R₁ = 0.0703, wR₂ = 0.1670. The skeleton of 1 is a centric nanoscale cluster and is composed of two asymmetric sandwich-type clusters {(α-H₂AsW₆O₂₆)[Ni₆(OH)₂(H₂O)(dap)₂](B-α-AsW₉O₃₄)}^7? linked by a symmetric cluster {[Ni₃(dap)(H₂O)₂]₂(H₂W₄O₁₆)}⁶⁺. Notably, 1 is an interesting polyoxometalate containing the trivacant Keggin [B-α-AsW₉O₃₄]^9?, hexavacant Keggin [α-AsW₆O₂₆]^11? and tetrameric [W₄O₁₆]^8? units. Magnetic measurements indicate that 1 shows the ferromagnetic interactions within Ni^II centers.     

Eu5(μ4-OH)(μ3-OH)4(μ-DBM)4(DBM)6 (DBM=dibenzoylmethide): a novel Eu5 square-pyramid polynuclear complex with a rare μ4-OH bridging mode

The reaction of EuOCl (EuCl₃) with dibenzoylmethane (HDBM) in the presence of N-methylmorpholine yields a novel Eu₅ square-pyramid polynuclear complex with a rare μ₄-OH bridging mode, Eu₅(μ₄-OH)(μ₃-OH)₄(μ-DBM)₄(DBM)₆ (1). The compound was characterized by elemental analysis, IR, fluorescence and Mössbauer spectra as well as by an X-ray single crystal structure determination. Crystallographic data for 1, C₁₅₀H₁₁₅Eu₅O₂₅, monoclinic, P2₁/c, a=22.223(5), b=17.427(1), c=35.708(5) Å, β=100.11(2)°, V=13614(4) ų, Z=4, R₁=0.0979, wR₂=0.1695.     

Two new selenidostannates with a [Sn3Se7]n2n− layer from the imidazolium-based ionic liquids: The role of (Bzmim)+ and aggregated cation of [(Emim)3Cl]2+

Herein, we report on the syntheses, crystal structures, and optical properties of two new selenidostannates, namely, [Emim]₅[Sn₃Se₇]₂Cl (1, Emim = 1-ethyl-3-methylimidazolium) and [Bzmim]₂[Sn₃Se₇] (2, Bzmim = 1-benzyl-3-methylimidazolium). The ionic liquids (ILs) of [Emim]Cl with a short ethyl chain and [Bzmim]Cl with a bulky substituent benzyl group were used in the syntheses of compounds 1 and 2, respectively. Although both the structures feature an anionic lamellar [Sn₃Se₇]_n^2n– layer, the packing of the layers are dramatically different; such structural diversity may be ascribed to the difference of structure-directing cations incorporated in between the layers, that is [(Emim)₃Cl]²⁺ aggregates in 1 and bulky [Bzmim]⁺ in 2, respectively.     

A novel transition-metal-linked hexaniobate cluster with photocatalytic H2 evolution activity

A novel transition-metal (TM) complex based on Lindqvist polyoxoniobate K₁₀[(Nb₆O₁₉)Cr^III(H₂O)₂]₂·28H₂O (1) has been synthesized by a new two-pot synthesis strategy and structurally characterized by single crystal X-ray diffraction analysis, IR spectrum, UV–vis spectroscopy, XRPD and TG analysis. Compound 1 crystallizes in the C2/m space group with a = 32.143(19) Å, b = 10.030(6) Å, c = 12.878(8) Å, β = 110.611(9)°, and V = 3886(4) ų. X-ray structure analysis reveals that polyanion [(Nb₆O₁₉)Cr^III(H₂O)₂]₂^10 − (1a) represents the first example of two nuclear dimeric polyoxoniobate, in which two Lindqvist anions [Nb₆O₁₉]⁸ are sandwiched by two {Cr^III(H₂O)₂} groups. Further, 1 exhibits photocatalytic H₂ evolution activity.     

X-ray structure and spectroscopic properties of some lanthanides(III) complexes derived from 2,6-diacetylpyridine-bis(benzoylhydrazone)

A series of trivalent lanthanide complexes of type [Ln(L) NO₃)(S)_n](NO₃)_m(S^′)_n, have been synthesized by the reaction of 2,6-diacetylpyridine-bis-(benzoylhydrazone) (H₂L) with lanthanide(III) nitrates in ethanol. These complexes have been characterized by analysis, molar conductance, magnetic measurements, infrared spectral studies and X-ray diffraction. The analytical data revealed the formation of 1:1 (metal:ligand) stoichiometry. Molar conductance in dmf gives 2:1 electrolytes in all the complexes. Magnetic moment values are close proximity of the Van Vleck values. IR study suggests the coordination of the ligand through the azomethine and the oxygen of the hydrazonic moiety. The nitrate ion is also found to be bidentate in all the complexes. The crystal structures were determined. 6, C₂₇H₃₁N₆O₇S₂Gd: a=b=8.6821(4) Å, c=84.363(5) Å, tetragonal P4₁2₁2 and Z=8. bf 7, C₂₅H₂₅N₆O₆SDy: a=11.750(3) Å, b=13.250(3) Å, c=36.000(6) Å, β=98.50(2), monoclinic, C2/c, Z=8. 9, C₂₄H₂₅N₆O₇Yb: a=10.750(2) Å, b=17.750(3) Å, c=14.250(4) Å, β=99.00(2), monoclinic, P2₁/n, Z=4. In these complexes the lanthanide ion assumes a nine coordinated geometry for Gd and an eight coordinated geometry for Dy and Yb.     

Hydrothermal synthesis,crystal structure and magnetic properties of a novel nickel carboxylate–phosphonate with a layered structure

Hydrothermal reactions of N-(phosphonomethyl)proline (H₃L) with nickel sulfate hexahydrate resulted in a novel nickel carboxylate–phosphonate: |H₂O|[Ni₃(O₃PCH₂–NC₄H₇–CO₂)₂(H₂O)₄] (complex 1). Single-crystal X-ray diffraction analysis revealed that complex 1 crystallizes in the triclinic space group P-1 (No. 2), with lattice parameters of a = 10.0167(5) Å, b = 10.3882(5) Å, c = 11.9528(5) Å, α = 90.132(3)°, β = 107.246(3)°, γ = 111.158(3)°, V = 1099.39(9) Å³, and Z = 2. Complex 1 features a 2D layered structure. The structure contains alternating Ni-centered octahedra (Ni(1)O₆, Ni(2)O₅N and Ni(3)O₅N) and O₃PC tetrahedra linked to construct a layer with rhombohedral 12-MRs holes. The cyclopentylamine moieties of H₃L were grafted onto the layer through coordination of CPO₃, CO₂ and (CH₂)₂NCH₂ with central nickel atoms. These layers are stacked in an AA sequence, which results in a one-dimensional channel in the [001] direction. Water molecules are located in these channels. Magnetic studies showed that complex 1 exhibits predominantly paramagnetic behavior.     

Synthesis of 1,1′-ferrocene bis(carboxypyrazole) compounds and displacement of the pyrazole ligands

The reaction of 1,1′-ferrocenedicarbonyl chloride with pyrazole or 3,5-dimethyl pyrazole generates novel 1,1′-ferrocene bis(amide) compounds 1 and 2, respectively. The crystal structure of 1 shows that the pyrazole rings are essentially co-planar with each other and with the cyclopentadienyl rings. Attempts to use the complexes as a chelating ligand were unsuccessful. Instead, treatment of 1 or 2 with Mo(CO)₄(pip)₂, pip = piperidine, led to displacement of the pyrazole ligands and formation of the known amide compound, 1,1′-ferrocene bis carbonyl piperidine. Replacement of the pyrazole is ascribed to the weakness of the amide bond caused by the aromaticity of the pyrazole ring. Crystal data for C₁₈H₁₄FeN₄O₂ (1): monoclinic P2(1)/c, a = 13.3907(18) Å, b = 10.2112(14) Å, c = 11.3082(16) Å, β = 105.209(2)°, V = 1492.1(4) Å³, Z = 4.     

Synthesis,crystal structure,characterization and magnetic property of a new organophosphonate-based polyoxovanadate

A novel organophosphonate-based polyoxovanadate, Cs_1·5Na_3.5[H{V₃(H₂O)O₃}{O₃PC- (OH)(CH₃)PO₃}₃]·15H₂O (1) has been synthesized and further investigated by single-crystal X-ray diffraction analysis, IR spectrum, UV–vis spectroscopy, X-ray powder diffraction, thermogravimetric analysis and X-ray photoelectron spectroscopy. Single-crystal X-ray analysis reveals that compound 1 crystallizes in the triclinic space group P-1 with a = 9.506(3) Å, b = 15.150(5) Å, c = 17.915(6) Å, V = 2437.9(14) ų and Z = 2. Compound 1 exhibits a ring-shaped cluster with three branches of the 1-hydroxyethane 1, 1-diphosphonic acid [HEDP = H₂O₃P(OH)C(CH₃)PO₃H₂] ligands. Furthermore, the magnetic property of compound 1 has also been studied.     

Effect of lanthanum on the phase evolution of perovskite barium stannate synthesized through polymerized complex method

In this study, electrically conductive perovskite lanthanum-doped barium stannate, La_xBa_1-x SnO_3-δ (x = 0, 0.05, 0.1 and 0.15) ceramics were synthesized through polymerized complex method. The evolution of BaSnO₃ phase with temperature and effect of La doping was investigated. Doping of La increased the lattice parameter from 4.1165 to 4.1208 Å, up to solubility limit (x = 0.1); doping further, secondary phase La₂Sn₂O₇ appeared. BaSnO₃ phase crystallization initiated at ∼528 °C from the reaction of BaCO₃ and SnO₂ and was retarded by La doping causing an increment in phase formation temperature from 528.4 to 531.1 °C. Fourier transform infrared spectroscopy evidence substantial increment in (SnO₃)^2- absorption band with temperature strengthening diffraction responses. An incremental response in the electrical conductivity was observed by La doping with a maximum value of ∼25 S cm⁻¹, attributed to the generation of charge carriers by substitution of Ba with La ion and oxygen vacancies. In parallel, generated charge carriers also contributed towards the ionic reduction of Sn⁴⁺ to Sn²⁺ aiding the lattice enhancement. La-doped BaSnO₃ ceramics can have a potential application in optoelectronic, thermoelectric devices and humidity sensors.     

Ionothermal synthesis and crystal structure of a new layered nickel(II) diphosphate,DRM-1

A new layered ammonium nickel(II) diphosphate, (NH₄)₂[Ni₃(P₂O₇)₂(H₂O)₂], has been synthesized ionothermally in the ionic liquid 1-butyl-3-methyl imidazolium bromide and characterized by powder X-ray diffraction, elemental analysis, scaning electron microscopy, thermogravimetry etc. The results of the characterization show that the crystal adopts the monoclinic space group P2₁/a with the lattice constants a = 9.23529(2) Å, b = 7.98489(2) Å, c = 9.40772(2) Å, β = 100.2608(2)° and Z = 2. Its structure consists of chains of cis- and trans-edge-sharing [NiO₆]-octahedra linked via [P₂O₇] units to form layers of [Ni₃(P₂O₇)₂(H₂O)₂]^2? in the ab plane. Adjacent layers are separated in the c-direction by ammonium ions.     

The synthesis and crystal structure of [M{H2B(tz*)2}2(H2O)] (M=Cu,Zn and tz*=3,5-dimethyl-1,2,4-triazole)

New ligand [KH₂B(tz^*)₂] (tz*=3,5-dimethyl-1,2,4-triazolyl) has been synthesized and the reactions of two different metal salts (copper and zinc) with the new ligand in agar gave two similar crystalline polymorphic forms: [Cu{H₂B(tz^*)₂}₂(H₂O)] (1) and [Zn{H₂B(tz^*)₂}₂(H₂O)] (2). A single crystal X-ray study revealed that the compound 1 was the monoclinic system with space group C2/c and a=8.462(3) Å, b=14.039(6) Å, c=19.991(8) Å, β=94.622(7)°, Z=4, R₁=0.0451, wR₂=0.1110. And the compound 2 was the monoclinic system with space group C2/c and a=8.4214(4) Å, b=13.8765(7) Å, c=20.2969(6) Å, β=95.615(2)°, Z=4, R₁=0.0667, wR₂=0.1375. The metal(II) ion in the complex is five-coordinated with four nitrogen atoms which come from triazolyl and one oxygen atom which come from water molecular. In both compounds, the hydrogen atoms of water molecule are connected by hydrogen bonding with N atoms of two adjacent complex molecules to form 2-D planes. The spectroscopic results are consistent with the crystallographic study.     

Hydrothermal synthesis and crystal structure of a new copper(II) molybdenum(VI) arsenate(III), (C5H5NH)2(H3O)2[(CuO6)Mo6O18(As3O3)2]

A new copper(II) molybdenum(VI) arsenate(III), (C₅H₅NH)₂(H₃O)₂[(CuO₆)Mo₆O₁₈(As₃O₃)₂], has been hydrothermally synthesized and characterized by single crystal X-ray diffraction and TG analysis. The compound crystallizes in the monoclinic space group P2₁/n with a=9.303(2), b=20.731(4), c=12.617(3) Å, β=104.17(3)°, V=2359.3(8) ų, Z=2 and R1(wR2)=0.0296(0.0683). The structure is composed of pyridinium cations, proton hydrates and [(CuO₆)Mo₆O₁₈(As₃O₃)₂]⁴⁻ polyanions. The polyanion framework derives from the Anderson type; the central octahedron is filled up by copper(II) and is capped on both sides by a cyclic As₃O₆ group.     

Synthesis and characterization of the zinc(II) complex of a bleomycin analogue: a unique polymeric 2-[((2-(4-imidazoyl)ethyl)amino)carbony]-6-[((2-amino-2-methylpropyl)amino)methyl]pyridine zinc(II) nitrate complex

The reaction of 2-[((2-(4-imidazoyl)ethyl)amino)carbonyl]-6-[((2-amino-2-methylpropyl)amino)methyl]pyridine (L) with Zn^II(NO₃)₂·6H₂O has afforded a novel one-dimensional polymeric Zn^II complex, (Zn^II(L)(NO₃)₂)_n (2). Complex 2 crystallizes in the space group P2₁/n with a=8.955(3), b=13.216(3), c=18.941(3) Å, β=103.39(2)°, V=2180.6(10) ų, and Z=4. The geometry of each Zn^II is approximately a trigonal bipyramid: three nitrogens and one oxygen of the amide group are coordinated to the zinc while the fifth site is occupied by the imidazole nitrogen of a neighboring unit.     

Unusual formations of superoxo heptaoxomolybdates from peroxo molybdates

Two novel dioxygen heptaoxomolybdates K₅[Mo₇O₂₂(O₂)(OH)]Cl·6H₂O (1) and K₅[Mo₇O₂₂(O₂)(O₂)]·8H₂O (2) were isolated from the solution of peroxo molybdate accidently. The solids were characterized by IR, EPR and X-ray single crystal analysis. Complex 1 contains a superoxo group with a short bond distance 1.27(1) Å, while 2 is a mixed complex with peroxo and superoxo groups [1.43(1), 1.27(1) Å]. All of the dioxygen groups coordinate to molybdenum atoms in side-on (η²) fashion. The two complexes are short-lived and will decompose into peroxo molybdates K₅[Mo₇O₂₁(O₂)₂(OH)]·6H₂O (3) and K₆[Mo₇O₂₂(O₂)₂]·9H₂O (4) very quickly.     

A novel two-dimensional chiral coordination polymer: bis(S-(-)-lactate)zinc(II)

The synthesis and X-ray characterization of a novel chiral two-dimensional condensed metal–organic coordination polymer, bis(S-(-)-lactate)zinc(II) (1), are reported. Its crystal structure determination shows that a chiral cavity with approximate dimensions of 5.4×5.4 Ų is present. Crystallographic data for 1, C₆H₁₀O₆Zn, monoclinic P2₁, a=7.4440(15), b=7.4550(15), c=7.4550(15) Å, β=95.73(3)°, V=429.48(15) ų, R₁=0.0272, wR₂=0.0751.