Synthesis,Structure and DNA-Binding Studies of Oxamido-Bridged Binuclear Copper(II) Complex: [Cu<Subscript>2</Subscript>(heap)](bipy)(ClO<Subscript>4</Subscript>)<Subscript>2</Subscript>

Abstract  

A new μ-oxamido-bridged copper(II)–copper(II) binuclear complex with formula of [Cu₂(heap)](bipy)(ClO₄)₂, where H₂heap and bipy are N,N′-bis(N-hydroxyethylaminopropyl)-oxamide and 4,4′-bipyridine, respectively, has been synthesized and characterized by elemental analyses, molar conductivity measurement, IR and electronic spectra studies, and single-crystal X-ray diffraction. The single-crystal X-ray analysis reveals that the complex has two embedded inversion centers at the mid-points of the C6–C6ⁱ bond of the oxamido group and the C7–C7ⁱⁱ bond of the 4,4′-bipyridine, respectively [symmetry code: (i) 2−x, 1−y, 1−z; (ii) =2−x, −y, 1−z]. Copper(II) atom is in a square-planar coordination geometry. The Cu···Cu separation through the oxamido birdge is 5.1430(8) ?. The bridging ligand (heap²⁻) adopts a bis-tetradentate trans conformation. A one-dimensional hydrogen bonding supramolecular structure parallel to the [2 1 0] direction is found in the crystal. The interaction of the binuclear copper(II) complex with herring sperm DNA (HS-DNA) was investigated by using absorption and emission spectra, electrochemical techniques and viscometry. The results suggest that the binuclear copper(II) complex interacts with HS-DNA by electrostatic interaction with intrinsic binding constant of 1.54 × 10⁴ M⁻¹.     

Crystal Growth and Structures of New Niobium and Tantalum Oxides: Sr<Subscript>3</Subscript>LiNbO<Subscript>6</Subscript> and Sr<Subscript>3</Subscript>LiTaO<Subscript>6</Subscript>

Abstract  

Single crystals of two new niobium and tantalum oxides, Sr₃LiNbO₆ and Sr₃LiTaO₆ were grown out of a Sr(OH)₂/LiOH·H₂O/KOH flux and characterized by single-crystal X-ray diffraction. The materials crystallize in the trigonal R-3c space group with a = 9.8029(14) ? (9.8111(11) ?), b = 9.8029(14) ? (9.8111(11) ?), c = 11.200(2) ? (11.2056(12) ?), α = β = 90°, γ = 120° for Sr₃LiNbO₆ (Sr₃LiTaO₆). The oxides exhibit the K₄CdCl₆ structure-type, and consist of alternating face-shared BO₆ octahedra (B = Nb⁵⁺ or Ta⁵⁺) and LiO₆ trigonal prisms.     

Observation of strong virtual scattering under three-beam (220, 371) X-ray diffraction in TeO<Subscript>2</Subscript> single crystal

A strong effect of virtual scattering has been experimentally observed when studying the nearly coplanar three-beam (220, 371) X-ray diffraction in a paratellurite single crystal under high-resolution double-crystal X-ray diffraction using MoK _α1 radiation. One characteristic feature of this effect is that the angular dependence of the first (strong) reflection intensity and its shape barely change in the three-beam range of parameters, whereas very strong changes are observed for the second (weak) reflection not only in the three-beam range but also far beyond it, which is related to the variation in the two-beam diffraction parameter due to virtual scattering. The changes observed are asymmetric and make it possible to determine the triplet combination of structure-factor phases.     

The crystal and molecular structure of a trifluoroacetylacetonate complex of scandium,Sc(CH<Subscript>3</Subscript>COCHCOCF<Subscript>3</Subscript>)<Subscript>3</Subscript>

The crystal and molecular structure of Sc(CH₃COCHCOCF₃)₃ has been determined by X-ray diffraction. The compound crystallizes as pure mer-isomer in the orthorhombic space group Pbca with lattice parameters a=15.166(8) ?, b=13.560(7) ?, c=19.327(10) ?, α=β=γ=90°, V=3974(4) ?³, Z=8. The complex at 100 K is partially disordered in the crystal structure in an approximate 5:1 ratio with 83% fluorine population at C-11 and 17% at C-15. NMR data is compared to that previously reported.     

Structure of phases of the sillenite family in the Bi<Subscript>2</Subscript>O<Subscript>3</Subscript>-V<Subscript>2</Subscript>O<Subscript>5</Subscript> system

X-ray diffraction studies of sillenite Bi₂₄V₂O₄₀ single crystals grown by the hydrothermal method are performed for a separate crystal and powdered crystals. It is found that the composition of the two specimens is described by the (Bi_{24 − x} ▭ _x )[Bi _y ³⁺V_1−y ⁵⁺]₂ O₄₀ general formula with completely populated oxygen sites but differs in the content of vacancies at the bismuth site (this was established for the first time) and the Bi: V ratio at the tetrahedral site. The structural models of all the vanadium-containing sillenites reported in the literature are considered, and the possibility that Bi atoms are located at the centers of BiO₄ tetrahedra is established.     

X-Ray diffraction study of KTiOPO<Subscript>4</Subscript> single crystals doped with hafnium

Single crystals of KTi_{1 − x} Hf _x OPO₄ (x = 0.015(2), 0.035(1), and 0.128(1) are reinvestigated by precision X-ray diffraction at room temperature. It is found that the implantation of hafnium atoms in the crystal structure of KTiOPO₄ does not lead to significant changes in the framework and affects only the positions of the potassium atoms in the channel. Our studies reveal the displacements of the potassium atoms from their main and additional positions in the structure of pure KTP in all three structures studied. The largest displacements from the K1′ and K1″ additional positions are observed in the structure with x = 0.035. At this hafnium concentration, the occupancy of the main positions of potassium atoms decreases and the occupancy of the additional positions increases in relation to those in KTP. This redistribution of potassium atoms enhances the nonuniformity of distribution of the electron density in the vicinity of their positions, which is probably responsible for the increase in the nonlinear susceptibility of KTP crystals that contain 3.5% hafnium in relation to crystals of pure KTP.     

Synthesis and Crystal Structure of a Cyano-Bridged Bimetallic Nickel(II)–Silver(I) Complex, [Ni(dmen)<Subscript>2</Subscript>{Ag(CN)<Subscript>2</Subscript>}<Subscript>2</Subscript>] · 0.5H<Subscript>2</Subscript>O

A cyano-bridged heteronuclear bimetallic complex [Ni(dmen)₂{Ag(CN)₂}₂] · 0.5H₂O (dmen = N,N′-dimethylethylenediamine) has been prepared and characterized by IR spectroscopy and X-ray Crystallography. The compound crystallizes in the monoclinic space group P2₁/c. The crystal structure of the complex consists of two independent centrosymmetric trinuclear molecules made up of a [Ni(dmen)₂] ⁺² unit linked to two [Ag(CN)₂]⁻ anions in a trans configuration. The trinuclear units are joined by hydrogen bonding to form irregular chains.     

Structure and properties of antimony-doped lanthanum molybdate La<Subscript>2</Subscript>Mo<Subscript>2</Subscript>O<Subscript>9</Subscript>

Polycrystalline samples of the composition La₂Mo_{2 − x} Sb _x O_{9 − y} , where 0 ≤ x ≤ 0.05, were prepared by solid-phase synthesis. Single crystals of La₂Mo_1.96Sb_0.04O_8.17 were obtained by spontaneous crystallization from flux. The structure of the metastable β _ms phase of this compound was determined at room temperature by X-ray diffraction. It was found that the La, Mo, and O1 atoms are displaced from the threefold axis on which they are located in the high-temperature β phase. It was shown that molybdenum atoms in the crystal structure are partially replaced by antimony atoms, which are located on the threefold axis. In antimony-doped crystals, lanthanum atoms partially return to the site on the threefold axis and the coordination environment of molybdenum cations becomes more ordered, thus facilitating the stabilization of the cubic phase at room temperature. Calorimetric measurements (DSC) showed that the introduction of Sb as the dopant into the La₂Mo₂O₉ structure leads to a decrease in the temperature of the α → β phase transition from 570 to 520°C and to the partial suppression of this transition. The temperature behavior of the conductivity confirms the DSC data. Thus, doping with Sb contributes to the stabilization of the cubic phase at room temperature.     

Synthesis and crystal structure of anhydrous copper suberate: [Cu<Subscript>2</Subscript>(OOC-(CH<Subscript>2</Subscript>)<Subscript>6</Subscript> -COO)<Subscript>2</Subscript>]

The title compound [Cu₂(OOC-(CH₂)₆-COO)₂] was synthesized and its crystal structure has been determined by single crystal X-ray diffraction methods. The complex crystallizes in the triclinic space group P-1 with a=5.1077(5) ?, b=8.362(2) ?, c=11.378(2) ?, α=93.773(6)°, β=97.587(9)°, γ=90.493(’9)° and D _cal=1.629 mg/m³ for Z=1.  The structure is polymeric and consists of discrete anhydrous centrosymmetric binuclear units [Cu₂(OOC-(CH₂)₆-COO)₂]. The two copper(II) centres bridged by the suberate groups in a syn-syn conformation, are in pentacoordinated distorted square-pyramidal coordination environment, with an intramolecular Cu–Cu distance of 2.5793(10) ?. Each binuclear unit, related to the next through μ_oxo bridges with a Cuμ_oxo–Cuμ_oxo separation of 3.2326(10)?, defines infinite chains of one-edge sharing CuO₅ square pyramid.     

Crystallographic and Conformational Analysis of [(<Emphasis Type="Italic">E</Emphasis>)-2-[(3-Chlorophenylimino)methy])-4-methoxyphenol]

Abstract  The crystal structure of C₁₄H₁₂ClNO₂ was determined by X-ray analysis. It crystallizes in the triclinic space group Pc with a = 12.5346(10) ?, b = 4.5101(3) ?, c = 12.0534(11) ?, α = 90.00o, β = 113.669(6)o, γ = 90.00o, Z = 2, Dx = 1.393 mg/m³, μ (MoK_α) = 0.298 mm⁻¹. The title compound is photochromic and molecule is non-planar. It adopts a phenol–imine tautomeric form with a strong intramolecular O–H···N hydrogen bond and a strong intermolecular C–H···O hydrogen bond. Minimum energy conformations AM1 were calculated as a function of the three torsion angles θ1(C10–C9–N1–C8), θ2(C9–N1–C8–C1) and θ3(N1–C8–C1–C6), varied every 10°. As in the X-ray experiment results, molecule has an angle that makes it non-planar between two aromatic rings in AM1 optimized geometry. Graphical Abstract  Molecular and crystal structure of [(E)-2-[(3-chlorophenylimino)methy])-4-methoxyphenol], C₁₄H₁₂ClNO₂, have been determined by single crystal X-ray diffraction study, and conformational analysis of the title molecule with respect to the selected torsion angle has been achieved by AM1 semi-empirical calculations.      

Crystal Structure of a New Quinternary Oxide: NaTl<Subscript>3</Subscript>Cu<Subscript>4</Subscript>Te<Subscript>2</Subscript>O<Subscript>12</Subscript>

Abstract  

A new quinternary oxide, NaTl₃Cu₄Te₂O₁₂, has been synthesized and characterized by single crystal X-ray diffraction. The reported material was synthesized by hydrothermal techniques using TlNO₃, CuO, TeO₂, and NaOH as reagents. The material exhibits a two-dimensional layered structure consisting of edge-shared CuO₆ and TeO₆ polyhedra separated by Na⁺ and Tl⁺ cations. NaTl₃Cu₄Te₂O₁₂ crystallizes in space group C2/m with a = 12.9800(17) ?, b = 9.3455(12) ?, c = 5.2335(7) ?, β = 104.276(2)°, V = 615.24(14) ?³, and Z = 2.     

Synthesis and Crystal Structure of 4,6-dihydroxy-2-[2-(4-hydroxy-phenyl)-vinyl]-benzene-1,3-dicarbaldehyde

Abstract The title compound, 3, 6-dihydroxy-2-[2-(4-hydroxy-phenyl)-vinyl]- benzene-1,3-dicarbaldehyde was synthesized by Vilslmeier reaction from resveratrol (trans-3,4′,5-trihydroxystilbene). Its structure was determined by X-ray single crystal diffraction. The crystal belongs to monoclinic, space group P2₁/n with crystallographic parameters: a = 7.2950(15) ?, b = 14.781(3) ?, c = 12.202(2) ?, β = 96.57(3)°, μ = 0.108 mm⁻¹, V = 1307.1(5) ?, Z = 4, Dx = 1.445 g/cm³, F(000) = 592, T = 293(2) K, 2.17°≤ θ ≤ 26.00°. The X-ray results demonstrated that the Vilslmeier reaction of resveratrol with DMF, POCl₃ and CH₃CN yielded 4,6-dhydroxy-2-[2-(4-hydroxy-phenyl)-vinyl]-benzene-1,3-dicarbaldehyde. Graphical Abstract In this article, a resveratrol derivative was prepared and structurally characterized by single crystal X-ray diffraction.      

The behavior of thermal conductivity in the chaotic phase of [N(CH<Subscript>3</Subscript>)<Subscript>4</Subscript>]<Subscript>2</Subscript>ZnCl<Subscript>4</Subscript> crystal

A thermal investigation of the modulated structure dynamics at the transition between metastable states in the incommensurate phase of [N(CH₃)₄]₂ZnCl₄ crystal have been performed. It is established that the anomalous behavior of the thermal conductivity in the absence of a defect-density wave is due to the inelastic scattering of thermal phonons from critical phonons of the soft optical branch. In the presence of a defect-density wave, the anomalous increase in thermal conductivity is caused by the existence of a chaotic phase and is related to the contribution that soft optical phonons make to the heat transfer due to the increase in their group velocity.     

Synthesis and Crystal Structure a Two-Dimensional Coordination Polymer: [Cd( μ -N3)( μ -HL)(H2O)]n [HL?=?Monodeprotonated 2,2′-bypyridine-3,3′-diol]

Abstract  Hydrated cadmium perchlorate reacted with sodium azide and 2,2′-bypyridine-3,3′-diol (H₂L) in ethanol solution and resulted in the formation of a two-dimensional coordination polymer: [Cd(μ-N₃)(μ-HL)(H₂O)]_n. The complex has been characterized by elemental analysis and IR spectrum, and its crystal structure determined by X-ray crystallography and the complex crystallizes in the monoclinic system with space group P2₁/c and a = 7.2849(14), b = 9.9568(19), c = 17.058(3) Ǻ, β = 102.254(2)°. In the complex both azide anion and monodepronated 2,2′-bypyridine-3,3′-diol anion (HL) act as bridge ligands and led to the formation of a two-dimensional sheet structure on (100) plane, and the O–H⋯N hydrogen bond made the sheets pile up along [100] direction, which forms a supramolecular three-dimensional structure. Graphical Abstract  The title two-dimensional Cd(II) coordination polymer was synthesized by cadmium perchlorate, sodium azide and 2,2′-bypyridine-3,3′-diol and its crystal structure determined. Single crystal X-ray diffraction analysis reveals that the two-dimensional coordination polymer was fabricated with azide anion and monodeprotonated 2,2′-bypyridine-3,3′-diol as mixed bridge ligands.      

Synthesis and Structure of Ba<Subscript>5</Subscript>(V<Subscript>2</Subscript>O<Subscript>7</Subscript>)<Subscript>2</Subscript>Cl<Subscript>2</Subscript>

Abstract  A new barium chlorovanadate, Ba₅(V₂O₇)₂Cl₂, was isolated by a high-temperature (850 °C) reaction employing a CsCl/RbCl flux. The structure was determined by single crystal X-ray diffraction methods. This compound crystallizes in an orthorhombic crystal system, Pmmn (No. 59), with a = 11.558(2) ?, b = 15.164(3) ?, c = 10.023(2) ?, Z = 4 and V = 1756.7(6) ?³. The structure of Ba₅(V₂O₇)₂Cl₂ was determined by full-matrix, least-squares methods with R ₁ = 0.0398, wR ₂ = 0.1069 and GOF = 1.048 for all data. This new structure can be described as a composite lattice made up of mixed covalent and ionic moities. The extended framework is orchestrated by stacked [Ba(V₂O₇)Cl]³⁻ slabs that are interconnected by Ba²⁺ cations through Ba–O bonds to the [V₂O₇] units. The Ba²⁺ and Cl^- ions form BN-type “[BaCl]” sheets with pseudo-hexagonal windows that are centered by [V₂O₇]⁴⁻ pyrovanadate units. Graphical Abstract  The structure of a new chlorovanadate, Ba₅(V₂O₇)₂Cl₂, exhibits an interesting BN-type salt lattice that consists of an extended [BaCl] sheet containing pseudo-hexagonal windows that are centered by [V₂O₇] pyrovanadate units.      

Convenient Route to Alkylene Dithiophosphato Ligands: Synthesis and Crystallographic Analysis of [OCH<Subscript>2</Subscript>CMe<Subscript>2</Subscript>CH<Subscript>2</Subscript>OPS<Subscript>2</Subscript>HNEt<Subscript>3</Subscript>]

Abstract  

Triethylammonium salts of O,O′-alkylene dithiophosphato like OGOPS₂HNEt₃, [where, G = –CH₂CMe₂CH₂–(1), –CH₂CEt₂CH₂–(2), –CMe₂CH₂CHMe–(3) and –CMe₂CMe₂–(4)] have been synthesized in quantitative yield by the direct reaction of P₂S₅ with 1,2- and 1,3-substituted glycols in presence of triethylamine, Et₃N, in 1:2:2 molar stoichiometry in toluene. These have been mainly characterized by molecular weight, IR and NMR (¹H, ¹³C and ³¹P) spectroscopic studies. Single crystal X-ray structure analysis of [OCH₂CMe₂CH₂OPS₂HNEt₃] reveals that phosphorus atom is tetrahedrally bonded to two sulfur atoms and two oxygen atoms in the ring and the molecule exists as discrete cation and anion. The structure is stabilized by cation–anion N–H···S hydrogen bonded interactions. Antiparallel pattern of triethylammonium ion is sandwiched within the two-dimensional layers of the ring system.     

Synthesis and crystal structure of a new composite complex between a hepta-coordinate ytterbium(III) and a heteropoly molybdic anion: [Yb(DMSO)<Subscript>7</Subscript>]H[SiMo<Subscript>12</Subscript>O<Subscript>40</Subscript>] (DMSO = dimethyl sulfoxide)

A new composite complex of the general formula [Yb(DMSO)₇]H[SiMo₁₂O₄₀] has been synthesized from H₄SiMo₁₂O₄₀⋅nH₂O, YbCl₃ and DMSO in mixed solvent of acetonitrile and water and characterized by elemental analysis, IR spectra and single crystal X-ray diffraction. Singe crystal X-ray structure analysis shows that it belongs to monoclinic system, space group P2₁/c, with a = 11.685(2) Å, b = 14.969(3) Å, c = 35.037(7) Å, β = 98.50(3)^∘, and Z = 4. There is one [Yb(DMSO)₇]³⁺ coordinated cation and one [SiMo₁₂O₄₀]⁴⁻ polyanion in one structure unit. The organic ligands (DMSO) do coordinate directly with ytterbium(III) to form a distorted pentagonal bipyramid complex ion by coordination bond, then combines to the SiMo₁₂O₄₀⁴⁻ anion by static electric force. The results of IR and X-ray diffraction show that there is strong interaction between polyoxometalate and organic donors.     

Copper(I) Complex [Cu(ca<Subscript>2</Subscript>dapte)(NCS)] with the Flexible N<Subscript>2</Subscript>S<Subscript>2</Subscript> Schiff-base Tridentate Ligand: Synthesis,Characterization and Crystal Structure

Abstract  

New copper(I) complex involving the flexible N₂S₂ Schiff-base ligand ca₂dapte [Cu(ca₂dapte)(NCS)], [ca₂dapte = N,N′-bis-(cinnamaldehyde)-1,2-di(o-iminophenylthio)ethane], has been synthesized and structurally characterized by X-ray diffraction analysis. The coordination polyhedron around the Cu(I) center is best described as a distorted tetrahedron. The flexible N₂S₂ Schiff-base ligand ca₂dapte acts as a tridentate ligand via two S atoms and one N atom, while the NCS^- ligand is coordinated to the metal ion through its nitrogen atom. Crystal data: space group P-1, a = 10.7486(7), b = 12.3737(13), c = 12.7578(11) ?, α = 89.385(7), β = 68.527(7), γ = 66.190(8)°; V = 1425.8(2) ?³, Z = 2, R = 0.0417, wR ₂ = 0.0744.     

Structural state of a radiation-modified Ti<Subscript>50</Subscript>Ni<Subscript>47</Subscript>Fe<Subscript>3</Subscript> single crystal

The structural state of a Ti₅₀Ni₄₇Fe₃ single crystal irradiated by fast neutrons (F = 2.5 × 10²⁰ cm⁻²) at 340 K was studied by thermal neutron diffraction at 78 and 295 K. The melt of this composition was chosen with the purpose of designing a radiation-resistant material exhibiting a shape-memory effect. It was found that the melt remains crystalline after irradiation, whereas the Ti₄₉Ni₅₁ crystal studied earlier becomes amorphous after an analogous irradiation. In spite of the fact that the main structural motif of the crystal remains unchanged after irradiation, martensitic transformations in the crystal do not occur and, consequently, the shape-memory effect is not retained. The radiation resistance of this class of crystals was estimated.     

The orthorhombic polymorph of diammonium trichromate(VI) decaoxide, <Emphasis Type="Italic">α</Emphasis>–(NH<Subscript>4</Subscript>)<Subscript>2</Subscript>Cr<Subscript>3</Subscript>O<Subscript>10</Subscript>

Synthesis and crystal structure of a trichromium(VI) decaoxide compound, α–(NH₄)₂Cr₃O₁₀, is reported. The crystal structure has been determined from three dimensional X-ray data collected at low temperature, 173 K. The structure is isomorphous with its Rb and Cs trichromate analogues, orthorhombic, space group Pbca, with a = 11.2558(3), b = 9.3193(3), c = 18.9819(5) ? and Z = 8. The title compound is composed of discrete [Cr₃O₁₀]^2– chains held together by the counter ion charge and a hydrogen bonding network. The different conformations adopted by trichromate anion within its ammonium, alkali and organic salts are discussed.