Color reactions of vanadium(V) with 8-hydroxyquinoline-5-sulfonic acid and ascorbic acid on PANV–AV-17 disks

The adsorption of vanadium(V) and 8-hydroxyquinoline-5-sulfonic acid (HQS) on polyacrylonitrile fiber disks filled with an AV-17 (PANV–AV-17) anion exchanger is studied by diffuse reflection spectroscopy. Vanadium(V) at pH 5?7 is adsorbed on PANV–AV-17; when a HQS solution is applied to the disk, a yellowish green complex compound formed, which changed color to almost black after the treatment of the disk with a HCl solution. The presence of sulfo groups in the HQS molecule ensures the preconcentration of the reagent on PANV–AV-17 disks with the registration of an analytical signal after the treatment of the disk with NaVO₃ and 0.1 M HCl solutions. A linear dependence of the analytical signal is observed in the HQS concentration range of 1?10 μg/mL. The presence of 20-fold amounts (by weight) of 8-hydroxyquinoline (HOQ) does not interfere with the determination. When ascorbic acid is applied to the disk with a vanadium(V)?HQS?HCl complex, the color changes from black to green. A test method for the determination of ascorbic acid is proposed. 8-Hydroxyquinoline can be determined by the intrinsic color of the adsorbate on PANV–KU-2 in the range of concentrations of HOQ solution in two drops 5?100 μg.     

Synthesis and crystal structure of pyridine and methanol coordinated a-octabutyloxyphthalocyaninatocobalt (II)

Phthalocyanines (Pcs) have been widely used as dyes and pigments, photoelectric materials and catalysts. They also bring general attention for potential applications, for example, in solar batteries and fuel cell, charge battery, electrochromic display devices, liquid crystal, sensors and molecular devices. The Pc抯 properties, such as spectroscopic, electronic, and magnetic properties, thermostabilities, and catalytic activities, may be adjusted by modifying the molecular structure. Therefor…     

Synthesis and crystal structure of d–f heteronuclear Gd(III)–Co(II) system

A carboxylate-bridged Co(II)–Gd(III) complex, [(bipy)CoL₃Gd(NO₃)L₃Co(bipy)] (HL =?α-methylacrylic acid, bipy =?2,2′-bipyridine), was prepared and characterized. Single crystal X-ray analysis reveals that the complex assumes a carboxylate-bridged CoGdCo unit. Magnetic measurements showed χ_m T decreases when the temperature is lowered.     

Synthesis and crystal structure of bis(N-o-methylphenyl-N ′-ethoxycarbonylthiourea) copper(I) chloride

The complex bis(N-o-methylphenyl-N′-ethoxycarbonylthiourea)copper(I) chloride was prepared by reaction of cupric chloride with the corresponding thiourea derivative. The complex was characterized by IR and ¹H NMR and its structure determined by X-ray diffraction methods. The complex is monoclinic, space group P2₁/n with cell dimensions a?=?8.014(3), b?=?21.018(7), c?=?15.891(5)?Å?and β?=?101.537(6). Two thiourea ligands and one Cl atom bond to Cu(I) to form a three-coordinate complex with trigonal planar coordination geometry. Intramolecular H-bonds influence the thiourea coordination properties and stabilize the configuration of the complex.     

Spectroscopic studies on the inclusion complex formation between 7-iodo-8-hyroxyquinoline-5-sulfonic acid and β-cyclodextrin

Formation of an inclusion complex between 7-iodo-8-hyroxyquinoline-5-sulfonic acid (IHQS) and β-cyclodextrin is studied by spectrophotometry and ¹H NMR techniques. Spectral changes in the emission spectra upon the addition of β-cyclodextrin to IHQS in aqueous media were too small to allow for the determination of the binding constant. On the other hand; absorption spectra show a pronounced changes upon the addition of β-cyclodextrin that allowed for the determination of the binding constant. Absorption measurements show 1:1 inclusion of IHQS in the β-cyclodextrin cavity with an association constant of 135 ± 25 M^?1. ¹H-NMR studies are used to confirm the inclusion and to provide information about the geometry of IHQS inclusion in the cavity of β-cyclodextrin.     

Synthesis and crystal structure of pyridine and methanol coordinated α-octabutyloxyphthalocyaninatocobalt (II)

Crystal structure of pyridine and methanol axially coordinated 1,4,8,11,15,18,22,25-octabutyloxyphthalocyaninatocobalt(II)(viz. α-octabutyloxyphthalocyaninatocobalt) [(n-BuO)₈Pc]. Co(Py)(MeOH) (1) was determined by X-ray diffraction methods. Crystal data: monoclinic, space group P2₁/n, Z = 4, a = 1.06482(4), b = 3.5487(2), c = 1.79428(9) nm, β=103.246(2)°, V = 6.5792(5) nm³, μ = 0.325 mm^-1. The result shows that the ring skeleton of 1 maintains planar conformation, which is similar to that of unsubstituted phthalocyanine but is remarkably different from the saddle shape conformation of 1,4,8,11,15,18,22,25-octabutyloxyphthalocyaninatocopper (II) [(n-BuO)₈Pc]Cu(2), which has no axial coordination. In the structure of 1, the substituents butyloxy groups of 1 somewhat deviate from the ring plane, while pyridine and methanol are coordinated to the center atom Co from opposite sides of the ring plane. In addition, all molecules are stacked along axis a to form one-dimensional molecule chain, the neighboring molecules in the chain overlap to some extent with a benzene ring and a distance of 0.3565 nm.     

Synthesis and crystal structure of 2′-(3,5-dioxo-1,2,4-triazinane-1-yl)acetic acid and the product of its reaction with copper(II) chloride

A new organic compound, 2-(3,5-dioxo-1,2,4-triazinane-1-yl)acetic acid, was prepared by transit template synthesis, and its crystal structure was determined. The ability of this compound to form stable metal complexes, where it acts as an N,O-chelating ligand, was demonstrated using its Cu(II) compound as an example.Translated from Koordinatsionnaya Khimiya, Vol. 31, No. 3, 2005, pp. 187–194.Original Russian Text Copyright © 2005 by Filippova, Bologa, Simonov, Gdaniec, Gerbaleu.This revised version was published online in April 2005 with a corrected cover date.This revised version was published online in April 2005 with a corrected cover date.     

Synthesis and crystal structure of lanthanum(III) Iodomercurate(II) complexes with ɛ-Caprolactam

The X-ray diffraction study of the crystalline products of the reaction between potassium tetraiodomercurate(II), ?-caprolactam, and lanthanum(III) nitrate at a ratio of 3: 16: 2 in an aqueous solution has shown the presence of the following three new crystalline compounds: [LaCpl₈]₂[HgI₄]₃ (I), [LaCpl₈][HgI₄]I₃ (II), and [LaCpl₇(H₂O)]₂[HgI₄]₂[Hg₂I₆] (III), where Cpl is ?-caprolactam ?-C₆H₁₁NO. Compounds I and II crystallize in tetragonal crystal system, space groups P4₂/n and $I\bar 4$ , respectively. For compound I, a = 18.59320(10) Å, c = 19.5782(3) Å, V = 6738.32(12) ų, Z = 2, and ρ_calc = 2.067 g/cm³. For compound II, a = 13.2245(10) Å, c = 20.0310(3) Å, V = 3503.17(6) ų, Z = 2, ρ_calc = 2.022 g/cm³. The crystals of compound III are monoclinic (space group P _{2 1}/n, a = 20.1202(6) Å, b = 14.0569(4) Å, c = 46.3228(12) Å, β = 93.4770(10)°, V = 13077.3(6) ų, Z = 4, ρ_calc = 2.274 g/cm³). [La(Cpl)₈]₂[Hg₂I₆]₃ (IV), a new double ionic complex salt, has also been synthesized and studied by X-ray diffraction. The crystals of compound IV are triclinic (space group $P\bar 1$ , a = 12.5021(3) Å, b = 14.6436(3) Å, c = 21.4695(4) Å, α = 84.2300(10)°, β = 87.2230(10)°, γ = 74.9970(10)°, V = 3776.30(14) ų, Z = 1, ρ_calc = 2.452 g/cm³). All complexes have a dicrete ionic structure, and the nearest surrounding of a La atom is distorted square-prismatic or trigonal-dodecahedral. The crystal packing of cations is distorted face-centered cubic (I and II) or body-centered cubic (III and IV) with anions located in its cavities.     

Synthesis and crystal structure of complexes of manganese(II), cobalt(II), and nickel(II) isothiocyanates with ?-caprolactam

The possibility of ?-caprolactam (CPL) to coordinate to manganese(II), cobalt(II), and nickel(II) rhodanides has been investigated. New complexes trans-[M(CPL)₄(NCS)₂], where M = Mn (I), Co (II), and Ni (III), have been synthesized. The complexes have been studied by chemical analysis and IR spectroscopy. According to X-ray diffraction, complexes are isostructural to each other and crystallize in monoclinic space group P2₁/c, Z = 2. For I: a = 6.9457(2) ?, b = 17.7751(6) 0A, c = 12.8999(4) 0A, ?? = 104.2670(10)°, V = 1543.51(8) ?³, ??_calc = 1.342 g/cm³, R ₁ = 0.0426. For II: a = 6.8925(2) ?, b = 17.8189(8) ?, c = 12.7278(6) ?, ?? = 104.421(2)°, V = 1513.93(11) ?³, ??_calc = 1.377 g/cm³, R ₁ = 0.0280. For III: a = 6.7804(2) ?, b = 18.4631(4) ?, c = 12.4841(3) ?, ?? = 105.2950(10)°, V = 1507.49(7) ?³, ??_calc = 1.382 g/cm³, R ₁ = 0.0273. Structures I?CIII are molecular; the metal atom in each of them coordinates four CPL molecules and two NCS groups via oxygen and nitrogen atoms, respectively.     

Synthesis and crystal structure of polymeric 4,4′-bipyridine cadmium(II) sulfate trihydrate

Polymeric 4,4′-bipyridinecadmium(II) sulfate trihydrate, [C₁₀H₈CdN₂O₇S] _n , has been synthesized and characterized by X-ray diffraction and spectroscopic methods. The compound crystallizes in space group P6₅22, with a?=?11.4465(15)?Å, c?=?20.7380(18)?Å. The coordination geometry around cadmium is distorted octahedral with Cd–N2?=?2.311(9), Cd–O1W?=?2.278(8) and Cd–O(SO₄)?=?2.247(7)?Å.     

Cobalt(II) hexaiododimercurate(II) complex with ε-caprolactam: Synthesis and crystal structure

The conditions of synthesis of a new binary complex salt [Co(Cpl)₆][Hg₂I₆] (Cpl is ε-caprolactam ε-C₆H₁₁NO) have been developed, and its structure has been characterized. The salt crystallizes in triclinic system, space group \(P\bar 1\), a = 10.1078(4) Å, b = 12.2680(5) Å, c = 13.0782(5) Å, α = 62.872(2)°, β = 72.394(2)°, γ = 76.834(2)°, V = 1367.98(9) ų, Z = 1, and ρ_calc = 2.297 g/cm³. The structure is insular and consists of isolated ions.     

Synthesis and crystal structure of dinuclear nickel (Ⅱ) complex

The crystal structure of Ni(Ⅱ) complex with 3-hydroxyl-1, 5-diazacycloheptane-N, N'-diacetate was determined by X-ray diffraction method. Crystal data for Ni2 (C9H14N2O5)2·2H2O: monoclinic, space group P21/n, a = 1.1717(5), b = 0.9794(3), c = 1.2971(2) nm, β= 96.62(3), V= 1.4786(7) nm3, Dc = 1.377 g/cm3, Z = 2,μ=13.321 cm-1 (Mo-Kα), F(000)=640. The final R and Rw are 0.075 and 0.089 respectively. The Ni(Ⅱ) ion forms 2:2 complex with ligand. Two ligands are bridged by two Ni(Ⅱ) atoms which are bridged by two O atoms. Every Ni(Ⅱ) is coordinated by two N atoms and four 0 atoms. The coordination polyhedron of the Ni(Ⅱ) ion is a distorted octahedron.     

Diiodo{N,N′-Bis(2,3,4-trimethoxybenzaldehyde)-ethylenediimine}mercury(II): Synthesis and crystal structure

Mononuclear mercury(II) complex [Hg((2,3,4-MeO-Ba)₂En)I₂] (I), where (2,3,4-MeO-Ba)₂En = N,N′-bis(2,3,4-trimethoxybenzaldehyde)ethylenediimine, has been synthesized and characterized by elemental analysis (C, H, and N) and confirmed by single-crystal X-ray diffraction analysis. The complex I crystallizes in the monoclinic system, with space group C2/c, having one symmetry-independent Hg²⁺ ion coordinated in distorted tetrahedral geometry by two N atoms of the Schiff base ligand and by two I atoms. The Schiff base ligand (2,3,4-MeO-Ba)₂En acts as a chelating ligand and coordinates via two N atoms to the mercury center and adopts an (E,E) conformation.     

Synthesis,characterization, crystal structure,and DNA binding of two copper(II)–hydrazone complexes

Two new Cu(II)–hydrazone complexes, [Cu(L)(Hbpe)ClO₄]·ClO₄·[Cu(L)Cl] (1) and [Cu(HL)₂]·1.5ClO₄·0.5OH (2) (where HL?=?(E)-N′-(1-(pyridine-2-yl)ethylidene)benzohydrazide and bpe = trans-1-(2-pyridyl)-2-(4-pyridyl)ethylene), have been synthesized and characterized by physicochemical methods. The structures of the complexes have been established by single-crystal X-ray diffraction direct methods, which reveal that the metal ions have distorted square-pyramidal and square-planar geometries in 1, and a distorted octahedral geometry in 2. DNA binding of HL, 1, and 2, performed by UV–vis titration in tris-buffer medium, yielded binding constants, which are 9.5 × 10³, 1.88 × 10⁴, and 4.66 × 10⁴ M^?1, respectively. Viscosity measurements suggest a surface or groove-binding mode of interaction between CT-DNA with HL, 1, and 2.     

Synthesis and crystal structure of bis{(μ-chloro)-chloro-[N-benzoyl-N′-(2-hydroxyethyl)thiourea] mercury(II)}

The complex bis{(µ-chloro)-chloro-[N-benzoyl-N′-(2-hydroxyethyl)thiourea] mercury(II)} was prepared by reaction of HgCl₂ with N-benzoyl-N′-(2-hydroxyethyl) thiourea(HL). The compound was characterized by IR and ¹H?NMR spectroscopy and its structure was determined by single crystal X-ray diffraction. The complex is binuclear with two Hg(II) ions tetrahedrally coordinated by a terminal chloride, two bridging chlorides and a HL molecule. The Hg(II) ion is coordinated with HL via S(1).     

Synthesis and crystal structure of β-hexanitrohexaazaisowurtzitane

A polycyclic caged compound with high strain—hexanitrohexaazaisowurtzitane (HNIW)—has been synthesized via a three-step reaction: condensation, hydrogenolysis debenzylation and nitrolysis, starting with benzylamine and glyoxal. HNIW is the most powerful high energy density compound (HEDC) ever tested. β-HNIW possesses a caged structure consisting of two five-membered rings and one six-membered ring with a nitro group attached to each of the six bridging nitrogens. The nitro group lies basically within a plane. The lengths of C—C bonds of β-HNIW range from 0. 156 nm to 0.159 nm, 0.002–0.005 nm longer than the sp³ C-C bond. The β-HNIW’s crystal belongs to orthorhombic system and space groupPca2₁ with parameters:a = 0.9670 (2),b = 1.1616 (2),c = 1.3032 (3) nm;V = 1.4638(5) nm³,Z = 4; D_c = 1.989 g/cm³ and D_m = 1.982 g/cm³. Project supported by the Advanced Research Funds (12060451867) from the Commission of Science and Technology for National Defence.     

Rhenium(IV)–copper(II) heterobimetallic complexes: Synthesis,crystal structure and magnetic properties

Two Re(IV)–Cu(II) heterometallic complexes {(CuL_α)[ReCl₄(ox)]}_n (where L_α = N-meso-5,12-Me₂-7,14-Et₂-[14]-4,11-dieneN₄), 1, and (CuL_β)[ReCl₄(ox)] (L_β = N-rac-5,12-Me₂-7,14-Et₂-[14]-4,11-dieneN₄N-rac-5,12-Me₂-7,14-Et₂-[14]-4,11-dieneN₄), 2, were synthesized. The [CuL²⁺] macrocyclic cation is coordinated from above and below by [ReCl₄(ox)]²⁻ units through the chloro-ligands and creates a chloro-bridged heterometallic Re^IV–Cu^II one-dimensional zig-zag chain. Compound 2 can be viewed as a heterobimetallic dinuclear unit, in which the Re(IV)-Cu(II) centers are linked by an oxalato bridge. The magnetic behavior of 1 and 2 has been investigated over the temperature range 1.8–300 K. Compound 1 behaves like a ferrimagnetic {Re(IV)–Cu(II)} bimetallic, one-dimensional chain with intrachain antiferromagnetic coupling. Compound 2 shows a weak antiferromagnetic interaction within the [Re(IV)–Cu(II)] unit along with a strong single-ion anisotropy, D(Re) = −63 cm⁻¹.