Synthesis, spectral characterization and crystal structure of copper(II) complexes of 2-benzoylpyridine-N(4)-phenylsemicarbazone

An interesting series of nine new copper(II) complexes [Cu₂L₂(OAc)₂]·H₂O (1), [CuLNCS]·½H₂O (2), [CuLNO₃]·½H₂O (3), [Cu(HL)Cl₂]·H₂O (4), [Cu₂(HL)₂(SO₄)₂]·4H₂O (5), [CuLClO₄]·½H₂O (6), [CuLBr]·2H₂O (7), [CuL₂]·H₂O (8) and [CuLN₃]·CH₃OH (9) of 2-benzoylpyridine-N(4)-phenyl semicarbazone (HL) have been synthesized and physico-chemically characterized. The tridentate character of the semicarbazone is inferred from IR spectra. Based on the EPR studies, spin Hamiltonian and bonding parameters have been calculated. The g values, calculated for all the complexes in frozen DMF, indicate the presence of the unpaired electron in the d_x²-y² orbital. The structure of the compound, [Cu₂L₂(OAc)₂] (1a) has been resolved using single crystal X-ray diffraction studies. The crystal structure revealed monoclinic space group P2₁/n. The coordination geometry about the copper(II) in 1a is distorted square pyramidal with one pyridine nitrogen atom, the imino nitrogen, enolate oxygen and acetate oxygen in the basal plane, an acetate oxygen form adjacent moiety occupies the apical position, serving as a bridge to form a centrosymmetric dimeric structure.     

Clathrate forming ability of some [MgA4X2] complexes where A=4-methylpyridine or pyridine and X=halogen or NCS

Three new compounds have been synthesized: [Mg(4-MePy)₄(NCS)₂]·0.67(4-MePy)·xH₂O (x=0.07–0.24 [Mg(4-MePy)₄(NCS)₂]·(4-MePy) and [MgPy₄(NCS)₂]·2Py·2H₂O. Their structures have been investigated by Raman spectroscopy and the first two compounds have been shown to be isostructural with the clathrates [Cu(4-MePy)₄(NCS)₂]·0.67(4-MePy)·0.33H₂O and [Ni(4-MePy)₄(NCS)₂]·(4-MePy). Thermal and other properties have been studied. It was concluded from an analysis of the literature that pyridine complexes of Mg and Ca are capable of forming clathrates with Py as guest molecule, although these compounds have not been examined before from the point of view of clathrate chemistry.Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences. Translated from Zhurnal Strukturnoi Khimii, Vol. 34, No. 2, pp. 66–73, March–April, 1993.     

Dissolution of gold in the DMSO—RX systems. The concept of a donor-acceptor electron transport system

Summary The liquid phase oxidation of gold in donor-acceptor organic and aqueous-organic media has been studied. The compounds [AuCl(Me₂S)], [AuBr(Me₂S)], [AuBr₃(Me₂S)], [Me₃S][AuBr₄], [Me₃S][AuBr₄(Me₂S)]·H₂O, [Me₃SO]-[AuBr₄]·H₂O, [Me₃S][Au₂Br₇(Me₂S)₂]·3H₂O, [Me₃S]₂-[Au₂Br₈]·2DMSO·H₂O, [Me₂(Bu)SO][AuBr₄]·H₂O and [Me₃S]Br were isolated by dissolution of Au⁰ in DMSO-RX mixtures (R = H or Bu; X = Cl or Br). The products were characterized by elemental analysis and i.r. spectroscopy. The nature of the Au⁰-DMSO-RX systems and the oxidant species are discussed in terms of a newly-developed concept of donor-acceptor electron transport (DAET) systems.     

Syntheses,crystal structures and electrochemistry of divalent metal 4-methylbenzenesulfonate complexes with o-phenanthroline

Three new compounds, namely [Mn(phen)₂(L)₂] · EtOH (1), [Zn(phen)₂(H₂O)₂]2L · 6H₂O (2) and [Cd(phen)₂(H₂O)₂]2L · 6H₂O (3), where HL = 4-methylbenzenesulfonic acid and phen = o-phenanthroline, have been synthesized, and their crystal structures determined by X-ray diffraction. In the complexes the metal atoms have two different coordination environments. Complex (1) consists of neutral molecules, [Mn(phen)₂(L)₂], in which Mn^II is six-coordinated by four nitrogen atoms from two o-phenanthroline molecules and two oxygen atoms from two sulfonate ions. Complexes (2) and (3) are isomorphous, each consisting of cationic species [M(phen)₂(H₂O)₂]²⁺ [M = Zn (2), Cd (3)], in which M^II is six-coordinated by four nitrogen atoms from two o-phenanthroline molecules and two water molecules. The electrochemical behavior and FT-IR of these compounds were also studied in detail.     

Complex Formation of Rhenium (V) with Benzimidazole in Acidic Media

Rhenium(V) complexes of 1H-benzimidazole (L), isolated from acidic media: (HL)₂[ReOX₅]·(H₂O) _n and [ReOL _x X _y (H₂O) _z ](H₂O) _n (HL and L are protonated and deprotonated forms of benzimidazole; X = Cl^-, Br^-) were studied by means of IR spectroscopy, ¹H NMR spectroscopy, and thermal analysis.     

Synthesis,electrochemical and e.p.r. spectral studies of binuclear copper(II) complexes with new pentadentate L-proline-based binucleating ligands

The synthesis, reduction, optical and e.p.r. spectral properties of a series of new binuclear copper(II) complexes, containing bridging moieties (OH^–, MeCO₂ ^–, NO₂ ^–, and N₃ ^–), with new proline-based binuclear pentadentate Mannich base ligands is described. The ligands are: 2,6-bis[(prolin-1-yl)methyl]4-bromophenol [H₃L¹], 2,6-bis[(prolin-1-yl)methyl]4-t-butylphenol [H₃L²] and 2,6-bis[(prolin-1-yl)methyl]4-methoxyphenol [H₃L³]. The exogenous bridging complexes thus prepared were hydroxo: [Cu₂L¹(OH)(H₂O)₂] · H₂O (1a), [Cu₂L²(OH)(H₂O)₂] · H₂O (1b), [Cu₂L³(OH)(H₂O)₂] · H₂O (1c), acetato [Cu₂L¹(OAc)] · H₂O (2a), [Cu₂L²(OAc)] · H₂O (2b), [Cu₂L³(OAc)] · H₂O (2c), nitrito [Cu₂L¹(NO₂)(H₂O)₂] · H₂O (3a), [Cu₂L²(NO₂)(H₂O)₂] · H₂O (3b), [Cu₂L³(NO₂)(H₂O)₂] · H₂O (3c) and azido [Cu₂L¹(N₃)(H₂O)₂] · H₂O (4a), [Cu₂L²(N₃)(H₂O)₂] · H₂O (4b) and [Cu₂L³(N₃)(H₂O)₂] · H₂O (4c). The complexes were characterized by elemental analysis and by spectroscopy. They exhibit resolved copper hyperfine e.p.r. spectra at room temperature, indicating the presence of weak antiferromagnetic coupling between the copper atoms. The strength of the antiferromagnetic coupling lies in the order: NO₂ N₃ OH OAc. Cyclic voltammetry revealed the presence of two redox couples Cu^IICu^II Cu^IICu^I Cu^ICu^I. The conproportionality constant K _con for the mixed valent Cu^IICu^I species for all the complexes have been determined electrochemically.     

Evidence of 13 hybrid fluoroaluminates in the composition space diagram of the Al(OH)3–tren–HF–ethanol system

Thirteen phases are now evidenced in the composition space diagram of the Al(OH)₃–tren–HF–ethanol system at 190 °C. Solvothermal syntheses are performed under microwave heating. Six new organic–inorganic fluorides crystallise and their structures are determined: (H₃O)·[H₄tren]₂·(AlF₆)₃·6H₂O (P-1, Z = 2), [H₃tren]₂·(AlF₅(H₂O))₃·8H₂O (C2/c, Z = 8), [H₃tren]₄·(AlF₆)₂·(Al₂F₁₁)·(F)·10H₂O (P2₁/n, Z = 2), [H₃tren]₂·(Al₄F₁₈)·3.5H₂O (P6₃, Z = 2), [H₃tren]₂·(Al₄F₁₈) (P-1, Z = 1), and [H₃tren]₄·(Al₈F₃₅)·(OH)·H₂O (P-1, Z = 1). The existence domains are approximately located for all phases. Tren amine is tetraprotonated at high HF concentration, otherwise it is triprotonated. A protonated water cluster, H₃O⁺(H₂O)₆, appears in (H₃O)·[H₄tren]₂·(AlF₆)₃·6H₂O while a new Al₄F₁₈ unit, found in [H₃tren]₂·(Al₄F₁₈), is evidenced; it results from corner and edge sharing association of four AlF₆ octahedra. Finally, the structure of [H₃tren]₄·(Al₈F₃₅)·(OH)·H₂O revealed the largest known fluoroaluminate polyanion, built from eight vertex sharing AlF₆ octahedra, (Al₈F₃₅)¹¹⁻.     

Conservation of [(C2H4NH3)3N]2·(ZrF7)2·H2O layers during the topotactic dehydration of [(C2H4NH3)3N]2·(ZrF7)2·9H2O

Tren amine cations [(C₂H₄NH₃)₃N]³⁺ and zirconate or tantalate anions adopt a ternary symmetry in two hydrates, [H₃tren]₂·(ZrF₇)₂·9H₂O and [H₃tren]₆·(ZrF₇)₂·(TaOF₆)₄·3H₂O, which crystallise in R32 space group with a_H = 8.871 (2) Å, c_H = 38.16 (1) Å and a_H = 8.758 (2) Å, c_H = 30.112 (9) Å, respectively. Similar [H₃tren]₂·(MX₇)₂·H₂O (M = Zr, Ta; X = F, O) sheets are found in both structures; they are separated by a water layer (O_w(2)-O_w(3)) in [H₃tren]₂·(ZrF₇)₂·9H₂O. Dehydration of [H₃tren]₂·(ZrF₇)₂·9H₂O starts at room temperature and ends at 90 °C to give [H₃tren]₂·(ZrF₇)₂·H₂O. [H₃tren]₂·(ZrF₇)₂·H₂O layers remain probably unchanged during this dehydration and the existence of one intermediate [H₃tren]₂·(ZrF₇)₂·3H₂O hydrate is assumed. O_w(1) molecules are tightly hydrogen bonded with -NH₃⁺ groups and decomposition of [H₃tren]₂·(ZrF₇)₂·H₂O occurs from 210 °C to 500 °C to give successively [H₃tren]₂·(ZrF₆)·(Zr₂F₁₂) (285 °C), an intermediate unknown phase (320 °C) and ZrF₄.     

Self-assembled macrocyclic molecular squares of Ni(II) derived from carbohydrazones and thiocarbohydrazones: Structural and magnetic studies

Four novel molecular square grids were achieved by self-assembly using the flexible ligands bis(di-2-pyridyl ketone) thiocarbohydrazone (H₂L¹), bis(quinoline-2-carbaldehyde) thiocarbohydrazone (H₂L²), bis(di-2-pyridyl ketone) carbohydrazone (H₂L³) and bis(2-benzoylpyridine) carbohydrazone (H₂L⁴). Three complexes were given a general formula of [Ni(HL)]₄[PF₆]₄ · nH₂O and one [Ni₂(HL²)L²]₂(PF₆)₂ · 7H₂O. The MALDI-MS spectra reveal the formation of tetranuclear molecular squares. The square grid of the Ni(II) centers in all the complexes were organized by deprotonated ligands. The complex [Ni(HL¹)]₄[PF₆]₄ · 11H₂O crystallized as [Ni(HL¹)]₄(PF₆)₄ · 0.5 CH₃CH₂OH · 2.8H₂O and X-ray study revealed octahedral geometries around the Ni(II) centers. Variable temperature magnetic studies suggest intramolecular antiferromagnetic coupling between the Ni(II) electrons by a super exchange mechanism through intervening sulfur/oxygen atoms.     

[H3tren] and [H4tren] fluoride zirconates or tantalates

Four new [H₃tren]³⁺ or [H₄tren]⁴⁺ fluoride zirconates and two new [H₃tren]³⁺ fluoride tantalates are evidenced in the (ZrF₄ or Ta₂O₅)-tren-HF_aq.-ethanol systems at 190 °C: the structurally related phases [H₄tren]·(Zr₂F₁₂)·H₂O and α-[H₄tren]·(Zr₂F₁₂) (P2₁2₁2₁), β-[H₄tren]·(Zr₂F₁₂) (P2₁/c), [H₃tren]₄·(ZrF₈)₃·4H₂O (I23), β-[H₃tren]₂·(Ta₃O₂F₁₆)·(F) (R32) and its monoclinic distortion α-[H₃tren]₂·(Ta₃O₂F₁₆)·(F) (C2/m). α and β-[H₄tren]·(Zr₂F₁₂) and [H₄tren]·(Zr₂F₁₂)·H₂O are built up from (Zr₂F₁₂) dimers of edge sharing ZrF₇ polyhedra while isolated ZrF₈ dodecahedra are found in [H₃tren]₄·(ZrF₈)₃·4H₂O. Linear (Ta₃O₂F₁₆) trimers build α and β-[H₃tren]₂·(Ta₃O₂F₁₆)·(F); they consist of two (TaOF₆) pentagonal bipyramids that are linked to two opposite oxygen atoms of one central (TaO₂F₄) octahedron. A disorder affects the equatorial fluorine atoms of the trimers and eventually carbon or nitrogen atoms of [H₃tren]³⁺ cations.     

Synthesis of MnOOH nanorods by cluster growth route from [Mn12O12(RCOO)16(H2O)n] (R=CH3, C2H5). Rational conversion of MnOOH into Mn3O4 or MnO2 Nanorods

Single-crystalline nanorods of γ-MnOOH (manganite) phase with diameters of 120 nm and lengths of 1100 nm have been prepared using a new cluster growth route under low-temperature hydrothermal conditions starting from [Mn₁₂O₁₂(CH₃COO)₁₆(H₂O)₄]·2CH₃COOH·4H₂O or [Mn₁₂O₁₂(C₂H₅COO)₁₆(H₂O)₃]·4H₂O without any catalyst or template agents. The so-obtained nanorods were studied by X-ray diffraction (XRD), infrared (IR) spectroscopy, Raman spectroscopy and high resolution transmission electron microscopy (HRTEM). Their thermal conversion opens an access to Mn₃O₄ (hausmannite) and β-MnO₂ (pyrolusite) nanorods, respectively, under argon or air atmosphere. A coercive field of 12.4 kOe was obtained for the Mn₃O₄ nanorods.     

3-(2-吡啶基)-1,2,4-三唑配体Co(II)Cu(II)和Cd(II)配合物的合成、结构及荧光性质

利用3-（2-吡啶基）-1,2,4-三唑配体（HL）和不同的金属盐设计合成了5个配合物[Co（HL）₂（H₂O）₂]（NO₃）₂（1）、[Cu₂（L）₂（NO₃）₂（H₂O）₄] （2）、[Cu₂（L）₂（AcO）₂（H₂O）₂]·6H₂O （3）、[Cu₂（L）₂（HL）₂（ClO₄）₂]·2CH₃CN （4）和[Cd₂（L）₂（HL）₂（NO₃）₂]·2H₂O （5）,并通过X射线单晶衍射、红外、元素分析、X射线粉末衍射和热重对配合物结构进行了表征。测试结果表明配合物1具有单核结构,并且可以通过氢键的相互作用形成二维超分子结构。配合物2~5为双核结构。配合物2和5可以通过氢键的相互作用形成二维超分子结构。配合物3通过氢键的相互作用形成三维超分子结构。研究了配合物中HL配体的配位模式。此外,研究了配体HL和配合物1和5的固态荧光性质及荧光寿命。     

Coordinate Structures of PrIII, GdIII, TmIII, and YbIII Complexes with Nitrilotriacetic Acids

The crystal and molecular structures of the [Pr^III(nta)(H₂O)₂]·H₂O (nta = nitrilotriacetic acids), K₃[Gd^III(nta)₂(H₂O)]·6H₂O, and K₃[Yb^III(nta)₂]·5H₂O complexes have been determined by single-crystal X-ray structure analyses. In [Pr^III(nta)(H₂O)₂]·H₂O, the Pr^IIINO₈ part forms a nine-coordinate pseudo-monocapped square antiprismatic structure in which one N and three O atoms are from one nta ligand in the same molecule, three O atoms from another nta ligand in the neighboring molecule and two O atoms from two coordinate water molecules. In K₃[Gd^III(nta)₂(H₂O)]·6H₂O, the [Gd^III(nta)₂(H₂O)^3- complex anion has a nine-coordinate pseudo-monocapped square antiprismatic structure in which each nta acts as a tetradentate ligand with one N atom of the amino group and three O atoms of the carboxylic groups. In K₃[Yb^III(nta)₂]·5H₂O, each nta also acts as a tetradentate ligand with one N atom of amino group and three O atoms of the carboxylic groups, but the [Yb^III(nta)₂ ^3- complex anion has an eight-coordinate structure with a distorted square antiprismatic prism. All the results including those for [Tm^III(nta)(H₂O)₂]·2H₂O confirm the inferences on the coordinate structures and coordination numbers of rare earth metal complexes with the nta ligand.     

Synthesis,spectroscopy and thermal analysis of nickel(II), palladium(II) and copper(II) complexes with N,N′-bis(2-hydroxyethyl)-oxamide

Summary The new complexes K₂[Ni(H₂heo)₂]·3H₂O, K₂[Pd-(H₂heo)₂], K₂[Cu(heo)]·3H₂O and [Cu₂(heo)·2H₂O] {heo = [(CONCH₂CH₂O)₂]^4-} were prepared and characterized by chemical analyses, conductivity measurements, thermogravimetry, magnetic susceptibility and i.r. and u.v. spectroscopy.Monomeric square planar structures with MN₄ coordination spheres are found for the nickel and palladium complex anions.For copper, two different complexes were identified. In slightly alkaline media, a green insoluble nonelectrolyte [Cu₂(heo)·2H₂O] was prepared; the two copper(II) centres are bridged by the tetra-deprotonated ligand in a trans-planar configuration with the H₂O molecules strongly coordinated to the copper(II). The copper(II) monomer has been prepared in strong alkaline media, this anion also contains the tetra-deprotonated ligand in a planar trans form.     

3-(2-吡啶基)-1,2,4-三唑配体Co(Ⅱ)Cu(Ⅱ)和Cd(Ⅱ)配合物的合成、结构及荧光性质

利用3-（2-吡啶基）-1,2,4-三唑配体（HL）和不同的金属盐设计合成了5个配合物[Co（HL）₂（H₂O）₂]（NO₃）₂（1）、[Cu₂（L）₂（NO₃）₂（H₂O）₄]（2）、[Cu₂（L）₂（AcO）₂（H₂O）₂]·6H₂O（3）、[Cu₂（L）₂（HL）₂（ClO₄）₂]·2CH₃CN（4）和[Cd₂（L）₂（HL）₂（NO₃）₂]·2H₂O（5）,并通过X射线单晶衍射、红外、元素分析、X射线粉末衍射和热重对配合物结构进行了表征。测试结果表明配合物1具有单核结构,并且可以通过氢键的相互作用形成二维超分子结构。配合物2~5为双核结构。配合物2和5可以通过氢键的相互作用形成二维超分子结构。配合物3通过氢键的相互作用形成三维超分子结构。研究了配合物中HL配体的配位模式。此外,研究了配体HL和配合物2和5的固态荧光性质及荧光寿命。     

Thermochemistry of NaRb[B4O5(OH)4]·4H2O

The enthalpies of solution of NaRb[B₄O₅(OH)₄]·4H₂O in approximately 1 mol dm⁻³ aqueous hydrochloric acid and of RbCl in aqueous (hydrochloric acid + boric acid + sodium chloride) were determined. From these results and the enthalpy of solution of H₃BO₃ in approximately 1 mol dm⁻³ HCl(aq) and of sodium chloride in aqueous (hydrochloric acid + boric acid), the standard molar enthalpy of formation of −(5128.02 ± 1.94) kJ mol⁻¹ for NaRb[B₄O₅(OH)₄]·4H₂O was obtained from the standard molar enthalpies of formation of NaCl(s), RbCl(s), H₃BO₃(s) and H₂O(l). The standard molar entropy of formation of NaRb[B₄O₅(OH)₄]·4H₂O was calculated from the Gibbs free energy of formation of NaRb[B₄O₅(OH)₄]·4H₂O computed from a group contribution method.     

A series of pure inorganic eight-connected self-catenated network based on Silverton-type polyoxometalate

In this paper, three pure inorganic eight-connected self-catenated networks based on the Silverton-type polyoxometalate [CeMo₁₂O₄₂]⁸⁻ with lanthanide, transition metal and alkali metal cations as linkers: [Li(H₂O)₄]₂Co(H₂O)₄Ce(H₂O)₃[CeMo₁₂O₄₂]·3H₂O (1), H_0.5[Li(H₂O)₄]_2.5[Ni(H₂O)₄]_0.5Ce(H₂O)₃[CeMo₁₂O₄₂]·3H₂O (2) and H[Li(H₂O)₄]₃Ce(H₂O)₃[CeMo₁₂O₄₂]·3H₂O (3) have been successfully synthesized and characterized by elemental analysis, IR spectroscopy, thermal gravimetric analysis, X-ray photoelectron spectroscopy, electrochemical analyses and single crystal X-ray diffraction. The single crystal X-ray diffraction analyses reveal that compounds 1-3 are isostructural. The [Ce^IVMo₁₂O₄₂]⁸⁻ polyoxoanions are connected by Ce⁴⁺ to form the infinite 1D chains. And then the parallel stacking chains linked by transition metal cations and lithium ions construct to an eight-connected self-catenated 4²⁴56³ topology framework.     

Geometrical aspects of complex formation by bicyclic bisureas

Geometrical characteristics of complexes of bicyclic bisureas (BBUs) of the octane series with biological metals (Co, Li, and Zn) have been studied using molecular mechanics. It was established that formation of the complexes [Co(BBU)₂-(H₂O)₂-X₂], [Li·BBU·(H_2O)₃]·X, [Zn·BBU·Cl₂·(H₂O)], and [Li₂·(-BBU)₂·(H₂O)₄]·X₂ is not sterically hindered.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2001–2006, September, 1990.     

The Effect of Concentration Parameters on Complexation in the Iron(0)–Iron(II)–Glycine–Water System

The processes of formation of iron(II) complexes in aqueous glycine solutions in the pH range of 1.0–8.0 at 298 K and ionic strength of 1 mol/L (NaClO₄) are studied using Clark and Nikolskii’s oxidation potential method. The type and number of coordinated ligands, the nuclearity, and the total composition of the resulting complexes are determined. The following complex species are formed in the investigated system: [Fe(OH)(H₂O)₅]⁺, [FeHL(H₂O)₅]²⁺, [Fe(HL)(OH)(H₂O)₄]⁺, [Fe(OH)₂(H₂O)₄]⁰, [Fe₂(HL)₂(OH)₂(H₂O)₈]²⁺, and [Fe(HL)₂(H₂O)₄]²⁺. Their formation constants are calculated by the successive iterations method using Yusupov’s theoretical and experimental oxidation function. The model parameters of the resulting coordination compounds are determined.     

Binuclear cyanide-bridged cobalt–iron complexes

Three new binuclear complexes: [(NO)(CN)₄FeCN–Co(en)₂] · H₂O (1), [(NO)(CN)₄FeCN–Co(pn)₂] · 2H₂O (2), and [(NO)(CN)₄FeCN–Co(tn)₂] · 3H₂O (3) (en = ethylenediamine, pn = 1,2-diaminopropane; tn = 1,3-diaminopropane) have been prepared and their properties studies by i.r., u.v. spectroscopy, cyclic voltammetry, and by magnetic measurements.