Tetrathioureamercury(II) tetrathiocyanatomanganate(II)

In the title complex, [Hg(CH₄N₂S)₄][Mn(NCS)₄], the Hg and Mn atoms sit at special positions with symmetry and are tetrahedrally coordinated to four thio­urea (TU) S and four thio­cyanate (SCN) N atoms, respectively. The structure consists of discrete cationic and anionic [Hg(TU)₄]²⁺ and [Mn(SCN)₄]²⁻ complexes, and weak N_TU—H⃛S_SCN hydrogen-bond bridges exist between these complexes.     

Double Hydrated Cobalt(II) Copper(II) and Nickel(II) Copper(II) Ammine Diphosphates

Synthesis of amorphous and crystalline double hydrated cobalt copper and nickel copper ammine diphosphates with a coordination structure is described.__________Translated from Zhurnal Prikladnoi Khimii, Vol. 78, No. 3, 2005, pp. 369–372.Original Russian Text Copyright © 2005 by Voitenko, Zhilyak, Kopilevich.     

Eisen (II) und Kobalt (II)

Ohne Zusammenfassung     

Crystal structures of ethylenediaminecadmium(II) tetracyanocadmate(II)-benzene(1/2) and ethylenediaminecadmium(II) tetracyanocadmate(II)

The crystal structure of ethylenediaminecadmium(II) tetracyanocadmate(II)-benzene(1/2),I, has been redetermined based on 1632 reflections collected anew for the crystal coated with epoxy resin, with a final conventionalR=0.038;I crystallizes in space groupP4₂22, witha=b=8.265(1) andc=15.512(3) Å, andZ=2. Ethylenediaminecadmium(II) tetracyanocadmate(II),II, is concluded to be identical with the residual metal complex host ofI, remaining after the liberation of the guest benzene molecules;II crystallizes from an aqueous solution containing bis- or tris-ethylenediaminecadmium(II) tetracyanocadmate(II) in space groupI4₁/acd, witha=b=14.366(1) andc=23.771(4) Å, andZ=16; refinement led to a conventionalR=0.043 for 1181 reflections. The bridging ethylenediamine ligand inI turns to a chelating one inII; dissociation and recombination should occur in the coordination sphere of the six-coordinate cadmium atom, whenII is derived fromI by the liberation of the guest molecules. Supplementary Data relating to this article are deposited with the British Library as Supplementary Publication No. SUP 82018 (30 pages).Dedicated to Professor H. M. Powell.     

Cadmium(II), manganese(II) and zinc(II) compounds

Three new compounds, [Cd(μ ₃ -Hpdh)(μ₂-Cl)] _n (1), Mn(Hpdh)₂(H₂O)₂ (2) and Zn(Hpdh)₂ (H₂O)₂ (3) (H₂pdh =?pyridine-2,3-dicarbo-2,3-hydrazide), have been synthesized and characterized by elemental analysis, IR spectra, TG and single-crystal X-ray diffraction. Under hydrothermal conditions, H₂pdh is generated by an in situ acylation of H₂pda (H₂pda =?pyridine-2,3-dicarboxylic acid) with hydrazine hydrate. Complex 1 features a 2D layer structure constructed by a dinuclear Cd(II) building block. In complexes 2 and 3, hydrogen bonding interactions connect mononuclear structures into 3D supramolecular frameworks.     

Hexaaquacobalt(II) bis(hypophosphite) and hexaaquacobalt(II)/nickel(II) bis(hypophosphite)

The title compounds, hexa­aqua­cobalt(II) bis­(hypophosphite), [Co(H₂O)₆](H₂­PO₂)₂, and hexa­aqua­cobalt(II)/nickel(II) bis(hypophosphite), [Co_0.5Ni_0.5(H₂O)₆](H₂PO₂)₂, are shown to adopt the same structure as hexa­aqua­magnesium(II) bis­(hypophosphite). The packing of the Co(Ni) and P atoms is the same as in the structure of CaF₂. The Co^II(Ni^II) atoms have a pseudo‐face‐centred cubic cell, with a = b～ 10.3 Å, and the P atoms occupy the tetrahedral cavities. The central metal cation has a slightly distorted octahedral coordination sphere. The geometry of the hypophosphite anion in the structure is very close to ideal, with point symmetry mm2. Each O atom of the hypophosphite anion is hydrogen bonded to three water mol­ecules from different cation complexes, and each H atom of the hypophosphite anion is surrounded by three water mol­ecules from further different cation complexes.     

Electrophilic Copper(II) → Metal(II) Substitution in Gelatin-Immobilized Copper(II) Hexacyanoferrate(II) Matrix Implants

Contact of thin layers of gelatin-immobilized copper(II) hexacyanoferrate(II) matrices with aqueous solutions of Co(II), Ni(II), Zn(II), and Cd(II) chlorides results in partial substitution of these ions for Cu(II) to give (dd)-heterobinuclear hexacyanoferrates(II) of copper(II) and the corresponding double-charged ion.     

Magnetic,epr and SOD studies of some Cu(II)-Cu(II), Cu(II)-Ni(II) and Cu(II)-Zn(II) imidazolate bridged complexes

Magnetic, spectroscopic and superoxide dismutase activity of imidazolate bridged [(Salala)Cu-Im-Cu(Salala)]Na, [(Salala)Cu-Im-Zn(Salala)]Na and [(Salala)Cu-Im-Ni(Salala)]Na (Salala=Salicyledenealiniate, Im=Imdiazolate) are described. The epr and electronic spectra of related mononuclear complexes, viz., [(Salala)Cu-OH(2)] and [(Salala)Cu-ImH] also described. Appearance of a half-field signal in polycrystalline and decrease in mu(eff) per copper(II) ion indicate super exchange coupling between copper(II) ion in [(Salala)Cu-Im-Cu(Salala)]Na binuclear complex. A pH-dependent epr and UV-vis study of 50% aqueous DMSO solution of binuclear complexes suggest that the complexes are stable in narrow pH range.     

N-acetyl-DL-leucinate cobalt(II), nickel(II) and zinc(II) complexes

Summary Complexes of the type M(AcLeu)₂ · B₂ (M = Co^II, Ni^II or Zn^II; B = H₂O, py, 3-pic, 4-pic; AcLeu =N-acetyl-DL-leucinate ion) and M(AcLeu)₂ B (M = Co^II or Zn^II and B = o-phen) were prepared and investigated by means of magnetic and spectroscopic measurements. The i.r. spectra of all the complexes are consistent with bidentate coordination of the amino acid to the metal ion. The room temperature solid state electronic spectra indicate that the symmetry of this species is closer toD _4h and that MO₆ and MO₄N₂ chromophores are present in the M(AcLeu)₂ · 2 H₂O and M(AcLeu)₂B_n · x H₂O (B = py, 3-pic, 4-pic, n=2 and x=0 for M = Ni^II; B = o-phen, n=1 and x=0 for M = Co^II; B = py, 3-pic, 4-pic, n=1 and x=1 for M = Co^II) complexes, respectively. By comparing the Dq values of the amino acid and those of other N-substituted amino acids previously studied, a spectrochemical series of the the cobalt(II) and nickel(II) complexes is proposed. The¹ H n.m.r. spectra of the zinc(II) complexes confirm the proposed stereochemistry.     

Metallatriazadiphosphorines of zinc(II), cadmium(II) and mercury(II)

Metallatriazadiphosphorine complexes corresponding to [{N(PPh₂NR)₂}M(OAc)] and [{N(PPh₂NR)₂}₂M], (R = Ph or SiMe₃; M = Zn, Cd or Hg) have been synthesized under strictly anhydrous and inert conditions by the reaction of the acyclic bis-silylated phosphazene ligand, [HN(PPh₂NSiMe₃)₂], or the bis-phenylated phosphazene ligand, [HN(PPh₂NPh)₂], with Zn, Cd and Hg acetate in 1:1 and 2:1 molar ratios. These complexes are highly soluble in common organic solvents, but unstable hydrolytically as well as thermally, even under reduced pressure. Molecular weight determinations in benzene indicated the monomeric nature of these complexes. Further, they have been characterized on the basis of elemental analysis and spectral studies: i.r. and n.m.r. (¹H, ¹³C and ³¹P) that plausibly reveal a trigonal planar and tetrahedral geometry around the metal atom in the complexes.     

Homoleptic Co(II), Ni(II), Cu(II), Zn(II) and Hg(II) complexes of bis-(phenyl)-diisoindol-aza-methene

The synthesis of five homoleptic transition metal complexes of bis-(phenyl)-diisoindol-aza-methene is described together with the optical, electrochemical and thermal properties of these compounds. Additionally, crystal structures for the Co and the Zn complex are reported.     

BisN(chlorophenyl)dithiocarbamato complexes of cobalt(II), nickel(II), palladium(II) and platinum(II)

Summary Cobalt(II), nickel(II), palladium(II) and platinum(II) complexes witho-(OCD),m-(MCD) andp-chlorophenyldithiocarbamate (PCD) ligands have been synthesised and characterised by chemical analyses, molecular weight determinations, conductance measurements, electronic and i.r. spectral studies. The thermal behaviour of the complexes has been studied by t.g. and d.t.a. techniques in a static air atmosphere and heats of reaction of different decomposition steps have been calculated from the d.t.a. curves. The thermal decomposition products of the complexes were identified by elemental analyses and i.r. spectra.     

Cadmium(II)bis(oxalato)cobaltate(II)- pentahydrate

A mixed metal carboxylate, cadmium(II)bis(oxalato)cobaltate(II)pentahydrate, has been synthesized and characterized by elemental analysis, IR spectral, reflectance and X-ray powder diffraction studies. Thermal decomposition studies (TG, DTG and DTA) in air showed that the compound decomposed to CdCoO3 at 370°C through the formation of an anhydrous compound at ~194°C. Finally, CdCoO₂ is generated at 1000°C. DSC study in nitrogen up to 550°C showed the formation of a mixture of CdO and Co₃O₄ as end products. The kinetic parameters have been evaluated for the dehydration and decomposition steps using four non-mechanistic equations, i.e., Freeman and Carroll, Coats and Redfern, Flynn and Wall, MacCallum and Tanner equations. Using seven mechanistic equations, the rate controlling processes of the dehydration and decomposition mechanism are also inferred. The kinetic parameters, DH and DS obtained from DSC are discussed. IR and X-ray powder diffraction studies identified some of the decomposition products. A tentative mechanism for the decomposition in air is proposed. This revised version was published online in August 2006 with corrections to the Cover Date.     

Synthetic, spectral and solution studies on imidazolate-bridged copper(II)-copper(II) and copper(II)-zinc(II) complexes

Synthesis, spectral and solution studies on 2-ethyl imidazolate-bridged (2-EtIm) homo-binuclear copper(II)-copper(II) and hetero-binuclear copper(II)-zinc(II) homologue are described. Magnetic moment values of homo-binuclear complexes indicate that the imidazolate group can mediate antiferromagnetic interactions. Optical spectra of hetero-binuclear complex at varying pH values suggest that the imidazolate-bridged complex is stable over the pH-range 7.15–10.0.