Salicylate of Uranium

The reactions of uranium pentaethoxide with salicylic acid have been carried out in different stoichiometric ratios, yielding products of the type, U(OEt)₃(C₇H₄O₃), U(OEt)(C₇H₄O₃)₂, U(C₇H₄O₂)₂(C₇H₄O₃), and U₂(C₇H₄O₃)₃. A detailed study of the complexation reactions of uranyl ion with salicylic acid have also been made by potentiomertic and conductometric methods. The formation of 1:1 and 1:2 complexes have been confirmed by preparative studies. Two compounds, viz. (C₅H₆N)₂UO₂(C₇H₄O₃)₂ (NH₄)₂UO₂(C₇H₄O₃)₂ have been isolated.     

Uranyl complexes with methyl derivatives of alicyclic dioximes

A reaction of uranyl dioxalate complexes with methyl derivatives of alicyclic ??-dioximes, 3-methyl-1,2-cyclohexanedione dioxime and 3-methyl-1,2-cyclopentanedione dioxime, was studied. The structure of (CN₃H₆)₄[(UO₂)₂(C₆H₈N₂O₂)(CO₃)(C₂O₄)₂] · (C₆H₁₀N₂O₂) · 2H₂O and NH₄(CN₃H₆)₃[(UO₂)₂(C₇H₁₀N₂O₂)(CO₃)(C₂O₄)₂] · 2H₂O based on binuclear complex anions with carbonate-dioximate fragment was studied by X-ray diffraction.     

New organically templated gallium oxalate-phosphate structures based on Ga4(PO4)4(C2O4) building unit

Five organic-inorganic hybrid gallium oxalate-phosphates, [Ga₂(PO₄)₂(H₂O)(C₂O₄)_0.5](C₃N₂H₁₂)_0.5(H₂O) (1), [Ga₂(PO₄)₂(C₂O₄)_0.5](C₂N₂H₁₀)_0.5(H₂O) (2), [Ga₂(PO₄)₂(C₂O₄)_0.5](C₃N₂H₁₂)_0.5 (3), [Ga₂(PO₄)₂(H₂PO₄)_0.5(C₂O₄)_0.5](C₄N₃H₁₆)_0.5 (H₂O)_1.5 (4) and [Ga_2.5(PO₄)_2.5(H₂O)_1.5(C₂O₄)_0.5](C₄N₃H₁₅)_0.5 (5), have been synthesized by using 1,3-diaminopropane, ethylenediamine and diethylene triamine as structure-directing agents under hydrothermal condition. The structures of 1-5 are based on Ga₄(PO₄)₄(C₂O₄) building unit made up from Ga₂O₈(C₂O₄) oxalate-bridging dimer and alternating PO₄ and GaO₄ tetrahedral units. Compound 1 is layered structure where the building units link together in the same orientation. Corner sharing of these similar layers result in three-dimensional (3-D) structure 2. However, in compound 3, the building units arrange in a wave-like way to generate two types of eight member ring (8MR) channels. Both 4 and 5 contain the layers where the building units have an opposite orientation. Those layers are linked by H₂PO₄ group and Ga(PO₄)(H₂O)₃ cluster, respectively, to form 3-D frameworks with 12MR large pore channels. Compounds 2-5 exhibit intersecting 3-D channels where the protoned amines are located.     

Thermal behavior of some new chromium complexes with potential biological importance

Summary This paper reports the investigation of the thermal stability of three new complexes of Cr(III) with acrylate anion, [Cr₂(C₃H₃O₂)₄(OH)₂(H₂O)₄], [Cr₃O(C₃H₃O₂)₆(C₃H₄O₂)₃](C₃H₃O₂)×5H₂O and [Cr₂(C₃H₃O₂)₅(OH)] ×2H₂O, respectively. This type of complexes is important in proper carbohydrate and lipid metabolism of mammals. The thermal decomposition steps were evidenced. The thermal transformations are complex processes according to TG and DTG curves including dehydration and oxidative degradation of acrylate ion processes. The final product of decomposition is the chromium(III) oxide.     

Thermal analysis of some polynuclear coordination compounds as precursors of iron garnets (M3Fe5O12, M=Y3+ or Er3+)

The thermal behaviour of four coordination compounds (NH₄)₆[Y₃Fe₅(C₄O₅H₄)₆(C₄O₅H₃)₆]·12H₂O, (NH₄)₆[Y₃Fe₅(C₆O₇H₁₀)₆(C₆O₇H₉)₆]·8H₂O, (NH₄)₆[Er₃Fe₅(C₄O₅H₄)₆(C₄O₅H₃)₆]·10H₂O and (NH₄)₆[Er₃Fe₅(C₄O₆H₄)₆(C₄O₆H₃)₆]·22H₂O has been studied to evaluate their suitability for garnet synthesis. The thermal decomposition and the phase composition of the resulted decomposition compounds are influenced by the nature of metallic cations (yttrium-iron or erbium-iron) and ligand anions (malate or gluconate).     

Thermal studies on yttrium,neodymium and holmium oxalates

The thermal decomposition patterns of Y₂(C₂O₄)₃ · 9 H₂O, Nd₂(C₂O₄)₃ · 10 H₂O and Ho₂(C₂O₄)₃ · 5.5 H₂O have been studied using TG and DTG. The hydrated neodymium oxalate loses all the water of hydration in one step to give the anhydrous oxalate while Y₂(C₂O₄)₃ · 9 H₂O and Ho₂(C₂O₄)₃ · 5.5 H₂O involve four or more dehydration steps to yield the anhydrous oxalates. Further heating of the anhydrous oxalates results in the loss of CO₂ and CO to give the stable metal oxides.     

The cation influence on substitution reactions in aqua dioxalate uranyl complexes

The cation influence on substitution reactions in aqua dioxalate uranyl complexes with the participation of a fluoride ion as an attacking ligand and two-charge cations of ethylene diammonium and propylene diammonium was considered. The structure of (C₂H₁₀N₂)₃[UO₂(C₂O₄)₂F]₂ · 6H₂O and (C₃H₁₂N₂)[UO₂(C₂O₄)₂(H₂O)] complexes was determined by X-ray crystallography.     

Fast orthometalation reactions at a binuclear dirhodium(II) complex. Synthesis,crystal structure and reactivity of Rh2(O2CCH3)3[(C6H4)PPh2]·(HO2CCH3)2

From the reaction of Rh₂(O₂CCH₃)₄(MeOH)₂, in hot acetic acid with PPh₃ the monometalated intermediate Rh₂(O₂CCH₃)₃[(C₆H₄)PPh₂](HO₂CCH₃)₂ has been isolated and characterized by an X-ray study. This compound rapidly reacts with an excess of PPh₃ in dichloromethane at room temperature to give Rh₂(O₂CCH₃)₂-[(C₆H₄)PPh₂]₂(PPh₃)₂ with a head-to-tail structure. The same procedure at higher temperatures gives a mixture of this compound and another doubly metalated compound with a head-to-head structure.     

Synthesis and structures of the six-coordinate donor-acceptor complexes R3(C6H4O2)Sb…L (R=Ph, L=OSMe2 or ONC5H5; R=Me, L=ONC5H5 or NC5H5) and R3(C2H4O2)Sb…L (R=Ph, L=ONC5H5; R=Cl or C6F5, L=OPPh3)

One-pot oxidation of R₃Sb (R=Ph, Me, Cl, or C₆F₅) withtert-butyl hydroperoxide in the presence of 1,2-diols and monodentate donor compounds was studied. The structures of the resulting neutral organic donor-acceptor Sb^V complexes, Ph₃(C₆H₄O₂)Sb…OSMe₂, Ph₃(C₆H₄O₂)Sb…ONC₅H₅, Me₃(C₆H₄O₂)Sb…ONC₅H₅, Me₃(C₆H₄O₂)Sb…NC₅H₅, Ph₃(C₂H₄O₂)Sb…ONC₅H₅, and Cl(C₆F₅)₂(C₂H₄O₂)Sb…OPPh₃, were established by X-ray diffraction analysis. In these complexes, the coordination environment about the Sb atoms is a distorted octahedron. The Sb?O(N) distances and the Sb?O?E angles (E=S, N, or P) vary over wide ranges.     

The first organically templated gallium phosphite–oxalates: Synthesis,structures, and characterizationseer

Three new gallium phosphite–oxalates formula as (C₆N₂H₁₄)₂[Ga₂(OH)₂(C₂O₄)₂(HPO₃)₂]·2H₂O (1), (C₆N₂H₁₈)_0.5[Ga(OH)(C₂O₄)_0.5(HPO₃)] (2), and Ga(C₂O₄)_0.5(C₃N₂H₄)(HPO₃) (3) have been hydrothermally synthesized by controlling the pH value of the reaction system. Compound 1 possesses a one-dimensional ladder-like chain structure, in which the C₂O₄^2? anion is coordinated to one Ga center and acts as mono-bidentate ligand. In 2 and 3, the C₂O₄^2? anions serve as bis-bidentates ligands bridging between two Ga atoms to form the two-dimensional layered structures. Furthermore, compound 3 displays a neutral layered network, which is decorated by the directly coordinated organic ligand.     

Two bismuth oxalate hydrates and revision of their chemical formulae

The crystal structures of two bismuth(III) oxalate hydrates, previously described as `Bi<sub>2</sub>(C<sub>2</sub>O<sub>4</sub>)<sub>3</sub>·H<sub>2</sub>C<sub>2</sub>O<sub>4</sub>' and `Bi₂(C₂O₄)₃·7H₂O', were solved and refined from single‐crystal X‐ray diffraction data. The results led to the revised chemical formulae Bi₂(C₂O₄)₃·6H₂O and Bi₂(C₂O₄)₃·8H₂O, respectively. Both dibismuth(III) trioxalate hexahydrate (tetra­aqua­tri‐μ‐oxalato‐dibismuth(III) dihydrate, {[Bi₂(C₂O₄)₃(H₂O)₄]·2H₂O}_n) and dibismuth(III) trioxalate octahydrate (tetra­aqua­tri‐μ‐oxalato‐dibismuth(III) tetrahydrate {[Bi₂(C₂O₄)₃(H₂O)₄]·4H₂O}_n) are characterized by a three‐dimensional network of Bi atoms connected by tetradentate oxalate groups. All ligand and `free' water mol­ecules are located in channels and voids. The mean Bi—O bond lengths are ∼2.51 Å. The lone electron pairs on all Bi³⁺ cations are stereochemically inactive.     

Yttrium-succinates coordination polymers: Hydrothermal synthesis, crystal structure and thermal decomposition

New polymeric yttrium-succinates, Y₂(C₄H₄O₄)₃(H₂O)₄·6H₂O and Y₂(C₄H₄O₄)₃(H₂O)₂, have been synthesized, and their structures (solved by single crystal XRD) are compared with that of Y₂(C₄H₄O₄)₃(H₂O)₂·H₂O. Three compounds were obtained as single phases, and their thermal behaviour is described.     

A Homochiral Metal‐Dipeptide Supramolecular Framework Including a Hydrogen‐bonded Guest Network of Water and Uncoordinated 4, 4′‐Bipyridine

Abstract. The self‐assembly of glycyl‐L ‐leucine, Cu(NO₃)₂ · 3H₂O and 4, 4′‐bipyridine resulted in the tetranuclear‐based metal‐dipeptide supramolecular framework [Cu₄(C₈H₁₄N₂O₃)₄(H₂O)₂(C₁₀H₈N₂)₂] · (C₁₀H₈N₂) · 13H₂O ( 1 ). In the structure, the 4, 4′‐bipyridine‐bridged tetranuclear complex of Cu^II‐glycyl‐L ‐leucine interacts with each other to form a 1D hydrogen‐bonded chain including uncoordinated 4, 4′‐bipyridine and an interesting water chain in different channels. Under similar reaction conditions, racemic glycyl‐D ,L ‐leucine gave rise to the centrosymmetric dinuclear complex [Cu₂(C₈H₁₄N₂O₃)₂(C₁₀H₈N₂)] · 2H₂O ( 2 ), which is linked into a 2D hydrogen‐bonded structure without 4, 4′‐bipyridine included.     

μ2‐Acetato‐κ2O:O′‐tris(μ2‐ferrocenecarboxylato‐κ2O:O′)bis[(N,N‐dimethylformamide‐κO)copper(II)]

The title compound, [Cu₂Fe₃(C₅H₅)₃(C₂H₃O₂)(C₆H₄O₂)₃(C₃H₇NO)₂], belongs to the classic dimeric paddle‐wheel structure type. It is an unusual example in that it contains two different carboxylate groups, viz. ferrocenecarboxylate and acetate. With three ferrocenecarboxylate groups and only one acetate group bridging the two Cu centres, a noncentrosymmetric molecular arrangement results.     

Synthesis and structure of uranyl complexes with malonic acid dianions

The uranyl complexes with malonic acid dianions [UO₂(C₃H₂O₄)(CO(NH₂)₂)]·H₂O (1), [UO₂(C₃H₂O₄)(CONH₂NMe₂)]·H₂O (2), and [UO₂(C₃H₂O₄)(MeCONMe₂)] (3) were synthesized and characterized by X-ray crystallography. The structural units [UO₂(C₃H₂O₄)L] in the crystals of 1–3 refer to the AK²¹M¹ crystal chemical group (A = UO₂ ²⁺, K²¹ = C₃H₂O₄ ^2?, M¹ = L) of uranyl complexes; the crystals of 1 have a framework structure and 2 and 3 have a chain structure. Some structural features of the [UO₂(C₃H₂O₄)L] complex groups are discussed.     

Dimeric copper(II) 3,3‐dimethyl­butyrate adducts with ethanol, 2‐methylpyridine, 3‐methylpyridine, 4‐methylpyridine and 3,3‐dimethylbutyric acid

In the crystals of the five title compounds, tetrakis‐(μ‐3,3‐dimethylbutyrato‐O:O′)bis(ethanol‐O)dicopper(II)–ethanol (1/2), [Cu₂(C₆H₁₁O₂)₄(C₂H₆O)₂]·2C₂H₆O, (I), tetrakis(μ‐3,3‐dimethylbutyrato‐O:O′)bis(2‐methylpyridine‐N)di­copper(II), [Cu₂(C₆H₁₁O₂)₄(C₆H₇N)₂], (II), tetrakis‐(μ‐3,3‐dimethylbutyrato‐O:O′)bis(3‐methylpyridine‐N)di‐copper(II), [Cu₂(C₆H₁₁O₂)₄(C₆H₇N)₂], (III), tetrakis‐(μ‐3,3‐dimethylbutyrato‐O:O′)bis(4‐methylpyridine‐N)di‐copper(II), [Cu₂(C₆H₁₁O₂)₄(C₆H₇N)₂], (IV), and tetrakis‐(μ‐3,3‐dimethylbutyrato‐O:O′)bis(3,3‐dimethylbutyric acid‐O)dicopper(II), [Cu₂(C₆H₁₁O₂)₄(C₆H₁₂O₂)₂], (V), the di­nuclear Cu^II complexes all have centrosymmetric cage structures and (IV) has two independent molecules. The Cu?Cu separations are: (I) 2.602 (3) Å, (II) 2.666 (3) Å, (III) 2.640 (2) Å, (IV) 2.638 (4) Å and (V) 2.599 (1) Å.     

catena‐Poly­[[tetrakis­[μ‐(3‐methoxy­phenyl)­acetato‐O:O′]­dicopper(II)]‐μ‐2‐aminopyrimidine‐N1:N3]

The structure of the title compound, [Cu₂(C₉H₉O₃)₄(C₄H₅N₃)], comprises a zigzag polymer of alternating tetrakis­(carboxyl­ato‐O:O′)­dicopper(II) and 2‐amino­pyrimidine units linked by axial Cu—N bonds, and the non‐centrosymmetric structure has four unique (3‐methoxy­phenyl)­acetate moieties.     

Magnetic properties of nanocrystalline CuFe2O4 and kinetics of thermal decomposition of precursor

CuFe₂(C₂O₄)₃·4.5H₂O was synthesized by solid-state reaction at low heat using CuSO₄·5H₂O, FeSO₄·7H₂O, and Na₂C₂O₄ as raw materials. The spinel CuFe₂O₄ was obtained via calcining CuFe₂(C₂O₄)₃·4.5H₂O above 400 °C in air. The CuFe₂(C₂O₄)₃·4.5H₂O and its calcined products were characterized by thermogravimetry and differential scanning calorimetry, Fourier transform FT-IR, X-ray powder diffraction, scanning electron microscopy, energy dispersive X-ray spectrometer, and vibrating sample magnetometer. The result showed that CuFe₂O₄ obtained at 400 °C had a saturation magnetization of 33.5 emu g^?1. The thermal process of CuFe₂(C₂O₄)₃·4.5H₂O experienced three steps, which involved the dehydration of four and a half crystal water molecules at first, then decomposition of CuFe₂(C₂O₄)₃ into CuFe₂O₄ in air, and at last crystallization of CuFe₂O₄. Based on KAS equation, OFW equation, and their iterative equations, the values of the activation energy for the thermal process of CuFe₂(C₂O₄)₃·4.5H₂O were determined to be 85 ± 23 and 107 ± 7 kJ mol^?1 for the first and second thermal process steps, respectively. Dehydration of CuFe₂(C₂O₄)₃·4.5H₂O is multistep reaction mechanisms. Decomposition of CuFe₂(C₂O₄)₃ into CuFe₂O₄ could be simple reaction mechanism, probable mechanism function integral form of thermal decomposition of CuFe₂(C₂O₄)₃ is determined to be 1 ? (1 ? α)^1/4.     

3D Coordination Polymer Incorporating Discrete Molecular Octahedra

Copper(II) oxalate coordination polymer [{Cu₄(C₂O₄)₄(L)₄}₃ · {Cu₃(C₂O₄)₃(L)₆}₂ · 3L · 25H₂O]_n (L = 3,3′,5,5′‐tetramethyl‐4,4′‐bipyrazole) reveals a structure that is related to the Pt₃O₄ net topology. The 3D linkage is sustained with copper‐oxalate squares and copper‐bipyrazole triangles sharing vertices. The framework supports giant icosahedral cages and entraps discrete molecular octahedra formed by two molecular complexes Cu₃(C₂O₄)₃(L)₆ associated by means of NH‐‐‐N hydrogen bonding. The coexistence of the discrete and 3D portions formed by the same components suggests self‐templation as a key feature of the system. Simpler copper oxalate compounds [Cu(C₂O₄)(L)₂(H₂O)] · CH₃OH · 3.75H₂O and [Cu₂(C₂O₄)₂(L)₅] · L · 11H₂O are concomitant products of the reaction mixture and they exist in the form of molecular mono‐ and binuclear complexes.     

Dimeric copper(II) trimethylsilyl­acetate adducts with pyridine, 2‐­methylpyridine, 3‐methylpyridine and quinoline,and a polymeric copper(II) trimethylsilylacetate

In the crystals of bis(pyridine‐N)tetrakis(μ‐trimethylsilylacetato‐O:O′)dicopper(II), [Cu₂(C₅H₁₁O₂Si)₄(C₅H₅N)₂], (I), the dinuclear Cu^II complexes have cage structures with Cu?Cu distances of 2.632 (1) and 2.635 (1) Å. In the crystals of bis(2‐­methylpyridine‐N)tetrakis(μ‐trimethylsilylacetato‐O:O′)dicopper(II), [Cu₂(C₅H₁₁O₂Si)₄(C₆H₇N)₂], (II), bis­(3‐methylpyridine‐N)tetrakis(μ‐trimethylsilylacetato‐O:O′)dicopper(II), [Cu₂(C₅H₁₁O₂Si)₄(C₆H₇N)₂], (III), and bis(quinoline‐N)­tetrakis(μ‐­trimethylsilylacetato‐O:O′)dicopper(II), [Cu₂(C₅H₁₁O₂Si)₄(C₉H₇N)₂], (IV), the centrosymmetric dinuclear Cu^II complexes have a cage structure with Cu?Cu distances of 2.664 (1), 2.638 (3) and 2.665 (1) Å, respectively. In the crystals of catena‐poly­[tetrakis(μ‐trimethylsilylacetato‐O:O′)dicopper(II)], [Cu₂(C₅H₁₁O₂Si)₄]_n, (V), the dinuclear Cu^II units of a cage structure are linked by the cyclic Cu—O bonds at the apical positions to form a linear chain by use of a glide translation.