Preparation and thermal decomposition of indium hydroxide

Summary Indium hydroxides were prepared by the mixing of aqueous indium nitrate solution with sodium or ammonium hydroxide solutions under various conditions. The thermal decomposition of the resulting materials was examined by thermogravimetry, differential thermal analysis, X-ray diffraction study and infrared spectroscopy. It has been found that sodium hydroxide solution is more suitable than the addition of ammonium hydroxide solution to prepare indium hydroxide in well crystallization; the thermal decomposition of indium hydroxide, in which the composition is In(OH)₃·xH₂O where x￡2, proceeds according to the following process: In(OH)₃·xH₂O?cubic In(OH)₃?cubic In₂O₃     

Darstellung und Eigenschaften der Diphthalocyaninate des Yttriums und Indiums

Synthesis and Properties of the Diphthalocyaninates of Yttrium and Indium Blue di(phthalocyaninato(2–))metalates of tervalent yttrium and indium are obtained by the reaction of yttrium acetate or anhydrous indium chloride with molten phthalodinitrile in the presence of potassium methylate and isolated as complex salts with organic cations. Anodic oxidation of (ⁿBu₄N)[M(Pc^2?)₂] (M = Y, In) yields crystals of green paramagnetic di(phthalocyaninato)metal(III)-dichloromethane solvate, [M(Pc)₂] · CH₂Cl₂ (μ_eff = 1.8/1.9 B.M. (Y/In)). Red brown di(phthalocyaninato)metal(III)-polybromide, [M(Pc^?)₂]Br_x is prepared by oxidation with bromine in excess. The redox properties of the di(phthalocyaninato)metalates(III) are investigated by cyclic voltammetry and difference pulse polarography. A quasi reversible (ΔE ? 60 mV) one electron process at 0.09 V (Y) and ?0.07 V (In) is assigned to the redox couple [M(Pc^2?)₂]^?/[M(Pc)₂]. Electronic absorption spectra as well as MIR/FIR and resonance Raman spectra are reported. The characteristic features of the three oxidation states and the influence of the ionic radius and the electron configuration of the metal ion are discussed.     

Synthesis and Crystal Structure of Potassium Indium Tribromide,KInBr3

KInBr₃, the first ternary indium bromide containing divalent indium, is synthesized from InBr₃, KBr, and elemental In at 450 °C. Its trigonal crystal structure (a = b = 853.24(1) pm, c = 1077.76(2) pm; P3¯; Z = 4) has been solved and refined from X-ray powder data. Indium atoms of oxidation state two are found in an [In₂Br₆]^2– unit with ecliptic ethane structure while potassium ions are located in two different polyhedra. There is an octahedral coordination by bromine anions for half of the K⁺ whereas the other K⁺ cations are located in trigonal Br^– prisms, tricapped by three additional Br^– anions.     

Mild and Efficient Debromination of vic-Dibromides to Alkenes with FeCl3·6H2O/Indium System

The FeCl₃ · 6H₂O/indium system efficiently causes debromination of various dibromides to the corresponding alkenes in good to excellent yields under mild conditions.     

Darstellung und Eigenschaften von Phthalocyaninato(2–)indaten(III) mit einzähnigen Acido-Liganden; Kristallstruktur von Tetra(n-butyl)ammonium-cis-difluoro-Phthalocyaninato(2–)indat(III)-Hydrat

Preparation and Properties of Phthalocyaninato(2–)indates(III) with Monodentate Acido Ligands; Crystal Structure of Tetra(n-butyl)ammonium cis -Difluorophthalocyaninato(2–)indate(III) Hydrate Tetra(n-butyl)ammonium cis-diacidophthalocyaninato(2–)indates(III) with the monodentate acido ligands fluoride, chloride, cyanide and formiate are synthezised by the reaction of chlorophthalocyaninatoindium(III) or cis-dihydroxophthalocyaninatoindate(III) with the respective tetra(n-butyl)ammonium salt or ammonium formiate and are characterized by their UV/VIS spectra and their vibrational spectra. The difluoro-complex salt crystallizes as a hydrate ((ⁿBu₄N)^cis[In(F)₂pc^2–] · H₂O) in the monoclinic space group P2₁/n (no. 14) with cell parameters: a = 13.081(3) Å, b = 13.936(2) Å, c = 23.972(2) Å; β = 97.79(1)°, Z = 4. Hexa-coordinated indium is surrounded by four isoindole nitrogen atoms (N_iso) and two cis-positioned fluorine atoms. The average In–F and In–N_iso distance are 2.0685(4) and 2.2033(5) Å, respectively, and the F–In–F angle is 81.5(1)°. The In atom is displaced outside the centre (Ct) of the N_iso plane towards the fluoride ligands: d(In–Ct) = 0.953(1) Å. The phthalocyaninato(2–) core is nonplanar (unsymmetrical concave distortion).     

Synthesis of potassium ferrite by precursor and combustion methods

The thermolysis of potassium hexa(carboxylato)ferrate(III) precursors, K₃[Fe(L)₆]·xH₂O (L=formate, acetate, propionate, butyrate), has been carried out in flowing air atmosphere from ambient temperature to 900°C. Various physico-chemical techniques i.e. TG, DTG, DTA, XRD, IR, Mössbauer spectroscopy etc. have been employed to characterize the intermediates and end products. After dehydration, the anhydrous complexes undergo exothermic decomposition to yield various intermediates i.e. potassium carbonate/acetate/propionate/butyrate and α-Fe₂O₃. A subsequent decomposition of these intermediates leads to the formation of potassium ferrite (KFeO₂) above 700°C. The same ferrite has also been prepared by the combustion method at a comparatively lower temperature (600°C) and in less time than that of conventional ceramic method.     

Thermal Decomposition of Thallium(I) Bis-oxalatodiaquaindate(III) Monohydrate

Thallium(I) bis-oxalatodiaquaindate(III) monohydrate was obtained by precipitation of indium(III) withoxalic acid from slightly acidic solution in the presence of thallium(I). The complex was subjected to chemical analysis. The thermal decomposition behavior of the complex was studied using TG, DTA and DTG techniques. The solid complex salt and the intermediate product of its thermal decomposition were characterized using IR absorption and X-ray diffraction spectra. Based on data from these physicochemical investigations the structural formula of the complex was proposed as Tl[In (C₂O₄)₂ (H₂O)₂]⋅H₂O. This revised version was published online in August 2006 with corrections to the Cover Date.     

Research of thermal decomposition of hydrated methanesulfonates

Hydrated methanesulfonates Ln(CH₃SO₃)₃·nH₂O (Ln=La, Ce, Pr, Nd and Yb) and Zn(CH₃SO₃)₂·nH₂O were synthesized. The effect of atmosphere on thermal decomposition products of these methanesulfonates was investigated. Thermal decomposition products in air atmosphere of these compounds were characterized by infrared spectrometry, the content of metallic ion in thermal decomposition products were determined by complexometric titration. The results show that the thermal decomposition atmosphere has evident effect on decomposition products of hydrated La(III), Pr(III) and Nd(III) methanesulfonates, and no effect on that of hydrated Ce(III), Yb(III) and Zn(II) methanesulfonates. This revised version was published online in August 2006 with corrections to the Cover Date.     

Novel Complexes of Gallium(III), Indium(III), and Thallium(III) with Pyridine‐Containing Proton Transfer Ion Pairs Obtained from Dipicolinic Acid – Synthesis,Characterization and X‐ray Crystal Structure

Three new complexes of group thirteen metals, gallium(III), indium(III), and thallium(III) with proton transfer compounds, obtained from 2,6‐pyridinedicarboxylic acid (dipicolinic acid), were synthesized and characterized using elemental analysis, IR, ¹H and ¹³C NMR spectroscopy and single crystal X‐ray diffraction. The gallium(III) and indium(III) complexes were prepared using (pydaH₂)(pydc) (pyda = 2,6‐pyridinediamine, pydcH₂ = dipicolinic acid) and thallium(III) complex was obtained from (creatH)(pydcH) (creat = creatinine). The chemical formulae and space groups of the complexes are (pydaH)[Ga(pydc)₂] · 3.25H₂O · CH₃OH, ( 1 ), [In(pydc)(pydcH)(H₂O)₂] · 5H₂O, Pna2₁ ( 2 ) and [Tl₂(pydcH)₃(pydc)(H₂O)₂], ( 3 ). Non‐covalent interactions such as ion‐pairing, hydrogen bonding and π‐π stacking are discussed. The complexation reactions of pyda, pydc, and pyda + pydc with In³⁺ and Ga³⁺ ions in aqueous solution were investigated by potentiometric pH titrations, and the equilibrium constants for all major complexes formed are described.     

Mössbauer study of the thermal decomposition of alkali tris(oxalato)ferrates(III)

The thermal decomposition of alkali (Li,Na,K,Cs,NH₄) tris(oxalato)ferrates(III) has been studied at different temperatures up to 700°C using Mössbauer, infrared spectroscopy, and thermogravimetric techniques. The formation of different intermediates has been observed during thermal decomposition. The decomposition in these complexes starts at different temperatures, i.e., at 200°C in the case of lithium, cesium, and ammonium ferrate(III), 250°C in the case of sodium, and 270°C in the case of potassium tris(oxalato)ferrate(III). The intermediates, i.e., Fe¹¹C₂O₄, K₆Fe¹¹₂(ox)₅. and Cs₂Fe¹¹ (ox)₂(H₂O)₂, are formed during thermal decomposition of lithium, potassium, and cesium tris(oxalato)ferrates(III), respectively. In the case of sodium and ammonium tris(oxalato)ferrates(III), the decomposition occurs without reduction to the iron(II) state and leads directly to α-Fe₂O₃.     

Studies on the thermal decomposition of alkali metal thiosulphatobismuthates(III)

The thermal decomposition of thiosulphatobismuthates(III) of alkali metals was investigated. The general formulae of the thiosulphatobismuthates are M₃[Bi(S₂O₃)₃]·H₂O where M = Na, K, Rb or Cs, and M₂Na[Bi(S₂O₃)₃]·H₂O where M = K or Cs.Typical thermal curves for thiosulphatobismuthates(III) and the results obtained in thermal, X-ray, chemical and spectrophotometrical analyses of the decomposition products are shown. The results were used to determine three stages of the thermal decomposition. At the first stage, at about 200°C, hydrated compounds are dehydrated. At the second stage, above 200°C, there is a rapid decrease in mass which is caused by evolving sulphur dioxide; bismuth sulphide and an intermediate decomposition product are formed. At about 320°C the thermal decomposition products are bismuth sulphide and alkali metal sulphate.     

Die Kristallstruktur von Tris(N,N-Diethyl-N′-benzoylselenoureato)indium(III)

The Crystal Structure of Tris(N,N-Diethyl-N′-benzoylselenoureato)indium(III) In(C₁₂H₁₅N₂OSe)₃ crystallizes in the monoclinic space group P2₁/c. The cell parameters are a = 11.792(2), b = 36.797(4), c = 18.574(2) Å, β = 92.15(2)° and Z = 4. The structure was solved with Patterson and direct methods and was refined to a final R-value of 3.41%. The asymmetric unit contains two complex molecules. The indium atoms are bidentally coordinated by three N,N-Diethyl-N′-benzoylselenourea molecules to form distorted octahedra with facial arrangement of the selenium and oxygen donor atoms. The chelate rings diverge strongly from planarity. The In? Se bond lengths vary from 2.643(1) to 2.657(1) Å, the In? O bond lengths from 2.179(4) to 2.203(4) Å, respectively.     

Thermal decomposition of some hexaborates

Thermal decomposition of iron(II) and cobalt(II) hexaborates has been investigated. The methods applied to investigate the process were differential thermal analysis, derivatography, crystallooptics and x-ray study. The following iron(II) hexaborate hydrates, FeO · 3B₂O₃ · 7.5H₂O, FeO · 3B₂O₃ · 5H₂O, FeO · 3B₂O₃ · 0.5H₂O; iron(III) borates, Fe₂O₃ · 6B₂O₃ and 2Fe₂O₃ · B₂O₃; cobalt(II)hexaborate hydrates CoO · 3B₂O₃ · 7.5H₂O, CoO · 3B₂O₃ · 5H₂O, CoO · 3B₂O₃ · 0.5H₂O, CoO · 3B₂O₃ and the decomposition product 2CoO · 3B₂O₃ have been isolated. Hepta- and semihydrates of cobalt(II) and iron(II) hexaborates have been proved to be isomorphous. It has been established that in the case of cobalt and iron hexaborates the exothermic maximum refers to a decomposition reaction and to the formation of a borate containing a smaller proportion of boron and boric anhydride.     

Crystallographic report: Tricarbonyl(η5‐cyclopentadienyl)(dichloroindium) molybdenum

In the solid state, [{Cp(CO)₃Mo}InCl₂]∞ forms a one‐dimensional coordination polymer in which the indium atoms are coordinated by four chlorine atoms (In? Cl: 2.448(2)–3.004(2) Å) and a {Cp(CO)₃Mo} group (In? Mo: 2.750(1) Å) in a distorted trigonal bipyramidal environment. Copyright © 2004 John Wiley & Sons, Ltd.     

Mechanism of thermal decomposition of cobalt acetate tetrahydrate

The thermal decomposition of cobalt acetate tetrahydrate (Co(CH₃COO)₂ · 4H₂O) has been studied via thermogravimetric (TG) analysis, in situ X-ray powder diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The results of TG and XRD showed that the parent salt melted and then the dissolved crystalline water was vaporized in two steps. The dehydration process was followed by a major step concerning the decomposition of the acetate group, leading to basic acetate as an intermediate, which then produced CoO and Co in N₂ and H₂ atmosphere, respectively. Three decomposition intermediates Co(CH₃COO)₂ · 0.5H₂O, Co(CH₃COO)₂, and Co(OH)(CH₃COO) were presumed. In situ XRD experiments revealed that the intermediate basic acetate was poorly crystallized or even amorphous. Evolved gases analysis indicated that the volatile products of acetate decomposition were water vapor, acetic acid, ethylenone, acetone, and CO₂. A detailed thermal decomposition mechanism of Co(CH₃COO)₂ · 4H₂O was discussed.     

Thermal behaviour of transition-and tetravalentmetal oxides and phosphorous oxide composites

The heat capacity of the solid indium nitride was measured, using the Calvet TG-DSC 111 differential scanning microcalorimeter (Setaram, France), in the temperature between (314–978 K). The temperature dependence of the heat capacity can be presented in the following form: C _p=41.400+0.499·10⁻³ T−135502T ⁻²−26169900 T ⁻³.     

Salze von Halogenophosphorsäuren. XIV. Darstellung und Kristallstruktur von Kalium-dikupferhydroxid-bis(monofluorophosphat)-Monohydrat Cu2K(OH)(PO3F)2 · H2O

Salts of Halogenophosphoric Acids. XIV. Preparation and Crystal Structure of Dicopper-potassium-hydroxide-bis(monofluorophosphate) Monohydrate Cu₂K(OH)(PO₃F)₂ · H₂O By the reaction of potassium monofluorophosphate and copper(II) salts in aqueous medium a crystalline, insoluble basic copper potassium monofluorophosphate Cu₂K(OH)(PO₃F)₂ · H₂O 1 is formed. The thermal decomposition of 1 has been studied. 1 crystallizes in the monoclinic space group B2/m with a = 9.094 Å, b = 7.755 Å, c = 6.333 Å, α = β = 90°; γ = 117.55°, and Z = 2.     

Understanding the Initial Decomposition Pathways of the n‐Alkane/Nitroalkane Binary Mixture

Addition of nitroalkanes into n‐alkanes can lower the activation barriers of free‐radical production and accelerate the decomposition of n‐alkanes at relatively low temperatures. Four initial decomposition mechanisms of the n‐butane/nitroethane binary mixture were proposed for the promoting effect and considered theoretically at the B3LYP, BB1K, BMK, MPW1K, and M06‐2X levels with MG3S basis set. Energetics above was compared to high‐level CBS‐QB3 and G4 calculations. Calculated results confirm the feasibility of the four initial decomposition pathways: (I) the C? NO₂ bond rupture of nitroethane to produce ethyl and ·NO₂, (II) HONO elimination from nitroethane followed by decomposition to ·OH and ·NO, (III) rearrangement of nitroethane to ethyl nitrite which further dissociates into CH₃CH₂O· and ·NO, and (IV) direct hydrogen‐abstraction of nitroethane with n‐butane.     

Synthesis and some properties of light lanthanide complexes with 4,4′-bipyridine and dibromoacetates

In this study, new complexes with formulae: Ce(4-bpy)(CHBr₂COO)₃·H₂O, Ln(4-bpy)_0.5(CHBr₂COO)₃·2H₂O (where Ln(III) = Pr, Nd, Sm; 4-bpy = 4,4′-bipyridine) and Eu(4-bpy)(CHBr₂COO)₃·2H₂O were prepared, and characterized by chemical and elemental analyses, and IR spectroscopy. The way of metal–ligand coordination was discussed. They are small crystalline. The complexes of Pr(III), Nd(III), and Sm(III) are isostructural in group. Conductivity studies (in methanol, dimethylformamide, and dimethylsulfoxide) were also performed and described. The thermal properties of complexes in the solid state were studied using TG–DTG techniques under dynamic flow of air atmosphere. TG–MS system was used to analyze principal volatile thermal decomposition and fragmentation products evolved during pyrolyses of Ce(III) and Sm(III) complexes in dynamic flow of air atmosphere.     

Evolution of water vapor from indium-tin-oxide transparent conducting films fabricated by dip coating process

Tin-doped indium oxide In₂O₃ (indium-tin-oxide) transparent conducting films were fabricated on silicon substrates by a dip coating process. The thermal analysis of the ITO films was executed by temperature-programmed desorption (TPD) or thermal desorption spectroscopy (TDS) in high vacuum. Gas evolution from the ITO film mainly consisted of water vapor. The total amount of evolved water vapor increased on increasing the film thickness from approx. 25 to 250 nm and decreased by increasing the preparation temperature from 365 to 600°C and by annealing at the same temperature for extra 10 h. The evolution occurred via two steps; the peak temperatures for 250 nm thick films were approx. 100-120 and 205-215°C. The 25 nm thick films evolved water vapor at much higher temperatures; a shoulder at approx. 150-165°C and a peak at approx. 242°C were observed. The evolution temperatures increased by increasing the preparation and the annealing temperatures except in case of the second peak of the 25 nm thick films. The evolution of water vapor at high temperature was tentatively attributed to thermal decomposition of indium hydroxide, In(OH)₃, formed on the surface of the nm-sized ITO particles. This revised version was published online in August 2006 with corrections to the Cover Date.