Indium Compounds Research Articles

Polymorphism of In5S5Cl – X‐ray and HRTEM‐Investigations

AbstractIn5S5Cl belongs to the group of mixed valence indium compounds with indium occurring simultaneously in three oxidation states (In5S5Cl = In+(In2)4+2In3+5S2–Cl–). It was shown in an earlier work that In5S5Cl obtained from InCl3, indium and sulfur at 550 °C, crystallises in a monoclinic structure type in contrast to the orthorhombic bromide, In5S5Br. The main difference of both structure types is an ordered mutual exchange of In+ and (In2)4+ in specific crystallographic positions. This exchange is possible due to the almost identical coordination pattern of both ions. A closer inspection of the real structure of monoclinic In5S5Cl by High Resolution Transmission Microscopy (HRTEM) already showed the presence of small orthorhombic domains in the real structure of this compound. Now we also obtained macroscopic quantities of orthorhombic In5S5Cl by the reaction of InCl3, indium and sulfur at reaction temperatures below 500 °C (Pmn21, a = 3.907(1) Å, b = 9.021(2) Å, c = 14.866(3) Å, Z = 2). The new polymorph is analysed by X‐ray single crystal and X‐ray powder diffraction and HRTEM investigations.

Hydrogenation of palladium rich compounds of aluminium, gallium and indium

Palladium rich intermetallic compounds of aluminium, gallium and indium have been studied before and after hydrogenation by powder X-ray diffraction and during hydrogenation by in situ thermal analysis (DSC) at hydrogen gas pressures up to 39 MPa and temperatures up to 700 K. Very weak DSC signals and small unit cell increases of below 1% for AlPd 2, AlPd 3, GaPd 2, Ga 5Pd 13, In 3Pd 5, and InPd 2 suggest negligible hydrogen uptake. In contrast, for both tetragonal modifications of InPd 3 (ZrAl 3 and TiAl 3 type), heating to 523 K at 2 MPa hydrogen pressure leads to a rearrangement of the intermetallic structure to a cubic AuCu 3 type with an increase in unit cell volume per formula unit by 3.6–3.9%. Gravimetric analysis suggests a composition InPd 3H ≈0.8 for the hydrogenation product. Very similar behaviour is found for the deuteration of InPd 3.

Causal Relationship between Indium Compound Inhalation and Effects on the Lungs

Recent case reports and epidemiological studies suggest that inhalation of indium dust induces lung damage. To elucidate the dose-dependent effects of indium on the lungs and to prove a causal relationship more clearly. A baseline observation was conducted on 465 workers currently exposed to indium, 127 workers formerly exposed to indium and 169 workers without indium exposure in 12 factories and 1 research laboratory from 2003 to 2006. Indium in serum (In-S) was determined as an exposure parameter, and its effects on the lungs were examined. The means of In-S in the current, former and no exposure workers were 8.35, 9.63 and 0.56 ng/ml, respectively. The current and former exposure workers had significantly higher levels of KL-6, and showed significant dose-dependent increases in KL-6, SP-D, and SP-A. Current exposure workers with In-S of 3 ng/ml or above demonstrated a significant increase of KL-6 in both GM and prevalence exceeding the reference value. Approximately a quarter of the former exposure workers had interstitial changes as seen on chest HRCT. In-S of exposed workers who had been working before improvements of the working environment (Group Bef) and those who started working after improvements (Group Aft) were 12.29 and 0.81 ng/ml, respectively. Adjusted odds ratios indicated 87%, 71% and 44% reductions among Group Aft workers who exceeded the reference values of KL-6, SP-D and SP-A, respectively. Dose-dependent lung effects due to indium exposure were shown, and a decrease of indium exposure reduced the lung effects. An In-S value of 3 ng/ml may be a cut-off value which could be used to prevent early effects on the lungs.

Novel indium(III) complexes with sterically hindered o-iminobenzoquinone

Abstract The first examples of indium(III) derivatives based on sterically hindered 4,6-di-tert-butyl-N-(2,6-di-iso-propylphenyl)-o-iminobenzoquinone (imQ) were synthesized and characterized in details. The interaction of sodium o-iminobenzosemiquinolate with indium(III) iodide produces bis[4,6-di-tert-butyl-N-(2,6-di-iso-propylphenyl)-o-iminobenzosemiquinonato]-iodo-indium(III) (1). The same product 1 was obtained by the reactions of imQ with InI or imQ disodium derivative with indium(III) iodide. The interaction of imQ with InI3 results in the formation of indium(III) compound (2) containing neutral form of o-iminobenzoquinone ligand. Structures of complexes 1 and 2 were determined by X-ray diffraction analysis.

Dihalogen–halogenomethyl complexes of indium(III) X2InCH2X (X=Br, I): Simultaneous coordination of soft and hard ligands

The reaction of halogenomethyl–dihalogen–indium(III) compounds X 2 InCH 2 X (X = Br, I) with dialkylsulfides, R2S opened the facile access to dialkylsulfonium methylide complexes of InX 3 of general structure X 3 (L)InCH 2 SR 2 (L = (CH 3 ) 2 SO, (C 6 H 5 ) 3 PO). Halogenomethyl–dihalogen–indium(III) compounds X 2 InCH 2 X (X = Br, I) obtained from indium monohalides and methylene dihalides were reacted with the soft donor ligands dialkylsulfides, R 2 S (R = CH 3 , CH 2 Ph) to afford the corresponding dialkylsulfonium methylide complexes of InX 3 , X 3 InCH 2 SR 2 (X = Br, R = CH 3 , 1 ; X = I, R = CH 3 , 2 ; X= I, R = CH 2 Ph, 3 ). Compound 1 was reacted with the hard donor ligands dimethylsulfoxide or triphenylphosphine oxide to give the corresponding 1:1 adduct, Br 3 (L)InCH 2 S(CH 3 ) 2 (L = (CH 3 ) 2 SO, 4 ; L = (C 6 H 5 ) 3 PO, 5 ). Compounds 1 – 5 were fully characterized in solution by NMR spectroscopy and in the solid state by X-ray methods.

Recovering Indium from the Liquid Crystal Display of Discarded Cellular Phones by Means of Chloride-Induced Vaporization at Relatively Low Temperature

Broadly speaking, indium (In) is extensively being used in the production of liquid crystal displays (LCDs). Nevertheless, LCDs, included in various types of end-of-life electronic devices (for example, discarded cellular phones), are generally discarded without recovering indium. Thus, the objective of this work is to recover indium from the LCD of the discarded cellular phone. The authors are putting forward a novel process in order to recover indium from the LCD of discarded cellular phones by means of chloride-induced vaporization at relatively low temperature. The samples are first treated with an aqueous solution of hydrochloric acid (HCl) to alter the structure of the indium(III) oxide found in LCDs into a chloride-induced indium compound and, therefore, enabling the vaporization of indium at relatively low temperature. The chloride-induced indium compound is then vaporized. Finally, the vaporized indium compound is condensed on a cooled surface of the apparatus and then recovered. The experimental results indicated that by using this process 84.3 pct of indium can be recovered from LCDs of discarded cellular phones.

New indium selenite-oxalate and indium oxalate with two- and three-dimensional structures

Two new indium(III) compounds with extended structures, [In 2(SeO 3) 2(C 2O 4)(H 2O) 2]·2H 2O ( I) and [NH 3(CH 2) 2NH 3][In(C 2O 4) 2] 2·5H 2O ( II), have been prepared under mild hydrothermal conditions and structurally characterized by single-crystal X-ray diffraction, thermogravimetric analysis and infrared spectroscopy. Compound I crystallizes in the triclinic system, space group P-1, with a=5.2596(11) Å, b=6.8649(14) Å, c=9.3289(19) Å, α=101.78(3)°, β=102.03(3)°, γ=104.52(3)°, while compound II crystallizes in the orthorhombic system, space group Fdd2, with a=15.856(3) Å, b=31.183(6) Å, c=8.6688(17) Å. In compound I, indium-selenite chains are bridged by oxalate units to form two-dimensional (2D) In 2(SeO 3) 2C 2O 4 layers, separated by non-coordinating water molecules. In compound II, the indium atoms are connected through the oxalate units to generate a 3D open framework containing cross-linked 12- and 8-membered channels.

Alkyl- and aryl-substituted main-group metal amides

Publisher Summary The main-group metal alkyls and aryls are valuable tools in preparative organic and inorganic chemistry, and many industrial applications are known for these reactive substances. This chapter describes the syntheses, structures, and physical properties of metal alkyls or aryls that have a further “chelating” amino ligand attached to the metallic center. The formal substitution of one of the alkyl or aryl groups at the metal by nonmetallic and electronegative groups leads to compounds that have both electrophilic and nucleophilic centers in the molecule. The existence of alkyl– or aryl–calcium amides has not as yet been unambiguously demonstrated. The chemistry of alkyl- and arylaluminum, gallium, indium, and thallium amides has been investigated much more than the comparable chemistry of Group II elements. Many of the structural principles found for organoaluminum amides also hold for the corresponding compounds of gallium, indium, and thallium. There are numerous examples of chelating ligands that have been used to obtain monometal-centered rings. Macrocycles have been used to chelate alkyl–metal compounds efficiently. The coordination number of the indium atom is increased by interaction with the nitrogen atom of a second molecule. The alkyl– and aryl–metal silazanes and poly(metal) silazanes described so far are representatives of an unusual class of compound containing simultaneously electron-deficient and electron-rich centers that can interact with one another. The very prominent bond fluctuations observed for these molecules are often due to competitive reactions between bases for the same acidic center.

Selective Sequential Dissolution for the Determination of Inorganic Indium Compounds in the Particulate Matter of Emissions and Workplace Air

A speciation method was developed for the determination of inorganic indium compounds in the particulate matter of emissions and from the workplace, based on selective sequential extractions. The main inorganic indium compounds that are expected to be present in the atmospheric particulate matter involving the industrial production of indium and in the manufacture of indium compounds were separated and determined. The procedure has been tested on standard reference materials. The indium recovery was in the range 93 - 105%.

Syntheses, Structures, and Characterizations of Two New Indium(III) Compounds from 1D ···In–OH–In–OH··· Chains and Pyridinedicarboxylic Ligands

The self-assembly of In2O3 with 2,5-pyridinedicarboxylic acid (2,5-H2PDC) and 3,5-pyridinedicarboxylic acid (3,5-H2PDC) generates two hybrid inorganic–organic compounds [In(OH)(2,5-PDC)]n (1) and [In2(OH)2(3,5-PDC)2(H2O)]n (2), respectively. The two compounds have been characterized by IR, XRPD, elemental analysis, and photoluminescent studies. The structure of 1 consists of corner-sharing InNO5 octahedra and 2,5-PDC ligands to form 2D frameworks with thermal stability up to ca. 347 °C. The 3D framework of 2 contains corner-sharing InN2O4 octahedra and InO7 decahedra with a 406 nm emission at 77 K. Both of the compounds possess similar one-dimensional ···In–OH–In–OH··· inorganic chains.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)

The Removal of Tin from ITO-scrap Using Molten NaOH

Indium demand has grown abruptly in the last few years at an average of ten percent per year. Consumption of indium is expected to increase throughout the next decade, especially by dint of growth for liquid crystal displays, high-definition television, semiconductor materials, batteries, low-temperature solders, and electronic application. Indium is used in various forms such as indium oxide/indium-tin oxide, indium metal and alloy, and indium compounds. 1,2 Indium-tin oxide (ITO) formed by doping indium oxide with approximately 10% of tin oxide, increases both electrical conductivity without significantly affecting transparency. Flat panel display applications for indium in the form of ITO are the most important end uses, more than onehalf of the world , s indium consumption. ITO, which has a high optical transparency and a high electrical conductivity, has been used as transparent electrodes for flat panel displays. ITO films are generally fabricated by DC magnetron sputtering using ITO ceramic target. Magnetron sputtering is favoured because it is easily applied to large area with good uniformity. However, ITO targets should be replaced before a large portion of ITO material (60-70%) has been used because of race track formation. 3-5 So, it might be said that the recycling of unused ITO target is indispensable as indium is a trace element and very expensive. As shown in In1.82Sn0.18O3 obtained by doping indium oxide with approximately 10% of tin oxide, tin is the major impurity in recovery process of indium metal from ITO target-scrap. Indium and tin are chemically very similar and separation one from the other in solution is a knotty problem. Tin has been removed from residue of acetate leaching by chemical replacement with zinc in 5-20% HCl. 6 Another method concerns neutralization of solutions containing tin to pH 1 followed by cementation with indium 7,8 or by treating with NaOH to a pH value of 2.8. 9,10 In this paper, I demonstrate a new method to remove tin and purify indium metal from ITO target scrap using molten NaOH.

Radical reactions initiated by the photochemical cleavage of carbon–indium bonds of organoindium compounds

Intra- and intermolecular reactions of carbon-centered radicals generated by photolysis of organoindium compounds were examined. The photolysis of vinylindium compounds and indium acetylides provided vinyl and alkynyl radicals, respectively, which were trapped with ethyl iodoacetate giving the corresponding β,γ-unsaturated esters. Allylic indium compounds, prepared from 8-bromo- or 8-iodooct-1,6-dienes and powdered indium metal, underwent an intramolecular radical cyclization to afford the 5- exo- trig product.

Solid-state 115In NMR study of indium coordination complexes

The feasibility of solid-state (115)In NMR studies is demonstrated by an examination of four different coordination complexes: indium(III) acetylacetonate, indium(III) tris(tropolonato), indium(III) triiodide bis(tris(4-methoxyphenyl)phosphine oxide) and indium(III) trichloride tris(2,4,6-trimethoxyphenyl)phosphine. The results provide information about the electric field gradients and magnetic shielding at the indium nuclei through the nuclear quadrupolar and chemical shift parameters, respectively. The C(Q) values in these four complexes range between 106.0 +/- 2.0 and 200.0 +/- 4.0 MHz, while the magnetic shielding anisotropies fall in the range from 85 +/- 15 to 550 +/- 60 ppm. Finally, this research demonstrates that solid-state (115)In NMR studies are facilitated by performing experiments at the highest possible magnetic-field strengths, and that NMR offers a promising tool for the characterization of indium compounds.

Molecular structures of M(But)3(M = Al, Ga, In) using gas-phase electron diffraction and ab initio calculations: experimental and computational evidence for charge-transfer processes leading to photodissociation

The gas-phase structures of AI(Bu')3 and Ga(Bu')3 have been investigated by electron diffraction and are shown to consist of monomeric units with very slightly pyramidal geometries. Salient structural parameters (r(hl)) include r(A1-C) = 2.008(2) A and r(Ga-C) = 2.032(2) A. For both compounds the ligand orientations and geometries are controlled by interligand interactions. The structures of M(Bu(t))3 (M = Al, Ga, In) have been calculated ab initio and those for the aluminium and gallium derivatives are in good agreement with the electron-diffraction structures. Comparison of the ab initio calculated structure of In(Bu')3 with those of Al(Bu(t))3 and Ga(Bu(t))3 suggests that the significantly different photochemistry exhibited by the former does not result from structural factors. In fact the compounds undergo a charge-transfer process in the UV region, with the wavelength required calculated to be slightly longer for the indium compound than for the other two.

Transition Metal-Indium Substitution in Y3Rh2-type Compounds

New rare earth metal-rich indium compounds RE3T2−xInx (RE = Gd, Tb, Dy, Ho, Er, Tm; T = Rh, Pd, Ir) were synthesized from the elements via high-frequency melting and subsequent annealing in sealed silica ampoules. These intermetallics crystallize with substitution variants of the tetragonal Y3Rh2-type structure, space group I4/mcm, Z = 28. All samples were studied by powder and single crystal X-ray diffraction: a = 1164.2(2), c = 2486.5(5) pm, for Tb3Rh1.25In0.71, a = 1139.4(2), c = 2480.8(5) pm for Er3Rh1.48In0.52, a = 1153.7(2), c = 2465.4(5) pm for Tm3Rh1.25In0.71, a = 1146.4(2), c = 2498.4(5) pm for Tb3Ir1.62In0.33, a = 1154.9(2), c = 2500.1(5) pm for Tb3Ir1.52In0.44, a = 1187.8(2), c = 2559.2(5) pm for Gd3Pd1.27In0.71, and a = 1169.1(2), c = 2530.3(5) pm for Ho3Pd1.27In0.71. The indium atoms show different site occupancies on the transition metal positions, and for most crystals small defects occur for one transition metal site. Gd3Rh1.30In0.64 (a = 1166.3(2), c = 2512.0(5) pm) and Dy3Rh1.31In0.64 reveal complete rhodium-indium ordering. These two indides crystallize with the translationengleiche subgroup I4/m. The rare earth atoms in these RE3T2−xInx indides have coordination numbers between 13 and 15. A striking structural motif is the tetrahedral indium coordination in the first coordination sphere of the RE5 position (305 pm Gd-In in Gd3Rh1.30In0.64). The transition metal atoms show trigonal prismatic or square anti-prismatic rare earth coordination. In all compounds investigated, the indium atoms substitute these metals only at the square prismatic sites and at one site of coordination number 10. The crystal chemical consequences of the different ordered and statistical transition metal-indium substitutions are discussed

Effect of various chelating agents on supercritical carbon dioxide extraction of indium(III) ions from acidic aqueous solution

Indium and its compounds have numerous industrial applications in the manufacture of liquid crystal displays and semiconductors. Indium compounds are considered hazardous materials that can be carcinogenic. Supercritical fluid extraction using carbon dioxide was utilized in this research as a sample pretreatment step for extraction of indium(III) ions from the synthetic etching wastewater of the semiconductor and optoelectronic industries. Several parameters, including various chelating agents, pH of solution, molar ratio of chelating agent to indium(III) ions, temperature and pressure were systematically investigated. Indium(III) ions were extracted by supercritical CO 2 combined with several various types of chelating agents including β-diketone (AcAcH), fluorinated β-diketone (TTAH), thiopyridine (PySH), and piperidinyldithiocarbamic acid (NCS 2H) to extract the ions from acidic aqueous solution. The performance of the various chelating agents from different studies indicated that the extraction efficiency by the supercritical CO 2 was in the order: NCS 2H ≧ PySH > TTAH ≫ AcAcH. The optimum pH for supercritical CO 2 extraction should fall in the range from 2.0 to 3.0. The optimum molar ratio of chelating agents to indium(III) ions was found to be a ratio of 10:1. It was also revealed that the optimal extraction pressure and temperature for the supercritical CO 2 extraction of indium(III) with various chelating agents AcAcH, PySH and NCS 2H were 70 °C 2000 psi, 60 °C 2000 psi, and 60 °C 2000 psi, respectively.

Toxicological assessment of indium nitrate on aquatic organisms and investigation of the effects on the PLHC-1 fish cell line

Indium nitrate is mainly used as a semiconductor in batteries, for plating and other chemical and medical applications. There is a lack of available information about the adverse effects of indium compounds on aquatic organisms. Therefore, the toxic effects on systems from four trophic levels of the aquatic ecosystem were investigated. Firstly, the bacterium Vibrio fischeri, the alga Chlorella vulgaris and the cladoceran Daphnia magna were used in the toxicological evaluation of indium nitrate. The most sensitive model was V. fischeri, with a NOAEL of 0.02 and an EC(50) of 0.04 mM at 15 min. Although indium nitrate should be classified as harmful to aquatic organisms, it is not expected to represent acute risk to the aquatic biota. Secondly, PLHC-1 fish cell line was employed to investigate the effects and mechanisms of toxicity. Although protein content, neutral red uptake, methylthiazol metabolization, lysosomal function and acetylcholinesterase activity were reduced in cells, stimulations were observed for metallothionein levels and succinate dehydrogenase and glucose-6-phosphate dehydrogenase activities. No changes were observed in ethoxyresorufin-O-deethylase activity. To clarify the main events in PLHC-1 cell death induced by indium nitrate, nine modulators were applied. They were related to oxidative stress (alpha-tocopherol succinate, mannitol and sodium benzoate), disruption of calcium homeostasis (BAPTA-AM and EGTA), thiol protection (1,4-dithiotreitol), iron chelation (deferoxiamine) or regulation of glutathione levels (2-oxothiazolidine-4-carboxylic acid and malic acid diethyl ester). The main morphological alterations were hydropic degeneration and loss of cells. At least, in partly, toxicity seems to be mediated by oxidative stress, and particularly by NADPH-dependent lipid peroxidation.

New Series of Indium Formates: Hydrothermal Synthesis, Structure and Coordination Modes

Three new indium(III) compounds, In(HCOO)3 (1), In2(HCOO)5(OH) (2), and In(HCOO)2(OH) (3), were synthesized under hydrothermal conditions and characterized by single crystal and powder X-ray diffraction experiments, as well as by IR spectroscopy, elemental analysis, and coupled TG-DSC-MS measurement. All of these compounds adopt 3D framework structures consisting of InO6 octahedra and the 2.11 binding modes of formate with the (syn, syn-; syn, anti-; anti, anti-) configurations. The structural investigation of these indium formates reveals that the gradual introduction of the hydroxyl groups into the structures induces the polymerization of the InO6 octahedra, that is, InO6 is isolated in 1, becomes dimeric in 2, and finally forms 1D chains in 3. In addition, a simple formula that may be used for estimating the overall coordination number of the formate in Ma(HCOO)bLc is proposed.

Exposure to hardly soluble indium compounds in ITO production and recycling plants is a new risk for interstitial lung damage

Objectives:To identify the effects of indium on the lung and to assess exposure-effect and exposure-response relations between indium exposure and effects on the lungs.Methods:Ninety three male indium exposed and 93...

インジウム触媒を用いた直接的・効率的分子変換法の開発

An indium-catalyzed reductive Friedel-Crafts reaction using chlorohydrosilane with carbonyls in aromatic solvents gave alkylated aromatics. When allylsilane was used instead of aromatics, hydro-allylation of carbonyls proceeded in high yield. A direct substitution of OH group in alcohols was also catalyzed by indium compounds in the reaction with silyl nucleophiles. The system provides the direct reduction, chlorination, allylation, or alkynylation pathways for substitution of alcohols in a catalytic manner. The direct reaction of alcohols with active methylene compounds instead of silyl nucleophiles catalyzed by InCl3 was accomplished without any activator or promoter. Allylic alcohols and benzylic alcohols served as electrophiles. α-Methoxyketone and indoles as nucleophiles were applicable to this system. Since H2O is the only side product of this system, the alkylated products were easily isolated in pure form. Indium compounds that have moderate (not strong) Lewis acidity and oxophilicity enables the catalytic reactions effectively.