7681-11-0Relevant articles and documents
Determination of micro-iodate in iodized salt by high performance liquid chromatography
Chen, Meilan,Ye, Mingli,Yang, Xinlei,Fawzi, El-Sepaia
, p. 7683 - 7686 (2014)
A novel method was developed to determine micro-iodate in iodized salt by high performance liquid chromatography via hydrazine hydrate reduction. Iodate was first reduced to iodide using 0.085 % hydrazine hydrate solution followed by HPLC analysis. The sample pretreatment process was simple without any significant interference from the large amount of chloride in the matrix sample during the final analysis. Linearity was validated in the range of 1 to 1000 μmol/L with high correlation coefficient (R2 = 0.9995) and the limit of detection (LOD) was 0.214 mg/kg (KIO3 content, S/N = 3). The relative standard deviation was less than 2 % (n = 5) and the spiked recoveries of four real samples were between 98.1 and 100.8 %. The proposed method was applicable for effective routine analysis of micro-iodate in iodized salt.
Extremely bulky copper(i) complexes of [HB(3,5-{1-naphthyl}2pz)3]- and [HB(3,5-{2-naphthyl}2pz)3]- and their self-assembly on graphene
Van Dijkman, Thomas F.,De Bruijn, Hans M.,Brevé, Tobias G.,Van Meijeren, Bob,Siegler, Maxime A.,Bouwman, Elisabeth
, p. 6433 - 6446 (2017)
The synthesis and characterization, using NMR (1H and 13C), infrared spectroscopy, and X-ray crystallography, of the ethene and carbon monoxide copper(i) complexes of hydridotris(3,5-diphenylpyrazol-1-yl)borate ([Tp(Ph)2]-) and the two new ligands hydridotris(3,5-bis(1-naphthyl)pyrazol-1-yl)borate ([Tp((1Nt))2]-) and hydridotris(3,5-bis-(2-naphthyl)pyrazol-1-yl)borate ([Tp((2Nt))2]-) are described. X-ray crystal structures are presented of [Cu(Tp(Ph)2)(C2H4)] and [Cu(Tp((2Nt))2)(C2H4)]. The compound [Cu(TpPh)2)(C2H4)] features interactions between the protons of the ethene ligand and the π-electron clouds of the phenyl substituents that make up the binding pocket surrounding the copper(i) center. These dipolar interactions result in strongly upfield shifted signals of the ethene protons in 1H-NMR. [Cu(Tp((1Nt))2)(CO)] and [Cu(Tp((2Nt))2)(CO)] were examined using infrared spectroscopy and were found to have CO stretching vibrations at 2076 and 2080 cm-1 respectively. The copper(i) carbonyl complexes form self-assembled monolayers when drop cast onto HOPG and thin multilayers of a few nanometers thickness when dip coated onto graphene. General macroscopic trends such as the different tendencies to crystallize observed in the complexes of the two naphthyl-substituted ligands appear to extend well to the nanoscale where a well-organized monolayer could be observed of [Cu(Tp((2Nt))2)(CO)].
Crystal structures and ionic conductivities of ternary derivatives of the silver and copper monohalides: I. Superionic phases of stoichiometry MA4I5: RbAg4I5, KAg4I5, and KCu4I5
Hull,Keen,Sivia,Berastegui
, p. 363 - 371 (2002)
The superionic properties of the compounds RbAg4I5, KAg4I5 and KCu4I5 have been investigated by powder neutron diffraction and complex impedance spectroscopy. RbAg4I5 and KAg4I5 have room-temperature ionic conductivities of σ = 0.21(6) and 0.08(5) Ω-1 cm-1, respectively, which increase gradually on increasing temperature. KCu4I5 is only stable in the temperature range between 515(5) K and its melting point of 605 K, and its ionic conductivity is σ = 0.61(8) Ω-1 cm-1, at T = 540 K. At lower temperatures, KCu4I5 disproportionates into KI + 4CuI and the ionic conductivity falls by over three orders of magnitude. Least-squares refinements of the powder neutron diffraction data for RbAg4I5 at ambient temperature confirm the reported structure (space group P4132, Z = 4, a = 11.23934(3) A), though with some differences in the preferred locations of the mobile Ag+. KAg4I5 and KCu4I5 are found to adopt the same basic structure as RbAg4I5, with the I- forming a β-Mn-type sublattice, with the K+ located in a distorted octahedral environment and the Ag+(Cu+) predominantly distributed over two sites which are tetrahedrally co-ordinated to I-. The implications for the conduction mechanism within these compounds are discussed, using a novel maximum entropy difference Fourier technique to map the distribution of the Ag+(Cu+) within the unit cell.
A versatile lead iodide particle synthesis and film surface analysis for optoelectronics
Awol, Nasir,Amente, Chernet,Verma, Gaurav,Kim, Jung Yong
, (2020)
Lead (II) iodide, PbI2, semiconductor was synthesized using versatile methods such as hydrothermal, refluxing, solid-state reaction, and co-precipitation for optoelectronics. All the PbI2 particles exhibited hexagonal-layered 2H structure in which the average crystallite size and optical bandgap (Eg) were 57 ± 10 nm and 2.31 eV, respectively. Then, PbI2films were prepared using dimethyl sulfoxide (DMSO) or dimethylformamide (DMF) on the top of a mesoporous TiO2 layer, yielding a wider Eg of 2.33–2.36. Finally, through water contact angle measurement, the surface and interfacial properties of the thin film were characterized, exhibiting initial solid-vapor surface tension (γsv) of 6.1–6.4 mJ/m2 and solubility parameter (δ) of 4.51–4.62 (cal/cm3)1/2. However, when these PbI2 films were exposed to H2O molecules in air, δ changes from 4.62 to 7.28 (cal/cm3)1/2 for PbI2 (DMSO) film or 4.51 to 12.98 (cal/cm3)1/2 for the PbI2 (DMF) film, respectively. Finally, by employing the theory of melting point depression combined with the Flory-Huggins lattice theory, the interfacial interactions between PbI2 and regioregular poly (3-hexylthiophene-2,5-diyl) were qualitatively characterized. The smaller the χ interaction parameter, the more depressed the melting point.
Thermal decomposition kinetics of potassium iodate
Muraleedharan,Kannan,Ganga Devi
, p. 943 - 955 (2011)
The thermal decomposition of potassium iodate (KIO3) has been studied by both non-isothermal and isothermal thermogravimetry (TG). The non-isothermal simultaneous TG-differential thermal analysis (DTA) of the thermal decomposition of KIO3
Ion Exchange of Layered Alkali Titanates (Na2Ti3O7, K2Ti4O9, and Cs2Ti5O11) with Alkali Halides by the Solid-State Reactions at Room Temperature
Ogawa, Makoto,Saothayanun, Taya Ko,Sirinakorn, Thipwipa Tip
, p. 4024 - 4029 (2020/04/08)
Ion exchange of layered alkali titanates (Na2Ti3O7, K2Ti4O9, and Cs2Ti5O11) with several alkali metal halides surprisingly proceeded in the solid-state at room temperature. The reaction was governed by thermodynamic parameters and was completed within a shorter time when the titanates with a smaller particle size were employed. On the other hand, the required time for the ion exchange was shorter in the cases of Cs2Ti5O11 than those of K2Ti4O9 irrespective of the particle size of the titanates, suggesting faster diffusion of the interlayer cation in the titanate with lower layer charge density.
2,6-diisopropylphenylamides of potassium and calcium: A primary amido ligand in s-block metal chemistry with an unprecedented catalytic reactivity
Glock, Carsten,Younis, Fadi M.,Ziemann, Steffen,Goerls, Helmar,Imhof, Wolfgang,Krieck, Sven,Westerhausen, Matthias
, p. 2649 - 2660 (2013/06/27)
Transamination of KN(SiMe3)2 with 2,6-diisopropylphenylamine (2,6-diisopropylaniline) in toluene at ambient temperature yields [K{N(H)Dipp}·KN(SiMe3)2] (1) regardless of the applied stoichiometry. Recrystallization of 1 in the presence of tetramethylethylenediamine (TMEDA) and tetrahydrofuran (THF) leads to the formation of [(μ-thf)K2{N(H)Dipp}2]∞ (2), whereas potassium bis(trimethylsilyl)amide remains in solution. Addition of pentamethyldiethylenetriamine (PMDETA) gives [(pmdeta)K{N(H)Dipp}]2 (3). In contrast to the thf and pmdeta adducts, which lead to dissociation of 1 into homoleptic species, addition of bidentate dimethoxyethane maintains the mixed complex [(dme)K{μ-N(SiMe3)2}{μ-N(H)Dipp}K] 2 (4). A complete transamination of 2,6-diisopropylaniline with KN(SiMe3)2 in toluene at 100 C yields [K{N(H)Dipp}] (5), which reacts with CaI2 to give [(thf)nCa{N(H)Dipp} 2] (6), [(pmdeta)Ca{N(H)Dipp}2] (7), and [(dme) 2Ca{N(H)Dipp}2] (8), depending on the solvents and coligands. Excess potassium 2,6-diisopropylphenylamide allows the formation of the calciate [K2Ca{N(H)Dipp}4]∞ (9). Hydroamination of diphenylbutadiyne with 2,6-diisopropylaniline in the presence of catalytic amounts of 9 gives tetracyclic 2,6-diisopropyl-9,11,14,15- tetraphenyl-8-azatetracyclo[8.5.0.01,7.02,13]pentadeca-3, 5,7,9,11,14-hexaene (10). Solid-state structures are reported for 2-4 and 7-10. Compound 10 slowly rearranges to tetracyclic 5a,9-diisopropyl-2,3,10,11- tetraphenyl-5a,6-dihydro-2a1,6-ethenocyclohepta[cd]isoindole (11), which is slightly favored according to quantum chemical studies.
Thermal decomposition kinetics of potassium iodate: Part I. the effect of particle size on the rate and kinetics of decomposition
Muraleedharan, K.
, p. 237 - 246 (2012/08/08)
The rate and kinetics of the thermal decomposition of potassium iodate (KIO3) has been studied as a function of particle size, in therange 63-150 μm, by isothermal thermogravimetry at different tempera tures, 790, 795, 800 and 805 K in nitrogen atmosphere. The theoretical and experimental mass loss data are in good agreement for the thermal decomposition of all samples of KIO3 at all temperatures studied. The isothermal decomposition of all samples of KIO3 was subjected to both model-fitting and model-free (isoconversional) kinetic methods of analysis. It has been observed that the activation energy values are independent of the particle size. Isothermal model-fitting analysis shows that the thermal decomposition kinetics of all the samples of KIO3 studied can be best described by the contracting cube equation.
Effects of amine fluoride cleaning chemistry on metallic aluminum IC films: II. Determining causal chemistry of OCPs by a time-dependent free energy relationship
Carter, Melvin Keith
, p. B30-B38 (2008/10/09)
A mathematical expression has been developed describing the change in thermodynamic free energy for a chemical system as a function of time to aid the interpretation of experimental time-dependent energy curves, such as the open circuit potential (OCP) plots, generated in corrosion studies. Accurate results of chemical potentials and reaction rates, one pair of constants for each causal chemical reaction, were found. Reaction rate constants were determined for OCPs of Fe(CN)64- + 1/2I2 → Fe(CN) 63- + I- at room temperature of ω1 = 0.011 ± 0.002/s, for oxidation of Fe(CN) 64- to Fe(CN)63- and ω2 = 0.108 + 0.003/s for reduction of I2 to I -, and the known half-cell potentials were reproduced. Experimental aluminum dissolution OCP data was fit using regression analysis describing a four to ten chemical reaction model. The formalism was useful in describing results of OCP plots of integrated circuits (IC) interconnect metals, cleaned by fluoride-based silicon wafer remover formulas, in terms of identifying the causal corrosion chemistry.
Chemical lithiation/delithiation of k+-β-ferrite (k-1+xfe11o17)
Ito,Omomo,Fujii
, p. 317 - 321 (2007/10/03)
The chemical lithiation/delithiation of K+-β-ferrite has been performed using butyllithium, lithium naphthalide (for lithiation), and iodine (for delithiation). In lithiation using butyllithium, the lithium content (y) in K1+xLiyFe11OI7 was dependent on the average grain size of K+-β-ferrite single crystals; small grains (5 μm) largely reacted with lithium to form K0.99Li1.65Fe11O17. Lithiation was performed by the reduction of Fe3+ to Fe2+. Since the same X-ray diffraction (XRD) patterns were obtained before and after lithiation, the reaction seemed to be restricted to only near the grain surfaces. In lithiation using lithium naphthalide, the lithium content (y), which attained to be 36, was independent of the average grain size of K+-β-ferrite single crystals. This lithium content was remarkably large, compared to y = ca. 1.6 in lithiation using butyllithium. A large amount of Fe° (metal) was detected in the samples. According to scanning electron microscope (SEM) and XRD studies, not only pulverization of grains, but also destruction of the β-structure, occurred upon lithiation. On the other hand, delithiation of deeply lithiated samples was achieved by using iodine as an oxidant.
