Materials Literature
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The reduction of Ni(II), Co(II), Cd(II), and Pb(II) was studied at glassy carbon electrodes in molten lithium chloride‐potassium chloride eutectic at 450°C using the technique of linear sweep voltammetry. Peak‐shaped voltammograms were obtained at scan rates of 10 mV to 1 V / sec . Linear dependence of peak currents o…
The i.r. and Mössbauer spetra of CdFe(CO)4 and of several complexes of the type L2MFe(CO)4(M = Zn or Cd; L = nitrogen donor ligand) have been recorded. The Mössbauer spectra indicate the presence of octahedrally co-ordinated iron atoms and, on this basis, possible structures for the complexes are discussed. The comple…
The structure of the title compound has been redetermined from three-dimensional X-ray data and shown to be in good agreement with the previous study. The structure consists of ammonium ions and approximately square pyramidal [SbCl5]2– ions with antimony–chlorine distances of 2·36, 2·58 (two) and 2·69 (two)Å.
Abstract Oxidative reactions in cellulose are commonly initiated by thermal, ultraviolet, and high‐energy radiations and by chemical oxidation. Long‐lived free radicals, formed in cellulose on the localization of energy from thermal, ultraviolet, and high‐energy radiations, and short‐lived free radicals, formed in cel…
The energy levels of the I4 ground term of Er3+ in single crystals of CaWO4 were established by absorption and fluorescence spectra measurements. The measurements were made using crystals at temperatures of 2, 20, and 85°K. The energy level scheme allows an interpretation of the 1.612-μ four-level CaWO4:Er3+ laser tra…
Methods are given to assist in choosing an appropriate equation relating product quality to storage time and temp. and for determining the constants of the equation. Figures prepared from these equations show contours of constant product quality as related to time and temp. From the plotted contours, storage condition…
The phase equilibria relationships in the Sr 3 ( PO 4 ) 2 ‐ Cd 3 ( PO 4 ) 2 system were established in air using DTA and melting point data obtained from compositions previously equilibrated by solid‐state reactions. In addition to the previously reported rapid, reversible α ⇄ β ‐ Sr 3 ( PO 4 ) 2 polymorphic inversion…
Heats of immersion of pure and doped magnesia in cyclohexane were measured at 35°C for samples heated at different temperatures in vacuo. For the pure samples, rise in temperature of thermal treatment leads to a gradual decrease in the heats of immersion normalized per unit area (h1, ergs cm–2), till a certain limitin…
The signs of Vzz(and e2qQ) at the 57Fe nucleus for the following compounds have been measured by use of the Mössbauer magnetic field technique: trans-FeCl2(p-MeO·C6H4·NC)4, trans-FeCl2(depe)2[depe = 1,2-bis(diethylphosphino)ethane]. Na3[Fe(CN)5NH3],H2O, K3[Fe(CN)5H2O],7H2O, all positive; cis-FeCl2(p-MeO·C6H4·NC)4 and…
Crystals of [C5H12N]+2[As4S6]2– are orthorhombic, space group Imm2, with a= 10·25, b= 19·61, c= 5·97 Å, Z= 2. The anion possesses a ‘basket’ structure in which the four arsenic atoms, and two of the sulphur atoms, lie on crystallographic mirror planes; the bond lengths are: As–As 2·579(12), As–S(terminal) 2·183(10), A…
Abstract The fine structures of the highly crystalline cellulose microfibrils from the cell walls of the marine algae Valonia ventricosa, and the extra cellular chitin spines of the euryhaline diatoms Thalassiosira fluviatilis , have been investigated by observation of deformed and un‐deformed specimens in the electro…
The analysis of wavelength data of the Gd II spectrum has resulted in the detection of 108 odd and 70 even levels in addition to those reported by previous investigators. The total number of classified lines is now 2 200, belonging to 2 300 transitions between 162 odd and 150 even levels. The wavelength list, includin…
The far-i.r. spectra (40–700 cm–1) of some complex chlorides of general formula A2MCl4 and A3MCl5(A = Rb or Cs; M = Fe, Co, Ni, Cu, and Zn) which contain distorted MCl42– tetrahedra have been examined. The observed bands are assigned to internal modes of vibration associated with the MCl42– tetrahedra and to lattice m…
The potential of a number of silicates, of the felspathoid, fibrous clay, zeolite and other silicate groups, has been investigated for the trapping and storage of inert gases. The crystals, suitably outgassed, were exposed to high pressures of inert gas at high temperature and then quenched while still under pressure.…
The crystal and molecular structures of copper(II) hydrogen maleate tetrahydrate and copper(II) maleate hydrate have been determined by three-dimensional X-ray methods. In copper(II) hydrogen maleate (monoclinic, a= 3·594, b= 18·79, c= 9·69 Å, γ= 93·25°, space group l2/m, diffractometer data, R= 0·039) the copper atom…
Abstract The crystal and molecular structure of nickel(II)‐1, 8, 8, 13, 13‐pentamethyl‐5‐cyano‐ trans ‐corrin chloride has been determined by X‐ray analysis. The shape and dimensions of the corrin nucleus are discussed in some detail.
The compositions of thin films of pyrolytically deposited borosilicate glass were correlated with the infrared spectra of these films over the entire composition range. Although the composition has been related to the ratio, R , of the absorbance maximum at about 1300 cm −1 to the maximum at about 1050 cm −1 , the rel…
X‐ray analysis and electrical conductivity measurements (800°–1000°C) on yttria‐hafnia solid solutions between 2 and 20 m/o (mole per cent) Y 2 O 3 were made to locate the cubic phase and to select the composition best suited as a solid electrolyte. The phase boundary is located near 7 m/o Y 2 O 3 . Total conductiviti…
Abstract Proton NMR. spectra of purine, adenine, guanine and methylsubstituted guanines have been measured in CF 3 COOH, FSO 3 H and FSO 3 HSbF 5 SO 2 at 27° and low temperatures. These conditions permit to study multiple protonation of purines, using chemical shifts of CH, NH and OH protons. The spectra of mono‐, d…
Measurements of the heat capacity, thermal expansion, and thermal conductivity on synthetic crystals of undoped and neodymium-doped fluorapatite are reported. Fitting the low-temperature specific heat data to a Debye model yields a Debye temperature of 550°K. At 25°C the thermal expansion coefficients are 10.0×10−6 °K…