Cadmium Phosphate Research Articles

燐酸カドミウム触媒: その物理化学的性質と活性度について

Density and surface area of cadmium phosphate catalyst, prepared from cadmium nitrate and sodium orthophosphate, were measured. The hydrogen adsorption by this cadmium phosphate becomes active from about 150°. Its activated adsorption began with comparatively rapid, initial adsorption followed by gradual adsorption. It was found that, in decomposition of isopropyl alcohol, dehydrogenation is chiefly effected and dehydration occurs in a slight degree at above 350°. Compared to cadmium oxide, the direction of decomposition is the same but the temperature at which activity appears is lower and the degree of activity is greater. Relationship between partial pressure and initial reaction velocity of isopropyl alcohol was examined using 4.5g. of this catalyst, at a reaction temperature of 250°, contact time 100-300min./mole, and benzene as the diluent, and it was found that the initial reaction velocity, at above partial pressure of 0.6, became approximately constant and namely the order of the reaction is nearly zero. Piperidine is dehydrogenated to pyridine by passage over this catalyst at 400°, 425°, or 450°, and the yield of pyridine was 32% of the piperidine used, at 450°.

Lead‐ and Manganese‐Activated Cadmium Fluorophosphate Phosphors

The characteristics of lead‐ and manganese‐activated cadmium fluorophosphates and homologous materials containing aluminum, barium, calcium, strontium, magnesium, zinc, sodium, and potassium as partial replacements for cadmium are described. With low activator concentrations in cadmium fluorophosphate, a double band emission is obtained with peaks at 4500 Aå and 5900 Aå. At high activator concentrations the blue peak is suppressed.The luminous output and spectral emission of the mixed phosphors are dependent upon activator concentration, the amount of halide relative to the cadmium phosphate portion of the phosphor, the amount of phosphorus relative to cadmium, and the cation which replaces cadmium. Substitutions of sodium, potassium, and zinc for cadmium shift the emission and excitation spectra toward longer wave lengths. The x‐ray patterns of these phosphors are quite complex and vary from sample to sample. However, they are all similar to an apatite configuration with the exception of the alkali modified phosphors which display quite different and unidentified patterns. In the case of the double band emission of the unmodified phosphor, the yellow band is suppressed at low temperatures and phosphorescence is enhanced. Above room temperature the fluorescence and phosphorescence of all the phosphors are decreased almost to extinction at 150°C.

接触気相反応によるピリジン塩基の合成 (第7報)

It has been revealed that the catalytic vapor phase reaction of allyl alcohol, ketones, and ammonia afforded pyridine bases with a substituent in 2 or in 2 and 3 positions. 2-Picoline and 2-phenylpyridine were obtained respectively from acetone and acetophenone, 2, 3-dimethylpyridine from methyl ethyl ketone, and 2-methyl-3-ethylpyridine from methyl propyl ketone. Reaction of diethyl ketone, allyl alcohol, and ammonia gave 2-ethyl-3-methylpyridine. Of the catalysts used, cadmium phosphate on activated white clay gave the best results, while the optimal reaction temperature was 350-400°. Use of about 3moles of ammonia to 1 mole each of allyl alcohol and the ketone afforded the desired base in 20-30% yield.

アセチレンとアンモニアの縮合に関する研究 (第6報)

A mixed vapor of allyl alcohol or allylamine and ammonia was passed over the catalyst of cadmium phosphate or cadmium tungstate and Fuller's earth, at 350-400°, and β-picoline was obtained as the chief product, with 3, 5-lutidine as the by-product. The mixed vapor of acetylene and allylamine passed over the cadmium phosphate-Fuller's earth catalyst gave pyridine. A mixed vapor of acetylene, ammonia, and acetone passed over the catalyst of cadmium and chromium tungstate or cadmium and lead chromate on Fuller's earth, at 400°, gave 2, 4, 6-collidine in a good yield, with mesitylene and mesityl oxide as the by-products. Formation of pyridine was extremely small when the vapor of N-methylpyrrole was passed over the catalyst of cadmiun phosphate-Fuller's earth at 400°.

A Study of the Exciting Power for Fluorescence of the Different Parts of the Ultraviolet Spectrum

Intensity of Fluorescence as a Function of Wave-length of Exciting Light, 0.55 to 0.2 \ensuremath{\mu}.---The purpose of the experiment was to determine what wave-lengths are effective in excitation and what relations exist between these wave-lengths and the corresponding absorption and fluorescence spectra. Light from a source giving a continuous spectrum was dispersed by means of a quartz spectrograph and allowed to fall on the substance to be studied which was spread on a flat surface. Then the parts of the spectrum which excited fluorescence were observed or photographed by means of the fluorescent light. A preliminary study of seventy substances showed that all the oxides (20) and simple chlorides (8) tested were not excited, a few substances (7) including zinc silicate, zinc sulphate and cadmium phosphate fluoresced faintly, a few responded well (anthracene, eosin, fluorescein, phenolphthalein, calcium tungstate, and phosphorescent willemite), while the uranyl compounds (20) fluoresced strongly. For the last group the effective spectrum extended from 0.55 to 0.35 \ensuremath{\mu} only, while for the others it extended continuously to 0.2 \ensuremath{\mu} except in the case of four substances for which light from 0.35 to 0.325 was ineffective. Excitation band spectrum for twelve uranyl compounds was determined by measuring the density of the plates as a function of the wave-length by means of a sensitive photoelectric spectrophotometer. Some curves are reproduced and the wave-numbers corresponding to from 35 to 105 maxima for each compound are given. Comparison with absorption spectra shows close agreement, an absorption band corresponding to an excitation band in every case. This relation had previously been found by Howe to hold for phosphorescent sulphides.Absorption Spectrum of Twelve Uranyl Compounds, from 0.55 to 0.32 \ensuremath{\mu}.---Because of the correspondence noted above the excitation bands may be taken to be absorption bands and thus the known absorption spectrum be considerably extended toward both the red and ultraviolet. Comparison of these bands with the fluorescence spectrum indicates clearly many new reversing regions where the fluorescent light obscures the absorbing effect. These are listed.