Acidic Methanol Solution Research Articles

Separation of95Zr and95Nb by means of sorption on silica gel from hydrochloric acid solutions

The adsorption behaviour of zirconium and niobium on silica gel from hydrochloric acid solutions was studied by batch equilibrations and passage through columns. On the basis of this, new methods are suggested for the separation and purification of95Zr and95Nb in hydrochloric acid and hydrochloric acid—methanol solutions. The methods are comparatively simple and rapid, and both zirconium and niobium can be obtained in a radiochemically pure state.

A new circular dichroism study of ketal formation of some steroidal ketones

Polycyclic ketones react reversibly with methanol, ethanol, and isopropanol in presence of hydrogen chloride. Treatment of 5α-cholestan-3-one ( 2) in acidic methanol solution gives the crystalline dimethyl ketal ( 7). In optically active substances, the percentage of ketal formed is easily followed by RD and CD, and is a function of structural and stereochemical factors. Furthermore, the reversibility of the ketone ⇌ ketal reaction is strongly dependent on the amount of water present in the reactive medium.

Photoalkylation of pyridine with methanol

Pyridine is photoalkylated in acid methanol solutions to yield 2- and 4-methylpyridines (I and II), 1-(2-pyridyl)-2-(4-pyridyl)ethane (III), and 1,2-di-(4-pyridyl)ethane (IV).

Assay for 9-acridanone in urban atmosphere by thin-layer chromatography fluorimetric procedures

9-Acridanone has been found in urban atmospheres. Four two-dimensional thin-layer Chromatographic methods have been described for the assay of this compound in urban atmospheres and in air pollution source effluents. Fluorimetric assay was done either directly on the plate or after elution. The best method involved two-dimensional separation on alumina-cellulose followed by elution and fluorimetric analysis of the acidic methanol solution. Urban atmospheres contain approximately 0·4 ng of 9-acridanone/m 3 of air.

Synthesis of D- and L-serine

The optical resolution of DL-O-methylserinamide (V), the intermediate in the serine synthesis from acrylonitrile, was described. Resolution of DL-O-methylserinamide (V) was carried out with L-tartaric acid in methanol solution. The precipitated L-hydrogentartrate of L- V, m.p. 172∼173°(decomp.), [α]20D+12.57°(c=1, NHCl), was isolated from the methanol solution, and L-hydrogentartrate of D- V, m.p. 150∼151°(decomp.), [α]20D+0.29°(c=1, NHCl), was crystallized from the mother liquor. Hydrolysis of these optically active V with 47% HBr solution afforded the corresponding L-and D-serine (VI). The synthesized L-serine (VI) was found to correspond to natural serine.

Platinum Metal Alloys in Electrocatalysis

The relative electrocatalytic activities of some binary platinum alloys for the oxidation and ionisation of hydrogen and the anodic oxidation of methanol are briefly described. For the hydrogen electrode reaction in acid solution the ruthenium-platinum and rhodium-platinum alloys are generally not as active as bright platinum itself. This is also found for the anodic oxidation of methanol in acid solution. At the low voltametric “sweep” rates used in the latter experiments the activities are somewhat greater on the reverse scan, from high to low positive potentials, than on the forward scan.

Isolation of bacterial polysaccharide B‐1459 through calcium hydroxide complex formation

AbstractA method is described for the isolation of bacterial polysaccharide B‐1459 from aqueous dispersion as a calcium hydroxide complex. The polysaccharide is liberated in fibrous form from the complex by means of hydrochloric acid in methanol solution. Overall recovery of the polysaccharide from aqueous dispersion is 85%. Direct conversion of the insoluble calcium hydroxide complex to aqueous polysaccharide solution appears to be a low‐cost procedure for preparing viscous solutions for industrial use.

On the pseudocapacitance of the reduction of oxygen on mercury in acidic methanol solutions

On the pseudocapacitance of the reduction of oxygen on mercury in acidic methanol solutions

Kinetics and Mechanism of the Proton Transfer between Methyloxonium Ion and Benzoic Acid in Methanol Solution

<b>Kinetics and Mechanism of the Proton Transfer between Methyloxonium Ion and Benzoic Acid in Methanol Solution</b>

メタクリル酸の放射線溶液重合

In the polymerization of methacrylic acid in methanol solution, the rate of polymerization decreased as the polymerization temperature decreased in the range from -78 to +30 deg C. An apparent activation energy was calculated to be 3.6 kcal/mol. The rate of polymerization was proportional to 0.47 power of dose rate. Benzoquinone inhibited the polymerization. These results indicate that the polymerization proceeds by a free radical mechanism. The infrared spectrum and x-ray-diffraction diagram of polymethyl methacrylate prepared from esterification of polymethacrylic acid indicated that a syndyotactic polymer was obtained by low temperature polymerization. In the polymerization in methanol solution, the syndyotacticity increased as the polymerization temperature decreased, and (E/sub S/--E/sub I/), the difference of activation energy between syndyotactic and isotactic propagation, was calculated to be --0.5 kcal/mol. It was also found that the systemprecipitating polymers reduced the syndyotacticity. (from NSA of Japan)

Properties of Polyadenylic Acid in Methanol Solution

UNTIL recent years, methanol and ethanol were universally regarded only as precipitants for nucleic acids. However, Geiduschek and Holtzer1, and later Coates and Jordan2, showed that at sufficiently low ionic strengths both the above lose their precipitating capacity for deoxyribonucleic acid (DNA) and in fact becomes fairly good solvents, depending upon the concentration of electrolyte.