Quantitative estimation of thorium by precipitating it from aqueous thorium chloride (or nitrate) solution by o-tolidine, dianisidine, ρ-phenylenediamine, o-anisidine and o-phene-tidine has been studied. The precipitated complex is ignited to constant weight and determined gravimetrically as ThO2.
Fatty acid salts of higher aliphatic amines were prepared and used as detergents. The micelle formation in the benzene solution was verified from the relation between the van’t Hoff factor and the concentration. It was shown that the amount of solubilized water is proportional to the concentration of the detergent. The value of the critical micelle concentration was determined from the extraporation of the proportionality. This value is within the region of the remarkable decrease in the curve between the van’t Hoff factor and the concentration. With the increases of the carbon number of the amine or the acid part, the critical micelle concentration increases and the solubilizing power decreases. This result is quite different from that of aqueous solutions.
LCAO MO’s and ionization potentials have been calculated for the 2B1 state of the free NH2 radical by using the LCAO-SCF method. The interactions of all electrons have been explicitly considered, but the orthogonal relationship between the 1s orbitals of nitrogen and hydrogen was assumed. Using these MO’s the lower electronic states have also been investigated without configuration interaction. The calculated value of a 2B1→2A1 transition is 1.8 ev in fairly good agreement with the observed one of the α bands of ammonia in the region of 4500 to 7400 Å. The calculated bond angles of the 2B1 and the 2A1 state are about 110° and 150°, respectively. These results are in good agreement with the observation and the opinion by Herzberg and Ramsay and the estimation by Luft.
Acetylation in fibrous state of holocellulose, its alkali-refined product, rayon pulp and Bemberg rayon was undertaken to disclose the effect of pentosan and the structure of holocellulose. 1) Acetylation of air-dried holocellulose is roughly controlled by surface resistance regardless of various ratios depending on conditions of acetylation and degree of refining. The rate of pretreated sample seems to be determined by internal diffusion. 2) The birefringence decreases at first abruptly and then increases and finally decreases again. The final higher birefringence compared to acetic acid content may be ascribed to acetolysis. Definite amorphous portion is acetylated easily at the initial stage and lost, so that residual crystallinity, and also birefringence, increase. 3) By alkali-refining, acetylation is retarded and initial abrupt change, which is caused by the amorphous portion is diffused. There is optimum point in the concentration of refining alkali, probably relating to hornification, loss of amorphous portion, transformation of crystal form and hindrance by residual pentosan layer. The refining temperature affects the acetylation slightly. 4) Pentosan in product is not reduced apparently, probably due to oxymethylfurfural yielding and poor solubility of acetate. Also pentosan may not be entirely accessible at initial stage.
The rate constants of the thermal dissociation of 1,3-dibenzylurea and 1-isopropyl-3,3-diethylurea in alcohols were determined. The rates of dissociation in fatty acids are faster than those in alcohols and it can be said that the process of protonation of ureas by solvents plays an important role in the dissociation. In the case of dissociation in alcohols, the reaction seems to proceed by a base catalysis. And the intermediate complex containing two alcohol and one urea molecules was considered. The experimental results were reasonably explained by the proposed mechanism.
1. The heats of combustion of the following four compounds have been measured at 20°C and at constant volume: Tetramethoxysilane, hexamethoxydisiloxane, octamethoxytrisiloxane and hexamethoxydisilane. 2. From these combustion results the corresponding heats of combustion and formation at constant pressure and Si-O bond energy have been calculated, and it has been found that the Si-O bond energy in methoxy-polysilanes and -polysiloxanes was slightly lower than that in amorphous silica.
The near ultra-violet absorption spectrum of pyridine N-oxide was measured in solution and vapor, and we concluded from the considerations of solvent effect, oscillator strength and the feature of vapor spectrum that the two of the four absorption regions are due to the excitation of the non-bonding electron, the others due to the excitation of π-electron. From the spectral behavior of pyridine N-oxide, it is also concluded that the pyridine N-oxide molecule forms hydrogen bond with alcohol or water molecule in vapor and solution state.
The water transference due to electroosmosis was studied for several cationexchange resin membranes of sulfonated phenol resin type, mainly in sodium chloride solution. It was shown that (1) the electroosmosis depended on the transport number of the membrane and the amount of water contained in the resin, and (2) the experimental results could be explained by introducing the idea of fixed water and mobile water in the membrane. The fixed water is supposed to be composed mainly of the hydration water attached to the polar groups of the resin.
Sound velocity was measured at the temperature ranging from 0° to 60°C for water and the aqueous solutions of NaCl. The amount of hydration was calculated from the sound velocity data for NaCl, which was shown to change linearly with the square root of temperature. Volume contraction due to the dissolution of NaCl was also calculated at various temperatures which was found to change proportionally with the amount of hydration. The proportionality constant (0.10) was the same as obtained when the nature of the salt was changed. The mean hydration pressure was estimated to be about 4000 atmospheres. A part of the cost of this study has been defrayed from the Scientific Research Expenditure of the Ministry of Education, given to one of the authors.
The pure quadrupole spectra of 2,5-dichloroaniline and 2,5-dichloronitrobenzene were observed at room temperature (292°K), and the effects of electron releasing or attracting power of amino- and nitro-group in the benzene ring were compared with each other. On the other hand, a linear relation between resonance absorption frequencies due to Cl35 and Hammett’s σ of the substituents in these compounds was found, and Hammett’s σ of o-amino-group was assumed to be −0.26. We are indebted to Prof. T. Ichikawa and Prof. D. Nakae for their generarity in granting us the use of their facilities, and to Prof. T. Kawano for the loan of the frequency meter.
Starting from 7-hydroxy-3-methoxyflavone-8-aldehyde (II), 3-methoxyflavone-7,8-furan-α-carboxylic acid (IV) was synthesised in good yield by the method of Tanaka for benzofuran synthesis and was decarboxylated in quinoline with copper powder into karanjin (I).
The temperature dependence of the dipole moment was investigated on monochloromethyl ether (I), sym-dichloromethyl ether (II) and monobromomethyl ether (III) in the gaseous state, and (III) and sym-dibromomethyl ether (IV) in heptane solution. The moment of (I), (II) and (IV) increases with temperature, while that of (III) does not. From the observed data the energy difference between the gauche and the trans position is 0. 7 kcal./mol. in (I), and zero in (III) Similarly ΔE’s between t,g- and g,g-form of (II) and (IV) are estimated to be 1.3 kcal. and obtained to be 0.9 kcal./mol. respectively from the observed results.
Chloromethylmethylpolysiloxane (I), 3-chloromethylheptamethyltrisiloxane (II) 3,5-di(chloromethyl)octamethyltetrasiloxane (III) and chloromethylpolysiloxane (IV) were reacted with thiourea in absolute alcohol to give silicon-containing thiuronium chlorides. Although in the case of (II) the corresponding thiuronium chloride was isolated an extensive fission and recombination of siloxane bonds took place in every case. Silicon-carbon bond in the thiuronium chloride derived from (I) was easily cleft by the treatment with an aqueous alkali to give three-dimensional methylpolysiloxane. In a similar manner the thiuronium chloride derived from (IV) gave silicic acid with aqueous alkali. The fission of silicon-carbon bonds in the silicon-containing thiuronium salts was facilitated by the electron-attracting substituents on the silicon atom.
1. The solubilities of barium sulfate in aqueous alcohol were measured. 2. The barium sulfate particles precipitated in aqueous alcohol became smaller with the increasing concentration of alcohol; namely, with the decreasing solubility of barium sulfate. 3. In the case of the aqueous alcohol of the certain percentage (for a definite solubility of barium sulfate) the precipitated particles became larger with the decreasing total concentration of barium sulfate. 4. The barium sulfate precipitates prepared in the aqueous alcohol were practically diamond shaped; and spindle, hexagonal and sphere particles were also found. The shape of the precipitated particles seemed to depend on the induced period of the precipitation. 5. The electron micro-diffraction method was applied to analyze the crystal structure and, of course, the patterns obtained from various types of crystals agreed with those of barium sulfate.