In order to investigate the molecular structure and rotational isomerism, the electron diffraction camera having a rotating sector was designed and constructed and its application to some fluorochloroethanes was made successfully. The shortening of the C–F and the C–Cl bond by the substitution of atoms attached to one and the same carbon atom with other fluorine atoms was also revealed in fluorochloroethanes as well as fluorochloromethanes, although in the case of the C–Cl bond distance the inaccuracy of the data does not permit a definite conclusion to be drawn. It was definitly confirmed that there exist two rotational isomers, the trans (or Cs) and the gauche forms, in the vapor state for the molecules in question. The energy differences between the isomers and the azimuthal angles of the gauche form were determined and further discussed from the standpoint of intramolecular potential. It was found that three fluorochloroethanes in question have almost equal and small energy differences in contrast to the remarkable variation in the case of chloroethanes. This is caused by the fluorine substitution which produces the decrease of the electrostatic part in the energy difference between the isomers.
The selenium dioxide-catalyzed oxidation of dimethylaniline with hydrogen peroxide was investigated kinetically at 40∼60° in 50∼95 volume % aqueous methanol. The rate of the consumption of hydrogen peroxide at constant acidity of the reaction mixture was expressed as v=k[H2O2] [SeO2] [Dimethylaniline]+k′[H2O2] [SeO2] The first term of this equation seems to correspond to the rate of a reaction between dimethylaniline and a complex (I) produced rapidly from selenium dioxide and hydrogen peroxide, while the second term corresponds mainly to a slow reaction between selenium dioxide and hydrogen peroxide to yield the complex (II) followed by a rapid reaction with dimethylaniline. The energy of activation was 11.7 kcal. When perchloric acid was added to the reaction mixture, the pseudo-first-order rate constant with respect to hydrogen peroxide first increased and then decreased via a maximum, which was explicable by the assumptions of the dissociation of the intermediate and the protonation of dimethylaniline. Electron-releasing groups tended to increase the rate. An increase of the water content in the solvent methanol decreased the rate. There was no evidence for the radical mechanism under these experimental conditions.
1) The two diastereoisomeric mixtures (IIa and lIb) of 5-(dimethylaminomethyl)-cyclopentanone-3-carboxylic acid hydrochloride were synthesized from the two enantiomorphs of cyclopentanone-3-carboxylic acid by means of the Mannich reaction. 2) The two diastereoisomeric mixtures (IIIa and IIIb) of methyl 5-(dimethylaminomethyl)cyclopentanone-3-carboxylate hydrochloride were degraded to give methyl (+)- and methyl (−)-5-methylenecyclo-pentanone-3-carboxylates (IVa and IVb), which were hydrolyzed into (+)- and (−)-5-methylenecyclopentanone-3-carboxylic acid (Va and Vb), respectively. 3) It was found that IVa and IVb possess high potency against Staph. aureus and both Va and Vb show significant antitumor activities of the same extent.
Cyclopentanone-3-carboxylate which is the starting material for the synthesis of dl-sarkomycin (2-methylenecyclopentanone-3-carboxylic acid) was obtained by a new route from butadiene and alkyl acrylate through alkyl cyclohexene-4-carbonylate and thence 3-alkoxycarbonyl adipic acid.
The effects of several-hundred-hour mechanical-mortar dry grinding of kaolinite were studied by X-ray, thermal, electron microscopic and other methods. It has been found that there are two sorts of structural change in the process of dry grinding of kaolinite. One is the production of a non-crystalline substance attended by the disordering of the crystalline part, and the other is the reaggregation process. The process of the reduction in the particle size and the process of the production of the non-crystalline substance are connected to the process of the reaggregation. In a certain stage of the dry grinding, the reaggregates are spherical particles which have a zeolitic structure. As the grinding further progresses, the structure of the crystalline part in this radial particle becomes disordered due to the mechanical stress, and it changes into an amorphous substance at last. Consequently, the effect of dry grinding of kaolin mineral depends on the structural perfectness of alumino-silicate layers of the kaolin mineral, that is, the internal crystallinity of the kaolin mineral.
The effects of several-hundred-hour mechanical-mortar dry grinding of Kibushi-clay which is a kaolin mineral of fireclay type were studied by X-ray diffraction, thermal, electron microscopic and other methods and compared with those of kaolinite. It has been found that the process of a production of a non-crystalline substance attended with a disordering of a crystalline part and the process of a reaggregation are present in the dry grinding of Kibushi-clay as in kaolinite. Finally, Kibushi-clay changes into an amorphous substance as the result of dry grinding. In a certain stage of grinding, a zeolitic structure is formed. As the grinding progresses, the particle size increases owing to reaggregation. When an amorphous substance like silicaalumina mixed gel is produced, the particle size grows irregularly. In Kibushiclay, the time it takes to become amorphous by dry grinding is shorter than in the case of kaolinite. Consequently, the effects of dry grinding of kaolinite and kaolin mineral of fireclay type depend on the structural perfection of unit layers of the original kaolin minerals.
The effects of several-hundred-hour mechanical-mortar dry grinding of halloysite were studied by X-ray diffraction, differential thermal, electron microscopic and other methods and they were compared with those of kaolinite and Kibushiclay. It has been found that there are two sorts of structural change caused by dry gringing in halloysite as in the case of kaolinite. One is the production of a non-crystalline material attended with disordering of crystallites, and the other is the process of reaggregation. In a certain stage of grinding, the reaggregates come to have a zeolitic structure. This stage of grinding corresponds to the maximum point on the base exchange capacity curve and the inflection point on the density curve. The particle which has a zeolitic structure is uniformly spherical. As the grinding progresses further, halloysite changes into an amorphous substance, and the particle size increases irregularly. In consequence, it was found that the effects of dry grinding on kaolin minerals depend strikingly on the structural perfectness of unit layers of the original kaolin minerals, that is, the internal degree of crystallinity.
The structure of trans-dibromo-bisethylenediamine cobalt(III) bromide hydrobromide dihydrate has been determined by X-ray analysis. [Co en2Br2]Br·HBr·2H2O is monoclinic, a=10.98, b=8.18, c=9.46 Å, and β=113.2°, space group P21⁄c, two formula units in the cell. The structure consists of [Co en2Br2]+, [H2O···H···H2O]+ and Br−, and is isotype with [Co en2Cl2]Cl·HCl·2H2O. The complex ion has a center of symmetry. Two enantiomorphous ethylenediamine molecules, taking “gauche” configration, are coordinated to a cobalt atom. A cobalt atom is surrounded in a square coplanar configuration by four nitrogen atoms at distances 2.0 Å, and on a line approximately perpendicular to the plane of nitrogen atoms are two bromine atoms at distances 2.44 Å. The marked dichroism of the crystal is explainable in terms of the characteristic features in the arrangement of the complex ions in the crystal.
The spectrophotometric method for the determination of microquantities of uranium with Neo-thorone was established. By this method 5 to 40 μg. of uranium in 25 ml. solution can be determined easily and accurately. Interference by a small amount of aluminum, zinc, lead, thorium and iron could be avoided by using sodium ethylenediaminetetra-acetate. Therefore, complete separation of iron, thorium, and aluminum is not necessary.
The catalysts have been prepared from pastes of zinc oxide powder kneaded with chromic acid solutions of different concentrations. From the pastes two series of the catalysts have been produced, namely the one directly from the paste and the other from the solid, free of the liquid, in the paste. Only the results on the latter series can give the correct relation of the catalyst composition to the catalytic activity, which indicates the activity rising with the higher chromic acid contents to an asymptotic maximum at the Cr/Zn ratio of 0.5. \qquadThecatalytic activity on the catalysts of different Cr/Zn ratios almost parallels the specific surface area of the catalysts, while the specific activity based on unit specific surface area of the catalysts changes in a far less degree than the change in activity per unit gram of the catalyst. These suggest an intercrystalline promoting effect of chromic acid. Moreover the closer investigation on the activity reveals that both the activation energy and the frequency factor of the reactions which are based on unit surface area show a downward tendency with the increasing Cr/Zn ratios asymptotically to their respective minimums of presumable zinc chromite spinel. This shows besides an intracrystalline promoting effect of chromic acid. \qquadWithinthe range of the present study, hardly any effect of chromic acid addition undesirable to the selectivity in the synthesis has been found.
The separation of cerium and thorium ions was studied with a lead-EDTA complex solution as eluant. The optimum conditions were determined as the following: the concentration of the lead-EDTA solution was 0.015 mole, pH 3.0 and the flow rate 1.0∼1.5ml./min. Thorium ions were completely eluted with 200 ml. of the eluant at the optimum conditions, while no cerium ions were detected in the effluent with 1000 ml. of the eluant. Thus the use of a lead-EDTA complex solution as eluant was concluded to be effective for separation of cerium and thorium ions.
Reactions of thionyl chloride with some substituted diphenylamines and with naphthylphenylamines were studied. N-Acetyldiphenylamine gave the known 1,3,7,9-tetrachlorophenothiazine. Methyldiphenylamine gave a small yield of the known 3,7-dichloro-10-methylphenothiazine besides the same tetrachlorophenothiazine as the main product. The following new compounds were obtained from respective starting materials and their structures were deduced: 3,7-dichloro-10-(4′-chlorophenyl)-phenothiazine from triphenylamine, 1,3,7,9-tetrachloro-2-hydroxyphenothiazine from 3-hydroxydiphenylamine, 2,4,7,9-tetrachloro-3-phenothiazone from 4-hydroxydiphenylamine, 3-amino-2,4,7,9-tetrachlorophenazathionium chloride from 4-aminodiphenylamine, 3,7-diamino-2,4,6,8-tetrachlorophenazathionium chloride from 4,4′-diaminodiphenylamine, 3-amino2,4,6,8-tetrachloro-7-methoxyphenazathionium chloride from 4-amino-4′-methoxydiphenylamine, x, 5,9,11-tetrachlorobenzo[a]phenothiazine from α-naphthylphenylamine, and 1,3,x,x′,11-pentachlorobenzo-[b]phenothiazine and x,6,8,10-tetrachlorobenzo[c]phenothiazine from β-naphthylphenylamine.
The spectrophotometric determination of a micro amount zirconium, using m-nitrophenylfluorone, has been described. The method recommended here, which is carried out in 0.1 N hydrochloric acid solution, shows nearly fifty times the sensitivity of the alizarin red S method, about five times that of the quercetin method, and about 1.2 times that of the phenylfluorone method reported previously as the most sensitive reagent by the author and K. Kimura. The solution becomes stable enough to carry on the spectrophotometric determination by adding some cyclohexanol and ethanol, and no precipitation is found for the small amount of zirconium. Furthermore, the stability for increasing acidity in the solution is greater than that of the phenylfluorone method. The method is found to be suitable for the determination of 0 to 0.5 p.p.m. of zirconium. Transfer the sample solution (less than 10 ml.) to a 25 ml. volumetric flask. Then add additional acid to bring the acidity up to 1.0 N hydrochloric acid and 7.5 ml. cyclohexanol-ethanol (1:2) mixed solution, and 5 ml. ethanolic solution containing 3 mg. m-nitrophenylfluorone in that order. Adjust the volume to 25 ml., shake the solution, allow to stand for one hour, and read the absorbance of the solution with a spectrophotometer at 550 mμ with 1-cm. glass cells and distilled water as a control solution. Oxalate, fluoride, phosphate, titanium, germanium, iron(III) and antimony cause serious interference.