The shape and the size of barium sulfate precipitate prepared within the range of the total concentrations from 1.0000 to 0.0001 M were observed by an electron microscope. The particles were observed to precipitate in various forms (spherical, spindle, diamond and rectangular) in response to the total concentration of barium sulfate. It was confirmed that the precipitation law advocated by von Weimarn was still substantiated so far as the particles of the same shape were concerned.
1. The amorphous precipitate of barium sulfate changed to a crystalline state by aging. 2. The precipitated particles produced in uniform size remained almost unchanged for a few months, but they became perfect for a long period (i. e. a few years). 3. When the particles of two different sizes formed directly after mixing the reagents, the smaller particles went into solution and the larger particles grew at the expense of the small ones. 4. In the case of dilute reagents the rapid change of conductivity was observed in an early stage of the reaction. The nucleus probably formed during this stage. 5. The precipitation was promoted by the nucleus added before the reaction, but the presence of the nucleus did not affect the shape of the precipitated particles.
The surface viscosity of the spread monolayers of synthetic polypeptides with non-electrolytic side chains was investigated in relation to the surface area and to the surface pressure. If the length of a side chain becomes longer than six carbon atoms, the limiting area becomes larger with the length of the side chain. Polypeptide with no side chains or very short ones such as glycinealanine copolymer might be changed to α-configuration from “extended” β-configuration merely by compression. The ease of transition from one configuration to another corresponds to the discovery by Elliott in bulk solution with poly-alanine. αII→β transformation of poly-γ-methyl-L-glutamate which had been reported in the previous paper, was observed also by the surface viscosity measurements. The difference of the nature of films of optical active and of racemic polypeptide was investigated. The polypeptide consisting of single optical isomeride was able to be more closely packed in the film than that of racemic. Our discovery by surface pressure measurement that the polymer of ε-aminocaproic acid, namely, amilan is not adequate as the model of protein, was again confirmed from the study of surface viscosity.
In the condensation of benzaldehyde with methyl ethyl ketone by aqueous sodium hydroxide, the lowered reaction temperature (3∼5°) favored the aldol condensation at the α-methylene group of the ketone as in the condensation of furfural with the ketone. On the other hand, the elevated reaction temperature (60∼65°) conducted exclusively the condensation at the α-methyl group of the ketone, giving 1-phenyl-1-penten-3-one (I). 3-Methyl-4-phenyl-4-butanol-2-one (II), obtained by the aldol condensation at the lowered reaction temperature (3∼5°), was dehydrated with acetic anhydride to 3-methyl-4-phenyl-3-buten-2-one (IV), which was oxidized, by sodium hypochlorite to afford α-methylcinnamic acid (V).
(1) The four-terminal electrical network is shown to be useful in the schematic representation of various mechanical systems. (2) A simple review on various types of torsionally oscillating rheometers is given according to the theory of four-terminal networks. (3) It is shown that complicated viscoelastic systems are easily solved so far as their formalistic treatment is concerned.
Methyl propyl ketone condensed with furfural by alkali both at the α-methyl and α-methylene groups of the ketone, giving 1-(2-furyl)-1-hexen-3-one (I) in a larger proportion and 3-ethyl-4-(2-furyl)-3-buten-2-one (II) in a much smaller proportion. The former furfurylidene ketone (I) gave γ, ζ-dioxocapric acid (III) on the ring-opening in alcoholic hydrochloric acid, and the latter (II) was oxidized by sodium hypochlorite to α-ethyl-2-furanacrylic acid (IV). The ring-opening of furfurylidenemethyl isopropyl ketone (V) and furfurylidenemethyl tert-bntyl ketone (VI) in alcoholic hydrochloric acid gave γ, ζ-dioxo-η-methylpelargonic acid (VII) and γ, ζ-dioxo-η, η-dimethylpelargonic acid (VIII) respectively.
From the condensation product of furfural with methyl ethyl ketone by aqueous sodium hydroxide were isolated 4-(2-furyl)-3-methyl-3-buten-2-one (I) and 1-(2-furyl)-1-penten-3-one (II). The former ketone (I) was oxidised by sodium hypochlorite to yield α-methyl-2-furanacrylic acid, (III) but gave no γ, ζ-dioxo-ε-methylcaprylic acid by refluxion with alcoholic hydrochloric acid. The latter ketone (II) gave γ, ζ-dioxopelargonic acid (IV) by refluxion with alcoholic hydrochloric acid, but was no acted upon by sodium hypochlorite. The semicarbazone of 1-(2-furyl)-1-penten-3-one (II) existed in two forms of the needle crystals melting at 183∼184° and the tabular crystals melting at 166∼167°.
1. Trichloroethylene has been dimerized by boiling with α, α′-azodiisobutyronitrile to C4H2Cl6, which has been identified as 1, 1, 3, 3, 4, 4-hexachloro-1-butene by degradation. 2. A compound of molecular formula C8H8Cl5N, whose structure is presumably 1, 1, 3, 3, 4-pentachloro-5-cyano-5-methyl-1-hexene, has been isolated. This fact indicates that the reaction is initiated by the addition of 1-cyano-1-methylethyl radical to trichloroethylene and propagated by the transference of a chlorine atom from the dimeric radical to a molecule of the monomer. 3. The decomposition of dibenzoyl peroxide in trichloroethylene gives the same dimer as above, the structural identity being confirmed infrared spectrometrically.
Dichroism of the crystals of bis (dimethyl-glyoximo)-copper (II), nickel (II) and platinum (II) has been quantitatively determined by the microscopic method in the region from 2400 to 7000 Å. The crystal of the copper compound has been found to show dichroism of the normal type, indicating that no specific metal-metal interaction can be expected in this crystal. The crystals of the nickel (II) and platinum (II) compounds exhibit anomalous dichroism. It has been concluded that in these crystals there should exist metal-metal interaction. A hypothesis has been presented, in order to explain the tendency that the specific metal-metal interaction similar to that proposed above has been found mostly with Ni (II), Pd (II) and Pt (II) compounds.
The dipole moments of several cyclosiloxanes and cyclothiosiloxanes were measured in benzene solution. The values obtained are: Hexamethyldisiloxane (I), 0.80D; octamethylcyclotetrasiloxane (III), 0.67D; hexamethylcyclotrithiosiloxane (V), 1.03D. The atomic polarizations obtained are: hexamethylcyclotrisiloxane (II), 10.9 cc.; tetramethylcyclodithiosiloxane (IV), 9.0 cc. The unexpectedly small bond moment of Si-O (1.55D) can be explained by the double bond character of the bond. For the configuration of (III) and (V), it is impossible to draw any definite conclusion from the study of the dipole moment alone.
The molecular structures of isopropyl alcohol and -chloride have been investigated by the electron diffraction method. The atomic distances, C-O : 1.45±0.03Å, C-C : 1.54±0.02Å and valence angles,<CCC≈<CCO : 110°±2.5° are determined for the former molecule, and distances C-Cl : 1.76±0.02Å, C-C : 1.55±0.02Å and angles <CCC≈<CCCl : 109.5±1.5° for the latter. The approximate thermal vibration factors have been taken into account for the determination of the best molecular models. The rotational configurations of methyl groups have been considered, but the equilibrium position of two methyl groups cannot be determined conclusively, in spite of the fact that this effect upon the intensity curves are not to be ignored in the case of isopropyl alcohol molecule.