The molecular structures of monofluorobenzene and monobromobenzene have been investigated by the electron diffraction method. The C–F and C–Br distances in each molecule have been determined as 1.30±0.03 A and 1.86±0.02Å respectively. These distances are shorter than the case in which the bonds have the normal single bond characters. The double bond characters for these bonds have been calculated and obtained 16.9% for C–F and 13.3% for C–Br, in which we have considered the corrected single bond lengths in both cases.
The crystal structure of [Co (NH3)3 (NO2)2Cl] is tetragonal, with eight formula units in a cell of dimensions a=9.87 Å and c=16.51 Å. The space group is C4n6-I4/a. The determination of atomic parameters was made by three dimensional Fourier syntheses. The configuration of the complex molecule is described. Two nitro-groups are found to be in transpositions with respect to each other. The main forces acting between these molecules in the crystal seem to be O … H-N bonds between the oxygen atoms of the nitro-group and the ammonia of the other. Molecules are linked together by these hydrogen bonds, forming a compact three-dimensional network in the crystal.
In the force-area curves of the monolayer of synthetic polypeptides of longer side chains, a plateau which is a region of very high compressibility appears. The appearance of the plateau can be attributed to the reorientation of the polymer molecule at the interface. The pressure at which the plateau appears, decreases with the rise of temperature. From the temperature dependence of this pressure, the heat of transformation was evaluated. The polypeptides of shorter side chains of four carbon atoms or less in length scarcely need any energy for reorientation. Accordingly, no plateau was found with these polypeptides. The thickness of the monolayer of these polypeptides at the pressure above and under the transition pressure was determined optically by Langmuir-Blodgett technique. The thickness of the monolayer observed was compared with that calculated by using Stuart model (for the most part.) Our views on the reorientatoin of the film were ascertained.
1) The molecular structures of acetamide and N-methylacetamide were determined using electron diffraction by gases. The results were compared with the values obtained from X-ray diffraction by crystals. 2) C=O distance is longer in the crystalline state than in the gaseous state, while C–N distance is shorter in the crystalline state than in the gaseous state. This is due to the hydrogen bond which is absent in the gaseous state but exists in the crystalline state.
The molecular structures of o-,p-fluoro-chlorobenzene and p-fluorobromobenzene have been investigated by the electron diffraction method. The following values have been obtained by the analysis based on coplanar structures; C–F=1.30±0.03Å, C–Cl=1.68±0.02Å for p fluorochlorobenzene; C–F=1.30±0.03Å, C–Br=1.87±0.02Å for p fluorobromobenzene; and C–F=1.30±0.03Å, C–Cl=1.69±0.02Å, and <C1–C2–F=<C2–C1–Cl 121±1° for fluorochlorobenzene. C–C=1.40Å, C–H=1.04Å are assumed throughthe analysis.
1. The curves of the surface pressure against area, the surface potential against area, and surface viscosity against area were obtained with diketopiperazine. All the three curves show the limiting area to be about 1.83 m2/mg or 34.6Å2 per molecule. 2. Comparing this result with that obtained by Corey, diketopiperazine molecules are thought to lie flat on the surface. 3. The above value is far larger than the limiting areas of native serum albumin or synthetic protein analogues. And the poly-peptide chain will not show the diketopiperazine configuration on the surface.
The intermolecular charge-transfer spectra of halogen-aromatic complexes have been studied theoretically. Especially, the dependence of absorption intensity on the structure of aromatic component has been investigated. To solve the discrepancies between experimental results and Mulliken’s theoretical predictions, we have introduced the statistical consideration for the relative configurations between two components. Using some reasonable assumptions, we have obtained the satisfactory agreement between theoretical predictions and experimental results, at least qualitatively.
(1) The rupture of aqueous saponin film was studied by measuring the variation of the frequency of the breaking with tension as well as by measuring the breaking time as a function of stress. The results showed that the irreproducibility of the observed data upon surface tension was due to the breaking of the solid film and this mechanism was also responsible for the nature of the stability of such a foam as that produced by saponin, which was also considered to consist of solid film. (2) A new method for the measurement of surface tension, applicable to the solution forming a solid adsorbed layer,was presented. (3) It was shown that the membrane effect is a breaking stress of the adsorbed layer.
1) The condition of synthesis to obtain pure 9-anthranol was established. 2) Times required for the complete disappearance of fluorescence of solution were measured and assumed to be measures of reaction velocities of tautomerism from 9-anthranol to anthrone. In ethanol, ether, dioxane and benzene the reaction velocities were small. 3) Dielectric constants of 9-anthranol in benzene, dioxane, benzene-dioxane mixtures and toluene solutions were measured. Reproduci-bility was satisfactory. In the said solvents 9-anthranol was relatively stable and ω∼ε12 curves were straight lines except in toluene. 4) The stability of 9-anthranol in solvent was supposed to be increased, by an interaction between π-electrons of solvent and proton of solute O–Hgroup in the case of benzene, or by O… H–O combination in the case of dioxane.
It seems that furfural can react with methyl ethyl ketone in two ways by alkali. In the condensation at 0∼3°, the main product was 4-(2-furyl)-3-methyl-4-butanol-2-one. This aldol was easily dehydrated to 4-(2-furyl)-3-methyl-3-buten-2-one, which was oxidised to α-methyl-2-furanacrylic acid by sodium hypochlorite. In the condensation at 60∼3°, the main product was the furfurylidene ketone, which gave the semicabazone melting at 182∼4° and the dioxocarboxylic acid by ring opening in alcoholic hydrochloric acid. It is presumed that this ketone is 1-(2-furyl)-1-penten-3-one, and the dioxocarboxylic acid resulting from it is γ,ζ-dioxopelargonic acid. It is also interesting that two species of 2,4-dinitrophenylhydrazone were obtained with respect to 4-(2-furyl)-3-methyl-3-buten-2-one.
An improved apparatus and technique for measuring low film pressures, have been described. Although the apparatus bears resem-balance to the Marcelin’s balance, the following improvements were achieved in order to enable the low pressure measurement to be generally accessible. (1) The main construction is laid beside the trough, unlike the usual apparatus whose construction is placed above the surface of water. This design is well suited for minimizing the chance of contamination which more or less occurs on the surface during assembling or operation of the instrument. (2) Since one of the disadvantages of this type balance lies in the possibility of leakage at the solid-thread connections, especially at the connection between rims of the trough and thread, properly designed metal blocks are used to ensure the perfect connection with simple technique. (3) An important point in the design of the apparatus is that it should be capable of easy dismantling and reassembling, so that the operation of cleaning can be easily conducted. This requirement is satisfied by the use of a carrier for the float and threads which is easily removable from the main construction of the apparatus. (4) The float is so designed that the connection between the float and the supporter is an independent bearing, when the float is allowed to be in contact with the water surface. Owing to such construction, the change of water level during run does not matter. (5) The optical system, which makes the deflection of the floating barrier visible, is equipped with the apparatus. Since the frosted glass, on which the light image is projected, lies just beside the reading scale, observations can be made with no unnecessary delay. These designs meet well the requirements for measuring low film pressures. Continuous use for eighteen months has shown the apparatus to be very convenient and reliable.
(1) The activity of symmetrical m- and p-substituted benzoyl peroxides on the rate of polymerization of vinyl acetate has been investigated at 40°C. and 60°C. in the absence of air. (2) The peroxides have been divided into two groups according to their activities. The activity of peroxides in each group is nearly inversely proportional to the square root of the dissociation constants of the corresponding substituted benzoic acids in the experimental conditions. (3) The thermal decomposition of the peroxides in vinyl acetate has been observed to be of first order at 40°C, but not always exactly so at 60°C. (4) In the decomposition of the peroxides at 40°C, carbon dioxide was not generated from all the peroxides excluding p,p-dimeth-oxybenzoyl peroxide; while in the decomposition at 60°C, carbon dioxide was produced from effective peroxides, such as dimethoxy-, dimethyl-, and p,p′-dichloro-benzoyl peroxides. (5) It has been confirmed that the velocity of the polymerization is affected not only by the rate of decomposition of the peroxides but also by the activity of radicals derived from the peroxides. (6) The results have been compared with those obtained in the polymerization of styrene.