It was found that most polycyclic aromatic hydrocarbons form molecular complexes with bromine or iodine. Those complexes which are black behave as typical semiconductors with energy gaps for conductivity of 0.1–0.2 eV., as well as with low electrical resistivity ranging from 10° to 103 ohm-cm. The complexes are unstable and a substitution reaction of halogen takes place; when this is not the case, e. g. the violanthrene-iodine complex, and the complex itself is quite stable, so also is the electrical property. It is concluded that the origin of the high conductivity is due to the interaction between hydrocarbon molecules and halogen molecules, and this is presumably due to the overlapping of molecular orbitals stretching throughout the crystal.
The photonitrosation of cyclohexane with nitrosyl chloride was investigated. It was established that cyclohexanone oxime may be easily produced in good yield (72%) under suitable conditions. The dilution of nitrosyl chloride with hydrogen chloride was most effective for preventing the side reactions, and the photonitrosation of cyclohexane was carried out successsfully at a temperature of 10°C. The color of the reaction liquid played the role of indicator for a successful photonitrosation; the side reactions seemed not to occur practically so long as the color of the reaction liquid is yellow, and hence, the addition rate of nitrosyl chloride into cyclohexane should be controlled following the color change of reaction liquid.
(1) Exchange reaction has the prominent feature that the rate does not change with the progress of the reaction and can be determined only by the mechanism of the reaction. Therefore we can immediately detect the effect of variation in any one of the reacting conditions by the observed conversion of the isotopic exchange reaction. (2) The relation between exchange reaction and isotopic exchange reaction is considered and an equation which gives the exchange reaction rate (R) using the integral conversion of the isotopic exchange reaction (x) is introduced. (3) The method is applied to the exchange reaction of oxygen atoms between gaseous oxygen and water vapor catalyzed by chromic oxide, and examination is made of the effect of the variation in the rate of feed gases and in the length of the catalyst bed. (4) At feed rates higher than 32.0 cc. (S. C.)/sec. cm2 the value R remains almost constant, but by the lowering of the feed rate more than this and by the shortening of the bed length, R is decreased. This decrease accompanied decreases both in activation energy and in frequency factor. (5) The results are explained by the effects of mass-transfer through the gas film, of eddy or diffusional mixing of the reacting gases and of other kinds of disturbances. Masstransfer resistance of the gas film is a small fraction of the retardation. Mixing of the reacting gases may contribute a higher percent. (6) The results are compared with the rate of exchange between hydrogen and deuterium measured by Holm and Blue.
(1) Tetramethylsilane, dimethylchlorosilane and methyldichlorosilane and a small amounts of trichlorosilane and hydrocarbon by-product were found in the lower boiling product (b. p. 26°–40°C) of silicon methylchloride reaction. (2) Dimethylethoxysilane and methyldiethoxysilane besides small amounts of dimethyldiethoxysilane and triethoxysilane were found in the ethanolysis product. (3) Owing to the contamination of the hydrocarbon by-product, dimethylchlorosilane could not be isolated by repeated distillation. To characterize this substance, it was synthesized from dimethylethoxysilane and benzoylchloride. (4) By hydrolysis, linear copolymers M′Dn′M′ and M′DnM′ were found. Of these, copolymers M′Dn′M′ having two to eight silicon atoms and M′DM′ have been characterized.
The amount of the phenolic hydroxyl group of the lignin in situ was estimated to be about one per 5-6 methoxyl. Phenolic hydroxyl group of low sulphonated lignosulphonic acid is the same as that of the lignin in situ. There exist two types of phenolic hydroxyl groups (I) and (II) in lignin and lignosulphonic acid, the former being conductometrically titratable and the latter untitratable. With several lignosulphonic acid preparations, the ratios of these two types of phenolic hydroxyl groups were measured, the ratio being 1: 1 with lignin in wood, low sulphonated lignosulphonic acid, and birch α-lignosulphonic acid and about 3: 7 with α-acid of gymnosperm origin. The structures of these two types of phenolic hydroxyl groups were suggested.
It was shown that the UV-absorption spectrum of thiolignin must be explained by assuming the existence of the carbonyl group, the double bond conjugated with the nucleus and the carboxyl group attached directly to the nucleus. The amount of the phenolic hydroxyl group and the carboxyl group of thiolignin were estimated by methylating with diazomethane and subsequently hydrolyzing the methylated lignin with alkali.
Mannich reactions on many lignin model compounds revealed that 1) model compounds of type (I) give without exception Mannich base with substituent at fifth position in very high yield, 2) those of type (II) do not react, 3) carboxyl group having phenolic hydroxyl group to its para position is split off as carbon dioxide and dimethylaminomethyl group is introduced to the same position, 4) methylol group having phenolic hydroxyl group to its para position reacts with dimethylamine resulting in the formation of dimethylaminomethyl group at the same position, 5) other groups remain intact even when phenolic hydroxyl group exists in para position, and 6) no reaction occurs when the phenolic hydroxyl group is etherified. By applying the Mannich reaction with dimethylamine on thiolignin, it has been concluded that about 25–40% of the phenolic hydroxyl group of thiolignin belongs to the simple guaiacol nucleus of type (I) having no C–C bond at its fifth position, admitting some uncertainty concerning the amount of carboxyl group having free phenolic hydroxyl group in its para position.
1. Hydrogen sulphide cooking of α-guaiacyl propanol (VI) gave bis(1-(4-hydroxy-3-methoxyphenyl)-1-propyl) monosulphide (VIII) and disulphide (VII). 2. Vanillyl monosulphide was decomposed with alkali at 130°. Vanillin, vanillyl alcohol and the secondary products from vanillyl alcohol were identified. 3. The mechanism of the kraft cooking process was discussed and a new mechanism was proposed.
A calorimeter equipped with a thermister capable of measuring the temperature change down to 0.5 ×10−4°C was constructed. By this apparatus the heats of dilution of three polystyrene solutions were measured and the values of interaction parameters were derived. The μ values for toluene solution and chloroform solution were both negative and large, but that for ethylbenzene solution was zero. In order to compare with the polymer solution, the heat of mixing of ethylbenzene, which may be regarded as the monomer-unit of polystyrene, with same solvents were also measured and it was found that the interaction parameters of polymer solutions have the same signs as that of the corresponding monomer-unit solutions.