The ultraviolet spectra of nitrones, the configurations of which were assumed from their dipole moments and chemical reactivities, and their related compounds have been measured in various solvents. The following results have been obtained: (1) Nitrones show a characteristic strong π-π* band in the 280∼370 mμ region as well as one or two additional bands with a relatively low intensity in the 200∼260 mμ region. The molecular extinction coefficient (ε) of the former is about 20000. The decrease in intensity of the π-π* band is observed in the spectra of the sterically-hindered compounds. (2) These bands always show a blue shifs with the increasing polarity of the solvent. The general rule of solvent effect on heterocyclic N-oxides applies also to nitrones, the conjugated N-oxide band of which has the same property as that of heterocyclic N-oxides. (3) It has been confirmed by ultraviolet and infrared spectra that the formation of a hydrogen bond such as N→O…H (solvent) plays an important role in this blue shift phenomenon.
The ultraviolet absorption spectra of benzylidene methyl amine, its protonaddition compound and benzylidene methyl amine N-oxide have been examined under various conditions. SMO calculations on those compounds have been carried out, and various physicochemical properties have been discussed. On the basis of these calculations, the spectra of the above compounds have reasonably been assigned by using the spectroscopic exchange integrals βs(1A1) and βs(1B1), which were evaluated from the spectra and the MO, including C. I., of styrene.
A new method for the spectrophotometric determination of titanium has been described. This method is based on the formation of the colored complex between titanium and xylenol orange in a slightly acidic solution. The effects of pH and the reagent concentration on the color development of the complex have been thoroughly investigated, and experimental conditions which make possible the determination of titanium at microgram levels have been devised. The compositions of the two 1 to 1 complexes have been determined from the data of spectrophotometric measurements. The apparant formation constants of these complexes have also been calculated.
Some experiments have been made in order to prove the hypothesis that the hydroxyl radical plays an important role in the oxidation of organic compounds by γ-radiolysis in aqueous solutions. Nitrous oxide and hydrogen peroxide have been found to be capable of converting radiation-induced hydrogen atoms (or their stoichiometrically-equivalent species) into hydroxyl radicals. In theγ-radiolysis of aqueous benzene solutions in the presence of nitrous oxide or hydrogen peroxide, the yield of the oxidation products from benzene has been found to equal, as had been expected, the sum of the yields of hydrogen atoms and hydroxyl radicals from water.
The absorption spectra of several oil-soluble dyes, 1-benzeneazo-2-naphthol and three 1-nitrobenzeneazo-2-naphthols, have been measured in aqueous solutions of polysoap and monosoap and in hydrocarbons. The spectra of the above dyes in monosoap solutions are similar to those in hydrocarbons, while the spectra of dyes with a nitro group in polysoap solutions, especially the spectrum of p-nitro-BAN, are different. The differences in the solubilization behavior of the dyes in polysoap and in monosoap solutions and the ways in which the dyes are solubilized have been discussed. It has also been proposed that the loci of the solubilization in the polysoap molecule are not only the dense hydrocarbon region in the interior but also the polar region near the polymer backbone. In this case, the nitro group of the dye molecule seems to play an important role in the solubilization.
The solubilization of several oil-soluble dyes, 1-benzeneazo-2-naphthol (BAN) and three 1-nitrobenzeneazo-2-naphthols (nitro-BAN), by a polysoap and a monosoap has been studied by measuring the solubilizing power, the viscosity and the electrical conductance of the solutions of both soaps. The polysoap is a better solubilizer than the monosoap. BAN was more solubilized than nitro-BAN at any given concentration of soap. The amount of nitro-BAN solubilized by the polysoap was increased in the order m-nitro-BAN>p-nitro-BAN>o-nitro-BAN, while the solubilization by the monosoap was in the order m-nitro-BAN>o-nitro-BAN>p-nitro-BAN. However, there appears to be no simple interpretation of the effect of the structure of dyes upon the solubilization. The addition of the dyes to the polysoap solutions decreased the viscosity, except for that of p-nitro-BAN at low concentrations of polysoap. p-Nitro-BAN produced an anomalous increase in the viscosity, the reason for this being not certain. In the case of polysoap, every solubilized dye produced a small increase in electrical conductance, but no significant difference among them could be found.
1) Aminoacetone-N, N-diacetic acid or 1-amino-2-propanone-N, N-diacetic acid has been synthesized. This is the first iminodiacetic acid derivative to have a keto group as an additional coordinating site. 2) The acid dissociation constant and the chelate stability constants of this ligand have been determined by the pH titration method, at 25°C and 0.10 M ionic strength, for such metal ions as copper(II), lead(II), nickel(II), zinc(II), cadmium(II), cobalt(II), calcium(II), strontium(II) and magnesium(II). 3) It has been proved that the coordination of the carbonyl oxygen of this ligand to metal ions is appreciable, and the increase in the chelate stability has been explained by the contribution of the carbonyl coordination.
An indirect procedure for the determination of V5+, Ce4+ and Cr6+ is given. Three re-ductants, viz., ascorbic acid, arsenous oxide and hydrazine have been employed for reduction of each oxidant. Iodine monochloride has been used as catalyst in the reduction of V5+ and Ce4+ by arsenous oxide. Reduction of Ce4+ with hydrazine presented certain difficulties and is not pursued at the present stage. The excess reductant in each case is determined amperometrically with chloramine T at the rotating platinum wire micro-electrode, and an impressed potential of +0.3 volt vs. S.C.E. The titrations are performed at a pH of 4.3∼4.9, using citrate-citric acid buffer. For titration of excess arsenous oxide and N2H4·H2SO4, 0.25 ml. of iodine monochloride (0.005 M) has been employed as catalyst. The procedure, which is rapid and accurate, has been employed for determination of amounts up to 1.05 mg. vanadium, 5 mg. cerium and 0.86 mg. chromium.
1) The single and mixture dyeing of Chrysophenine G (C.I. Direct Yellow 12) and Sirius Red 4B (C. I. Direct Red 81) have been examined kinetically. 2) The affinity and the diffusion coefficient of each dye at 90, 85 and 80°C have been evaluated. The apparent activation energy of diffusion at a constant surface concentration has been calculated. 3) In the mixture dyeing, although the apparent diffusion coefficient of each dye became larger than that in the single dyeing, whose surface concentration was similar to that in the mixture dyeing, the dye with the smaller diffusion coefficient had a more profound effect on the diffusion of the dye with the larger diffusion coefficient than in the reverse case.
The electronic spectra and electronic structures of amino substituted benzenes have been studied by the semiempirical MO method, with the explicit inclusion of the electron repulsion. According to the calculated results, we can interpret the difference between the spectra of various poly-substituted aminobenzenes; also, the calculated excitation energies and oscillator strengths are in satisfactory agreement with the observed values. The relation between the present calculation and the simple Hückel MO calculation has been analyzed. Moreover, several interesting relations between the Hückel MO quantities of substituted benzenes and naphthalenes have been demonstrated and discussed. The calculated π-moment of aniline in the ground state is in satisfactory agreement with the experimental value. Furthermore, the π-moment of aniline in the lowest excited singlet state has been calculated and compared with the experimental value obtained from the measurement of the solvent shifts of the absorption and fluorescence spectra.
The quenching constants (k) of quinoline for the fluorescence of several substances in n-hexane have been determined. The values, obtained are as follows; they are independent of the frequency of the exciting light. 2-Naphthylamine 120 (20°C) 140 (40°C) N,N-Dimethyl- 2-naphthylamine 90 (20°C) 100 (40°C) 2-Naphthol 100 (21°C) 2-Naphthylmethyl- ether 53 (21°C) The results clearly show that the hydrogen bond is not necessary for the quenching to occur, in contradiction to the mechanism proposed by Mataga for the case in which pyridine is used as a quencher. To elucidate the mechanism, the quenching phenomena in the fluorescence of the above substances have been further studied in benzene and ethanol, using pyridine and quinoline as quenchers. The most notable finding has been that, in ethanol, pyridine can quench the fluorescence of 2-naphthylamine and N,N-dimethyl-2-naphthylamine equally well, the k value for 25°C being, respectively, 16 and 15. A mechanism has been proposed which involves the charge transfer from fluorescer to quencher. When the quenching is considerable, the rate-determining step is the diffusion proces, irrespective of the molecular mechanism for the quenching.
The photoreduction of acridine in methanol and isopropanol has been studied and the following results obtained : 1) The quantum yield for the photoreduction in the dagassed solution is, for methanol, 0.13 and, for isopropanol, 0.09. The photoreduction can take place even in an air-saturated solution with quantum yields of 0.032 for methanol) and of 0.032 (for isopropanol). 2) In case of a degassed solution, the product is acridan for both isopropanol and methanol, while in an aerated solution the product is acridan in the case of methanol and mainly diacridan in the case of isopropanol. 3) When the concentration of oxygen is of the order of that of acridine, the reaction proceeds at first at a rate equal to that of an air-saturated solution and then, from the point at which the oxygen is exhausted, the rate increases up to the value of a degassed solution. 4) The ratio of the quantities of oxygen and of acridine consumed before the break is, for methanol, about 3 and, for isopropanol, 5.3. 5) By the sensitizing action of acridine, acridan is oxidized to acridine in the presence of aldehyde (or acetone) and a small quantity of oxygen. 6) On the basis of the scheme proposed in the preceding paper and from the reaction product, some tentative discussion of the scheme has been undertaken. It seems plausible that, in the case of ethanol and methanol, AH· + RH· → AH2 + R occurs, while in the case of isopropanol, AH· + AH· → AH2 + A and RH· + RH· → take place (for a degassed solution).
Some copper complexes which have only chloride ions in the coordination spheres have been prepared and their EPR spectra examined at the microwave frequency of the X-band. Most of these compounds gave single EPR lines with half-widths ranging from 110 to 220 oe; this seems to indicate the existence of superexchange interaction. Only the yellow plates of dimelammonium hexachlorocuprate-(II) showed the fine structure of an anisotropic g-tensor, from which fact the g-components were evaluated as g||=2.32 and g⊥=2.08 for this compound. The dark green color of diethylenetriammonium chlorocuprate(I, II) is probably due to the interaction of Cu+ and Cu2+ in the crystal lattices. Brown chlorocuprates with a chlorine to copper ratio of 3 : 1 are probably coordination polymers ; the EPR lines of these compounds are so broad as to cover thousands of oersteds.
A photoconductive polymer, poly[1, 3-diphenyl-5-(4-vinylphenyl)-2-pyrazoline], has been synthesized from polystyrene via polyvinyl-acetophenone and polyvinylbenzalacetophenone. Under carefully controlled preparative conditions, a high degree of substitution has been obtained without its being insoluble. The photoconductive behavior of the polymer has been measured using a sandwich-type cell. The current obeyed Ohm’s law, and the value of Ip/Id was 34 or 147 depending on whether the illuminated electrode was positive or negative respectively.
Uranyl ion has been found to form an orange-yellow coloured complex with thiomalic acid. Spectrophotometric measurements reveal a composition of 1:1 as UO2(II) : TMA in the complex, where TMA stands for thiomalic acid. Thiomalic acid is found to behave as a bidentate ligand with UO2(II) in this complex. This has been concluded by potentiometric method. Magnetic susceptibility measurements, however, show an anomolous magnetic behaviour. The formation constant logK, at fixed pH and ionic strength as calculated from the spectrophotometric curves, comes out to be 3.0±0.1 and the corresponding free energy of formation has been calculated as −4.2±0.2 at 25°C.
The ESR and electronic spectra of the 4-nitropyridine and 4-nitropyridine 1-oxide anions have been measured. The nitrogen and hydrogen hyperfine splitting constants of these two compounds have been determined. In order to analyze the ESR spectra exactly, the measurements have also been carried out with respective compounds containing 15N instead of 14N in the nitro group. The spin densities on the nitrogen and carbon atoms of these two anions have been estimated from the splitting constants. It has thus been found that the spin densities on the ring nitrogen and carbon atoms are undoubtedly larger in the 4-nitropyridine 1-oxide anion than in the 4-nitropyridine anion. The electronic spectrum of the 4-nitropyridine anion has been measured and three peaks found at 313, 440 and 640 mμ. According to the molecular orbital calculations carried out with the π-electron system of the 4-nitropyridine anion, it has been concluded that the 440 mμ band may be regarded as the intramolecular charge transfer band, and that the 313 mμ band can be interpreted as the blue shifted band of the pyridine anion.
In the case of a complex of p-phenylenediamine with iodine, a nonstoichiometrical composition has been established; the minimum values for both the magnitude and the temperature dependence of resistivity exist on the complex the coordination number of which is around 0.8. On the other hand, the maximum value of the apparent density appears in the vicinity of 1.0. In comparison with the complex of p-phenylenediamine-iodine and that of p-phenylenediamine-chloranil, even though the redox potential of chloranil is larger than that of iodine, the resistivity and the activation energy of the p-phenylenediamine-iodine system are smaller than those of the chloranil complex.
Water-soluble polysaccharide extracted from the pulp of jackfruit (Artocarpus Integerifolia) has been shown to be composed of L-rhamnose, D-xylose, L-arabinose, D-glucose, D-galactose and D-galacturonic acid. The jackfruit pectic acid has subsequently been extracted with ammonium oxalate and purified. The results of electrophoresis, mild hydrolysis and methylation studies indicate the presence of chains of 1 : 4 linked α-D-galacturonic acid residues in the pectic acid, which is physically associated with a neutral polysaccharide, a glucan. Periodate oxidation studies have also been reported.
RAPOX (resacetophenone oxime) in certain water-immiscible organic solvents is found to extract nickel from an aqueous medium as a nickel RAPOXimate complex. Cyclohexanone was found to be the best solvent for this purpose. The brilliant green-coloured solution of the complex in cyclohexanone gave a maximum absorption at 600 mμ on a Beckman spectrophotometer DU. The coloured solution obeyed Beer’s law in the lowest range—six parts per million. The extraction of this complex was quantitative in the pH range from 8 to 11. The composition of the complex as determined by Job’s method and the slope ratio method in a two-phase system was 1 : 2 (nickel to RAPOX). The back extraction study for the metal from the complex in the organic solvent was carried out and quantitative results obtained using an aqueous solution with a pH value below four.