1) The gas chromatographic separation of the isomer of aromatic hydrocarbons has been investigated on the aromatic stationary liquids. 2) It has been established from the experimental results on the xylene series that the S12–σp diagram of Fig. 1 of the previous paper4) is applicable to the separation of the ethyltoluene series. 3) ΔS12 has been defined, and it has been proven that this value was roughly constant between two series of dialkylbenzenes. Moreover, this value seems to throw a light on the prediction of the separation of the isomers of aromatic hydrocarbons. 4) This separation seems to be affected by π-complex formation between aromatic hydrocarbons and aromatic stationary liquids of both the π-acidic and π-basic types.
A new, sensitive spectrophotometric method for the determination of palladium (II) by using xylenol orange as a color reagent has been described. The palladium-xylenol orange complex has an absorption maximum at 518 mμ. The effects of the concentration of perchloric acid and of the reagent have been investigated. In addition, various conditions, including the duration of heating, the stability of the color, and the effect of diverse ions, have been investigated. In a solution of perchloric acid (1.1 to 1.7 N), xylenol orange is a highly selective reagent for palladium, although it reacts with a number of metal cations in a slightly acidic or a neutral solution. Beer’s law is obeyed in the range from 0.2 to 4.0 p. p. m. of palladium at 518 mμ. The results of Job’s method and of the mole ratio method show a complex consisting of two molecules of the reagent to one palladous ion. The formation constant was calculated to be 2×1010.
The irradiation of a benzene solution of sulfur gave thiophenol, diphenyl disulfide, diphenyl sulfide, hydrogen sulfide, hydrogen and some polymers. The formation of thiophenol and of hydrogen sulfide is considered to be initiated by the radiolysis of benzene, which gives phenyl and hydrogen radicals, which in turn combine with sulfur in succeeding steps. However, the thiophenol formed is oxidized to the disulfide as the radiation energy absorbed in benzene transfers to thiophenol. The effect of the initial concentration of thiophenol and of the radiation dose has been measured. The relative stability of the S–H and C–S bond for radiation was about 1:200. The radiolysis of diphenyl disulfide or hydrogen sulfide in benzene were found to form thiophenol. In a kinetical study of the decomposition of thiophenol in benzene, 0.7 benzene molecule is excited by the 100 eV. of gamma rays absorbed, while the ratio between the energy transfer to thiophenol from excited benzene and the deactivation of excited benzene itself is about 100 to 1.
When polyglycine was reacted with acetaldehyde in liquid ammonia in the presence of metallic sodium, it was observed that 7∼9% of the threonine residues were formed from glycine residues. From the hydrolyzate of the modified polyglycine, threonine could be isolated by the aid of the O→N acetyl shift reaction. It was shown that the threonine thus isolated was 35.6% allothreonine.
The authors have tried to divide the conjugation-stabilization energy between monomer and attacking polymer cation, ECM, and that between monomer and attacking polymer anion, EAM, into four terms by means of the equations ECM=ECoMo+EC+EM++E′CM and EAM=EAoMo+EA+EM−+E′AM, respectively. Here, ECoMo is the stabilization energy between polyethylene cation and ethylene monomer, EC and EM+ are the increments in the stabilization energies of systems of (substituted polyethylene cation–ethylene monomer) and (polyethylene cation–substituted ethylene monomer) with respect to ECoMo as standard. E′CM is the surplus increment in the stabilization energy of the system of substituted polyethylene cation and substituted ethylene monomer. EAoMo, EA, EA, EM− and E′AM have the significance analogous to ECoMo, EC, EM+ and E′CM, respectively. The E′CM values for most cation-monomer pairs have been found to be negligibly small. This result correlates with the experimental findings that the products of r1r2 are nearly equal to unity for all the cationic copolymerization systems investigated so far. The equation, kCM=PC+QM+exp(–eCM+), is assumed to be applicable to cationic polymerization, the e+-terms being, however, negligible for any cation-monomer pair. Here, Pc+ is the reactivity associated with polymer cation, QM+ is the general reactivity term of monomer in cationic polymerization, and e+ is the corrective term characteristic of polymer cation and monomer. On the other hand, the E′AM values were often found to play a large part in EAM. This result is consistent with some experimental findings by Szwarc et al. The relative reactivity value of vinyl monomers toward carbonium ions is considered to be the general reactivity term in cationic polymerization, Q+. A good correspondence of Q+ with EM+ has been observed.
The reduction of hexamminechromium(III) ion at the dropping mercury electrode has been studied in neutral and acid aqueous solutions. Hexamminechromium(III) ion gives no well-defined d. c. polarographic wave in an unbuffered neutral solution, whereas in an acid solution it gives a well-defined two-step wave, the first wave corresponding to the reduction of chromium(III) to chromium(II) and the second, to that of chromium(II) to chromium-(0). The first wave of the d. c. polarogram obtained in an acid solution is diffusion-controlled and gives a slope of the log-plot close to that expected for a reversible wave. The a. c. and the Kalousek polarogram, however, are of the irreversible type. No chemical reaction involving hydrogen ions, ammonium ions or ammonia takes place preceding the electron transfer. Considering these results, the following mechanism is temporarily suggested for the reduction of hexamminechromium(III) ions at the dropping mercury electrode: [Cr(NH3)6]3++e\
Current-potential curves of various oxalato complexes of chromium (III) were obtained at the dropping mercury electrode in acid or neutral aqueous solutions. The reduction potentials that were defined as potentials at \barl=\barll⁄10 were found to shift to more negative potentials with an increasing number of oxa-lates coordinated. The ionic charge effect on the reduction potentials was discussed in connection with the electrostatic interaction between the reacting species and the electrode.
S-Carboxymethyl-cysteine (SCMC) cyclizes by dehydration to form 3-oxo-5-carboxy-per-hydro-1,4-thiazine (SCMC-lactam) when the aqueous solution was heated at 110∼180°C. SCMC-lactam was also obtained from N-acetyl-SCMC when the latter was treated with N,N′-dicyclohexylcarbodiimide and hydrolyzed subsequently at pH 9.0.
It has been attempted, by the ESR technique, to study the steady-state photopolymerization of vinyl acetate and methyl methacrylate, using hydrogen peroxide as the initiating substance. The observed steady-state radical concentration has been found to coincide within a factor of two with the calculated value, Eq. 3, derived under the assumption of a simple kinetic treatment. Although, it has been shown that the calculated decay curve deviates from the observed curve in the later period of decay, especially in the case of methyl methacrylate; such a discrepancy seems to be explainable if the reaction rate decreases with the chain length of the polymerizing radicals.
Thermal annealing curves given from the chemically-distributed phosphorus-32 formed by neuton irradiation in a nuclear reactor were obtained by heating several orthophosphates, sodium pyrophosphate, and disodium hydrogen phosphite samples in crystal. The separation was accomplished by one-dimensional paper chromatography. The amounts of phosphorus-32 in the chemical species different from the parent species decreased upon the heating of the salts, except in the case of sodium dihydrogen phosphite, whereas retention always increased. By the analysis of thermal annealing curves obtained from the initial distribution of activation energies, it was found that there was a difference between the thermal-annealing behavior of the polyphosphate fraction and that of the reduced species fraction. The activation energies of the polyphosphate fractions were in the range of 0.60 to 1.0 eV., but the pyrophosphate sample showed an exceptionally high value, i. e., 0.78 to 1.3 eV. Higher activation energy values were estimated for the annealing of the reduced species fraction than for those of the polyphosphate fractions.
The electron spin resonances of 4-methyl biphenyl and p, p′-bitolyl mononegative ions were observed in either dimethoxyethane or tetrahydrofuran, using potassium metal as a reducing agent. Well-resolved proton hyperfine spectra were observed in each case, and the g-value, the overall width, and the hyperfine splitting coefficients due to the methyl protons and ring protons were determined. The theoretical spectra were constructed according to the spin densities calculated by Hückel’s MO treatment, and these results were compared with the observed spectra.
The distribution of nickel in the two phase system, sodium formate-pyridine is studied in detail. The effects of pH, volume of pyridine and molarity of formate are studied and the optimum conditions for the complete extraction are established. The possibility of using this extraction technique for the separation of nickel and chromium has also been worked out and a procedure for the analysis of a syn-thetic mixture of nickel and chromium is given.
The oxidation of methyl alcohol by ceric perchlorate in perchloric acid solution was studied at 13, 20 and 26°C. The stoichiometry consisted of two cerie ions for the oxidation of one molecule of methanol. While the rate of disappearance of ceric ions directly depended on the concentration of ceric ions, the dependence on methanol concentration was such as to suggest a ‘broken order’: \frac−dCeivdt=\frack(Ceiv)(MeOH)1+k′(MeOH) This rate also depended on the concentration of perchloric acid in such a way that at high acidity it became independent of it. These data were explained on the basis of Duke’s mechanism for 2,3-butane diol-ceric perchlorate reaction, i. e. the oxidation of methanol by ceric ions proceeded via an intermediate complex between one Ce4+ ion and one methanol molecule. The formation of this complex was also proved independently by a spectrophotometric method. The kinetic data were further used to derive the true heat of formation of the methanol-cerate complex and the heat of hydrolysis of the cerie ions in aqueous perchloric acid.
The oxidation of methanol by cerie sulfate in sulfuric acid solutions was studied in the temperature range 40∼70°C. The rate of oxidation depended directly on the concentration of cerium(IV) and methanol. At constant ionic strength the rate was directly dependent on the concentration of sulfuric acid. But when the ionic strength is not maintained, the rate changes inversely with sulfuric acid. At constant acid concentration, a negative salt effect is observed. The reaction occurs without the intermediate formation of a complex. The activation energy was derived to be 26300 cal. mol−1. It has been shown that the mechanism of Waters for the oxidation of α-hydroxyacids by manganese pyrophosphate can be used to explain the present data.
The Raman spectra of acetaldehyde, its aqueous solution and its heavy water solution have been recorded at various temperatures and in various concentrations in order to find the Raman frequencies characteristic of the hydrated species and in order to investigate the reversible hydration process. Almost all the lines have been assigned tentatively on the assumption that the hydrate molecule has Cs symmetry. The lines at 325, 480, 567, 1353, 1440, 1449, 2874, 2939 and 2996 cm−1 can be referred to as the lines characteristic of the hydrate. Supporting data have also been obtained for the related compounds for the sake of comparison. Moreover, through the intensity measurements, equilibrium constants, as well as the heat of hydration, have been evaluated as the basis for a discussion of the hydration process.
The adsorbed water of the low polymer of formaldehyde was determined by extraction with dry methanol and Karl Fischer titration. The sum of the adsorbed water and the water formed by the pyrolysis of the sample was determined by titration with the specially prepared Karl Fischer reagent SS, after the sample had been dissolved in propylene glycol by heating. The method of the separation and the determination of the two kinds of water was thus established. When the average numerical degree of polymerization of the polymers was calculated from the content of bound water determined by this method, satisfactory results were obtained. To verify the accuracy of the determination of water content, formaldehyde and methanol were determined independently; their sum was found to be almost 100%.
Tait’s equation for water and Harned and Owen’s treatment of an electrolyte solution, together with sound velocity data, enabled the calculation of the molar volume of electrolytes in the solution state. The results agreed fairly well with the molar volume of the super-cooled molten electrolyte extrapolated to room temperature. The concentration coefficient of electrostrictive pressure, L=Pe/C1C2, the volume contraction due to the dissolution of one mole of solute, ΔV, and the volume of hydration water per mole of solute, Vh, as an incompressible part of water have been evaluated. We have found a common variable, [h], for L, ΔV and Vh, and it has been proposed that this variable can be used as a parameter of hydration expressing the mole number of hydration water per mole of electrolyte. A conventional hydration number, [h*], was also proposed.
N-Nitroso-p-chloro(36Cl)acetanilide has been decomposed in mixtures of benzene and mono-substituted benzene C6H5X (X=NO2, Cl, OCH3, and CH3), and the reaction products have been analyzed for 4-chlorobiphenyl and isomeric 4-ClC6H4C6H4X by the isotope dilution method. On the basis of these results, the partial rate factors for the p-chlorophenylation have been calculated to be, for nitrobenzene: o, 4.35; m, 0.61; p, 6.18; for chlorobenzene: o, 2.70; m, 0.87; p, 1.33; for anisole: o, 3.93; m, 0.94; p, 1.54 and for toluene: o, 2.97; m, 1.07; p, 1.32. The values of the partial rate factor for the meta position give a satisfactory Hammett plot with a slope of −0.27. This fact demonstrates that the p-chlorophenyl radical shows a measure of electrophilic character in the homolytic aromatic substitution.
N-Nitroso-p-nitroacet(anilide-14C) and N-nitroso-p-methoxyacet(anilide-14C) have been decomposed at 20.0°C in mixtures of benzene and monosubstituted benzenes C6H5X (X=NO2, Cl, OCH3, and CH3), and the reaction products have been analyzed for 4-nitro-and 4-methoxybiphenyl and isomeric 4-NO2C6H4C6H4X and 4-CH3OC6H4C6H4X by the isotope dilution method. From the results of these competitive experiments, the partial rate factors for the p-nitrophenylation and p-methoxyphenylation have been calculated (Tables I and II). The values of the partial rate factor for the meta position give a satisfactory Hammett plot with a slope of −0.81 for the p-nitrophenylation and one with a slope of +0.09 for the p-methoxyphenylation, showing that the p-nitrophenyl radical has a pronounced electrophilic character while the p-methoxyphenyl radical has little, if any, nucleophilic character.
N-Nitrosoacet(anilide-14C) and N-nitroso-(p-methyl-14C)acetanilide have been decomposed at 20.0°C in mixtures of benzene and monosubstituted benzenes, and the reaction products have been analyzed for biphenyl and substituted biphenyls by the isotope dilution method. From the results of these competitive experiments, the partial rate factors for the phenylation and p-methylphenylation have been calculated (Tables I and II). The values of the partial rate factor for the meta position give a satisfactory Hammett plot with a slope of +0.05 for the phenylation and one with a slope of +0.03 for the p-methylphenylation, suggesting that the p-methylphenyl radical has little, if any, measure of polar character. The correlation of the ρ values for various arylations with the inductive constant for the substituent group on the arylating radical indicates that the effect of the substituent group in the radical is purely inductive in nature. The partial rate factor for the para position, kp/k, is found to be related to Hammett’s substituent constant by the following equation: log(kp⁄k)=ρσp+τp where ρ is the Hammett reaction constant for this arylation as determined from the Hammett plot of the partial rate factors of the meta position. τp is found to be tolerably constant for each substituted benzene, irrespective of the nature of the attacking aryl radical, and represents that part of the conjugative effect of the substituent which is independent of the polar nature of the attacking radical. Molecular orbital calculations have given results which rationalize the trend found in the τp values.
1. DPPH in a benzene solution was decom-posed by sun-light on a relatively large scale in the presence of air, and the prducts were separated on a cellulose column. The products were identified as α,α-diphenyl-β-picrylhydrazine (I), α-phenyl-α-(p-nitrophenyl)-β-picrylhydrazine (II), and a third component (III) with a chemical composition of (C18H10−11-N3O3)n (the n is greater than 3). 2. The method of separation by means of a cellulose column was applied in the quan-titative estimation of the reaction products. The ratios of the products in the course of the decomposition were determined. From the ratio at the final stage, the over-all reaction can be written as follows: 4 DPPH→I+2II+III 3. The physical and chemical properties of the third component have been described, and a possible structure for III has been pro-posed. 4. From the material balance and the chemical compositions of the reaction products, it is presumed that the early stage of the decomposition of DPPH induced by light is an intermolecular nitration of DPPH.
The infrared spectra of some esters, lactones, carbonates, ketones and aldehydes in methanol and t-amyl alcohol have been determined. With few exceptions, they showed either two carbonyl peaks separated by 15∼27cm−1 or a broad carbonyl peak shifted by 9∼19cm−1from the wave number as determined in carbon tetrachloride. The relative intensities of the two bands are independent of the concentration. Some possible explanations for this phenomenon have been discussed, and as a result these doublet carbonyl bands have been attributed to the mono-hydrogen-bonded carbonyl and the di-hydrogen-bonded carbonyl.
The phase transition of the potassium thiocyanate crystal at ca. 140°C has been studied by thermal and infrared methods. The transition is of a higher-order type, accompanied by an entropy change of 1.30±0.05 e. u., which is nearly equal to R ln 2. The infrared band due to the in-plane bending vibration of a thiocyanate ion shifts to lower frequencies in the course of the phase transition. From these results, it has been concluded that the phase transition is connected with the dynamical disordering of the direction of thiocyanate ions in crystal, a disordering which is mainly brought about by the frequent excitation of the out-of-plane torsional oscillation and the flipping motion.
The phase transition of potassium thiocyanate has been investigated by the X-ray diffraction. It was confirmed that it is an order-disorder type transition with regard to the orientation of the thiocyanate ions. The temperature dependence of the ordering and the anomalous volume expansion near the transition temperature seem capable of being interpreted by the molecular field approximation if the volume dependence of the interaction energy is taken into account.
1) In the Cs+–(NH4++NH3) exchange system, the distribution coefficients of cesium can be approximately expressed as follows: logKd=pH−1.6log[NH4++NH3]−8.8 2) In the Cs+–Na+ and Cs+–K+ exchange systems, the distribution coefficients of cesium can be expressed with a good approximation by: logKd=0.25log[OH−]−0.90log[Na+]+2.4 and logKd=0.25log[OH−]−0.90log[K+]+1.7 In the Cs+–NH4+ exchange system, the distribution coefficients of cesium can be expressed by: logKd=−1.1log[NH4+]+0.62 3) The specific adsorption of cesium by the active phenolic groups is observed when the pH value of the outer solution is above 12, and high selectivity is obtained above 13 for the Cs+–Na+ exchange system. For the Cs+–(NH4++NH3) exchange system, the specific adsorption of cesium is observed above pH 11, and an extremely high selectivity can be obtained when the total concentration of the outer solution is below 1 mol./l.