Showing papers in "Bulletin of the Chemical Society of Japan in 1967"

Preparation of Esters of Carboxylic and Phosphoric Acid via Quaternary Phosphonium Salts

Abstract: When n-valeric acid was treated with allyl diethyl phosphite and diethyl azodicarboxylate, allyl valeriate and diethyl N-(diethyl)phosphoryl hydrazodicarboxylate were obtained in good yields. Similarly ethyl benzoate was obtained in a nearly quantitative yield by the reaction of benzoic acid with triethyl phosphite and diethyl azodicarboxylate. The reaction of carboxylic acid with triphenyl phosphine and diethyl azodicarboxylate in the presence of an alcohol resulted in the formation of the corresponding esters of the carboxylic acid, triphenyl phosphine oxide, and diethyl hydrazodicarboxylate. The mechanisms of these reactions are also discussed.

Use of Anhydrous Hydrogen Fluoride in Peptide Synthesis. I. Behavior of Various Protective Groups in Anhydrous Hydrogen Fluoride

Abstract: The properties of anhydrous hydrogen fluoride (HF) as a reagent for the acidolysis of various protective groups have been studied. Amino acids with various protective groups were each treated with HF at 0 or 20°C in the presence of anisole, and the reaction products were tested. Thus, HF was found to be much better than the other known reagents, such as hydrogen bromide and trifluoroacetic acid. In the present study, the following groups were shown, for the first time, to be removed safely: the nitro group in nitroarginine, the diphenylmethyl group in diphenylmethylamide, the t-butyl group in S-t-butylcysteine, the isopropyloxycarbonyl group, and the isopropyl ester group. A new and convenient apparatus was designed for the safe handling of HF for peptide synthesis.

Preparation of Esters of Phosphoric Acid by the Reaction of Trivalent Phosphorus Compounds with Diethyl Azodicarboxylate in the Presence of Alcohols

Abstract: Trivalent phosphorus compounds, phosphine or trialkylphosphites, have been oxidized by means of diethyl azodicarboxylate and either benzyl or allyl alcohol to give the corresponding phosphine oxide or trialkyl phosphates. The reaction was then extended to the phosphorylation of alcohols. When allyl diethyl phosphite was treated with diethyl azodicarboxylate in the presence of an alcohol at room temperature, a corresponding alkyl diethyl phosphate and diethyl N-allyl hydrazodicarboxylate were obtained in good yields. On the other hand, when phenol was treated with allyl diethyl phosphite and diethyl azodicarboxylate, diethyl phenyl phosphate, allyl phenyl ether and diethyl hydrazodicarboxylate were obtained. The mechanism of their formation will also be discussed.

Effect of Molecular Vibrations on Gas Electron Diffraction. II. Probability Distribution Function and Phase Parameter for Polyatomic Molecules

Abstract: A method has been presented for calculating the first, second, and third moments of the displacement of an internuclear distance in a polyatomic molecule, ⟨Δr⟩, ⟨Δr2⟩, and ⟨Δr3⟩. The moments, which depend on the frequencies of normal vibrations, the cubic potential constants, and the temperature of the system, have been related to the extent of distortion of the probability distribution function of the internuclear distance from a Gaussian function caused by the anharmonicity in the potential function. An approximate expression has been obtained for the phase parameter κ in the molecular intensity of gas electron diffraction in terms of the moments. Numerical results are given for CO2, CS2, SO2, H2O, D2O, CH4, and CD4 by the use of experimental or estimated cubic potential constants. The phase parameters for bonded distances agree with simple estimates based on “diatomic approximation” to the accuracy of current experimental studies, while the phase parameters for nonbonded distances are similar in magnit...

Effect of Molecular Vibrations on Gas Electron Diffraction. I. Probability Distribution Function and Molecular Intensity for Diatomic Molecules

Abstract: General expressions and their practical approximations are presented for the molecular intensity of gas electron diffraction and the radial distribution function for an atom pair in the molecule which exerts moderately anharmonic intramolecular motion in thermal equilibrium. The calculations are based on a polynomial expansion of the probability distribution function of the internuclear distance around a Gaussian function representing harmonic vibration. The coefficients of the expansion for a diatomic system are calculated by the second-order perturbation method in terms of the coefficients of the potential energy expanded to the fourth order of the displacement in the internuclear distance. The structural parameters under various definitions (the mean internuclear distances, the mean square amplitudes, and the phase parameters) of a number of diatomic molecules are tabulated by the use of the spectroscopic values ωe, αe, and χe taken from the literature. The temperature dependence of the structural para...

Solvent Effects on the g-Value of Di-t-butyl Nitric Oxide

Abstract: The effects of solvents on the g-value of di-t-butyl nitric oxide (DTBNO) have been examined. Plots of the g-value vs. the hyperfine coupling constant of 14N of DTBNO in various solvents formed two...

Studies of the Mixed Amino-acid Complexes of Cobalt(III). II. A Complete Series of [Co(ox)x(gly)y(en)z] Complexes

Abstract: Five new complexes, C1-cis(O)[Co(gly)2(en)]Br·3H2O, C2-cis(O)-[Co(gly)2(en)]Br·H2O, trans(N)-K[Co(ox)(gly)2], C1-cis(N)- and C2-cis(N)-Na[Co(ox)(gly)2], have been synthesized. The geometrical isomers of both the [Co(gly)2(en)]+ and the [Co(ox)(gly)2]− complex have been separated by ion-exchange column chromatography. The geometrical structures have been determined on the basis of the visible absorption spectra and of the NMR spectra, and from a consideration of the reaction processes of derivation. The visible and near-ultraviolet absorption spectra of a complete series of the sixteen complexes of the [Co(ox)x(gly)y(en)z] type, have been measured and discussed.

Absorption Spectra and Circular Dichroisms of Metal Complexes. I. Platinum(II)-, Palladium(II)- and Gold(III)-Complexes Containing Optically Active Diamines

Abstract: In order to study the nature of absorption bands in square-planar metal complexes of d8 type, a number of platinum (II), palladium (II) and gold(III) complexes containing l-propylenediamine and l-cyclohexanediamine were prepared and their circular dichroism (CD) and rotatory dispersion (RD) as well as absorption spectra (AB) were measured. Three or four absorption bands corresponding to d–d transitions were observed for each platinum(II) and palladium(II) complex. All the complexes, except for [Au(l-pn)2]Cl3, [Au(l-chxn)2]Cl3 and [PdCl2(l-pn)], give two possitive CD bands in the wavelength region from visible to 210 mμ, which are assigned to the spin-forbidden and spin-allowed A1→E transition. Both [Au(l-pn)2]Cl3and [Au(l-chxn)2]Cl3 exhibit only one strong positive CD band corresponding to the ligand field transition probably mixed with charge transfer transition. [PdCl2(l-pn)] gives a weak negative and a strong positive band corresponding to the transitions, A1→A2 and A1→E, respectively. The CD strength ...

The Surface Activity of Tetrabutylammonium Halides in the Aqueous Solutions

Abstract: The surface activity of the tetrabutylammonium halides at the air/aqueous solution interface or at the hexane/aqueous solution interface has been studied. The surface or inter facial tension versus the concentration curves of the electrolytes are markedly dependent on the kind of their counter-ions, just as with these electrolytes in aqueous solutions. The surface activity of tetrabutylammonium iodide is fairly strong; it approximately corresponds to that of the surface-active straight-chain electrolyte with an octyl group. From the thermodynamic parameters of the adsorption of tetrabutylammonium iodide, it is found that the standard free energy of adsorption becomes negative as a result of the large positive values of the standard entropy of adsorption, irrespective of the positive values of the standard enthalpy change. This suggests that the adsorption is a “hydrophobic” effect; that is, the “icebergs” around the nonpolar groups of the electrolyte return to the original water by the process of the tran...

Anionic Copolymerization of Styrene and 1, 1-Diphenylethylene

Abstract: Anionic copolymerization of isoprene (M1) and 1,1-diphenylethylene (M2) was carried out in tetrahydrofuran (THF), dioxane, benzene, and n-heptane by using n-butyllithium (n-BuLi), Na-naphthalene, Na- and K-dispersions as initiators. An alternating copolymer was obtained in the copolymerization in THF, which proceeded without a chain transfer and a termination. Monomer reactivity ratios, r1 obtained by assuming the rate constant k22=0, were 0.12 (Li+), 0.11 (Na+), and 0.11 (K+) in THF at 0°C. The r1 value in benzene at 40°C, however, was affected by the counter ion as follows: 37 (Li+), 0.38 (Na+), and 0.05 (K+). With Li+ counter ion the values were 0.50 in dioxane at 30°C and 29 in n-heptane at 40°C. The order of rate constants in the copolymerization in THF with n-BuLi at 0°C, was k12>k11>k21, the last of which was 2.64×10−3l/mol sec.

Equilibria in the V2O3-VO2 System at 1600°K

Abstract: Phase equilibria in the V2O3-VO2 system were established at 1600°K by varying the oxygen partial pressures from 10−13 to 10−3atm. The phases of V2O3, V3O5, V4O7, V5O9, V6O11 and VO2 are stable under these conditions. The only phases of V2O3 and V6O11 have extensive ranges of solid solution. The stability ranges of vanadium oxides with respect to the oxygen partial pressure were determined: V2O3, from 10−13 to 10−6.36atm; V3O5, from 10−6.36 to 10−4.90atm; V4O7, from 10−4.90 to 10−4.20atm; V5O9, from 10−4.20 to 10−4.04atm; and V6O11 from 10−4.04 to 10 −3.53atm, while VO2 is in equilibrium with V6O11 at the oxygen partial pressure of 10−3.53atm. The oxygen partial pressures were measured accurately by means of a solid electrolyte cell composed of (ZrO2)0.85(CaO)0.15; these pressures were then compared with the values calculated from the thermochemical data. On the basis of the equilibrium oxygen partial pressures, the standard free energies of oxidation of various vanadium oxides were calculated.

Heats of Sublimation of Polycyclic Aromatic Hydrocarbons and Their Molecular Packings

Abstract: The vapour pressure of some polycyclic aromatic hydrocarbons was measured by means of the effusion method. From the temperature dependence of the pressure, the heat of sublimation (ΔH kcal/mol) and the entropy (ΔS° cal/mol·deg) were calculated for the following hydrocarbons: 1,2-benzanthracene (ΔH=22.8; ΔS°=44.8), tetracene (29.8; 43.3), chrysene (28.1; 43.0), triphenylene (25.6; 33.9), 3,4-benzophenanthrene (25.4; –) p-terphenyl (28.3; 47.9), 1,12-benzperylene (30.0; 40.7), 3,4-benztetraphene (32.6; 45.9), 1,2,5,6-dibenzanthracene (33.9; 49.3), pentacene (37.7; 48.9), picene (33.5; 45.9), coronene (30.7; 36.9), 1,2,4,5-dibenzpyrene (32.9; 48.3), 1,2,6,7-dibenzpyrene (35.1; 45.6), 1,3,5-triphenylbenzene (34.0; 55.6), tetrabenzonaphthalene (33.9; 47.4), isoviolanthrene A (52.2; 54.6), violanthrene A (46.8; 48.1), violanthrene B (36.7; 38.0) and tetrabenzoperylene (28.2; 44.7). The small values of ΔH for violanthrene B, tetrabenzoperylene and tetrabenzonaphthalene may reflect the existence of the non-coplan...

Infrared Spectra and Molecular Vibrations of Ethylene Glycol and Deuterated Derivatives

Abstract: The infrared spectra of ethylene glycol and ethylene glycol-d2 have been measured in the liquid and crystalline states in the region 4000—300 cm−1. The infrared and Raman spectra suggest that ethylene glycol molecule takes only the gauche conformation as to the C-C bond in both states (the likely models are TGT, TGG and GGG). To establish the vibrationarassignments, the normal coordinate treatments of ethylene glycol and its three deuterated derivatives have been carried out for these models by the use of GF matrix method. The modified Urey-Bradley force field has been used and the force constants have been transferred from similar molecules. The potential energy distributions have also been calculated and the nature of the observed infrared bands and Raman lines in the liquid state has been discussed. The empirical assignments of the methylene rocking modes by the previous investigators have been revised by the present normal coordinate analyses.

Microwave Spectra and Equilibrium Structure of Carbonyl Sulfide

Abstract: Microwave spectra have been measured for various vibrationally excited states of the OCS molecule The l-type doubling constants obtained for the excited states of the bending vibration, ν2, have led to the determination of the zero-order coupling constant, qe It has been shown that the qe value thus obtained is useful for the evaluation of the harmonic force constants The Fermi resonances have been discussed; they lead to the conclusion that the effect due to the cubic constant, k223, cannot be ignored, nor can that due to k122 With due consideration for this situation, the equilibrium structure has been found to be:re(O–C)=11572±0002 A and re(C–S)=15606±0002 A

The Metal Ammine Cyanide Aromatics Clathrates. I. The Preparation and Stoichiometry of the Diamminemetal(II) Tetracyano-niccolate(II) Dibenzene and Dianiline

Abstract: Benzene and aniline clathrates of metal-complex host lattices with a general formula of M(II)(NH3)2Ni(CN)4·2G, in which M(II) was nickel, copper, or cadmium, and G, benzene or aniline as the guest molecule, were prepared. The stoichiometry was established through the analytical data and the structural information obtained from the powder X-ray diffractometric data. They are tetragonal with reasonable lattice parameters except for Cu(NH3)2Ni(CN)4·2C6H5NH2, which may be estimated to be orthorhombic or monoclinic. The host lattices of all the compounds have almost the same space character. The occupation of divalent metal M(II) at the octahedral site of the metal-complex host lattice was proved through the magnetic data.

Studies on the chemical constitution of agar-agar. XXIV. Isolation of a new disaccharide as a reversion product from acidic hydrolysate.

Abstract: The careful separation of the products of the complete hydrolysis of commercial agar on charcoal-Gelite columns has led to the isolation of a new reducing disaccharide, named “isoagarobiose,” in a yield of 1.5% of the agar sample. Its crystalline phenylosazone and crystalline hexa-acetate have also been prepared. On methanolysis the disaccharide gave methyl D-galactoside and 3, 6-anhydro-L-galactose dimethyl acetal. Complete methylation, followed by methanolysis, yielded 2, 4, 5-tri-O-methyl-3, 6-anhydro-L-galactose dimethyl acetal and methyl 2, 3-di-O-methyl D-galactoside. It follows from these results that the disaccharide has an unusual structure, in which the C1 of the 3, 6-anhydro-aldehydo-L-galactose residue is linked, through cyclic acetal linkages, with the C4 and C6 of the D-galactose residue. Evidence is provided that the disaccharide is not involved in the polysaccharide molecule, but has been formed by acid reversion from D-galactose and 3, 6-anhydro-L-galactose during the hydrolysis of the po...

Heat Capacities and Thermodynamic Properties of Ammonium Nitrate Crystal: Phase Transitions between Stable and Metastable Phases

Abstract: The heat capacities of ammonium nitrate were measured between 15 and 410°K for the stable and metastable phases by use of adiabatic- and conduction-type calorimeters. The phase transformations between stable phases; i.e., V–IV, IV–III, III–II and II–I, and the metastable one between IV and II, were all found to be of first-order type. The direct transition between V and II, which is only realized for the sample treated with a minute amount of surface active agent, was ascertained to be typical higher-order type. Heat and entropy of transition of five kinds of transitions were determined. These results conclude that the heat capacity data by Stephenson et al. at low temperature region are much more reliable than the recent values by Eichenauer et al. The possibility of the existence of the seventh phase below 156°K has been proposed.

Phosphorescence Bands of Quinones and α-Diketones

Abstract: Phosphorescence bands, their life times, and the excitation spectra of anthraquinone, α-naphthoquinone, phenanthrenequinone, acenaphthenequinone, benzophenone, benzil, furil, and camphorquinone at 77°K in a rigid solution and in the crystalline state have been studied. In a rigid solution the lifetimes of these phosphorescence bands are in the range (10–0.1 msec). The solvent effect on lifetimes shows clear differences between o- and p-quinones. The behavior of these phosphorescence bands is similar to that of the n→π* bands of these compounds. From these facts, these bands are all safely identified as π*→n bands. The phosphorescence bands of p-quinones in the crystalline state are at far longer wavelengths than those in a rigid solution, and the lifetimes of the former are far longer than those of the latter. The dichroism of excitation spectrum of the phosphorescence band of anthraquinone proved that the phosphorescence band is polarized perpendicularly to the 320 mμ band and parallel to the 270 mμ band.

The Solubility of Hydrogen Chloride in Volcanic Rock Melts at a Total Pressure of One Atmosphere and at Temperatures of 1200°C and 1290°C under Anhydrous Conditions

Abstract: The solubility of hydrogen chloride in volcanic rock melts was experimentally determined at temperatures of 1200°C and 1290°C with the variation in the partial pressure of hydrogen chloride mixed with nitrogen under one atmosphere. The solubility of hydrogen chloride decreases not only with a rise in the temperature, but also with an increase in the silica content of volcanic rock melts, while it increases with an increase in the partial pressure of hydrogen chloride. The equilibrated concentration of chlorine obtained by experiments was compared with those in natural basalts collected from Japan and Hawaii.

The Cyclization of Ethyl Acetoacetate and Ketones by Ammonium Acetate

Abstract: It was found that a cyclized product containing one nitrogen atom could be obtained by the reaction of ethyl cyanoacetate with various ketones in the presence of excessive ammonium acetate. On the basis of this experiment, pyridone derivatives such as 3-cyano-5,6-dihydro-4,6-dialkyl-6-methyl-2-pyridones (I), pyridine derivatives such as 3-cyano-4,6-dialkyl-2-hydroxypyridines (IV), quinoline derivatives such as 4-alkyl-3-cyano-2-hydroxy-5,6,7,8-tetrahydroquinolines (VII), and related heterocyclic compounds were prepared.

Kinetics of the Catalytic Decomposition of Methanol, Formaldehyde and Methyl Formate over a Copper-wire Surface

Abstract: In order to reveal the selective action of nickel and copper in the catalytic decomposition of methanol, kinetic studies of the decomposition of methanol, and methanol-d1 (CH3OD), and also of that of formaldehyde and methyl formate, both the assumed intermediates of the methanol decomposition, were undertaken over the temperature range between 100 and 330°C and the pressure range up to 30 mmHg. We also made studies of the exchange reaction of methanol, formaldehyde, or methyl formate with deuterium. The obtained rate equation for the methanol decomposition and the results on the deuterium exchange lead to the following conclusion: the rate is controlled by the unimolecular dehydrogenation of adsorbed methanol, which gives formaldehyde at first and finally hydrogen and carbon monoxide via a more stable intermediate, methyl formate. A comparison of activities between copper and nickel was made on the basis of the different behavior of formaldehyde on these catalyst surfaces. The nature of the catalyst surfa...

Internal Rotation of Propane from the Microwave Spectrum

Abstract: The microwave spectrum of propane was observed in the first-excited states of the CH3torsion. Each transition was split into a symmetric triplet; the splittings were 14–19% larger for the (−) state than for the (+) state. The top-top interaction and its effect on the rotational spectra were treated by the perturbation theory, and the results were applied to the analysis of the triplet splittings. The two barrier parameters, V3 and V3″, were thus determined to be 3325±20 and −170±30 cal/mol respectively.

Theoretical Calculation of Fluorescent X-Ray Intensities of Nickel-Iron-Chromium Ternary Alloys

Abstract: The fluorescent X-ray intensities of nickel-iron-chromium alloys which cover the entire range of the system are obtained by theoretical calculation. The calculated results show that the iron fluorescent X-ray intensity is much affected by the amount of the other elements, while the nickel and chromium fluorescent X-ray intensities are less affected. The calculated results agree with the experimental results; their difference is less than 1%. In the calculations, the intensities of the primary, the secondary, and the tertiary fluorescent X-rays are obtained, where the primary fluorescent X-rays are defined as being excited by incident X-rays only; the secondary fluorescent X-rays as excited by the primary, and the tertiary fluorescent X-rays, as excited by the secondary fluorescent X-rays. The calculated results show that the secondary fluorescent X-rays are significant, but the tertiary fluorescent X-rays form only a small percentage of the total fluorescent X-rays at most.

Studies of Poly-β-benzyl-L-aspartate Helix. III. Infrared Spectra of Copolymers of β-Benzyl-L-aspartate with β-p-Methyl, Chloro, Cyano, or Nitrobenzyl-L-aspartate in a Chloroform Solution

Abstract: Infrared studies of the copolymers in a chloroform solution have revealed that, in each series of copolymers, the transition from the left- to the right-handed α-helix simultaneously brings about sharp changes in the characteristic amide frequencies. The frequencies of the NH-stretching, amide I, and amide II bands of the copolymers in the left-handed α-helix are higher by ca. 13 cm−1, ca. 10 cm−1, and ca. 5 cm−1 respectively than those in the right-handed α-helix. The amide bands of the copolymers in the right-handed form lie in the normal frequency ranges as established for α-helical polypeptides. On the contrary, the amide frequencies of poly-β-benzyl-L-aspartate or the copolymers in the left-handed form are anomalous. The anomalous amide frequencies of the lefthanded helix are to be ascribed to the reversal in the helical sense, but not to the particular aspartate group, since the copolyaspartate esters in the right-handed helix exhibit normal amide frequencies. The transition in the helical sense is ...