By means of the cell method and using the Sutherland type potential function for pair interactions between molecules, a statistical theory was formulated for binary liquid mixtures consisting of rigid spherical molecules differing in size. A formula was derived for cohesive energy as a function of the volume of liquid, and studied in combination with the radial distribution function. The applicability of the square-well type potential function within a cell was also examined. Formulas for excess thermodynamic functions were derived and their applicability investigated. For 22 binary systems consisting of nearly spherical molecules, excess thermodynamic functions were calculated and compared with data in literature. The results show that the theory is applicable to the mixtures.
The phosphorescence spectrum of quinoxaline doped in durene crystal is observed at 4.2°K. The spectrum is composed of a number of sharp bands, many of which being interpreted as arising from the coupling with the ground state molecular vibrations of quinoxaline. Associated with the 0,0 and vibronic bands three weak bands were observed which are separated from the vibronic band by 19, 30 and 52 cm−1. The nature of these three bands is not well understood, but it is certain that they are not due to the lattice vibrations of the durene host. The decay of the phosphorescence is investigated at fifteen different temperatures between 4.21 and 1.59°K. Above 2.41°K the decay is single exponential with a lifetime of 0.246 sec. Below 2.19°K, however, the decay is expressed as a sum of two exponential decays whose lifetimes are 0.757 and 0.093 sec. The shorter one is approximately one third of the lifetime at 4.21°K. The change of the decay characteristics at a temperature between 2.19 and 2.41°K is interpreted to be associated with the spin alignment. In terms of these data, together with the polarization ratio observed by Chaudhuri and El-Sayed, radiative and radiationless rate constants are estimated for each of the three magnetic subcomponents of the triplet state. The experimental results and their interpretation are partly in disagreement with the work by de Groot, Hesselmann and van der Waals, and the source of the discrepancy is analyzed.
By infrared studies it has been ascertained that trans-2-halocyclohexanols possess two conformers, namely, the ee-isomer and the aa-isomer, both in the liquid and in a solution, while only the eeisomer exists in the solid. In a dilute solution the ee-isomer is more stable and exists exclusively in the form with an intramolecular hydrogen bond. The values of the energy difference between the two isomers are 1.3, 1.9, and 2.2 kcal/mol for the chloro-, the bromo-, and the iodo-derivative respectively. The magnitude of the frequency shifts of the O–H stretching bands increases in the order: Cl<Br<I. These facts show that the intramolecular hydrogen bond stabilizes the ee-isomer and that the strength of the hydrogen bond increases in the order: Cl<Br<I. The electrostatic energy increases in the order: Cl>Br>I, while the delocalization energy due to the chargetransfer increases in the opposite order. Therefore, it can be concluded that the energy due to the charge-transfer contributes dominantly to the energy of the intramolecular hydrogen bond formed in the ee-isomer of trans-2-halocyclohexanols.
For the purpose of investigating the correlation between the crystal structure of titanium dioxide and its catalytic activity, the catalytic oxidation rate of carbon monoxide and the desorption rate of oxygen from the sample surface have been measured on anatase, rutile, and an anatase-rutile mixture. The oxidation of carbon monoxide was investigated by a static method at temperatures of 250–550°C and under gas pressures of 10−2–150 mmHg. The desorption of oxygen was carried out at 600–750°C. The reaction rate was proportional to PCO and did not depend on either PCO2 or PCO2 The activation energy was 16.0 kcal/mol for anatase and 6.7 kcal/mol for rutile. The catalytic activity per unit of the surface area of rutile was 3—6 times as much as that of anatase. The reaction rate almost coincided with the rate of the reduction of titanium dioxide by carbon monoxide. The electric resistance of the sample was little affected by the PO2. The following reaction mechanism is proposed to explain the results. The rate-determining step is the reaction between the surface oxygen of the sample and the carbon monoxide physisorbed or that which has just collided with the surface coming from the gas phase; the oxygen vacancy thus formed on the surface is quickly filled with oxygen of the gas phase. The difference in the activation energy of the catalytic action between the two structures is based upon the difference in the activation energy of the oxygen desorption from the surface structure; the activation energies are 57.8 kcal/mol for anatase and 38.4 kcal/mol for rutile.
Enzyme catalyzed hydrolysis of maltodextrin was studied with enzyme-maltodextrin and enzyme-maltodextrin-sodium dodecylsulfate systems. Sodium dodecylsulfate (SDS) is a complex forming agent for maltodextrin. When endo-enzyme such as Taka-amylase A was used as the enzyme, ratio of the initial velocity of the hydrolysis of the system containing SDS to that without SDS decreases with the increase of degree of polymerization (D.P.) of the maltodextrin and becomes zero with the maltodextrin of D.P. above about 60. When the liquefying α-amylase of Bacillus subtilis was used as an endo-enzyme, a similar result was also obtained. When exo-enzyme such as Glucoamylase of Rh. Delemar was used, the ratio decreases gradually with the increase of D.P. of maltodextrin, and remains in a relatively high level even in the case of maltodextrin of D.P. above 60. In the case of Taka-amylase A, the enzyme action is suppressed by the presence of the stiff helical segments of SDS complex and the initial velocity of the system with SDS decreases compared with the one without SDS. In the case of Glucoamylase, the presence of the stiff helical segment does not distinctively induce such a depression of the enzyme action as that in the case of Taka-amylase A. The depression is partly dependent on the inhibitory interaction of SDS with the enzyme.
The Monte Carlo method is employed on a high-speed digital computer in order to generate non-intersecting random chains simulating polymer molecules. For this purpose the GT-model of polyethylene is used. Suitable potential functions are used to calculate the energy and the probability of each chain conformation thus generated. The nonbonded-interaction energy is calculated by the Lennard-Jones “6–12” potential function. The average dimensions are then calculated by using this energy. It is suggested that the hydrogen atoms contribute largely to the statistical properties of the ethylene polymers.
The π-electron structures of several unsaturated molecules containing hetero-atoms were studied by SCFMO-CI scheme employing the Pariser-Parr-Pople method, special attention being paid to the effect of doubly excited configurations upon calculated transition energies, transition moments and π-electron distributions in the ground and lower excited states. The transition energies and oscillator strengths calculated for pyridine, phenol, aniline, pyrrole and furan were compared with their experimental values. Consequently, the inclusion of doubly excited configurations was found to improve the coincidence between the theoretical and observed values and to remove some difficulties in the application of the Pariser-Parr-Pople method to molecules containing hetero-atoms. One-center integrals WP and γPP for hetero-atoms were taken as parameters in the calculations of phenol and aniline. Their fittest values were determined reasonably to be WN=−24.71, Wo=−30.08, γNN=13.75, and γOO=16.78 eV.
The effect of carbon tetrachloride on the radiolysis of isobutane and methylcyclohexane at 77°K is studied by ESR spectroscopy and by product analysis. The yields of solvent radicals from the γ-irradiation of isobutane and methylcyclohexane are not changed by the presence of conventional electron scavengers. This indicates that solvent radicals are not formed by the neutralization of solvent cations with electrons. On the contrary, the yields of solvent radicals decrease remarkably upon the addition of CCl4. Though the yield of propylene from the γ-irradiation of isobutane is not affected by the addition of electron scavengers, it decreases significantly upon the addition of CCl4. Though the decrease in the hydrogen yield in the radiolysis of methylcyclohexane at 77°K upon the addition of electron scavengers is only about 1G-unit, it amounts to more than 3.5G-units upon the addition of CCl4. These characteristic effects of CCl4 can possibly be explained in terms of excitation transfer from the excited solvent molecule to CCl4. A kinetic treatment suggests that its mechanism may be an exciton transfer.
The dependence of the g factors of p-benzosemiquinone and its tetrahalogenated derivatives on the solvent composition has been studied in the dimethyl sulfoxide-water system. When the water content of the solvent increases, the g factor of p-benzosemiquinone decreases, that of tetrachloro-p-benzosemiquinone scarcely changes, and the g factors of tetrabromo- and tetraiodo-p-benzosemiquinones increase. These phenomena are interpreted qualitatively by assuming that the water molecule solvates to the carbonyl oxygen atom of semiquinones and by using Stoned equation for the g factor of the polyatomic radical. The dependence of the g factor of p-benzosemiquinone on the solvent composition is quantitatively studied by means of the theory of solvent effects proposed by Gendell, Freed and Fraenkel and by using the 2-site model of Stone and Maki and also the 4-site model. The former model assumes that one carbonyl oxygen atom has one site occupied by a solvent molecule, thus resulting in a dominant g shift. In the later model, two solvent molecules interact with one carbonyl oxygen atom. Both models predict the same relation between the g shift and the solvent composition; this experiment cannot confirm which model is more adequate, although the deduced values of the equilibrium constants indicate that the 4-site model is preferable.
An idealized one-dimensional model of a conduction calorimeter, composed of a container in which thermal change occurs, a thermal bath, and a solid thermal conductor connecting the container with the thermal bath, is presented. The boundary-value problem of heat conduction in the model calorimeter is solved by the Laplace transformation method. A proportionality relation between the quantity of heat evolved in the calorimeter container and the area enclosed by the recorded temperature curve and the time axis is establised.
An ideal three-dimensional model of a conduction calorimeter is presented. In the model, the heat transfer takes place only by conduction. The proportionality relation between the quantity of heat and the area enclosed by the recorded temperature curve and the time axis is proved under several sets of ideal conditions under which the proportionality relation is valid are examined, and thermal compensation is recommended for more precise measurements of heat and for convenience in obtaining thermogenesis curves.
The density of the binary B2O3-H2O liquid system with concentrations of from 4.9 to 83.0 mol% B2O3 has been measured, and the mean volume expansivity has been calculated. The molar volume and the expansivity of this system has then been compared with those of other binary borates. The experimental results suggest a change in the boron-to-oxygen coordination number between the 3B2O3·H2O and B2O3·H2O compositions. The thermal expansivity of this system shows a different trend from those of alkali borate melts.
The crystal structure of bis(2-hydroxyethyliminosalicylaldehydato)copper(II) has been determined by means of an X-ray diffraction study of a single-crystal specimen. Four formula units are contained in the monoclinic unit cell, the P21⁄c space group, with lattice parameters of: a=18.41 A, b=4.82 Å, c=19.86 Å, and β=99.1° (Dm=1.50 g·cm−3; Dx=1.50 g·cm−3). The structure has been refined, by means of three-dimensional difference syntheses and the least-squares method, to R=0.095. It has been confirmed that copper(II) links to the 2-hydroxyethyliminopyruvate anion through the phenolic oxygen and the nitrogen of the Schiff base linkage, while the alcoholic oxygen in the ethanol-amine moiety is free from coordination. The two Schiff-base ligands are coordinated around copper(II) in the trans-configuration. All the bond distances and angles in the complex are within the range of normal values. The N-Cu-O angles (91.3 and 91.8°) in the chelate rings are close to a right angle, showing that there is less strain in the chelate structure than in the case of a similar chelate of the pyruvate Schiff base (84.6°).
The zero-point average structure of acetone has been determined from the moments of inertia obtained by means of microwave spectroscopy by Nelson and Pierce, as incorporated with the average distances from gas-electron diffraction by Kato et al. In addition to the normal species (CH3)2CO, three isotopically-substituted species, (13CH3)2CO, (CH3)2C18O, and (CD3)2CO, have been used in the analysis. The following values of the rz-parameters have been determined: C=O, 1.2122±0.0025 Å; C–C, 1.5190±0.0008 Å; C–H, 1.0614±0.0010 Å; ∠HCH, 108°30′±6′; and ∠CCC, 116°9′±10′ (∠CCC for (CD3)2CO, 115°51′±10′). The slightly smaller value of ∠CCC found for the deuterated species has been reasonably attributed to the anharmonicity associated with the symmetric rocking motion of the two methyl tops. The equilibrium values for C-H(D) and ∠CCC have also been estimated to be 1.078 Å and 115°0′ respectively.
The visible absorption spectra were observed on bis(8-quinolinolato)nickel(II) in molten 8-quinolinol as well as in other solvent systems such as molten naphthalene, molten β-methoxynaphthalene or toluene containing various amounts of 8-quinolinol at 80°C. Little interaction was found between the solute and naphthalene or toluene. However, a weak interaction was observed between the solute and β-methoxynaphthalene or 8-quinolinol. The extent of interaction between the solute and 8-quinolinol in toluene was evaluated spectrophotometrically.
With a 14MeV neutrol generator the optimum irradiation position of disk or square samples of appropriate numbers are given as a function of the configuration of the sample relative to the source. Calculated values are compared with experimental data.
The following cobalt (III) complexes containing nitrilotriacetic acid (NTA), nitrolopropionicdiacetic acid (NPDA) and nitriloisopropionicdiacetic acid (NIPDA) were prepared: (NH4)3[Co-(nta)2]·2H2O (pink) (I), NH4[Co(Hnta)2]·2H2O (pale pink) (II), K3[Co(npda)2]·2H2O (pink) (III), K[Co(Hnpda)2]·3H2O (pale pink) (IV), [Co(npda)(o-phen)]·H2O (reddish violet) (V), [Co-(npda)(bipy)] (reddish violet) (VI), K[Co(OH)(nipda) (H2O)]·H2O (bluish violet) (VII) and [Co-(nipda) (o-phen)] (reddish violet) (VIII); where nta, npda, nipda, o-phen and bipy are the abbreviations of nitrilotriacetate-, nitrilopropionicdiacetate-, nitriloisopropionicdiacetate-ion, o-phenanthroline and 2,2′-bipyridyl, respectively. On the basis of electronic spectra, it was found that complexes I to IV have the trans form, while complexes V, VI and VIII have the mer form structure with respect to the nitrogen atoms in the coordinating ligands. Complex VII showed a dehydrationdimerization reaction on heating by “Derivatograph”. Comparison of chemical and physical properties of the complexes with those of the corresponding chromium (III) complexes was made.
We have prepared a variety of binuclear and trinuclear complexes of the composition Cu-(TDSB)·MX2 and 2Cu(TDSB)·M(ClO4)2, where Cu(TDSB)=N,N′-ethylenebis(salicylideneiminato)copper(II) or N,N′-1,2-propylenebis(salicylideneiminato)copper(II), and M=Co, Ni, Cu and Zn. A few higher polynuclear species were also prepared. The previously reported empirical rule found in binuclear copper(II) complexes, where the two copper ions are in the same environment, that the “higher energies of d-d bands - lower magnetic moments,” was proved to hold in the binuclear copper complexes of the present study, even though the two copper ions are in different environments. For a series of complexes with M = Cu or other metals, and with X = NO3 or ClO4, it was observed that “d-d bands of Cu(TDSB) apperas at the shortest wavelengths when M = Cu.” For perchlorate complexes, the energy of the d-d band is in the order, Co<Ni<Cu>Zn, the same as the Irving and Williams’ order of complex stability. It can then be generalized that in a hetero-polynuclear complex molecule, the strengthening of the coordinate bonds around one metal ion strengthens the coordinate bonds around the other metal ion or ions.
Three representative copper(II) β-diketone chelate complexes, bis-(ethylacetoacetato)copper-(II), bis-(salicylaldehydato)copper(II), and bis-(acetylacetonato)copper(II), have been investigated by the ESR method in order to estimate their structures in various solvents. The super-hyperfine structures due to the equal coupling of the unpaired electron with two nitrogen atoms were clearly observed for the first two complexes dissolved in pyridine or γ-picoline. The structures of these two complexes in pyridine or γ-picoline could be estimated to be as follows; a new square-planar coordination occurs through two nitrogen atoms of these basic solvent molecules and two oxygen atoms of the four originally-coordinating ligand oxygen atoms, and the other oxygen atoms are coordinated as apical ligand atoms with less strength. On the other hand, the ESR spectra of the latter complex dissolved in pyridine or γ-picoline show a significantly strong ligand field only in the axis normal to the molecular plane; this indicates that the coordination of the basic solvent molecules along the axis normal to the molecular plane occurs.
The internal-reference method proposed previously has been applied to the photon-activation analysis of niobium using molybdenum as the reference element. For the determination of niobium, 92mNb produced by the (γ,n) reaction was utilized and 95mNb or 96Nb activities coming from molybdenum by the (γ,p) processes were used as reference. A series of molybdenum and niobium mixtures with known compositions were irradiated by bremsstrahlung photons with a maximum energy of 17 MeV for an hour. After niobium activities were separated chemically, their γ-ray spectra were measured with a lithium-drifted germanium detector. A good proportionality was obtained between the activity ratio, RA0, and the weight ratio, RW. Niobium down to 5μg can be determined with a relative error within ±3% under the present experimental conditions.
Some new metal chelate compounds of ethanediylidenetetrathiotetraacetic acid (H4ETTA), Co2L·5H2O, Cu2L·4H2O, Zn2L·3H2O, Ni2L·6H2O, and FeHL·3.5H2O, where H4L is H4ETTA, were obtained. The infrared spectra and other properties of these compounds were compared with those of the metal complexes of other thioglycolic acid derivatives, some of which are also new compounds. Judging from the wave numbers of the stretching bands, the carboxyl group of these complexes can be said to be rather ionic. Though the bond is not very strong, thioglycolic acid derivatives seem to bond with the central metal ion with both the sulfur atom and the carboxyl group.
The thermal decomposition of tetrakispyridineiron(II) chloride, tetrakis(γ-picoline)iron(II) chloride, and tetrakispyridineiron(II) isothiocyanate has been studied in nitrogen. These complexes presumably decompose in the following sequences: Fe(py)4Cl2 → Fe(py)2Cl2 → Fe(py)Cl2 → Fe(py)2⁄3Cl2 → FeCl2, Fe(γ-pic)4Cl2 → Fe(γ-pic)Cl2 → FeCl2 and Fe(py)4(NCS)2 → Fe(py)2(NCS)2 → Fe(NCS)2. The Mössbauer spectra of these complexes and of their decomposition products have been studied in terms of the structural change about the iron atom during the thermal decomposition process.
The hydrolysis equilibria of the UO22+ ion in heavy water containing 3M NaClO4 as an ionic medium were studied at 25°C by potentiometric titrations, employing a technique of constant-current coulometry. The deuterium-ion concentration was measured by means of a glass electrode. The most probable hydrolysis scheme chosen in the range of the total uranyl concentration from 1 to 10mM was: (UO2)2(OD)22+−(UO2)3(OD)42+−(UO2)3(OD)5+; the respective stability constants were −log β2,2=6.80±0.02, −log β4,3=14.00±0.07, and −log β5,3=18.63±0.02. The above results reveal that the composition of the hydrolysis species in heavy water are generally the same as those in light water, while the values of the stability constants are smaller in heavy water than in light water.
The absorption and circular dichroism (CD) spectra of twelve optically active chromium (III) complexes containing three bidentate ligands have been measured in the near-infrared to ultraviolet region. CD spectra in the spin-forbidden d-d absorption band region have been considered mainly in relation to the CD bands in the first spin-allowed d-d absorption band region. It has been concluded that the absolute configurations of chromium (III) complexes can be determined on the basis of the signs of the CD bands in the spin-forbidden band region. The splitting components of the CD bands in the spin-forbidden band region have been discussed considering the crystal field treatment by Macfarlane.
Catalytic hydrolysis of p-acetoxybenzoic acid by 1-[4(5)-imidazolyl]-4-aminomethylnaphthalene was carried out at 30°C in aqueous systems using a pH-stat. The catalytic rate leveled off at high substrate concentrations and increased remarkably at high pH. The data indicated that both the neutral catalytic species (AmIm) and the monoprotonated catalytic species (Am+Im) acted as enzyme-like catalysts, the catalytic rate conforming to the Michaelis-Menten kinetics, although their catalytic efficiencies were quite different: Km (dissociation constant of the catalyst-substrate complex)=0.011M and k3 (pseudo-intramolecular rate constant of the product-formation)=0.19 min−1 for AmIm, and Km=0.041M and k3=0.036 min−1 for Am+Im. The binding function was attributed to hydrophobic interaction, on the ground that Km was smaller for AmIm than for Am+Im and that an increase in the ionic strength of the medium caused rate enhancement. The hydrolysate showed an inhibitory action. The wide variation of the catalytic efficiency between AmIm and Am+Im may be related to the structural difference of the Michaelis complexes. 1-Aminomethylnaphthalene similarly catalyzed the hydrolysis and showed a substrate binding phenomenon, though the saturation phenomenon was much less pronounced as compared with the imidazole catalyst.
Photochemically-induced hydrogen shifts in 7-(p-chlorophenyl), 7-phenyl, 7-(p-methoxyphenyl) and 7-p-tolylcycloheptatrienes (Ia—d) were studied. The possibility of hydrogen 1,7 and 1,3 shifts in these compounds was examined on both experimental and theoretical grounds. It was concluded that the hydrogen 1,7 shift is the only suprafacial hydrogen shift possible in the excited cycloheptatriene system. In this study all the isomers of p-chlorophenylcycloheptatriene were separated by applying the Diels-Alder reaction to the photo-reaction mixture; the method of preparing each of those isomers will also be described.
Telomerization of vinyl chloride with carbon tetrachloride was investigated in reaction systems containing amines and cupric chloride. The yield of telomers CCl3(CH2CHCl)nCl and the content of the telomer with n=1 were high when aliphatic amines with relatively long chains were used. An increase in basicity of amines raised the yield of telomers. When bifunctional amines such as diamines and alkanolamines were used, the yield of telomers was low and the content of higher telomers was high. The effect of added solvents on the yield of telomers was not so remarkable and an increase in the dielectric constant of solvents decreased the yields. The results were examined on the basis of Asscher-Vofsi mechanism, but could not be explained satisfactorily. A partly modified scheme was proposed for the radical addition in the cage complex stabilized with amine.
Benzenediazonium tetrafluoroborate in DMSO decomposed instantaneously with evolution of nitrogen upon addition of a DMSO solution of sodium nitrite. Orientations and partial rate factors for phenylation of substituted benzenes indicated that not phenyl cation but phenyl radical was produced as an intermediate. Hammett’s plots of partial rate factors of meta and para positions yielded good straight lines with ρm=0.46 and ρp=1.67. Plausible mechanisms were discussed. From m-dinitrobenzene 2,6- and 2,4-dinitrobiphenyl were produced in 47 and 23% yields, respectively, and the synthetic value of this method was pointed out.
The reactions of carbon suboxide with aromatic amines were found to give various 4-hydroxycarbostyril derivatives. The reaction between aniline and carbon suboxide usually gives malonanilide. However, it was found that the reaction of aniline with carbon suboxide in ether in the presence of aluminum chloride produced phenylcarbamoylacetic acid in a good yield and that cyclization to 4-hydroxycarbostyril occurred when the solvent was replaced by benzene before the decomposition of the reaction mixture with water. The solvent effect on the formation of 4-hydroxycarbostyrils and the possible reaction mechanism were discussed.
The CD and ORD of D-phenylglycine and L-phenylalanine were measured at various pH’s. The superficial small pH dependence of the CD maximum around 220 mμ and the anomalous large [θ] value at the CD maximum in both aromatic amino acids suggest an interaction between the 1La transition of the benzene ring and the n→π* transition of the carboxyl group. The ORD and CD of L-α-amino-β-benzalpropionic acid, L-α-amino-β-benzylpropionic acid, and L-2-amino-4-phenyl-butanol-1 were also measured, and the screening effect of the methylene groups which exist between a benzene ring and an asymmetric carbon atom was discussed.
Several 1′- and 2-substituted 1-methylferrocenes were prepared, and their NMR spectra were measured. From the consideration of the chemical shifts, the transmission coefficient of the electronic effect through the ferrocene nucleus was calculated to be 0.28. 1′-Substituted 1-acetylferrocenes were also prepared, and their NMR spectra were discussed in connection with those of methylferrocenes.
Olefin-palladium(II) chloride complexes reacted with n-butylamine to form Schiff’s bases. N-Ethylidene-n-butylamine was obtained by the reaction of the ethylene complex with n-butylamine, accompanied by reduction of palladium(II) to the metal. A tris(n-butylamine)palladium chloride complex was formed simultaneously by ligand substitution reaction. The yield of N-ethylidene n-butylamine was 15–19mol% (calcd on palladium) in 2.5 hr at 25°C, and decreased at temperatures higher than 60 °C with increasing reduction of palladium(II), owing to conversion of N-ethylidene-n-butylamine into either N-crotylidene-n-butylamine or a tarry polymeric substance by aldol type condensation reaction. The n-butylamine-palladium(II) chloride complex did not react with ethylene at 25°C, but reacted with ethylene at 150°C to form a large amount of tarry polymer and a small amounts of N-ethylidene-n-butylamine and N-crotylidene-n-butylamine. The propylene complex and the cyclohexene complex reacted with n-butylamine to yield both 2- and 1-N-propylidene n-butylamine, and N-cyclohexylidene-n-butylamine respectively. The yield of Schiff’s bases from olefin complex decreased in the order, ethylene>propylene>>cyclohexene.
In order to investigate the oxidation reaction which is catalyzed by transition metal complexes in a homogeneous system under mild conditions, the oxidation reactions of styrene and triphenylphosphine catalyzed by various iridium complexes have been studied. The Vaska complex (IrX(CO)(PPh3)2) and the biphosphine chelate complex have been found to be effective as oxidation catalyst. It was found that the SnCl3 ligand which has a strong trans effect promotes the oxidation of styrene. For the sake of comparison with the iridium compounds, oxidation with palladium salts was also studied.
dl-Dihydroanisoin bis-m-bromobenzoate produced from the reaction between p,p′-dimethoxy-trans-stilbene and m,m′-dibromobenzoyl peroxide labeled with oxygen-18 at the carbonyl oxygen was found to possess completely equilibrated oxygens, and this finding indicated that a four-centerd mechanism was unlikely.
Disubstituted aminotriphenylphosphonium bromides were obtained in excellent yields from the reaction of triphenylphosphine dibromide and the secondary amines using simple procedures. This method has an advantage in the preparation of cyclic aminophosphonium salts, such as those of morpholine or piperidine. The treatment of the disubstituted aminophosphonium salt with bases resulted in dehydrohalogenation, followed by a Hofmann-like decomposition, and gave imine and triphenylphosphine.
The synthesis is described of an octadecapeptide amide, β-alanyl-tyrosyl-seryl-methionyl-glutamylhistidyl-phenylalanyl-arginyl-tryptophyl-glycyl-lysyl-prolyl-valyl-glycyl-lysyl-lysyl-arginyl-arginine amide, corresponding to the first eighteen amino acid residues of corticotropin except for the amino end which has been substituted by a β-alanine for the serine in native hormone. The adrenalstimulating activities of the octadecapeptide amide are compared with those of the corresponding 1-serine or 1-glycine octadecapeptide amide to show that the 1-β-alanine peptide is remarkably more active than the latter when assayed by in vitro, subcutaneous and intamuscular approaches, and that the activities of the former are maintained for a longer period of time than those of the latter. The 1-β-alanine peptide as a lipotropic agent is also shown to be more active than the synthetic analogs and a native corticotropin on rat adipose tissue. The differences among these octadecapeptide analogs in the biological properties are discussed in terms of their susceptibility toward the action of aminopeptidase.
The ppt-metal-catalyzed reduction, which is performed by refluxing the substrates with water in the presence of ppt-metals, was investigated in detail. The participation of water as a hydrogen donor was demonstrated by the fact that benzaldehyde was reduced to the corresponding deuterated alcohols when heated with D2O in the presence of ppt-Ni. The scope of the reduction was established by the reaction of cyclohexanone with ppt-metals and water. The most preferable H2O/cyclohexanone molar ratio was found to be about 15 : 1. The reaction was accelerated when a 0.25N aqueous solution of sodium chloride was used instead of water. It was found that the order of the abilities of various ppt-metals to decompose water is different from that of the abilities to catalyze the reduction of cyclohexanone. The values of the activation energies for the reduction catalyzed by ppt-Ni and ppt-Ni,Co were found to be 4.0 kcal/mol and 7.5 kcal/mol respectively. From these facts, it was concluded that the ppt-metal-catalyzed reduction consists of two steps: the reaction of water with zinc or zinc compounds to supply a hydrogen source necessary for the hydrogenation, followed by ordinary catalytic hydrogenation.
The kinetics of the photosensitized decomposition of deoxyguanosine with methylene blue was studied by means of spectrophotometric measurements. The reaction rate increased with an increase in the concentration of the reactant or of oxygen up to a saturation level for each case at a given concentration of the dye. In a buffer solution of a lower phosphate concentration, a larger rate was observed. On the basis of these dependencies of the rate, the reaction scheme was discussed, and the ratios of some rate constants were estimated based on Schenck’s mechanism. A preliminary NMR measurement of the protons of deoxyguanylic acid in D2O suggested that the basepart of the nucleotide was specifically attacked by this photosensitized reaction.
The Baudisch reaction was applied to 1- and 2-naphthols, and 2-nitroso-1-naphthol was obtained as the sole product in both reactions. In a reinvestigation of the products obtained from phenols, it was also found that in some cases the nitroso group replaced the hydroxy group and a hydroxy group was newly introduced into the position ortho to the nitroso group. These results indicate that a copper(II)-hydroxylamine-catechol complex will be a possible intermediate of the reaction of phenol. The product studies on the reaction of catechols support the assumption. Kinetically, the formation of the complex seems to be the rate-determining step in the reaction of phenols.
The reaction of β-amino alcohols with triphenylphosphine dibromide was found to give the corresponding aziridines in good yields. The reaction opened a new route to the synthesis of aziridine compounds which seems to be more convenient than the Gabriel and Wenker methods. In the ring closure of ephedrine, a Walden inversion was observed. A possible mechanism is suggested.
Aluminum chloride-catalyzed rearrangement of aryl sulfides leads to thermodynamically controlled equilibrium mixtures at room temperature. On treatment of o-, m- or p-tolyl phenyl sulfide without solvent, the isomer distribution converges to an equilibrium point, 17% ortho, 47% meta and 36% para isomer by intramolecular isomerization. Intermolecular disproportionation by methyl-group exchange to produce diphenyl sulfide and ditolyl sulfide accompanied isomerization. In addition, a new type of aromatic rearrangement, intermolecular disproportionation by exchange of the arylthio group, was found to occur simultaneously giving benzene, toluene and thianthrene derivatives. The rate of this reaction is slower than that of the methyl rearrangement. A similar treatment of α-naphthyl phenyl sulfide gave the β-isomer from intramolecular isomerization and diphenyl sulfide, naphthalene, thianthrene and benzene from intermolecular disproportionation. The mechanisms of the rearrangement of aryl sulfides are discussed.
5,5′-β-alanine-gramicidin S having a larger ring size by two methylene groups than that of gramicidin S was synthesized to investigate the contribution of the ring size of gramicidin S to antibacterial activity. Cyclization of a protected linear decapeptide active ester in pyridine gave the protected 5,5′-β-alanine-gramicidin S in a good yield. The product obtained after the cyclization of a protected linear pentapeptide active ester consisted of the protected 5-β-alanine-cyclosemi and 5,5′-β-alanine-gramicidin S. Pure compounds were obtained by column chromatographic separation of Sephadex LH-20. Hydrogenolysis of these protected cyclic peptides in the presence of hydrogen chloride afforded crystalline hydrochlorides of cyclic deca- and pentapeptide. These hydrochlorides exhibited no antibacterial activity against any of the microorganisms tested. Optical rotatory dispersion measurements of these peptides were also carried out.
In order to investigate the contribution to antibacterial activity of the leucine residues at 3- and 3′-position in gramicidin S, 3,3′-glycine- and 3,3′-L-alanine-gramicidin S (XII-G and XII-A) were prepared and tested for antibacterial properties. A crude product obtained after cyclization of a linear pentapeptide active ester consisted of a protected monomer and a dimer. The pure protected dimer was obtained by a Sephadex LH-20 column from the crude product. Hydrogenolysis of the pure protected dimer afforded the crystalline hydrochloride of XII-G or XII-A. It was found that XII-G showed no activity in any of the microorganisms tested, whereas XII-A exhibited substantial activity though weaker than that of gramicidin S.
The graft copolymerization of 3-O-methacryloyl 1,2; 5,6-diisopropylidene-α-D-glucofuranose (MDG) onto polypropylene fibers was carried out by the γ-ray pre-irradiation technique in the presence of oxygen. The isopropylidene groups of the glucose residue grafted on the copolymer were removed by hydrolysis in aqueous formic acid, and the hydroxyl and hemiacetal groups were regenerated. The deacetonated fibers exhibited a considerable affinity for water vapor and could be dyed with a reactive dye.
The reduction of a number of tosylated, mesylated, sometimes further-benzoylated derivatives of methyl 4,6-O-benzylidene-α-D-glucopyranoside (I) with lithium aluminum hydride in tetra-hydrofuran has been investigated; it has thus been found that methyl 4,6-O-benzylidene-2,3-di-O-tosyl-α-D-glucopyranoside (II) gave methyl 4,6-O-benzylidene-3-deoxy-α-D-ribo-hexopyranoside (III, major), methyl 4,6-O-benzylidene-2-deoxy-α-D-arabino-hexopyranoside (IV, minor), and methyl 4,6-O-benzylidene-2-deoxy-α-D-ribo-hexopyranoside (V, minor) as deoxy derivatives through two kinds of monotosyl derivatives (VIII and X), and that methyl 2-O-benzoyl-4,6-O-benzylidene-3-O-tosyl-ribo-D-glucopyranoside (VII) and methyl 3-O-benzoyl-4,6-O-benzylidene-2-O-tosyl-α-D-glucopyranoside (IX) gave VIII and X respectively, as intermediates. 2-O-Methyl-3-O-tosyl (XI) and 2-deoxy-3-O-tosyl derivatives (XIII) gave detosylated derivatives, (XII) and (IV) respectively. These and other results suggest, for detosyloxylation, a mechanism through the formation of an alkoxy-aluminum hydride.
In the proton magnetic resonance spectrum of octa-O-acetylsucrose, an individual acetoxy group signal was assigned by direct comparisons of the spectra of specifically deuterated octa-O-acetylsucroses and that of nondeuterated one. The structures of 2,3,6,3′,4′-penta-O-acetylsucrose and 2,3,4,3′,4′-penta-O-acetylsucrose were further confirmed definitively by the present studies.
It was found that thioethers reacted with sulfenyl chlorides to give four kinds of products. When the alkyl part of the thioether is capable of producing a rather stable carbonium ion, the thioether gives the chloride and an olefin, which are derived from the cation, the latter reacting also with the sulfenyl chloride to give adducts. There is another path to afford alkyl chloride; that is, an SN2-type reaction takes place when the alkyl part gives a less stable carbonium ion. The third and fourth products are α-chloro sulfide and α,β-unsaturated sulfide, which are seemingly produced via a common intermediate. The latter may react further with the sulfenyl chloride to give enedithiol derivatives.
The rates of the reaction of methyl α-phenethyl sulfide with benzenesulfenyl chloride were measured by means of product analyses. It was found that the reaction was general-acid-catalyzed and autocatalyzed. The rate-determining step was suggested to be the formation of a sulfonium ion derived from the reactants. Mechanisms for the formations of the products are suggested.
Various α-methylthio-β-arylthiostyrenes were prepared by the action of arenesulfenyl chloride on α-methylthiostyrene. The configuration of the stereoisomers of the styrene derivatives was determined by studying the nuclear Overhauser effect in the proton magnetic resonance. The relative stabilities of α-methylthio-β-phenylthiostyrene isomers were determined by equilibrating with the aid of hydrogen chloride at various temperatures.
The microbiological transformation of progesterone by the local moulds Aspergillus niger and Rhizopus nigricans was studied. To a 48 hr old culture, progesterone (0.4 g/l medium) dissolved in ethanol was added and the transformation was left to proceed for 72 hr. Thereafter, the different transformation products were resolved chromatographically. The identity of each product was established through the determination of mp, mixed mp, optical rotation and ultraviolet as well as infrared absorption spectra. A comparison of the Rf values of each product with that of the corresponding reference using different solvent systems as well as their colours with two spray reagents was used as a further proof for the identity of the isolated products. In case of A. niger, progesterone was converted to 17α-hydroxyprogesterone; 21-hydroxyprogesterone (cortexone); 11α-hydroxyprogesterone; 11α,17α-dihydroxyprogesterone; 6β,11α-dihydroxyprogesterone and 11α, 17α, 21-trihydroxyprogesterone (epicortisol). These products together with 11α-hydroxy-5α-pregnane-3,20-dione were also identified in case of R. nigricans.