Showing papers in "Australian Journal of Chemistry in 1955"
TL;DR: In this paper, the authors considered the general problem of the biosynthesis of depsides and depsidones and demonstrated that the mould Penicillium griseofulvum Dierckx (Raistrick's strain P68) elaborates 2-hydroxy-6-methylbenzoic acid (VII) by the head-to-tail linkage of acetic acid units.
Abstract: The general problem of the biosynthesis of depsides and depsidones is considered. Feeding experiments using sodium acetate isotopically labelled in the carboxyl group have demonstrated that the mould Penicillium griseofulvum Dierckx (Raistrick's strain P68) elaborates 2-hydroxy-6-methylbenzoic acid (VII) by the head-to-tail linkage of acetic acid units in accord with the hypothesis of Birch and Donovan (1953). This demonstration constitutes the first definite support for the hypothesis based on bio- chemical experiments.
116 citations
TL;DR: In this paper, it is suggested that the reason for the success of the method of Demediuk (1952) for the removal of unsoundness of dolomitic limes, and other limes high in magnesium oxide, by the action of salt solutions lies in the conversion of free magnesium oxide to magnesium oxychlorides.
Abstract: The reactions which take place in the system MgO-MgCl2-H2O at concentrations of MgCl2 solutions up to 45 per cent. and temperatures from 0 to 110 °C have been studied in detail. Four oxychlorides have been found, namely, 9Mg(OH)2.MgCl2.5H2O, 5Mg(OH)2.MgCl2.8H2O, 3Mg(OH)2.MgCl2.8H2O, and 2Mg(OH)2.MgCl2.4H2O ; and an equilibrium diagram has been produced which gives the conditions at which each is stable. It is probable that in the formation of the oxychlorides a complex ion forms first and this reacts with Mg(OH)2, formed by rapid hydration of MgO, to produce amorphous oxychloride gels which slowly crystallize. The reactions in the systems MgO-CaCl2-H2O, CaO-MgCl2-H2O, Ca(OH)2-MgCl2-H2O, CaO-CaCl2-H2O, Ca(OH)2-CaCl2-H2O, and between calcined dolomite and MgCl2, or CaCl2. solutions have been studied briefly. Oxychlorides form in these reactions also. It is therefore suggested that the explanation for the success of the method of Demediuk (1952) for the removal of " unsoundness " of dolomitic limes, and other limes high in magnesium oxide, by the action of salt solutions lies in the conversion of free magnesium oxide to magnesium oxychlorides. The optical properties and stabilities of the magnesium oxychlorides are briefly discussed.
102 citations
TL;DR: There are two extreme types of activated carbon and carbon black although structures intermediate between these two extremes are more usual as mentioned in this paper, and it has been established that in one extreme, the oxidized form ("H " carbon), the carbon has a pronounced quinonoid structure which creates a number of fixed olefinic bonds.
Abstract: There are two extreme types of activated carbon and carbon black although structures intermediate between these two extremes are more usual. This work has established that in one extreme, the oxidized form (" H " carbon), the carbon has a pronounced quinonoid structure which creates a number of fixed olefinic bonds. In the other, the reduced form (" L " carbon), the structure is more aromatic and has the characteristics of a hydroquinone. Carbons having properties intermediate between those of a pure " H " or " L " carbon acquire some semiquinone characteristics and become less diamagnetic. It is experimentally shown that the chemical behaviour of these carbons parallels in many ways that of simple quinone-hydroquinone compounds. The quinonoid structure of an " H " carbon accounts for the formation of peroxygen complexes, its ability to catalyse the ionization of oxygen in the presence of an electron donor, its oxidizing properties, and its reactivity with rubber. The hydroquinone character of an " L " carbon is responsible for its ability to adsorb alkali, its reducing properties, and its ability to fog a photographic plate (" Russell effect "). The change in properties which occurs in chars carbonized above 650" C is due to the transition from an " L " to an " H " carbon.
102 citations
TL;DR: In this article, the stability of the magnesium oxychlorides under natural atmospheric conditions is discussed and a lower hydrate with 2 molecules of water is found for the 2-and 9-forms.
Abstract: X-ray, differential thermal analysis, and dehydration methods have been used to study the magnesium oxychlorides 3Mg(OH)2.MgCl2.8H2O and 5Mg(OH)2.MgCl2.8H2O formed at temperatures below 100 °C, and 2Mg(OH), . MgCl2.5H2O and 9Mg(OH)2.MgCl2.6H2O formed at temperatures at and above 100 'C. Lower hydrates of the 3-form exist with 5 and 4 molecules of water, results which differ from those of Feitknecht and Held (1944), Feitknecht (1953), and Wehner (1933). It 1s not clear from the new results whether the lower hydrates for the 5-form hare 5 and 3 or 4 and 3 molecules of water, but the latter seems the more likely ; the results of Feitknecht and Held suggested the former. For the 2- and 9-forms a lower hydrate with 2 molecules of water exists. In addition all forms have an anhydrous phase with the crystal structure of Mg(OH)2. The stability of all phases under natural atmospheric conditions is discussed.
86 citations
TL;DR: In this paper, the reduction of some acid amides by sodium and proton sources in liquid ammonia has been examined, and the results showed that under the right conditions this process is of preparative value for aldehydes.
Abstract: The reduction by sodium and ethanol, with or without liquid ammonia as solvent, of various amidines followed by acid hydrolysis, leads in many cases to a good yield of the corresponding aldehyde. Further reduction in liquid ammonia of several 2-aryl-imidazolines or imidazolidines followed by acid hydrolysis leads to the 2,5-dihydro-benzaldehyde derivative. The reduction of some acid amides by sodium and proton sources in liquid ammonia has been examined. Under the right conditions this process is of preparative value for aldehydes.
78 citations
TL;DR: In this paper, the C=O stretching fundamental and first overtone in acetone, acetaldehyde, and diisopropyl ketone, for the chloroform C-H stretching fundamental, and for the acetonitrile C-C stretching fundamental were reported for a variety of non-polar and polar solvents.
Abstract: Frequency displacements and intensities are reported for the C=O stretching fundamental and first overtone in acetone, acetaldehyde, and diisopropyl ketone, for the chloroform C-H stretching fundamental, and for the acetonitrile C-C stretching fundamental, all in a variety of non-polar and polar solvents. The solvent displacement of C-C is very small (?1 K), for C-H and C=O it is to the red and of the order of 10-20 K, with C=O overtones being displaced about twice as much as the fundamentals. The Kirkwood relation between the frequency displacement and solvent dielectric constant is inadequate if the static D is used. The C=O results can be. interpreted in terms of two superimposed effects : (i) the electronic polarization of the solvent causes a frequency shift related to the solvent refractive index, and (ii) in polar solvents there is an additional shift due to solvent dipole orientation. Effect (ii) causes an added contribution to the intensity. The C-H results do not fit easily into this interpretation.
52 citations
TL;DR: In this article, it was shown that 1-(p-hydroxypheny1)butan-3-one (V) is a possible rheosmin, based on its properties and possible biosynthesis.
Abstract: Benzalpiperitone (I) has been dehydrogenated to 3-hydroxy-4-isopropylstilbene (II), which on ozonolysis gave rise to 3-hydroxy-4-isopropylbenzaldehyde (IV), which is unlikely to be identical with rheosmin. This substance appears on the basis of its properties and possible biosynthesis to be 1-(p-hydroxypheny1)butan-3-one (V).
32 citations
TL;DR: The second virial coefficients of the mixtures CH4-C(CH3)4, CH4Si(CH 3)4 and CH4SF6 have been measured for several compositions and at several temperatures.
Abstract: The second virial coefficients of the mixtures CH4-C(CH3)4, CH4-Si(CH3)4, and CH4-SF6 have been measured for several compositions and at several temperatures. Values of the coefficients B12, derived from the results, fail to conform to Guggenheim and McGlashan's (1951) extension of the principle of corresponding states. Reasons are given for this disagreement.
31 citations
TL;DR: In this paper, liquid-vapour equilibrium data were given for the systems acetonitrile + benzene at 45.00 °C and acetitrile+ nitromethane at 60.00°C.
Abstract: Liquid-vapour equilibrium data are given for the systems acetonitrile + benzene at 45.00 °C and acetonitrile + nitromethane at 60.00 °C. These data are used to calculate the excess free energy of mixing for these systems.
29 citations
TL;DR: In this article, the infra-red spectra of a series of alkyl and aryl esters of boric acid have been obtained in the region from 1800 to 670 cm-1.
Abstract: The infra-red spectra of a series of alkyl and aryl esters of boric acid have been obtained in the region from 1800 to 670 cm-1. These all show a strong characteristic absorption band at 1340 ± 10 cm-1 which is assigned to the asymmetrical stretching frequency of the BO3 group. Comparison of the infra-red and Raman spectra of trimethyl borate suggests the assignment of the 728 cm-1 Raman band to the symmetrical stretching mode. The non-coincidence of infra-red and Raman bands indicates a fairly high degree of symmetry with restriction of the rotation of the methyl groups round the B-O link. This contrasts with other data on the behaviour in the vapour where such rotation may occur.
28 citations
TL;DR: The absorption spectra and other properties of these compounds suggest a polycyclic tautomeric enolone structure as mentioned in this paper, possibly of the indandione type, and the results indicate that the aglycone of Haemodorum corymbosum Vahl is a poly-cyclic enolic α-diketone.
Abstract: The bulbous roots of Haemodorum corymbosum Vahl. yield a red crystalline glycoside, haemocorin, which is readily hydrolysed to cellobiose and the purple-red aglycone, C20H14O4. The latter contains one methoxyl group and gives a diacetate and isomeric mono- and dimethyl ethers. The absorption spectra and other properties of these compounds suggest a polycyclic tautomeric enolone structure. Oxidation of a dimethyl ether gives a compound C22H18O7, believed to be a lactol ester, and a compound C20H14O5, which is apparently a polycyclic aromatic anhydride. These results indicate that the aglycone is a polycyclic enolic α-diketone, possibly of the indandione type.
TL;DR: The bark and leaves of the rain-forest tree Kopsia longiflora Merrill (Apocynaceae) contain four new alkaloids; kopsinine, C21H26O2N2, (0.2 per cent), kopsilongine, c24H30O6N2(0.06 per percent), and kopsamine, C25H30 O7N2 ( 0.02 per cent) occurring in the bark as discussed by the authors.
Abstract: The bark and leaves of the rain-forest tree Kopsia longiflora Merrill (Apocynaceae) contain four new alkaloids ; kopsinine, C21H26O2N2, (0.2 per cent.), kopsilongine, C24H30O6N2 (0.06 per cent.), and kopsamine, C25H30O7N2 (0.02 per cent.) occurring in the bark ; and kopsilongine (0.07 per cent.), kopsamine (0.3 per cent.), and kopsiflorine, C23H28O5N2, (0.04 per cent.) in the leaves. The bark also contains β-amyrin (0.35 per cent.) while the leaves afford a mixture of paraffin hydrocarbons, mainly n-hentri- acontane, β-sitosterol, a sterol, C29H50O2, and a triterpene alcohol acetate, C32H52O2. Kopsamine, kopsilongine, and kopsiflorine each contain two methoxyl groups, while kopsinine contains only one ; kopsamine and kopsilongine also contain methylene-dioxy-groups. No reactive carbonyl groups were detected. The alkaloids all titrated as monoacid bases and formed monomethiodides: while the ultraviolet spectra recorded in acid and neutral media show that the basic (tertiary) nitrogen atom does not contribute to the chromophoric system.
TL;DR: Senecionine, seneciphylline, and retrorsine have been isolated from Erectites quadridentata D.C. where they occur mainly in the form of their N-oxides as discussed by the authors.
Abstract: Senecionine, seneciphylline, and retrorsine have been isolated from Erectites quadridentata D.C. where they occur mainly in the form of their N-oxides. The alkaloids, hieracifoline and pterophine, are shown to be mixtures of senecionine and seneciphylline.
TL;DR: In this paper, the order of emergence of 27 acids from column of strongly basic anion exchange resins was recorded and the RF values for 30 acids in two solvent systems were recorded.
Abstract: Displacement chromatography on columns of strongly basic anion-exchange resins has been used to separate, isolate, and purify some water-soluble organic acids. The order of emergence of 27 acids from these columns is recorded. Using this method pure l-quinic, succinic, L-malic, and citric acids were isolated from the flesh of the apricot fruit. The method was also used for the purification of hydroxy-acids. The detection of acids on paper chromatograms with a silver nitrate reagent is described ; silver nitrate-sodium hydroxide was used to detect acids having a vic.-glycol or α-keto group. The RF values for 30 acids in two solvent systems are recorded.
TL;DR: In this paper, the validity of substitution rules based on the hydrogen bending vibrations in this region and the number of adjacent hydrogen atoms in the molecules was investigated. And the results showed that the substitution rules were generally valid for groups of two, three, or four hydrogen atoms.
Abstract: Infra-red spectroscopic data on a number of mono- and disubstituted naphthalene derivatives have been obtained in the range 670-900 cm-l, in order to test the validity of the substitution rules based upon the hydrogen bending vibrations in this region and the number of adjacent hydrogen atoms in the molecules. It was found that the rules based on benzene substitution are generally valid for groups of two, three, or four hydrogen atoms in the naphthalene nucleus, although substituents which interact with the ring tend to widen the limits within which a band may be expected to fall. In the case of a single hydrogen atom the relevant bands are often weaker and their position variable.
TL;DR: In this paper, an interface reaction with some proton donor prior to the reduction to the trivalent state of dilute chromate solutions in a range of bicarbonate-carbonate buffers at the dropping mercury electrode is suggested.
Abstract: Current-voltage relationships have been determined for the electroreduction of dilute chromate solutions in a range of bicarbonate-carbonate buffers at the dropping mercury electrode. Double waves are obtained whose relative heights are a function of the pH value. By analogy with the behaviour of pyruvic acid an interface reaction with some proton donor prior to the reduction to the trivalent state is suggested (CrO42- +HB- → HCrO4- + B-). The rate constants for the interface reaction are computed for different donors by the method of Koutecky and Brdicka (1947). Adsorption-desorption processes in the region of the electrocapillary zero may account for the shape of the current-voltage curves, and, if so, the explanation based simply on an interface reaction will require modification. The occurrence of interface reactions and of adsorption-desorption processes in other inorganic systems is discussed.
TL;DR: In this paper, the equation of the A.C. polarographic current for processes where the frequency of the alternating field is comparable with the rate of the electrode reaction is derived, and relative values of equilibrium rate constants of some first order electrode reactions are evaluated experimentally.
Abstract: The equation of the A.C. polarographic current for processes where the frequency of the alternating field is comparable with the rate of the electrode reaction is derived. Relative values of equilibrium rate constants of some first order electrode reactions are evaluated experimentally.
TL;DR: The adsorption and possible mechanisms for the surface transport of stearic acid and some of its derivatives on solids have been investigated using radioactive tracers as mentioned in this paper, where mono-and multimolecular layers of these compounds were deposited on quartz glass, mica, and metal specimens, which were then held at various temperatures for a short period.
Abstract: The adsorption and possible mechanisms for the surface transport of stearic acid and some of its derivatives on solids have been investigated using radioactive tracers. mono- and multimolecular layers of these compounds were deposited on quartz glass, mica, and metal specimens, which were then held at various temperatures for a short period. The resulting changes in amount and distribution of activity were determined by autoradiography or an appropriately designed Geiger tube. On unreactive surfaces such as platinum or quartz glass the pure acid is only weakly adsorbed and thermal desorption, in general, readily occurs, especially of layers deposited on an initial monolayer. Layers of copper or calcium soaps on all surfaces, either deposited as such or formed in situ, are very much more stable. There is also some evidence that desorption is favoured by the presence of water vapour. Both pure acid and soap layers have some resistance to mechanical abrasion, but none to dissolution by hot benzene unless the adsorption involves a chemical bond. Part B of the present paper describes an experimental search for a long-range surface diffusion, using the same surfaces and adsorbates. It is shown that, under favourable conditions, material desorbed from one part of a surface will readsorb elsewhere after movement over considerable distances in the vapour phase. This mechanism may account for some examples of apparent surface diffusion reported by earlier workers. If, however, this vapour phase transport is suppressed, then no evidence can be detected of a true surface diffusion over macroscopic distances.
TL;DR: In this paper, a convenient synthesis of 2,3-dihydrobenzo-1,4-thiazine has been developed, and the preparation of substituted diphenylamines, phenothiazines, and phenoselenazines is described.
Abstract: A convenient synthesis of 2,3-dihydrobenzo-1,4-thiazine has been developed, and the preparation of a number of substituted diphenylamines, phenothiazines, and phenoselenazines is described.
TL;DR: A number of new glycosides and their acetates, principally β-glucosides, have been synthesized and their physical constants are reported as discussed by the authors, and certain limitations have been found to the application of the modified Helferich synthesis (Jermyn 1954).
Abstract: A number of new glycosides and their acetates, principally β-glucosides, have been synthesized and their physical constants are reported. Certain limitations have been found to the application of the modified Helferich synthesis (Jermyn 1954).
TL;DR: The results of a study of glyoxaline, pyrrole, and pyrazole by the molecular-orbital method are reported in this paper, which provides a detailed interpretation of the observed course of electrophilic substitutions in these heterocycles.
Abstract: The results of a study of glyoxaline, pyrrole, and pyrazole by the molecular-orbital method are reported. The theoretical data provide a detailed interpretation of the observed course of electrophilic substitutions in these heterocycles. Unequivocal predictions of the orientations for nucleophilic and radical substitutions in these compounds also emerge, but at present no relevant experimental information is available, with the exception of a possible case of radical substitution in glyoxaline. The present study also indicates that in conjugated systems, the electronegativity of a nitrogen atom carrying a formal negative charge (or a formal negative half-electronic charge) is appreciably less than that of a neutral carbon atom. This should assist in the assignment of electronegativity parameters in future molecular-orbital calculations.
TL;DR: In this paper, seven ω-hydroxy acids have been identified as constituents of carnauba wax, i.e., 18-hydroxydooosanoic, 20-hexadecanoic, 21-hexacosanic, 28-hydrohexacoxaneic and 30-hydroid triacontanoic acids.
Abstract: Seven ω-hydroxy acids have been identified as constituents of carnauba wax. They are 18-hydroxyoctadecanoic, 20-hydroxyeicosanoic, 22-hydroxydooosanoic, 24-hydroxytetracosanoic, 26-hydroxyhexacosanoic, 28-hydroxyoctacosanoic, and 30-hydroxytriacontanoic acids.
TL;DR: In this paper, it was shown that the aglycone is a dihydroxymethoxyphenylnaphthalic anhydrides with the methoxyl groups attached to the naphthalene ring system.
Abstract: Oxidation of the aglycone dimethyl ether B gives a cyclic anhydride isomeric with that previously obtained from dimethyl ether A. The chemical properties and absorption spectra of the two anhydrides and their derivatives suggest that they are dimethoxyphenylnaphthalic anhydrides with the methoxyl groups attached to the naphthalene ring system. Further degradation of the anhydrides eventually gives diphenyl-2,3,4-tricarboxylic acid. This is proved by decarboxylation to diphenyl and by the formation of an anilide phenylimide identical with a synthetic specimen. These results indicate that the aglycone is a dihydroxymethoxyphenylperinaphthenone, and further support is given by a study of model hydroxyperinaphthenones.
TL;DR: The synthesis of 2,5,7-trimethoxynaphthoquinone (XI) is described in this article, which is identical with flaviolin trimethyl ether.
Abstract: The synthesis of 2,5,7-trimethoxynaphthoquinone (XI) is described. This substance is identical with flaviolin trimethyl ether. Biogenetic relationships of several quinones are discussed.
TL;DR: In this paper, seven normal alcohols have been isolated from the unsaponifiable part of wool wax and identified as n-octadecanol, n-eicosanol, N-docosanol and N-triacontanol.
Abstract: Seven normal alcohols have been isolated from the unsaponifiable part of wool wax and identified as n-octadecanol, n-eicosanol, n-docosanol, n-tetracosanol, n-hexacosanol, n-octacosanol, and n-triacontanol.
TL;DR: In this article, it is suggested that barbaloin contains an aloe-emodinanthrone ring system which cannot enolize to form the anthranol, which is consistent with the formula C21H24O9.
Abstract: The reactions of barbaloin are shown to be consistent with the formula C21H24O9. It is suggested on the basis of absorption spectra and published data that the molecule contains an aloe-emodinanthrone ring system which cannot enolize to form the anthranol.
TL;DR: In this article, the preparation of some chloro-substituted o-aminobenzenethiols and their conversion to phenothiazines are described. But the scope and limitations of some methods for preparing the former are discussed.
Abstract: The preparation of some chloro-substituted o-aminobenzenethiols, and their conversion to phenothiazines, are described. The scope and limitations of some methods for preparing the former are discussed.
TL;DR: The direction of the conjugation of double bonds in 2,5-dihydroanisole derivatives has been further examined in this article, showing that double bonds can be conjugated in two different directions.
Abstract: The direction of the conjugation of double bonds in some 2,5-dihydroanisole derivatives has been further examined.
TL;DR: In this paper, a new formula C38H58O9N8 having a cyclic structure and containing seven amino acid residues was proposed, which was shown to be a peptide.
Abstract: Evolidine, formerly described as an alkaloid, is shown to be a peptide. A new formula C38H58O9N8 having a cyclic structure and containing seven amino acid residues is proposed.