bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermodynamic changes associated with the formation of aminopolycarboxylate chelates
Authors: Martell Arthur E.
Published: September 2010

By emf. measurements of cells of the type Pt‐H2, H+, A− (buffer), KCl, Ag‐AgCl, and extrapolation of the data to infinite dilution, thermodynamic dissociation constants and metal chelate stability constants have been obtained for ethylenediaminetetraacetic and nitrilotriacetic acid. From measurements of this type made over a series of temperatures, the enthalpy and entropy changes associated with complex formation were calculated. In all cases the enthalpy changes were found to be relatively small, while the entropy contributions to the stability of the chelate compounds were found to be considerably greater. The results are interpreted on the basis of the structures of the compounds, and of present theories of chelate ring formation.
Collision complexes
Authors: Ketelaar J. A. A.
Published: September 2010

The observation of simultaneous vibrational transitions in mixtures of compressed gases: CO2 with N2, O2 and H2, as well as in liquids, such as CS2, with Br2, I2, CCl3SCl, PCl3, and S2Cl2, is explained as being due to the presence of collision complexes.

The theory of these simultaneous vibrations and the intensity rules are given.
Complexes in coal
Authors: Schuyer J.
Published: September 2010

A considerable portion of the coal is composed of aromatic structural units ‐ lamellae ‐ that contain 20 to 100 carbon atoms. These lamellae show a strong packing tendency resulting in the formation of crystallites. The interlamellar binding energy in these crystallites may be very high, higher even than that of the saturated CC bonds.

By assuming that charge‐transfer may occur between the lamellae in the crystallites and that the lamellae may function both as electron donors and as electron acceptors, it will be understood why anthracite behaves as an intrinsic semi‐conductor.

The influence of this charge‐transfer on the optical properties ‐ refraction and absorption of light ‐ is explained with the aid of strongly schematized models.
Structure and magnetic properties of Co3O4 and ZnCo2O4
Authors: Cossee P.
Published: September 2010

Measurements are described of the paramagnetic susceptibilities of Co3O4, ZnCo2O4, and mixed crystals of ZnAl2O4‐ZnCo2O4 and the results are given in a table of X‐values and two plots of 1/X against absolute temperature.

To explain the very low value of the mean Bohr magneton number, found for these compounds, the assumption is made that Co3+ in these spinel structures is situated at octahedral interstices and covalently bonded as in the other complex compounds of CoIII, thus not contributing to the paramagnetism.

This assumption gives the reasonable, although somewhat high value of 4.7 μB for the Co2+ ion in Co3O4. This high value of μ for Co2+ and the weak paramagnetism of ZnCo2O4 may be caused by a slight oxygen deficiency of the compounds or a small energy difference between the diamagnetic and paramagnetic states of Co3+ in octahedra.
Volumetric determination of hypophosphite in the presence of phosphite by oxidation with ferric iron
Authors: Sastri M. N. , Kalidas Ch.
Published: September 2010

A rapid volumetric method for the determination of hypophosphite based on oxidation with ferric iron and estimation of the ferrous iron formed, is described. Phosphite does not interfere.
Application of paper chromatography to the identification of accelerators and antioxidants: IV. Detection of antioxidants
Authors: Zijp J. W. H.
Published: September 2010

In this paper the paper‐chromatographic separation and identification of various antioxidants is described. Because only few antioxidants can be separated by paper chromatography after coupling with diazotized arylaminosulphonic acids, it is preferable to separate these compounds, which are generally insoluble in water, by means of acetylated filter paper.

The identification of antioxidants, using acetylated filter paper, is described.
Application of paper chromatography to the identification of accelerators and antioxidants: V. Detection of accelerators and antioxidants in rubber of unknown composition
Authors: Zijp J. W. H.
Published: September 2010

In this article a detailed procedure is given for the identification of accelerators and antioxidants in rubber mixes and vulcanisates of unknown composition.
Polymerisation of p‐methoxy‐isopropenylbenzene (p‐methoxy‐α‐methyl‐styrene) under the influence of 43 % sulphuric acid
Authors: van der Zanden J. M. , Rix Th. R.
Published: September 2010

Following up the publications concerning the polymerization of methyl‐chavicola) and of orthomethoxyallylbenzeneb), p‐methoxyisopropenyl‐benzene (I) has now been studied. The structure of the dimer obtained has been determined. Further the course of the reaction during dimerization is discussed.
Hydrocarbures polycycliques aromatiques. II. La formylation du pérylène et du 3‐méthylpérylène
Authors: Buu‐Hoï N. P. , Long C. T.
Published: September 2010

Il est montré que le pérylène peut être formylé par la N‐méthylformanilide en présence d'oxychlorure de phosphore, et que le monoaldéhyde obtenu est le 3‐formylpérylène. Cette réaction constitue une voie d'accès vers de nombreux dérivés monosubstitués du pérylène, et s'applique également au 3‐méthylpérylène.
Synthesis of 5‐ and 5,8‐dimethoxy‐2‐methylchromones
Authors: Rao C. Ramachandra , Venkateswarlu V.
Published: September 2010

A new method of synthesis of some derivatives of 2‐methylchromone with possible physiological activity similar to kellin and visnagin but not containing the furan ring has been reported. Starting from 2‐hydroxy‐6‐methoxy‐acetophenone, 5‐methoxy‐2‐methylchromone has been obtained by way of the intermediate, 2‐hydroxy‐6‐methoxy‐ω‐acetylacetophenone. By alkaline persulphate oxidation, 5‐hydroxy‐2‐methylchromone is converted into 5,8‐dihydroxy‐2‐methylchromone. Its acetate, partial and complete methyl ethers have been obtained. Demethylation of 5,8‐dimethoxy‐2‐methylchromone gave the isomeric 5,6‐dihydroxy‐2‐methylchromone, the constitution of which has been established by independent synthesis.
Chemistry of acetylenic ethers XX. Note on the preparation of secondary ethoxyethynylcarbinols
Authors: Postma J. C. W. , Arens J. F.
Published: September 2010

Secondary ethoxyethynylcarbinols cannot be obtained from aldehydes and ethoxyethynylmagnesium bromide. The substances can be prepared, however, by interaction of the aldehydes with ethoxyethynyl‐lithium. The secondary carbinols are rearranged to α,β‐unsaturated esters by acids.
The stability constants of metal complexes of some N‐dialkyldithtocarbamic acids: Part. I. Copper complexes in 75 % (v/v) ethanol water
Authors: Janssen M. J.
Published: September 2010

The stability constants for the formation of copper complexes of N‐dimethyl‐, diethyl‐, di‐n‐propyl‐, di‐n‐butyl‐, cyclotetramethylene‐, and cyclopentamethylene‐dithiocarbamic acids were measured spectrophotometrically in a 75 % ethanol/water mixture by a competition method using 8‐hydroxyquinoline as the third component.

This method was especially developed for the evaluation of stability constants in the presence of “mixed” complexes, containing both hydroxyquinoline and the dithiocarbamic acid.
Chemistry of acetylenic ethers XXI: Reactions of 1,1‐diazido‐1‐ethoxyethane with amines
Authors: Sinnema Y. A. , Arens J. F.
Published: September 2010

By the interaction of 1,1‐diazido‐1‐ethoxyethane, II, and ammonia, acetamidinium azide, III, was obtained. The same substance was formed by catalytic reduction of II. With n‐butylamine, II yielded N,N′‐di‐n‐butylacetamidinium azide, IV. The reaction of II with diethylamine was slow and yielded no identifiable derivatives of II. Triethylamine did not react with II.

Diphenylamine and II yielded N‐acetyldiphenylamine, V, ethylazide, VI, and 1‐azido‐1‐ethoxyethane, VII, which was obtained also from ethyl vinyl ether and hydrazoic acid.
Investigations on pyrazine derivatives
Authors: Mager H. I. X. , Berends W.
Published: September 2010

A simple method is given for the preparation of pyrazine tetracarboxylic acid from o‐diaminobenzene. A stable 1,4‐dihydro‐compound only is produced on hydrogenating tetraethyl pyrazine tetracarboxylate at relatively high pressures and temperatures. The cause of this stability must be sought in the presence of two, probably mutually independent, mesomeric systems.
Isomerisation of unsaturated fatty acid esters. Part II: Location of double bonds by oxidative degradation methods
Authors: Keppler J. G.
Published: September 2010

For the location of the double bonds in di‐ethenoid acids, ozonolysis is recommended in preference to degradation with KMnO4, as the former method leads to a higher yield of the primarily formed mono‐ and di‐carboxylic acids and the latter method may result in the formation of interfering secondary degradation products. By subjecting some pure dicarboxylic acids or their half‐esters to the action of the oxidising agents Ag2O or KMnO4, it was found that the latter causes a fairly considerable secondary degradation of the higher homologues.
Über Muscarin. III
Authors: Kögl F. , Salemink C. A. , Schouten H. , Jellinek F.
Published: September 2010

Die in einer Untersuchung aus dem Jahre 1931 für Muscarin angenommene Konstitution eines quaternären Trimethylammoniumsalzes von α‐Amino‐β‐oxy‐valeraldehyd [C8H18O2N]+Cl− hat sich als unrichtig erwiesen. Die nunmehr mit Hilfe chromatographischer Methoden ausgeführte Isolierung dieses Alkaloids aus Fliegenpilzen führte in Übereinstimmung mit neueren Untersuchungen aus anderen Laboratorien zur Bruttoformel [C9H20O2N]+Cl−. Es zeigte sich, dass Fliegenpilze auch das beim pharmakologischen Test am Froschherzen noch aktivere Acetylcholin enthalten. Beim Hofmannschen Abbau des Muscarins konnte ausser Normuscarin nur Trimethylamin als Abbauprodukt identifiziert werden. Die beiden Sauerstoffatome liegen in einer Hydroxylgruppe und einem Tetrahydrofuranring vor. Letzteres ergab sich u.a. aus dem Infrarot‐Absorptionsspektrum. Durch Reduktion des Muscarins mit Jodwasserstoffsäure und nachfolgende Hydrierung entstand Trimethyl‐hexyl‐ammonium‐jodid. Diese Verbindung enthält ‐ abgesehen von den Sauerstoffatomen ‐ das gesamte Skelett des Muscarin‐kations. Schliesslich führte die Röntgenanalyse zur endgültigen Festlegung der Struktur und des räumlichen Baus. Muscarin ist das quaternäre Trimethylammoniumsalz von 2‐Methyl‐3‐oxy‐5‐(amino‐methyl)‐tetrahydrofuran.
Resorption of cholecalciferol from an intramuscular oil depot
Authors: Bots J. P. L.
Published: September 2010

By injecting chickens intramuscularly with radioactive cholecalciferol (vitamin‐D3) in oil and determinating the radioactivity still present after various times, it is shown that an intramuscular depot of vitamin‐D3 is only slowly absorbed in the course of at least seven months.
Quantitative determination of antioxidants, after a chromatographic separation on completely acetylated filter paper. I. Determination of phenyl‐1‐naphthylamine and of phenyl‐2‐naphthylamine
Authors: Zijp J. W. H.
Published: September 2010

In this paper a general method for the quantitative determination of antioxidants is described. After isolation from the rubber compound the antioxidants are separated by partition chromatography, using completely acetylated Whatmanpaper no. 1.

A detailed procedure is given for the quantitative determination of phenyl‐1‐naphthylamine and of phenyl‐2‐naphthylamine. These antioxidants are coupled with diazotized sulphanilic acid and determined colorimetrically.
Quantitative determination of antioxidants, after a chromatographic separation on completely acetylated filter paper. II. Determination of some p‐phenylenediamine derivatives
Authors: Zijp J. W. H.
Published: September 2010

In this paper methods are given for the quantitative determination of three antioxidants, viz. N.N′‐diphenyl‐p‐phenylenediamine, N.N′‐di‐2‐naphthyl‐p‐phenylenediamine and N‐phenyl‐N′‐cyclohexyl‐p‐phenylenediamine.

According to these methods the antioxidants are extracted from the rubber compound, separated by partition chromatography on completely acetylated filter paper and oxidised to the corresponding p‐quinonediimines, where after these oxidation products are determined colorimetrically.
The halogenation of aromatics: Part I. Gas phase chlorination of chlorobenzene
Authors: Engelsma J. W. , Kooyman E. C. , van der Bij J. R.
Published: September 2010

The gas phase chlorination of chlorobenzene has been investigated at temperatures between 275 and 500° C, using empty glass reactor tubes. Intake ratios of chlorine and aromatics were 1/2 and nitrogen was used as a diluent. Contact times were 1/2‐1 minute.

Dichlorobenzenes were obtained in high yields based on chlorobenzene converted. Carbon formation was negligible at temperatures below 465° C; no indications as to formation of by‐products were obtained.

Whereas chlorine conversions increased from 2 to 70% over the temperature range studied, isomer compositions of dichlorobenzenes showed little variation, viz. 68‐62% meta, about 24% para and 8‐13% ortho, the first‐mentioned figures applying at the lower reaction temperatures.

Meta/para ratios were, therefore, always appreciably higher than 2. A transition of the substitution type, such as has been observed in some cases by Wibaut and his coworkers1), did not occur.
On the absolute configuration of sedamine and sedridine: (Preliminary communication)
Authors: Beyerman H. C. , Eenshuistra J. , Eveleens W.
Published: September 2010

The resolution of (±)‐allo‐sedamine into its optical components and of (±)‐sedridine yielding (+)‐sedridine is recorded.

An alkaloid of undetermined constitution previously obtained from Lobelia inflata L. by H. Wieland et al. seems identical with one of the enantiomorphs of (±)‐allo‐sedamine.

The determination of the absolute configuration of the piperidine part of the alkaloids sedamine, allo‐sedamine and sedridine is described. The results agree with the conception of the biosynthesis of (‐) ‐sedamine and (+)‐sedridine from L‐amino‐acids.
Hydrocarbures polycycliques aromatiques. V.) La réaction d'Elbs chez les dibenzoyl‐2,7‐diméthyl‐naphtalènes
Authors: Buu‐Hoï N. P. , Lavit Denise
Published: September 2010

Il est démontré que, dans la réaction de Friedel‐Crafts entre 2 mol. de chlorure de benzoyle et une mol. de 2,7‐diméthylnaphtalène, il se forme trois dicétones, et non une seule comme l'indiquait la littérature; on étudie le comportement de chacune de ces dicétones dans la réaction de pyrolyse d'Elbs, et il est montré que l'une des dicétones le naphto[2,3a]‐naphtacène, une autre fournissant un composé oxygéné, probablement dérivé de l'anthra[1,2‐a]anthracène, et la troisième dicétone n'ayant fourni aucun produit défini. Il est montré que le naphto[2,3‐a] naphtacène donne un aldéhyde par formylation (probablement le 9‐formyl‐naphto[2,3‐a] naphtacène.
Studies in polarography: III. Reduction of permanganate in presence of telluric acid at the dropping electrode
Authors: Issa I. M. , Khalafalla S. E. , Issa R. M.
Published: September 2010

The polarography of alkaline permanganate solutions in presence of telluric acid has been studied. It is shown that reduction of Mn+7 passes through an ill‐defined zero wave to Mn+3. This latter is then reduced to Mn+2 along a sloping wave. The waves of telluric acid and the Mn+2‐Mn are vitiated by the precipitation of manganous tellurate. The lowering of id of the Mn+7/Mn+2 wave and the early reduction of telluric acid indicates the formation of a double salt between permanganate (A) and tellurate (B) of the formula AB2.
The Raman and infra‐red spectra of some compounds (iH7C3O)2PXO
Authors: Maarsen J. W. , Smit M. C. , Matze J.
Published: September 2010

The Raman and infra‐red spectra of a series of compounds, represented by the general formula (iH7C3O)2PXO, in which X may be H, CH3, OH, O‐iC3H7, F, Cl, NH2, NHCH3, and N(CH3)2, have been investigated.

It was shown that there exist at least two frequencies for P‐O stretching,viz, symmetrical and asymmetrical. To the symmetrical stretching has been assigned a frequency at 720‐750 cm−1, which is very strong in Raman. To the asymmetrical stretching belongs a frequency at 973‐1030 cm−1, very strong in infra‐red, but weak or even missing in Raman.

Other frequencies of the compounds could be interpreted in accordance with assignments given in the literature.
A relationship between dipole moments and the Hammett equation
Authors: van Beek L. K. H.
Published: September 2010

An empirical formula is proposed relating the constant ω in the Hammett equation to the observed dipole moment of a compound (para‐ or meta‐ C6H4XY). This relationship is checked by using data which have been cited in the literature. These data appear to confirm the proposed linear behaviour when log μ is plotted against σ.
Determination and adjustment of the activity of adsorbents for chromatography and of the eluting power of elution solvents by means of the “shake test”: (Analysis of fat soluble vitamins III))
Authors: Keuning K. J. , van Dijk G. J. , de Vries M. J. Wiggers
Published: September 2010

Adjustment of the activity of adsorbents for chromatographic use (e.g. Al2O3 or CaHPO4 by the controlled take‐up of water) can be done in a reproducible and accurate manner with the aid of the “shake‐test”. It consists in shaking a weighed sample (2 g) of the adsorbent with a measured volume (10 ml) of the elution solvent in which the substance to be eluted (e.g. 1000 I.U. of vitamin‐A) has been dissolved. The activity is suitable if about 50% is adsorbed. The following operations can be performed by means of the shake test.

(1) determination of the activity of adsorbents; (2) adjustment of the activity of an adsorbent; (3) replacement of an adsorbent by another of the same activity; (4) finding the correct composition of the elution solvent; (5) replacement of one solvent by another of equal eluting power.

The shake test has been developed for a 10 cm column containing 10 g of Al2O3; 40 % adsorption is satisfactory for rapid elution. If slower elution is wanted, or if thinner columns (containing less adsorbent) are employed, the percentage adsorption must be larger than 40%, up to 60%. The shake test is a purely practical test; no theoretical significance can be attached to it.
The vibrational spectrum and force constants of P4S3
Authors: Gerding H. , Maarsen J. W. , Nobel P. Chr.
Published: September 2010

The Raman spectra of P4S3 in the solid and molten states and in solution in CS2 have been determined.

It appeared impossible to obtain reliable quantitative depolarization factors; the assignment was therefore based on the visually estimated state of polarization.

The spectra in CS2 solution contained several unexplained frequencies, much higher than was to be expected.

Force constants for the P‐S and P‐P bonds have been calculated, on the basis of the C3v symmetry, assumed for the molecule.

The values found are distinctly lower than those calculated with Badger's or Gordy's formulae from known bond distances. The calculations in the main support the structure for P4S3 determined by electron diffraction and X‐ray analysis.
The phosphorylation of thiamine in the livers of normal and alloxan‐diabetic rats
Authors: Vincent J. E.
Published: September 2010

A procedure for the separation and isolation of thiamine and cocarboxylase from liver extracts has been described using repeated chromatography on Amberlite IRC‐50 columns.

The phosphorylation of thiamine in normal and alloxan‐diabetic rats was investigated with the aid of thiamine‐35S. No difference in the rate of formation of radioactive cocarboxylase in the liver could be observed at different times after the intraperitoneal injection of thiamine‐35S. We conclude that the phosphorylation of thiamine is not impaired in alloxan‐diabetic rats.
The electronic spectra of aromatic hydrocarbon anions
Authors: de Boer E. , Weissman S. I.
Published: September 2010

The electronic spectra of several hydrocarbon anions have been measured. A comparison is given between these spectra and the spectra obtained by Hoytink et al.2). It appeared that the positions of the absorption bands are only shifted about 0.2 kK to lower wavelengths, using potassium instead of sodium as reducing agent.
Hyperconjugation and induction in 1‐methylpolyenyl negative ions
Authors: Bouman N. , Hoijtink G. J.
Published: September 2010

The influence of 1‐methyl substitution on the charge distribution in the allyl, pentadienyl and heptatrienyl negative ion has been investigated.

It appears that the results of the theoretical computations are qualitatively the same for hyperconjugation and for induction.
A general theoretical approach to the course of chemical reduction, electrochemical reduction and catalytic hydrogenation of hydrocarbons with conjugated double bonds
Authors: Hoijtink G. J.
Published: September 2010

The course of reduction and hydrogenation of various conjugated hydrocarbons has been investigated theoretically on the basis of a general ionic mechanism. The structures of the partial and final reduction products have been predicted from the charge distribution in the intermediately formed negative ions under the influence of a homogeneous electric field, the magnitude of which depends on the conditions of the experiment. The predicted results prove to be in good agreement with the experimental data. It appears that the main contribution to the electric polarisation of the intermediately formed ions is due to the electric field in the electrical double layer at the “electrode” surface.

The reduction and hydrogenation of the following hydrocarbons has been considered: benzene, naphthalene, anthracene, phenanthrene, pyrene, triphenylene, 1,2‐benzanthracene, biphenyl, terphenyl and quaterphenyl. The good agreement between the results of the present theory and the experimental data is a strong argument in favour of the supposition that in catalytic hydrogenation the primary reaction involves the addition of two electrons to the hydrocarbon molecule.
Synthesis of peptides by means of ethyl α‐chlorovinyl ether and α, α‐dichlorodiethyl ether
Authors: Heslinga L. , Arens J. F.
Published: September 2010

Ethyl α‐chlorovinyl ether IV and α, α‐dichlorodiethyl ether V can be used for the synthesis of peptides. The reactions are performed by refluxing a mixture of an acylamino acid I, an amino acid ester‐hydrochloride II and one of the chlorinated ethers IV or V in ethyl acetate. Optically pure acyl peptide‐esters VII are obtained. The method has been applied mostly for the preparation of acyl dipeptide‐esters, but higher peptides have also been obtained. Acylamino acid chlorides VI are most probably intermediates.
The physical meaning of the constants in Smittenberg's formula
Authors: Fortuin J. M. H.
Published: September 2010

A relation between the physical constants and the number of methylene groups per molecule of hydrocarbons belonging to a homologous series is derived. The formula obtained is of the same type as the emperical one proposed by Smittenberg. The physical meanings of the constants in this formula are indicated. Reduced values of physical constants are introduced. The relation between these values and the number of methylene groups per molecule is nearly linear.
Investigations on organic insecticides II. Preparation and acaricidal properties of substituted diphenylsulphones, diphenylsulphides and diphenylsulphoxides
Authors: Huisman H. O. , Uhlenbroek J. H. , Meltzer J.
Published: September 2010

The preparation and acaricidal properties of a number of variously substituted diphenylsulphones, diphenylsulphides and diphenylsulphoxides are described. A few of them possess strong acaricidal properties. The most outsanding proved to be 2,4,5,4′‐tetrachlorodiphenylsulphone ‐ “Tedion V18” ‐ which combines high activity on all stages, except adult spider mites with total absence of phytocidal side‐effects and toxicity for warm‐blooded animals.
Total synthesis in the steroid series. III: Synthesis of aldosterone
Authors: van der Burg W. J. , van Dorp D. A. , Schindler O. , Siegmann C. M. , Szpilfogel S. A.
Published: September 2010

The transformation of the substituted D‐homoandrostane derivative IV (see preceding paper) into a known aldosterone intermediate is described.
Chemistry of acetylenic ethers XXX. Additions of trichloroacetic acid, its anhydride and its chloride to ethoxyacetylene
Authors: Broekema R. , van der Werf S. , Arens J. F.
Published: September 2010

By adding one equivalent of trichloroacetic acid to ethoxyacetylene (I) an addition product (IIIa) is formed. The reverse procedure if carried out very slowly gives rise to a different compound (VII), which can also be obtained from ethoxyacetylene and trichloroacetic anhydride.

Addition of trichloroacetic acid to the substance IIIa produces ethyl acetate and trichloroacetic anhydride. The same substance is formed directly by adding ethoxyacetylene to two equivalents of trichloroacetic acid.

Ethoxyacetylene can also add trichloroacetyl chloride, this yields X.

These transformations and the reactions performed for establishing the structures of IIIa, VII and X are summarised in a reaction scheme.

The addition of one and two moles of hydrogen bromide respectively to ethoxyacetylene yields ethyl α‐bromovinyl ether (XV, X = Br) and α,α‐dibromodiethyl ether (XVI, X = Br).
The viscosity of cis‐ and trans‐decalin
Authors: Boelhouwer C. , Waterman H. I.
Published: September 2010

Viscosity data on cis‐ and trans‐decalin are discussed in respect to recent investigations on the viscosity‐temperature dependence of liquids. No abnormal behaviour of the viscosity in the temperature range (−30° C to + 180° C) considered was observed.
The action mecanism of actidione
Authors: Latuasan H. E. , Berends W.
Published: September 2010

Investigation of the action mechanism of actidione on yeasts has made it quite clear that yeasts with a high respiratory quotient, i.e. strongly aerobic fermenting, are especially sensitive to actidione. These observations led to attempts to examine whether actidione intervenes in the Embden‐Meyerhof cycle in dormant yeasts. There appears to be a check on the enzyme alcoholdehydrogenase. The enzyme lactic acid‐dehydrogenase from muscle, which also contains DPN as coenzyme, shows exactly the same type of sensitivity. From an examination of the cause of this effect it appears that in vitro glutarimide and succinimide can imitate the action of actidione on these enzymes exactly. Substitution of the imido group completely destroys the activity of these substances. It is shown that it is probably worth while to examine a whole series of glutarimide and succinimide derivatives for fungicidal and anti‐tumour activity.
The structure of solid phosphorus pentabromide
Authors: Gerding H. , Nobel P. C.
Published: September 2010

The Raman frequencies of solid phosphorus pentabromide, excited by the green and yellow mercury lines, are: 72(6), 140(14), 189(0+), 227(26), 367(2−) and 474(9). 72(v2.3), 140(v4,5,6), 227(v1) and 474(v7,8,9) are the fundamental vibrations of the nearly regular tetrahedron ‐formed by the group PBr4+, which together with Br− build up the lattice of solid PBr5.

The force constants according to the Urey‐Bradley field are: K1 = 2.19, K2 = 0.18 and γ3 = 0.028 all in 105 dynes/cm. The corresponding values for SiBr4, isoelectronic with PBr4+, are 1.99, 0.12 and 0.11 × 105 dynes/cm.
Nucleic acid metabolism and induced enzyme formation
Authors: Chantrenne H.
Published: September 2010

The relation between nucleic acid metabolism and enzyme formation is discussed in the light of recent results obtained in the author's laboratory. It is pointed out that the inhibition of enzyme synthesis by purine or pyrimidine analogues is probably due to interference with the metabolism of oligonucleotidic compounds, rather than with the formation of specific ribonucleic acid templates. Enzyme induction in resting yeast is accompanied by changes in the physical properties of some ribonucleic acid fractions.
Synthesis and properties of the chlorination products of methyl 4‐amino‐2‐hydroxy‐benzoate. IV
Authors: van der Stelt C. , Reiding D. J. , Nauta W. Th.
Published: September 2010

As described earlier, two isomers with the structure of a methyl 1,3,3,5,5,6‐hexachloro‐4‐chlorimino‐cyclohexanone‐2‐carboxylate‐1 (XXIII

Structural formulae of compounds numbered up to XXXVII are already given in previous publications.

and XIV) were isolated from the reaction mixture, obtained by chlorination of methyl 4‐amino‐2‐hydroxybenzoate in carbon tetrachloride.

Now still an other isomer (mp 146–148° C) (XXXIX) was isolated which differs from XXIII and XXIV by a different spatial arrangement of the chlorine atoms attached to carbon atoms 1 and 6.

This was proved by conversion of XXXIX into 1,1,2,3,5,5,5‐heptachloro‐3‐carbomethoxy‐pentanone‐4‐carboxylic acid‐1 (XIX).

Reaction of XXXIX with methanolic hydrogen chloride yielded the same reaction product as obtained earlier from XXIII and XXIV. This fact makes clear that the ring opening during this reaction does not take place between carbon atoms 2 and 3 as was supposed earlier, but between carbon atoms 1 and 2. The reaction product must therefore be described as a dimethyl 1,1,3,3,4,5,5‐heptachloro‐2‐imino‐1,5‐pentane‐dicarboxylate (XXXIIIA). The consequence of this correction is that also for several other compounds mentioned previously changed structures are proposed.

Reaction of XXXIX with an aqueous potassium iodide solution yielded methyl 1,3,5,5,6‐pentachloro‐4‐amino‐cyclohexene‐3‐one‐2‐carboxylate‐1 (XL) which differs from its isomer obtained from XXIII and XXIV by an analogous reaction. Both XXXIX and XL could be converted into methyl‐4‐amino‐3,5‐dichloro‐2‐hydroxy‐benzoate by treatment with stannous chloride.
Synthesis and some physical constants of four isomeric tripropylbenzenes
Authors: Wibaut J. P. , Paulis B.
Published: September 2010

The synthesis is described of four tripropylbenzenes:

1,3,5‐triisopropylbenzene,

1,2,4‐triisopropylbenzene,

1,3,5‐tri‐n‐propylbenzene,

1,2,4‐tri‐n‐propylbenzene.

Physical constants of these compounds are given.
Electrophoresis of the proteins in the eye lens of calf and cow
Authors: Bon W. F. , Nobel P. C.
Published: September 2010

α‐Crystallin from the eye lens of calves has a smaller mobility in agar electrophoresis experiments than α‐crystallin from the eye lens of adult cows. In addition there are other differences between “young” and “adult” α‐crystallin, for which a possible explanation is given.

The investigation described in this paper indicates that proteins undergo development during ontogenesis. Therefore the idea of “chemical differentiation” of embryology ought to be extended to the proteins themselves.
Investigations on pyrazine derivatives II. The preparation of pyrazine 2,3,5‐tricarboxylic acid and of pyrazine 2,5‐ and 2,6‐dicarboxylic acids
Authors: Mager H. I. X. , Berends W.
Published: September 2010

A satisfactory preparative method for pyrazine tricarboxylic acid has been found in the oxidation of the readily available 2‐(D‐arabo)‐tetrahydroxybutylquinoxaline. Pyrazine tricarboxylic acid is easily decarboxylated to pyrazine 2,5‐ and 2,6‐dicarboxylic acids. In connection with the poor yield obtained in the oxidation of 2,5‐dimethylpyrazine to pyrazine 2.5‐dicarboxylic acid, it is an advantage first of all to convert the starting material into a condensation product with an appropriate aldehyde.
The synthesis of diduryl ketone
Authors: Galenkamp H. , Faber A. C.
Published: September 2010

On repeating the synthesis of diduryl ketone (duryl = 2,3,5,6‐tetramethylphenyl) by means of the Friedel and Crafts reaction it was found that the resulting product is a mixture of isomeric ketones. The main component is duryl 2,3,4,6‐tetramethylphenyl ketone.

Diduryl ketone together with two of the possible isomeric ketones can be synthesized by way of the Grignard reaction.
On the determination of free phenol in phenol‐formaldehyde resins
Authors: Dijkstra R. , Lammers M. F.
Published: September 2010

The time necessary for the determination of free phenol in phenol‐formaldehyde resins and moulding powders can be appreciably reduced by the addition of glycol to the resin during the steam distillation.
On the reactivity of organophosphorus compounds. I. The alkaline hydrolysis of some dialkyl p‐nitrophenyl phosphates
Authors: Ginjaar L. , Vel S.
Published: September 2010

The alkaline hydrolysis of some dialkyl p‐nitrophenyl phosphates (RO)2P(O)OC6H4NO2, where R = methyl, ethyl, n‐propyl, isopropyl, n‐butyl, isobutyl and sec‐butyl is described. The effects of α‐, β‐ and γ‐substitution on reactivity as expressed in ΔH* and ΔS* are discussed.
Chemical studies on insecticides VIII: Ultraviolet spectra and opposing resonance in phosphate esters
Authors: Gersmann H. R. , Ketelaar J. A. A.
Published: September 2010

A calculation is given for the opposing resonance in an “energy”‐rich phosphate ester from the hypsochromic shift of the first ultraviolet absorption maximum for phenyl and nitrophenyl phosphates. The effects contributing to the standard free energy of hydrolysis in energy‐rich phosphate bonds are discussed.
Tripyridyl carbinols: A group of tertiary alcohols with amphoteric properties: 104th Communication on pyridine derivatives
Authors: Wibaut J. P. , Otto P. Ph. H. L.
Published: September 2010

The synthesis of five new tripyridyl carbinols is described, so that seven out of the ten possible isomers of this group are now known. The tripyridyl carbinols are not only weak bases, they show also the properties of very weak acids; the acid dissociation constants are of the order of magnitude of 10−12 to 10−14 and were determined from the relationship between the solubility in dilute alkali and the hydroxyl‐ion concentration. The connection between structure and acid properties is discussed.
Polarography of potassium manganate
Authors: Den Boef G. , Poeder B. C.
Published: September 2010

The polarography of compounds in the higher valency states of manganese, already carried out for permanganate by other authors, is extended to alkaline solutions by investigating the polarographic reduction of the manganate ion at the dropping mercury electrode, as well as at the rotating platinum electrode. Quantitative determinations of manganate appear to be possible in the concentration range from 2 × 10−3 M to 2 × 10−5 M.
Researches on the alkoxy‐amino‐nitrobenzenes: VIII. Preparation and anaesthetic properties of a number of dialkylaminoalkyl and bis (dialkylamino) alkyl esters of (alkoxynitrophenyl) carbamic acids
Authors: Verkade P. E. , Strube R. E. , Witjens P. H.
Published: September 2010

The preparation of a number of dialkylaminoalkyl and bis (dialkylamino) ‐alkyl esters of (alkoxy‐nitrophenyl) carbamic acids is described. The substances obtained were tested for (local) anaesthetic activity with the aid of the rabbit cornea test, the frog muscle sciatic nerve test and the goldfish test.
Researches on plant growth regulators, XXV. Structure/activity, X. On the influence of the polar group on growth substance transport: Comparative investigations with14C‐labeled indolylacetic acid and indolylmethanesulphonic acid
Authors: van de Westeringh C. , Veldstra H.
Published: September 2010

By comparative investigations with 3‐indolylacetic acid and its sulphonic acid analogue, both labeled with14C in the CH2‐group of the side chain, it was shown that the uptake of the partly dissociated carboxylic acid is much higher than that of the completely dissociated sulphonic acid. This explains the high external concentrations required for the latter to show physiological activity.

As the synergist di‐n‐amylacetic acid does not influence the uptake of the growth substances, its action must be concerned with a redistribution of the active compounds inside the cell.
Chemistry of acetylenic ethers XXXIII: The addition of ethoxyethyne to diphenylketene
Authors: Nieuwenhuis J. , Arens J. F.
Published: September 2010

Ethoxyethyne reacts easily with diphenylketene. I. The nature of the product depends upon the reaction temperature and the solvent. In benzene at room temperature, a 34% yield of 1‐phenyl‐2‐ethoxy‐4‐hydroxynaphthalene, VI, is obtained, whereas in nitromethane at −20° the product is 1,1‐diphenyl‐2‐ethoxycyclobut‐2‐ene‐4‐one. XXX. These structures have been proved by several reactions and by synthesis of degradation products. Similar reactions have been performed between 1‐ethoxy‐1‐propyne (XXXIV, R = C2H5), 1‐methoxy‐1‐propyne (XXXIV, R = CH3) and diphenylketene, I, yielding again acyclobutenone, XXXV, and a naphthol, XXXVI.
Chemistry of acetylenic ethers XXXV. Reactions of alkali metal derivatives of ethoxyethyne and of ethylthioethyne with epichlorohydrin
Authors: Vollema G. , Arens J. F.
Published: September 2010

The reaction between epichlorohydrin and ethylthioethynyl‐lithium affords the enynol V and furfuryl ethyl sulphide VI. The same reaction with ethoxyethynyl‐lithium, however, produces the epoxy compound VII.
The effects of ultraviolet light on some components of the nucleic acids: III. Apurinic acid
Authors: Beukers R. , Ijlstra J. , Berends W.
Published: September 2010

Apurinic acid, prepared from deoxyribonucleic acid, is destroyed by ultraviolet light much more rapidly than would be expected from the behaviour of the component pyrimidine‐nucleotides under this radiation.

It is confirmed by analysis that both thymine and cytosine are sensitive. The destruction of thymine is supposed to be due to the occurrence of this pyrimidine in a more sensitive form, presumably comparable to the form present in a frozen solution.

Upon adding an amount of adenine comparable to that of the purines removed, to apurinic acid, the decrease in extinction on irradiation resembles closely that of deoxyribonucleic acid.

Consequently, it seems likely that the purines in deoxyribonucleic acid protect the pyrimidines to a certain extent against the U.V. radiation and that the sensitivity of deoxyribonucleic acid to U.V. radiation is caused by the pyrimidines present as constituent parts of the molecule. The primary action of this radiation on living cells may be caused by destruction of the pyrimidines in the nucleic acids.
Chemistry of acetylenic ethers XXXVI. Preparation and properties of some 1‐alkylthio‐1‐alkynes
Authors: Boonstra H. J. , Brandsma L. , Wiegman A. M. , Arens J. F.
Published: September 2010

Aldehydes can be converted into 1‐alkylthio‐1‐alkenes II (thioenol ethers) via either α‐chlorothioethers I by elimination of hydrogen chloride or, better, thioacetals VI by acid catalysed elimination of thiol. Bromination of the thioenol ethers II followed by subsequent dehydrobromination with diethylaniline and potassium hydroxide affords 1‐alkylthio‐1‐alkynes V, which are relatively stable liquids.

Electrophilic as well as nucleophilic additions to 1‐ethylthio‐1‐propyne proceed slowly. The orientations during these additions are similar to those observed earlier for alkylthioethynes HCCSR; that is to say, that electrophilic as well as nucleophilic reagents attack the β carbon atom. This again39 suggests that the direction of the polarisability of the alkylthio group depends on the character of the substance added. During the approach of electrophilic reagents the polarisation is magnified image, but nucleophilic reagents induce the reversed polarisation magnified image.
The temperature variation of orthobaric density difference in liquid‐vapour systems: V. Amines
Authors: Costello J. M. , Bowden S. T.
Published: September 2010

The density of a series of aliphatic amines together with that of aniline and its methyl derivatives has been measured over ranges of temperature below and above the normal boiling point. The variation of orthobaric density difference may be represented by equations of the Verschaffelt type using estimated values of the critical temperature. On this basis it is found that the exponent for the lower members is slightly higher than that for non‐associated liquids and that its value decreases with increasing complexity of the amine. In general, the exponent for secondary amines is lower than that for primary amines, and the still lower values for tertiary amines is to be ascribed to causes other than hydrogen bonding. The behaviour of aniline and its N‐methyl derivatives is well represented by the Verschaffelt equation over a range of 300°.

It is shown that the Lewis equation relating to zero and critical densities is obeyed closely by associated substances.
The vapour pressure of tungsten trioxide
Authors: Meyer G. , Oosterom J. F. , de Roo J. L.
Published: September 2010

Measurements of the vapour pressure of solid tungsten trioxide between 1100° and 1250° C show that these vapour pressures cannot be calculated by extrapolation from the measurements carried out by Közo Inoue between 800 and 850°.

Conversely, the vapour pressure formula, which we have found, is in good agreement with the measurements between 800 and 850°.
α‐L‐Glutamyl Choline
Authors: Amiard Gaston , Heymès René
Published: September 2010

La N‐tritylation des diesters glutamiques, en protégeant la fonction ester en α, permet d'accéder au N‐trityl‐L‐glutamate d'α‐(β'‐chloro éthyle). Le traitement usuel par la triméthylamine suivi de la détritylation en acide acétique aqueux conduità l'α‐L‐glutamyl choline qu'on isole sous forme d'iodure et de nitrate cristallisés.
On the sulphonation of pyridine‐N‐oxide
Authors: van Ammers M. , den Hertog H. J.
Published: September 2010

The sulphonation of pyridine‐N‐oxide with fuming sulphuric acid and mercuric sulphate as a catalyst yields, together with the 3‐sulphonic acid as chief product, the 2‐ and 4‐isomers.
The polymerisation of 4‐chloropyridine
Authors: Wibaut J. P. , Broekman F. W.
Published: September 2010

The polymerisate of 4‐chloropyridine consists of a mixture of water‐soluble substances showing the properties of pyridyl‐4‐chloropyridinium chlorides. These compounds are rapidly decomposed by water, the chlorine in the pyridine ring being split off hydrolytically.

From measurements on the U.V. spectra, it appears that 4‐hydroxypyridine and N(4′‐pyridyl)‐4‐pyridone are produced in the hydrolysis of the polymerisate. These compounds were isolated in the form of their picrates. In addition, two other picrates have been isolated, which are in all probability derived from compounds containing more than two pyridine rings.
The decomposition of organic hydroperoxides: Part II. The effects of magnesium and zinc stearate on 1,2,3,4‐tetrahydronaphthyl‐hydroperoxide
Authors: van Leeuwen H. B. , Wibaut J. P. , Bickel A. F. , Kooyman E. C.
Published: September 2010

The decomposition of 1,2,3,4‐tetrahydronaphthyl‐1‐hydroperoxide (α‐tetralyl hydroperoxide) in the presence of catalytic amounts of zinc and magnesium stearate has been investigated in chlorobenzene and other solvents. For comparison, α, α‐dimethylbenzyl hydroperoxide (α‐cumyl hydroperoxide) and tert.butyl hydroperoxide have also been decomposed in the presence of the above catalysts.

With zinc stearate, α‐tetralyl hydroperoxide predominantly yields phenolic products, the zinc soap apparently acting as a Lewis acid. Hydrogen is also obtained; it is probably generated by interaction of the phenolic aldehyde formed (γ‐(ortho‐hydroxyphenyl) butyraldehyde) and the hydroperoxide. The zinc stearate shows little effect, however, on the decomposition of α‐cumyl and tert.butyl hydroperoxide.

Magnesium stearate causes a free‐radical chain decomposition of α‐tetralyl hydroperoxide (see Part I

H. B. van Leeuwen et al., Rec. trav. chim. 77, 17 (1958).

) yielding mainly tetralone and tetralol. This metal soap also accelerates the decomposition of tert.butyl hydroperoxide and, to a less extent, of cumyl hydroperoxide.

The catalytic influence of both magnesium and zinc stearate is markedly affected by the solvents employed.
The interaction between two cylinder shaped colloidal particles
Authors: Sparnaay M. J.
Published: September 2010

The theory of the stability of lyophobic colloids, as given by Derjaguin and by Verwey and Overbeek for the flat‐plate model or the sphere model of colloidal particles, is applied to cylindershaped colloidal particles.

Anisometry was taken into account by considering the interaction between two parallel particles and between two particles in a crossed position. Mathematical expressions are given for the repulsive and the attractive potential energy in these two cases. It should be inferred from these expressions that the behaviour of two parallel cylinders is intermediate between the behaviour of two flat plates and two spheres whereas two crossed cylinders behave in much the same way as two spheres.
The use of U.V. absorption spectra for the determination of configurations of some aromatic oximes
Authors: Rekker R. F. , Veenland J. U.
Published: September 2010

The U.V. absorption spectra of a series of benzophenone oximes are discussed. Notwithstanding relatively small differences in absorption of the isomers, incontestable conclusions as regards configurations can be drawn, even if only one of the conceivable isomers is available. The results agree with what might be expected on the assumption that the Beckmann rearrangement proceeds via an anti‐migration.
Studies on the oxidation of isomeric 6‐octadecenoic acids. Characterisation of 6(7)‐hydroxy‐7(6) ketostearic acids
Authors: Farooq M. O. , Osman S. M.
Published: September 2010

Oxidation of petroselinic or petroselaidic acid with neutral potassium permanganate gave mainly a mixture of two structurally isomeric hydroxy‐ketoacids, characterised as 7‐hydroxy‐6‐ketostearic acid, m.p. 77.5‐78.5 and 6‐hydroxy‐7‐ketostearic acid, m.p. 74.5‐75.0°. Lead tetraacetate is shown here to be an effective cleavage reagent for 1,2‐ketols and 1,2‐diketones. The oxidation of the cis‐ and trans‐6‐octadecenoic acids with hydrogen peroxide with and without catalyst (OsO4) has been studied. The cis‐hydroxylation of petroselinic and petroselaidic acids is also described.
A synthesis of oxytocin
Authors: Beyerman H. C. , Bontekoe J. S. , Koch A. C.
Published: September 2010

The synthesis is described of the “protected” linear nonapeptide: N‐benzyloxycarbonyl‐S‐benzyl‐L‐cysteinyl‐L‐tyrosyl‐L‐isoleucyl‐L‐glutaminyl‐L‐asparaginyl‐S‐benzyl‐L‐cysteinyl‐L‐prolyl‐L‐leucylglycine amide (XI). In the new reaction steps N,N′‐dicyclohexylcarbodiimide was used as sole coupling agent in combination with a variety of blocking groups.

The conversion of XI into the pituitary hormone oxytocin is known.
Studies on vitamin D and related compounds IX: Remarks on the iodine‐catalyzed isomerisations of vitamin D and related compounds
Authors: Verloop A. , Koevoet A. L. , van Moorselaar R. , Havinga E.
Published: September 2010

Details on the iodine‐catalyzed reactions of previtamin D, tachysterol, cis‐ and trans‐vitamin D (influence of solvent, concentration, wavelength of light) are given. The possibility of a previtamin D determination based on the cis/trans isomerisation is indicated. Some results and products obtained from the iodine‐catalyzed reactions in the vitamin D3 series are reported.
Square wave electrolysis II: The cyclic current‐step method
Authors: Wijnen M. D. , Smit W. M.
Published: September 2010

A new method, designated the cyclic current‐step method, for the evaluation of kinetic parameters of electrochemical processes (especially the exchange current j0) is introduced in addition to the well‐known (single) current‐step method. Its essential basis is that a square wave current is forced through a polarisable electrode and the voltage response of the electrode is measured.

It is shown mathematically that the voltage response approaches a constant pattern when “coulomb‐symmetry” is present and a gradually changing pattern is observed when a departure from coulomb‐symmetry occurs. Even when the pattern is continuously changing due to the presence of coulomb‐asymmetry the evaluation of j0 may be easily achieved.

By means of the cyclic current‐step method it is easily visualised whether or not the influence of the double layer capacity is negligible. Moreover, the method provides a ready means for the elimination of the ohmic part of the voltage response of the electrolytic cell.