bluuebunny/crossref_metadata_2025 huggingface dataset:
Atom transfer and electron exchange processes with cobalt complexes
Authors: Adamson Arthur W.
Published: September 2010

The results of some investigations of several redox processes involving cobalt complexes are presented. For the first group of reactions below, oxidation appears to be accomplished in a single act by the direct addition of the oxidizing atom or group to the cobaltous complex:

On the other hand, cases studied which appear to involve an electron transfer type of process include:

Co(CN)5−3+Fe(CN)6−3+H2O= [Co(CN)5(H2O)]−2+Fe(CN)6−4

Co(C2O4)3−4+Ce(IV)=Co(C2O4)5−3+Ce(III)

CoV−2+Fe(CN)5−3=CoV−1+Fe(CN)6−4 (V=ethylene diaminetetracetate)

Co*(C2O4)3−4+Co(C2O4)3−3 = exchange

Co V−2+Co*V−1 = exchange

Reactions of the first type are generally faster than those of the second, and possible explanations are discussed, along with some details of the kinetics of the reactions and a description of the several new complexes involved. In particular, an examination of the energy level diagrams predicted by Crystal Field Theory provides some explanation of the slowness of the electron transfer processes.
The basicities of the methyl 1,2‐benzanthracenes
Authors: Mackor E. L. , Dallinga G. , Kruizinga J. H. , Hofstra A.
Published: September 2010

The basicity constants of eleven methyl 1,2‐benzanthracenes and the absorption spectra of their conjugate acids were measured in anhydrous hydrofluoric acid. It could be shown that in every case two isomeric ions, in which the proton has reacted with either of the two meso carbon atoms, were present.

The basicity constants of the conjugate acids could be determined. The relative increase of this constant on methyl substitution is compared with theory.
Molecular complexes and their spectra. VI. Some problems and new developments
Authors: Mulliken Robert S.
Published: September 2010

Although the charge‐transfer theory probably affords a correct general account of major aspects of the structure and spectra of molecular complexes, its application to the detailed structures of particular types of complex presents a variety of problems whose definitive solution will require much new experimental and theoretical research, but should then yield many interesting conclusions. The effects of London dispersion forces and classical electrostatic forces as well as charge‐transfer forces must always be taken into account. Orientation isomerism, acceptation cross‐sections of acceptor molecules, paraffin‐halogen interactions and their contact charge‐transfer spectra, intensity problems, the blue shift of the iodine visible band in the spectra of iodine complexes, and complexes with two charge‐transfer spectra, are discussed below.
Etude Spectroscopique des Complexes Moléculaires: Halogènes‐Substances Organiques”
Authors: D'Or L. , Alewaeters R. , Collin J.
Published: September 2010

Le spectre‐infrarouge de solutions de chlore et de brome dans le benzène a été étudié. Les bandes à 526 cm−1 et à 301 cm−1 (dans l'état libre 557 cm−1 et 231 cm−1), respectivement celles qui disparaissent après élimination du halogène, sont attribuées aux molécules de halogène engagé dans un complexe avec le benzène. La structure possible de ces complexes est discutée.
Complexes of aromatic nitrocompounds
Authors: Bier A.
Published: September 2010

Equilibrium constants, enthalpy and entropy of formation, together with maxima of absorption, are recorded for a number of molecular compounds of symm.‐trinitrobenzene with aromatic hydrocarbons and aromatic amines in chloroform solution. The data are compared with van de Stolpe's findings on complexes of iodine, and some other regularities are discussed.
Synthesis and properties of the chlorination products of methyl 4‐Amino‐2‐Hydroxy‐Benzoate. II
Authors: van der Stelt C. , Nauta W. TH.
Published: September 2010

Whereas methyl 1,3,3,5,5,6‐hexachloro‐cyclohexanedione‐2,4‐carboxylate‐1 (XIV) was obtained by the chlorination of methyl 4‐amino‐2‐hydroxy‐benzoate (XIII) (P.A.S. methyl ester) in a mixture of glacial acetic acid and hydrochloric acid (s.g. 1.19), chlorination of XIII in carbon tetrachloride yielded two isomers with gross formula C8H4O3NCl7 (XXIII and XXIV), to which the structure of a methyl 1,3,3,5,5,6‐hexachloro‐4‐chlorimino‐cyclohexanone‐2‐carboxylate‐1 is assigned. The isomerism of XXIII and XXIV is thought to be of the syn‐anti type with regard to the attachment of the chlorine atom to the nitrogen. Reduction with stannous chloride converted both XXIII and XXIV into methyl 4‐amino‐3,5‐dichloro‐2‐hydroxy‐benzoate (XV). Hydrolysis of the two isomers led to the same nitrogen‐free compound C8H4O4Cl0, which is believed to be a stereo‐isomer of XIV and to which consequently the same name is attributed (XXV). With regard to the chlorine atoms attached to the carbon atoms 1 and 6, XIV is supposed to be the cis and XXV the trans form. Both XIV and XXV could be converted into methyl 3,5‐dichloro‐2,4‐dihydroxy‐benzoate (XVIII) by reduction. A mixture of XIV and XXV was obtained by chlorination of XIII, XV, XVIII and methyl 2,4‐dihydroxy‐benzoate in glacial acetic acid alone. In alkaline medium XXV decomposed, dichloro acetic acid and monomethyl trichloroglutaconate being the decomposition products. With hypochlorous acid XXV reacted to give trichloro‐acetic acid and methyl pentachloro‐glutarate (XXVI). Aniline converted XIV and XXV into two isomeric addition products: C14H11O4NCl6. Whereas XXV is reduced to XVIII by an aqueous potassium iodide solution, XIV yielded a compound for which the structure of a methyl 1,3,5,5,6‐pentachloro‐2‐hydroxy‐cyclohexene‐2‐one‐4‐carboxylate‐1 (XXIX) is made plausible. Further reduction converts XXIX into XVIII. Our view on some of the structures is supported by evidence from U.V. and I.R. spectra. Of several compounds tested, XXIV showed a considerable fungicidal activity.
An electron‐diffraction investigation into the vapours of cyclohexanone and 2‐methylcyclohexanone: Second communication on the molecular structures of ketones
Authors: Romers C.
Published: September 2010

The vapours of cyclohexanone and 2‐methylcyclohexanone are investigated with the aid of electron‐diffraction. The bond distances are 1.54 ± 0.01 Å, 1.24 ± 0.02 Å, and 1.09 ± 0.02 Å for CC, CO, and CH respectively. All the carbon bond angles are 109.5 ± 2.5°, with the exception of the bond angles of the carbonyl carbon atom, which are 117 ± 3° and 121.5 ± 1.5° for CCC and CCO angle respectively.

The methyl group of 2‐methylcyclohexanone is found in equatorial orientation.
The behaviour of membranes between electrolyte solutions : IV. Electrochemically active precipitates in membranes; the membrane potential at the barium sulphate‐cellophane membrane
Authors: Hirsch‐Ayalon P.
Published: September 2010

Impregnated membranes show peculiarities as to membrane potentials and permeability. The special behaviour of such membranes is examined by means of the example of a BaSO4‐cellophane membrane.

The membrane potential at the BaSO4 membrane is affected in a different way by different electrolytes in the adjacent solutions. The relation between the membrane potential and the pH of the adjacent solutions is expressed in

MP = 2.3026 RT/F · (pH1 − pHo).

Under the given conditions the membrane is impermeable to Ba2+ and SO42−. permeable to H+ and OH−.
Chemical and pharmacological data on aminoethoxypyridines and their acetyl derivatives
Authors: Bijlsma U. G. , den Hertog H. J.
Published: September 2010

Syntheses of 2‐amino‐4‐ethoxy‐, 3‐amino‐2‐ethoxy‐, and 3‐amino‐4‐ethoxypyridine are described. A survey is given of the group of aminoethoxypyridines, all the possible members of which are now known. The picrates and monoacetyl derivatives of these compounds have been prepared.

The antipyretic effect of the monoacetyl compounds of nine isomeric amino‐ethoxypyridines is compared with that of phenacetin (= p‐acetylaminoethoxy‐benzene). Not the para‐substituted, but some of the other isomers compete with the benzene derivative.

3‐Amino‐4‐ethoxypyridine may be considered to be an analogon of the 1‐alkoxy‐2‐amino‐4‐nitrobenzenes, sweeting substances, studied by Blanksma and Verkade; it has no sweet, but a bitter taste and possesses an anaesthetic effect which approaches that of procaine.
The preparation of 2,4,6‐trimethoxymethyl phenol
Authors: de Jonge J. , van Den Bergh H. J.
Published: September 2010

The preparation of 2,4,6‐trimethoxymethyl phenol has been described.
Synthesis of β‐phenyl‐ethylamine derivatives. IV . A new vasodilator
Authors: Moed H. D. , van Dijk J.
Published: September 2010

The synthesis and properties of a new vasodilating agent are described:

magnified image
Some observations on the oxidation products of phloroglucinol
Authors: Stein H. N. , Tendeloo H. J. C.
Published: September 2010

Measurements of the diffusion coefficients of products of the oxidation of phloroglucinol indicate that substances are formed containing a number of benzene rings per molecule.
The ortho/para distribution of methylol groups in the reaction of phenol and formaldehyde. I
Authors: de Jong J. I. , Dijkstra R. , de Jonge J.
Published: September 2010

In the reaction between phenol and formaldehyde in aqueous solution at 90° C and pH = 5.5‐6.5 about 58% ortho substitution and 42 % para substitution takes place initially.

A colorimetric method for the determination of methylol phenols in solution is described.
Chemistry of acetylenic ethers. XIX. The reaction of aldehydes with ethoxyethynylmagnesium bromide
Authors: Postma J. C. W. , Arens J. F.
Published: September 2010

The reaction of aldehydes with ethoxyethynylmagnesium bromide does not yield the expected secondary carbinols. In the case of aromatic aldehydes the reaction products are formed from two molecules of the aldehyde and one molecule of the acetylenic compound.

The structures of these compounds have been established by several transformations (see reaction scheme I) and the chemistry of their formation has been studied (reaction scheme II).

Aliphatic aldehydes and ethoxyethynylmagnesium bromide give products derived from three molecules of the aldehyde and one of the acetylenic compound. In this case also the structures of the different transformation products have been investigated (reaction scheme III).
A note on the theory of aromatic substitution
Authors: Wepster B. M.
Published: September 2010

Some new experimental data are given in favour of the view that the charge distribution in the ground state of the phenyltrimethylammonium ion as well as of nitrobenzene does not correspond to the meta orientation found with electrophilic substitution.
La réaction de l'ammoniac sur le mercure en présence de traces d'eau
Authors: Michels A. M. J. F. , Dumoulin E. M. L. , Gerver J. H.
Published: September 2010

Il apparait dans certains cas des phénomènes qui semblent indiquer l'existence d'une action de l'ammoniac sur le mercure, aboutissant à la formation d'un composé explosif. Nous montrons ici qu'il s'agit de la formation d'un oxyde d'amminomercure, où des traces d'eau fournissent l'oxygène. Un ammoniacate plus stable se forme, avec plusieurs molécules de NH3.
Formation of α‐pyridones from α‐acylbenzyl cyanides
Authors: Wajon J. F. M. , Arens J. F.
Published: September 2010

Heating α‐acetylbenzyl cyanide I with a mixture of acetic acid and sulphuric acid leads to the formation of the α‐pyridone IV, formed by condensation of the amide II with the ketone III, both of which originate from the cyanide I (see scheme 1). A similar reaction has been observed with some other α‐acylbenzyl cyanides.

Several α‐pyridones have been prepared by condensation of α‐acylbenzyl cyanides Ia with a variety of ketones IIIa (scheme 2).
Reactions of amino‐acids and peptides with aromatic aldehydes I
Authors: Havinga E. , Spitzer E. L. T. M.
Published: September 2010

The reactions of some glycine derivatives with aromatic aldehydes (“Plöchl‐Erlenmeyer reaction”) have been studied,

a) using acetic anhydride as an acetylating medium and sodium acetate as a catalyst according to the conditions elaborated by Dakin;

b) according to the directions of Bergmann et al. in which ethanol is used as the solvent and no extra catalyzing agent is added.

It was confirmed that for method a) glycine residues with a free carboxyl group are essential, whereas for method b) it is necessary for the glycine residue to have a free amino group. Other amino‐acid residues may also react but less readily than glycine and possibly in a different way. Some new condensation products are described.
Studies in the pyrazole series, VI, some derivatives of 3,5‐dimethyl‐1‐(3′‐quinolyl) pyrazole
Authors: Scott F. L. , Ahearne A. , Reilly J.
Published: September 2010

The synthesis of the prototype (I A) of a new class of pyrazoles, the 1‐(3′‐quinolyl) pyrazoles, is described. The chlorination, and bromination of (I), to yield the 4‐halogenopyrazolyl compounds (I B and I C) has been shown to involve the hydrohalide salts of (I B) and (I C) as unstable intermediates.
On the reaction of acetophenone with formaldehyde
Authors: Heeringa L. G. , Beets M. G. J.
Published: September 2010

The discrepancy between the results of Fuson's work and our own on the alkali‐catalyzed reaction of acetophenone with formaldehyde in alcohol has been studied. Several compounds have been isolated and identified but 5‐benzoyl‐m‐dioxan, which according to Fuson should be the main reaction product, has not been found.
Acid anilides. VI. Quantitative paper chromatographic analysis of fatty acid anilides
Authors: de Jonge A. P. , Verhage A.
Published: September 2010

From relevant investigations, evidence had been obtained that a quantitative analysis of saturated fatty acid anilides is possible. In the present paper a description of this method of analysis is given, with particular reference to the behaviour of the anilides during analysis.
Steric effects on mesomerism. XV. Comparative investigations involving ultra‐violet absorption spectra, molecular refractions, basic strengths, and rates of reaction of derivatives of nitrobenzene
Authors: Wepster B. M.
Published: September 2010

For several series of compounds the variation in ultra‐violet spectrum, molecular refraction, basic strength, and rate of reaction, due to the presence of a more or less strong inhibition of mesomerism, has been investigated. The members of these series are derivatives of nitrobenzene, para‐nitroaniline, and para‐nitroacetanilide, substituted in such a way that the steric inhibition concerns exclusively the mesomeric interaction between the nitro group and the rest of the system.

When comparing these data, it appears that the percentual decrease of the importance of the mesomerism according to each of the criteria in question is approximately the same; several linear relations are found. The non‐linearity between the extinction coefficients of nitrobenzenes and para‐ nitroanilines is interpreted as the consequence of a decrease of the average angle of twist of the nitro group upon substitution of an amino group in para position.

By extrapolation of the straight lines found, data are obtained about:

the exaltation in the molecular refraction of nitrobenzene resulting from the mesomeric interaction between benzene ring and substituent.

the energy of mesomerism in para‐nitroaniline due to the interaction of the substituents.

the relative importance of mesomeric and inductive effects of the nitro group for the basic strength of para‐nitroaniline, and for the rate of deacylation of para‐nitroacetanilide.

the meta/para ratio of the inductive effect in benzene derivatives.

Finally the conclusions resulting from the data with regard to the effective sizes of alkyl groups are discussed.
The energy difference between the rotational isomers of some simple dipolar compounds in the liquid state
Authors: Ketelaar J. A. A. , van Meurs N.
Published: September 2010

Starting from the dipole moments of 1,2‐dibromoethane, 1,3‐dibromopropane and ethyl oxalate and isopropyl oxalate the energy difference between the rotational isomers of these compounds was calculated. The presence of only two stable conformations for every dipole substance was incorporated in the calculation. The energy values computed for both dibromides were in good agreement with those obtained from infra‐red and Raman measurements.
Preparation of pure lactulose
Authors: Bots J. P. L.
Published: September 2010

A simple method is described for the preparation of lactulose octaacetate by acetylation of the reaction product obtained by treating lactose with lime.

Pure lactulose was prepared by deacetylation of lactulose octaacetate with 0.1 N‐HCl at 71° C.
The action of hydrazine on 1,4‐DI‐(p‐ethoxybenzoyl)‐butane. 3,8‐DI‐p‐ethoxyphenyl‐4,5,6,7‐tetrahydro‐1,2‐diazocine
Authors: van der Zanden J. M. , de Vries G.
Published: September 2010

The action of hydrazine on 1,4‐di‐(p‐ethoxybenzoyl)‐butane affords products similar to those obtained in the reaction between 1,4‐dianisoyl‐butane and hydrazine1).
Reactions of amino‐acids and peptides with aromatic aldehydes II) ): Condensations of sarcosine esters under the influence of ultra‐violet irradiation
Authors: Spitzer E. L. T. M. , Havinga E.
Published: September 2010

The reactions of the ethyl and methyl esters of sarcosine with aromatic aldehydes under the influence of ultra‐violet irradiation have been studied. From the condensation reaction of each of the esters with p‐nitrobenzaldehyde three stereoisomeric racemic oxazolidines were isolated in a pure form. Probable configurations of these compounds are indicated. The condensation of sarcosine ethyl ester with p‐nitrosalicylic aldehyde also led to the isolation of three reaction products, two being analogous to the oxazolidines obtained with p‐nitrobenzaldehyde, the third having a different, as yet unelucidated structure. A preliminary investigation of the reaction mixture obtained from condensing the sarcosine ester with p‐chlorobenzaldehyde yielded one of the oxazolidines in a pure state.
Le point de charge nulle des sols lyophobes de AgI, AgBr et AgCl dans les mélanges eau‐acétone
Authors: Overbeek J. Th. G. , Watillon A. , Serratosa J. M.
Published: September 2010

D'après Mackor, la variation du point de charge nulle des suspensions colloïdales de AgI dans les mélanges eau‐acétone est dû tout d'abord au saut brusque du potentiel x de Lange aux faibles concentrations en acétone, et ensuite, à la variation de l'enthalpie libre de solvatation de l'ion Ag+ aux plus fortes teneurs en acétone. Utilisant la méthode microélectrophorétique à fond noir, nous trouvons pour AgI et AgBr un saut du potentiel x de 225 mV et pour AgCl un saut de 105 mV. Toutefois, la variation de l'enthalpie libre de solvatation de l'ion Ag+ pour les trois types de suspensions colloïdales est identique, ce qui vérifie parfaitement l'hypothèse de Mackor.
On the theory of chromatography I
Authors: Smit W. M. , van den Hoek A.
Published: September 2010

A theory of the chromatography of binary liquid mixtures resembling that of de Vault is given. In the present theory, however, preferential adsorption isotherms are used whereas in de Vault's theory absolute isotherms are employed. It is shown that de Vault's theory leads to impossible consequences. Unlike the absolute isotherms, the preferential adsorption isotherms of the components of a liquid mixture are experimentally determinable and may become negative. As a result of the introduction of preferential adsorption isotherms into the theory of chromatography the theory can be checked by experiments and possibilities can be predicted that could not be foreseen by de Vault's theory. Further, the influence of the adsorption of the “solvent” is automatically accounted for when preferential adsorption isotherms are used. Neglect of the adsorption of the solvent is not generally allowable, not even when some very general conclusions concerning three component systems are aimed at. The present theory has been subjected to a careful experimental check showing fair agreement between theory and experimental results. The experiments are described in part II.
Electrometric end points in the argentometric determination of cerium
Authors: Sant B. R.
Published: September 2010

Volumetric determination of cerium (IV), based on its reduction to cerium (III) by excess KSCN and the electrometric titration of the excess against standard silver nitrate, is described. It is shown that the potentiometric end points in the KSCN‐AgNO3 reaction in the presence of sufficiently large concentrations of sulphuric acid and/or cerium(III) yield accurate results. Amperometric studies on the cerium (IV)‐thiocyanate reaction are now under investigation.
Hydrolysis of ethyl acetate in hydrochloric acid solutions containing mannitol
Authors: Sadek Hussein , Elamayem M. S. Abu
Published: September 2010

Hydrolysis of ethyl acetate in 0.05 N‐HCl at 25°, 30°, 35°, and 40° C was carried out in the absence and presence of mannitol. The addition of mannitol lowers the velocity constant while the activation energy remains constant. The reaction is accompanied by reduction of the entropy of activation as a consequence of solvation effects. The results agree with Laidler's theory of electrostatic interaction.
A one‐electron L.C.A.O.M.O. treatment of hydrocarbon negative ions
Authors: Balk P. , de Bruijn S. , Hoijtink G. J.
Published: September 2010

It is shown that the one‐electron L.C.A.O.M.O. treatment is much more reliable for hydrocarbon mono‐ and di‐negative ions than for hydrocarbon molecules. The results of this treatment in which both the interaction between non‐adjacent 2p‐orbitals and overlap have been included, have been compared with polarographic half‐wave potentials, giving a mean value of the resonance parameter for adjacent 2p‐orbitals: β′o = −2.60 ± 0.030 eV.

It appears that by neglecting both interaction between non‐neighbouring 2p‐orbitals and overlap the same mean value is obtained, whereas the inclusion of overlap only, leads to a noticeably less negative value: β′o = −2.30 ± 0.020 eV. Apparently these effects of overlap and interaction between non‐neighbouring 2p‐orbitals compensate each other.
Electrochemical researches on paraffin membranes II: The specificity of special paraffin membranes as calcium‐ion electrodes
Authors: Tendeloo H. J. C. , Krips A.
Published: September 2010

A membrane consisting of a mixture of pure paraffin of low melting point, a calcium salt of low solubility in water and a non‐ionogenic detergent can be used as an electrode for the determination of calcium‐ion concentrations, viz. pCa. Investigations are here reported on solutions of mixtures of CaCl2 and KCl, or MgCl2.
Chemistry of acetylenic ethers XXVIII: α,α‐Dichlorodiethyl ether and its use for the preparation of acyl chlorides
Authors: Heslinga L. , Katerberg G. J. , Arens J. F.
Published: September 2010

Addition of two equivalents of hydrogen chloride to ethoxyacetylene yields α,α‐dichlorodiethyl ether (III). This substance reacts easily with carboxylic acids to yield acyl chlorides (X). α, α, β ‐Trichlorodiethyl ether (XIII), obtainable in two steps from trichloroethene (XI), shows the same reaction.
Chemistry of acetylenic ethers. XXIX.: Reactions of acetylenic ethers with some aromatic isocyanates. Formation of derivatives of 2‐quinolone
Authors: Nieuwenhuis J. , Arens J. F.
Published: September 2010

Ethoxyacetylene slowly adds phenyl isocyanate to yield 4‐ethoxy‐2‐quinolone I (R=H). A similar reaction occurs with p‐tolyl isocyanate.

From the Grignard derivative of ethylthioacetylene and phenyl isocyanate the anilide of ethylthiopropynoic acid VIII is obtained. The corresponding reaction with ethoxyacetylene does not yield a pure product.
The decomposition of organic hydroperoxides: Part I. Catalytic effects of the second group metal stearates on the decomposition of tetralyl hydroperoxide
Authors: van Leeuwen H. B. , Wibaut J. P. , Bickel A. F. , Kooyman E. C.
Published: September 2010

The decomposition of tetralyl hydroperoxide has been studied at 100° C in chlorobenzene solution, using glass reaction vessels.

The uncatalyzed reaction is very slow; initial decomposition may show irregularities depending on the pretreatment of the walls of the reaction flasks.

Whereas the stearates of beryllium, barium and mercury have little influence when added in amounts of a few percent molar based on the hydroperoxide, decomposition is markedly accelerated by cadmium, calcium, strontium, zinc and magnesium stearate; the effect increases in the order mentioned.

From the fact that the catalytic decomposition is suppressed by a phenolic inhibitor (2,6‐di‐t‐butyI‐4‐methylphenol) only in the case of magnesium stearate, it is concluded that a free radical chain decomposition occurs only in the presence of the latter catalyst.
The temperature variation of orthobaric density difference in liquid‐vapour systems. III. Alcohols
Authors: Costello J. M. , Bowden S. T.
Published: September 2010

The density of a variety of alcohols has been measured over ranges of temperature below and above the boiling point. It is shown that the variation of orthobaric density difference with temperature may be represented fairly well by the Verschaffelt equation. In general the exponent of the equation is substantially lower than that found for normal liquids, and its value depends on the temperature range examined.
Agarelectrophoresis of proteins
Authors: Bon W. F. , Nobel P. C.
Published: September 2010

Descriptions are given of an apparatus for agarelectrophoresis for use in the study of proteins and its application to the study of horse serum.
Phosphatide acids and derivatives. VII. The use of silver phenyl benzyl phosphate for the synthesis of monophenyl esters of phosphatidic acids
Authors: Pzn S. Mostert , Stegerhoek L. J. , Verkade P. E.
Published: September 2010

The preparation of phenyl benzyl esters of phosphatide acids and their debenzylation to the monophenyl esters by hydrogenolysis in the presence of a palladium/active carbon catalyst is described.
Total synthesis in the steroid series. II: d,l −3‐ethylenedioxy‐11 β‐hydroxy‐17‐oxymethyl‐D‐homoandrosta‐5: 16‐diene 18‐acid lactone (18 → 11), an intermediate to aldosterone
Authors: Szpilfogel S. A. , van der Burg W. J. , Siegmann C. M. , van Dorp D. A.
Published: September 2010

Attempts to transform potential intermediates prepared earlier into 18‐oxygenated steroids are described. One of the routes lead to the substiuted D‐homoandrostane derivative (XXIX) mentioned in the title.
Investigations on herbicides I. 2‐(Substituted amino)‐4,6‐dichloro‐1,3,5‐triazines
Authors: Koopman H. , Daams J.
Published: September 2010

In view of their herbicidal properties a number of 2‐(substituted amino) −4,6‐dichloro‐1,3,5‐triazines was synthesized by a method described in the literature. The influence of the side chain on the herbicidal properties was determined. For this reason some derivatives mentioned in the literature were included to compare them with the new compounds in our biological tests.
Synthesis of β‐phenylethylamine derivatives V: Bronchodilators II
Authors: Moed H. D. , van Dijk J. , Niewind H.
Published: September 2010

The chemistry is described of three adrenaline‐like compounds: magnified image

The compounds were examined for their ability to protect guinea pigs from bronchial spasm induced by acetylcholine. The possible influence of the hydroxylated benzene nucleus of the side chain on the drug‐receptor combination is discussed.
Foam stability: Part IV. Kinetics and activation energy of film rupture
Authors: de Vries A. J.
Published: September 2010

High‐speed cinematography of collapsing lamellae of an aqueous Tee‐pol solution reveals that spontaneous rupture always takes place in the thinnest part of the lamella. The rate of hole expansion is dependent on the thickness of the lamella; its value is found to be in the order of some hundreds of cms per second. Dupré's assumption that the released surface energy will be completely converted into kinetic energy of the liquid appears to be essentially correct. Film rupture in a foamed aqueous solution of ammonium oleate is shown to proceed at a rate which is at least of the same order of magnitude as that in the isolated lamellae.

Deformation of a foam lamella occurs locally when a hole is about to be formed. The deformation and the very first beginning of hole expansion require an energy of activation which is calculated with the aid of a geometrical model. The energy is more than 1,000 kT units in a “black” film of an aqueous soap solution. This amount of energy has to be supplied in order to increase the interfacial area. The activation energy is proportional to the square of the film thickness and its value is hardly influenced by the magnitude of the electric double‐layer interaction.

The formation and relative stability of “black spots” in films of much larger thickness than the spot itself is shown to be the result of an equilibrium, existing at a thickness between 100 and 150 Å, of the three forces coming into play: London‐Van der Waals attraction, double‐layer repulsion and surface tension.
Electrochemical researches on paraffin membranes III. Measurements of the activity of the calcium ions in solutions of gelatin and gum arabic
Authors: Tendeloo H. J. C. , Krips A.
Published: September 2010

A membrane consisting of a mixture of pure paraffin, calcium oxalate and a non‐ionogenic detergent can be used as an electrode to determine pCa in solutions of gelatin and gum arabic.
The effect of U.V.‐light on some components of the nucleic acids: I. Uracil, thymine
Authors: Rörsch A. , Beukers R. , Ijlstra J. , Berends W.
Published: September 2010

At least three different reactions occur on irradiation of uracil in aqueous solution with light from a low pressure mercury lamp. One of these is reversible. The most rapid irreversible reaction may be a cause of the mutagenic and lethal effect of this light. The slow irreversible reaction, which also occurs in the irradiation of thymine, is probably brought about by the peroxide, which is produced to a small extent.

When they are dissolved in water many compounds have an absorption maximum in the neighbourhood of 200 mμ.
Oxidation of cholesterol. Influence of the stereochemical configuration of halogenated cholestane derivatives on the yield of 17‐ketosteroids
Authors: Maas S. P. J. , de Heus J. G.
Published: September 2010

Several halogenated and hydrohalogenated cholesteryl acetates were subjected to comparative oxidations with chromic acid. In addition 5α‐cholestan‐3β‐yl acetate, 5β‐cholestan‐3β‐yl acetate and 3β,5α,6β‐trihalogenated cholestane were used as a starting material. Comparison of the results of the experiments showed that the bromine atom in the β‐position at C6 exerted the greatest‐influence on the formation of 17‐ketosteroids.
The chemical effect of light on sodium ρ‐methoxybenzenediazosulphonate
Authors: Dijkstra R. , de Jonge J.
Published: September 2010

It could be derived from kinetic measurements that irradiation of an aqueous solution of ρ‐methoxybenzenediazosulphonate with ultra‐violet light causes a dissociation of the sulphonate ion to form a ρ‐methoxybenzene‐diazonium ion and a sulphite ion. The ions produced photochemically slowly recombine in the dark to form back the original sulphonate ion.

The reactions may be represented by the scheme: magnified image

The occurence of a labile or cis‐diazosulphonate can practically be precluded.
Implications of template theories of protein biosynthesis
Authors: Dalgliesh C. E.
Published: September 2010

The organization, during biosynthesis, of the specific structures of proteins can reasonably be explained on the basis of the ability of macromolecules (provided they are formed from more than a few distinguishable monomeric forms) to carry information. In such “template mechanisms” the template may function by determining either a sequence of reactions in time, or a sequence of reactions in space. In the latter case a template might be a “positive” or a “negative” of the protein being formed. A “negative” relationship is usually assumed, with nucleic acid playing the complementary role. Even if a template determines primarily a sequence of reactions in space, rather than in time, the individual reactions (i.e. formation of individual peptide bonds) probably occur successively rather than simultaneously. Possible “template mechanisms” for protein synthesis are outlined in general terms, and some simple kinetic consequences are considered. Other problems discussed include the desirability of assessing the contribution of exchange (if it occurs) in the incorporation of amino acids into proteins, and the implications of a template mechanism for incorporation of intact peptides.
Electrochemical researches on paraffin membranes IV. Measurements of the binding of calcium ions by human serum albumin
Authors: Tendeloo H. J. C. , Krips A.
Published: September 2010

To test the usefulness of a paraffin membrane containing calcium oxalate as an electrode for the determination of concentrations of calcium ions the binding of these ions by human serum albumin has been investigated. It has been found that 0.13 ± 0.02 milligram atoms of calcium ions are bound by one gram of human serum albumin.
Equilibria in the ternary system sodium metaborate ‐ sodium perborate ‐ water
Authors: van Gelder D. W.
Published: September 2010

The equilibria between the solid and liquid phases in the system sodium metaborate–sodium perborate–water have been investigated at 18°, 25°, 37.5° and 50° C. Three stable solid phases were found: NaBO2.4H2O, NaBO3.3H2O and NaBO2.NaBO3.4H2O. Metastable equilibria with NaBO3.4H2O as the solid phase could be realised for a long time over the whole region.
Self‐cooling in solid reactions. A.‐ dehydration of alums
Authors: Anous M. M. T.
Published: September 2010

Single crystals of potash alum of different weights were grown on copper‐constantan thermocouple junctions. The self‐cooling was determined during dehydration. Very small increase in self‐cooling with increase in weight was noticed above ∼3 g. The self‐cooling was also determined for chrome alum crystals of mass ∼ 1 g during dehydration at thermostat temperatures of 19.5 to 39.5°. The rate of propagation previously determined

Anous, Bradley and Colvin, J. Chem. Soc. 1951, 739, 3348.

), as well as the actual crystal temperature measured in this work, were used to calculate the activation energy. It is ∼ 26 kcal per mole which is in very good agreement with that obtained by using the theoretically calculated self‐cooling.
Corrections of the theory of the flat diffuse double layer
Authors: Sparnaay M. J.
Published: September 2010

The potential distribution in the diffuse part of the ionic double layer, which is formed at the interface between a solid and an electrolyte solution, is given by the Poisson Boltzmann equation. This equation, involving some approximations, is modified such, that now the following effects are included:

The effect of ionic sires.

The effect of the dependence of the dielectric constant upon the ionic concentration and upon the electric field, present near the interface. Two opposed tendencies can be distinguished here: a) the solution near the interface is polarized [Prigogine, Mazur and Defay) usually giving rise to a decrease of the ionic concentration near the interface; b) Coulomb interactions near the interface, between the ions and the interface, are different from those, predicted from the unmodified theory. This will give rise to a relative increase of the ionic concentration. It appears, that tendency b) outweighs tendency a).

A flat interface and a 1‐1 electrolyte solution are considered only. The effects are represented as correction terms added to the original Poisson Boltzmann equation. The new equation is integrated using elementary methods. The result of the calculations is, that corrections are negligibly small, when the electrolyte concentration is of the order of 10−3 normal. When the concentration is 10−2 normal, the corrections amount to 10‐20% of the value of the double layer potential, whereas the given treatment breaks down, when the concentrations are 10−1 normal or higher.
Selective reduction by calcium hexammine II. Reductive cleavage of sulphur compounds
Authors: van Schooten J. , Knotnerus J. , Boer H. , Duinker Ph. M.
Published: September 2010

Calcium hexammine suspensions as developed in earlier work for reduction of aromatics

H. Boer and Ph. M. Duinker, Rec. trav. chim. 77, 346 (1958).

have now been found to constitute mild and convenient agents for effecting reductive cleavage of aromatic types of sulphur compounds, in which the sulphur atom is linked either directly to the aromatic nucleus or to a methylene group which is attached to an aromatic nucleus.

This reduction process is always accompanied by the cleavage of a carbon‐sulphur bond, the sulphur compound being split into lower molecular weight products, unless the sulphur was bound in a ring. Alkyl benzyl sulphides are split into a mercaptan and toluene and alkyl phenyl sulphides into a thiophenol and an alkane, while benzothiophenes quantitatively yield 2‐alkylthiophenols and dibenzothiophene yields about 80 mol% 2‐cyclohex (en) ylthiophenol.

Sulphur linked to two CH2‐groups, each adjacent to an aromatic nucleus, is removed as H2S.

The relations between the structures of the sulphur compounds and those of their reduction products are discussed with respect to possible reaction mechanisms.
The preparation of some dialkyl p‐nitrophenyl phosphates
Authors: de Roos A. M. , Toet H. J.
Published: September 2010

Dialkyl p‐nitrophenyl phosphates have been prepared by the interaction of dialkyl phosphorochloridates and sodium p‐nitrophenoxide. Physical constants of these faintly yellow coloured phosphates are recorded, infrared spectra included.
Chemistry of acetylenic ethers XXXIV: On the reactivity of acetylenic ethers and thioethers; the dual character of alkylthio groups
Authors: Volger H. C. , Arens J. F.
Published: September 2010

In this paper we compare addition reactions to ethoxyethyne with those to ethylthioethyne, in order to show up similarities and differences with respect to the orientations. The similarities are due to the similarity in character of OR and SR groups. Both groups allow the following polarisation: magnified image

Electrophilic reagents are therefore added to the β‐carbon atom. The differences, on the other hand, concern additions of nucleophilic reagents BH. Ethoxyethyne, polarised as above, yields adducts of the type: magnified image

Ethylthioethyne, however, is converted into products of the type:

equation image

This important difference is explained by the ability of sulphur to accomodate a decet of electrons in its valence shell. It can therefore also act as an electron acceptor, allowing reversed polarisation of ethylthioethyne thus: magnified image

This is especially favourable for reactions with nucleophilic reagents and results in the observed mode of addition.

Differences between the effects of alkoxy and alkylthio groups encountered in the literature can be understood from this dual nature of alkylthio groups.
Investigations on pyrazine derivatives IV. The preparation and specific oxidation of a number of 2,3‐dialkoxy‐ and 2,3‐diaryloxy‐quinoxalines
Authors: Mager H. I. X. , Berends W.
Published: September 2010

The preparation of a number of 2,3‐dialkoxy‐ and 2,3‐diaryloxyquinoxalines is described in detail. Unlike many other substituted quinoxaline derivatives, these compounds appear to be relatively very stable towards potassium permanganate.

It is demonstrated that the introduction of particular substituents into the benzene ring of these quinoxaline derivatives again produces starting materials for the preparation of pyrazine carboxylic acids.
The preparation of some iso‐propyl p‐nitrophenyl alkylphosphonates
Authors: de Roos A. M. , Toet H. J.
Published: September 2010

In the series of the iso‐propyl p‐nitrophenyl alkylphosphonates the lower homologues have been prepared by interaction of iso‐propyl alkylphosphonochloridates and sodium p‐nitrophenoxide. All these p‐nitrophenyl derivatives are yellow liquids; boiling points and refractive indices are given, as well as an example of the infrared spectra.
Quantitative interpretation of ultra‐centrifugal and electrophoretical investigations on the eye‐lens protein, α‐crystallin
Authors: Bon W. F.
Published: September 2010

From ultracentrifugal and electrophoretical data it appears to be probable that solutions of α‐crystallin of the eye‐lens contain two subunits of equal molecular weight, differing in shape only.
Isotherms for preferential adsorption from binary liquid mixtures, based on langmuir equations
Authors: Klinkenberg A.
Published: September 2010

The isotherms for preferential adsorption from a binary liquid mixture may be of so‐called “U” or “S” shape. Those of “U” shape are in certain cases describable by Langmuir‐type equations in terms of two parameters. These are the relative adsorbability of the two components and the volume of the adsorbed layer, the latter being considerably smaller than the volume of the pores within the particles of the adsorbent. It is shown, how these parameters may be derived from experimental data.
Cupric tetramminosulphate. I. Thermal decomposition
Authors: Anous M. M. T.
Published: September 2010

A completely anhydrous sample of cupric tetramminesulphate has been prepared. The product previously reported to be anhydrous was found to contain up to 4% of moisture on keeping over calcium chloride. Thermal decomposition of the slightly hydrated, as well as the completely anhydrous compounds, was followed in a closed apparatus at atmospheric pressure and/or in a vacuum. Two molecules of ammonia were reversibly liberated on two successive steps. In a vacuum, the completely anhydrous, deep violetblue Cu(NH3)4SO4 lost one ammonia molecule at 30° and a second molecule at 55°, giving the pale blue Cu(NH3)2SO4. At temperatures above ∼90°, irreversible decomposition of the diammine occurs with the gradual formation of a dark‐grey to brown product, accompanied by sublimation of ammonium sulphate.
Investigations on pyrazine derivatives. V. A more detailed investigation on the catalytic hydrogenation of esters of pyrazine carboxylic acids
Authors: Mager H. I. X. , Berends W.
Published: September 2010

In the first publication in this series it was shown that only partial reduction of the pyrazine ring occurs in the catalytic hydrogenation of tetra‐carbethoxypyrazine. The remaining double bonds in the resultant reaction product are apparently stabilised. In agreement with the hypotheses put forward to explain this result, esters of other pyrazine carboxylic acids also are only partially reducible with palladium on carbon at room temperatures. The conclusion must be drawn that a carbalkoxy group attached to a pyrazine ring protects an adjacent double bond in the ring against catalytic hydrogenation.

The partially hydrogenated products from the esters of some pyrazine carboxylic acids are extraordinarily labile. Dehydrogenation by dismutation or reoxidation, which occurs to some extent, can be followed from the spectra.

Similar phenomena have been encountered in the pyridine series, which may be put forward as supporting the conclusions reached.
Lyotropic numbers of the formate and acetate ions and related thermodynamic properties
Authors: Morris D. F. C.
Published: September 2010

The data of Buchner and Kleijn on the flocculation of agar have been employed to calculate the lyotropic numbers of the formate and acetate ions. Hydration heats of the ions, comparable to those of Latimer, Pitzer and Slansky, have been derived from the lyotropic numbers. Other magnitudes, which have been obtained, include lattice energies and standard enthalpies of formation of formates and acetates.

Estimates of the standard enthalpies of formation of the formate and acetate radicals are quoted, and values for the electron affinities of the radicals are given.
A combined paper‐ and agar‐electrophoresis apparatus
Authors: Bon W. F. , de Vries J.
Published: September 2010

A combined agar‐ and paper‐electrophoresis apparatus which can be constructed in a normally appointed chemical laboratory, is described.
Electrochemical researches on paraffin membranes V. Antagonism of uni‐ and higher valenced cations
Authors: Tendeloo H. J. C. , Krips A.
Published: September 2010

Measurements are described on the e.m.f. of cells with electrodes of paraffin and polystyrene membranes of different composition in a number of solutions containing uni‐ or higher valenced cations. From these researches it follows that uni‐ and higher valenced cations behave antagonistically.
Theoretical study of nitrogen heterocyclics. IV. Molecular diagrams and carcinogenic activity of some naphthindoles
Authors: Fernandez‐Alonso J. I. , Domingo Rosario , Vila L. Carbonell
Published: September 2010

Molecular‐orbital calculations of structural static parameters (bond orders, π‐electron densities and free valences) and dynamic indices (atom, ortho‐ and para‐localization energies) are presented for a number of naphthindoles. The results are used to predict the chemical properties of the molecules. We have made a comparison of the carcinogenic inactivity and the static and dynamic complex indices used to characterize the K region in some benzindoles and these naphthindoles.
The preparation of some p‐nitrophenyl dialkylphosphinates
Authors: de Roos A. M. , Toet H. J.
Published: September 2010

The lower homologues in the series of the p‐nitrophenyl dialkylphosphinates have been prepared by the interaction of dialkylphosphinic chlorides and p‐nitrophenol in the presence of triethylamine. Physico‐chemical constants of the yellow phosphinates are recorded; an example of the infrared spectra is given.
Analytical applications of a celite/dinitrophenylhydrazine column
Authors: Begemann P. Haverkamp , de Jong K.
Published: September 2010

A method is described for the conversion of carbonyl compounds, which are present in very small concentrations in a light petroleum solution, into their 2,4‐dinitrophenylhydrazones. The light petroleum solution is passed through a column in which Celite acts as a carrier for 2,4‐dinitrophenyl‐ hydrazine hydrochloride. The carbonyl compounds then become almost quantitatively bound as 2,4‐dinitrophenylhydrazone.

This same column can also be used for the decomposition of ozonized, unsaturated compounds, with the simultaneous formation of the dinitrophenylhydrazones of carbonyl fragments, so enabling the location of double bonds in minute amounts of material.
Reaction products of primary β‐hydroxyamines with carbonyl compounds: XV. Condensation of Carbonyl Compounds with 3‐Mercaptopropylamine
Authors: Bergmann Ernst D. , Kaluszyner A.
Published: September 2010

3‐Mercaptopropylamine gives with formaldehyde and cyclohexanone tetrahydro‐1,3‐thiazines, whilst with benzaldehyde largely the corresponding Schiff base is obtained.

Some observations on the synthesis of 3‐mercaptopropylamine are recorded.
Reaction products of primary β‐hydroxyamines with carbonyl compounds: XVI) Condensation of Carbonyl Compounds with 4‐Hydroxy‐ and 4‐ Mercaptobutylamine
Authors: Bergmann Ernst D. , Kaluszyner A.
Published: September 2010

The condensation of 4‐hydroxybutylamine with various carbonyl compounds gave a cyclic compound (hexahydro‐1,3‐oxazepine) only in the case of formaldehyde. Benzaldehyde and acetophenone yielded the corresponding Schiff bases, cyclohexanone a mixture of the Schiff base with the isomeric cyclic compound. 4‐Mercaptobutylamine gave with cyclohexanone only the (cyclic) hexahydro‐1,3‐thiazepine.

Easy methods for the preparation of the two substituted amines are described.
Reaction products of primary β‐hydroxyamines with carbonyl compounds: XVII) Condensation of Carbonyl Compounds with Tetramethyleneglycol
Authors: Bergmann Ernst D. , Kaluszyner A.
Published: September 2010

The behaviour of tetramethyleneglycol towards aldehydes and ketones has been compared with that of ethyleneglycol and trimethyleneglycol. There is a certain disinclination to form the seven‐membered 1,3‐dioxepane ring. In several instances, open‐chain acetals have been obtained; many ketones did not react at all or only under relatively stringent conditions.

The infrared spectra of the condensation products have been determined and compared with those of the 1,3‐dioxolanes and 1,3‐dioxanes.