bluuebunny/crossref_metadata_2025 huggingface dataset:
Acid Anilides: II. The preparation of saturated fatty acid anilides from fatty acids and their esters
Authors: de Jonge A. P. , van der Ven B. , den Hertog W.
Published: September 2010

In the previous preliminary communication

A. P. de Jonge, Rec. trav. chim. 74, 760 (1955).

on the chromatography of acid anilides an outline was given of the method.

In this and forthcoming publications, details of the preparation, the ultraviolet and infra‐red absorption spectra and of the chromatography are described.

In the present communication the preparation of saturated fatty acid anilides is described. The melting points of the pure acid anilides have been determined, and the relevant data compared with those given in the literature. In addition, the solubility in water of the first four members of the homologous series has been determined.

In connection with analytical application, procedures are given for a quantitative preparation of the anilides starting from small amounts of acid or ester.
Acid Anilides: III. The ultra‐violet absorption spectra of fatty acid anilides
Authors: de Jonge A. P. , den Hertog W.
Published: September 2010

In this communication the ultra‐violet spectra in different solvents of the anilides of the homologous series of straight‐chain fatty acids from formic acid to capric acid (C10) and of the higher acids with an even number of carbon atoms as far as stearic acid (C18) are discussed.
Some fluoro‐substituted phenoxyacetic acids
Authors: Klaassens K. H. , Schoot C. J.
Published: September 2010

The preparation of 2,4‐dichloro‐6‐fluorophenoxyacetic acid, 2,4‐dichloro‐3‐fluorophenoxyacetic acid and 2,4‐dichloro‐5‐fluorophenoxyacetic acid is described.
5,7‐Dichlorocoumaran‐3‐one
Authors: Schoot C. J. , Klaassens K. H.
Published: September 2010

The preparation of 5,7‐dichlorocoumaran‐3‐one is described.
Molecular volumes and structural chemistry
Authors: McGowan J. C.
Published: September 2010

A list of atomic parachors is given and with its aid, parachors and molecular volumes of all kinds of molecules may be estimated. It is suggested that the atomic volume of a given element depends upon its electronic state so that the study of molecular volumes can throw light upon structural problems in chemistry, and this is illustrated by a consideration of certain compounds of the transition elements. In addition, examples are given to show how parachor values are likely to prove helpful in the study of ions in aqueous solutions.
The vibrational frequencies of S2Br2. Simultaneous spectrum in CS2 mixtures and infrared absorption spectrum
Authors: Ketelaar J. A. A. , Hooge F. N. , Blasse G.
Published: September 2010

From the simultaneous infrared spectrum of CS2 and S2Br2 three fundamental vibrational frequencies of S2Br2 could be determined. A fourth fundamental frequency was observed in the infrared absorption spectrum of pure S2Br2, where also overtones and combination tones were observed. The S2Br2 spectrum was compared with the S2Cl2 spectrum.
Synthesis of 4 (2′‐piperidyl) butanediol‐1,2 and of some nitrogen‐substituted derivatives; the degradation of these diols by means of lead tetraacetate(Experiments on the synthesis of alkaloids from punica granatum, 5th communication
Authors: Wibaut J. P. , Hirschel M. I.
Published: September 2010

4‐(2′‐piperidyl)butanediol‐1,2 (IX) and some of its nitrogen‐substituted derivatives were synthesized. These diols are subjected to a dehydrogenating degradation by means of lead tetraacetate. From IX is formed through this treatment, besides the formaldehyde to be expected, β‐(2‐piperidyl)‐propanal (I), a substance which, however, appeared to be unstable and could not be isolated as such. Dehydrogenating degradation of the N‐acetyl derivative, of the N‐benzoyl derivative or of the urethane of IX gives rise to the corresponding nitrogen‐substituted derivatives of I, which were previously obtained by Spielman et al. by a different route.
Crossed cannizzaro reaction with aromatic and heterocyclic aldehydes
Authors: Tiwari R. D. , Srivastava N. P.
Published: September 2010

Crossed Cannizzaro reaction furnishes a very convenient and useful procedure for the reduction of aromatic and heterocyclic aldehydes to the corresponding alcohols. In the present investigations aromatic aldehydes related to naphthalene and heterocyclic aldehydes related to furane have been subjected to crossed Cannizzaro reaction. From alpha‐naphthaldehyde, alpha‐naphthylcarbinol has been obtained in much better yield than by methods hitherto reported. From 5‐methyl‐furfural, 5‐methyl‐furyl carbinol has been obtained in 60% yield by a process much simpler than those previously employed for its preparation. Concentration of alkali and the temperature of the reaction have to be varied in different reactions as in some cases higher concentration of alkali leads to resinification.
Preparation and proof of the constitution of 3,5‐di‐tert. butyltoluene
Authors: Geuze J. , Ruinard C. , Soeterbroek J. , Verkade P. E. , Wepster B. M.
Published: September 2010

It is proved that the hydrocarbon of m.p. 31‐32° obtained by di‐tert.‐butylation of toluene is 3,5‐di‐tert.butyltoluene.
Dielectric properties of dilute solutions of polyvinyl acetate in toluene
Authors: de Brouckère Lucia , van Beek L. K. H.
Published: September 2010

Measurements of the complex dielectric constant have been carried out for solutions of polyvinyl acetate in toluene at concentrations ranging from about 5 to about 11 g/100 ml, at temperatures ranging from 235 to 261° K. The molecular weights of the polymer samples were 22, 65, 100, and 200 times 104. These samples were characterized by viscosimetry, osmometry, light‐scattering and dissymmetry.

It is found that the dipole moment of the molecule is proportional to the root mean square end‐to‐end distance and to the square root of the molecular weight. The frequency at which the loss curve has its maximum is independent of molecular weight, in contradistinction to the results predicted by Kirkwood and Fuoss and by Kuhn. This result can, however, be explained on the basis of the simple model used by Bueche and by Rouse.
Synthesis and properties of the chlorination products of methyl 4‐amino‐2‐hydroxy‐benzoate. I
Authors: van der Stelt C. , Suurmond B. G. , Th. Nauta W.
Published: September 2010

Exhaustive 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) yielded methyl 1,3,3,5,5,6‐hexachloro‐cyclohexanedione‐2,4‐carboxylate‐1 (XIV). Methyl 4‐amino‐3,5‐dichloro‐2‐hydroxy‐benzoate (XV), methyl 2‐amino‐4‐hydroxy‐benzoate (XVI), methyl 2,4‐dihydroxy‐benzoate (XVII), and methyl 3,5‐dichloro‐2,4‐dihydroxy‐benzoate (XVIII) could also be used as starting material for XIV. Reduction of XIV with stannous chloride yielded XVIII. With hypochlorous acid, XIV reacted with ring fission to form 1,1,2,3,5,5,5‐heptachloro‐3‐carbomethoxy‐pentanone‐4‐carboxylic acid‐1 (XIX). Both compounds XIV and XIX decomposed in alkaline medium and yielded monomethyl trichloro‐glutaconate (XX). In the first case the latter compound was accompanied with dichloro‐acetic acid, in the second case trichloro‐acetic acid was the other decomposition product. Glutaconic acid (XXI) was formed when XIX was reduced with sodium amalgam, while the structure of a 5‐carbomethoxy‐6‐trichloromethyl‐pyrone‐2 (XXII) is proposed for the reaction product of XIX with stannous chloride.
The application of Raman spectroscopy in the determination of structures of some complex compounds
Authors: Gerding H.
Published: September 2010

Results are discussed which have been obtained in the last few years by the application of Raman spectroscopy to the unravelling of structures of complex compounds, e.g. addition compounds of aluminium chloride with nitrosyl chloride, selenium tetrachloride, and tellurium tetrachloride.

Arguments are brought forward for considering NOCl. AlCl3 as a compound intermediate in structure between NO+AlCl4− and NOCl…. AlCl3. Compounds such as SeCl4. AlCl3 and TeCl4. AlCl3 clearly show features of the ionic structures SeCl3+AlCl4− and TeCl3+AlCl4− respectively.

In Cl3Al. NH3, on the contrary, a covalent bond between Al and N is present. Preliminary results for compounds SeCl4. SO3 and TeCl4. SO3 argue the presence in these compounds of SeCl3+ and TeCl3+ ions respectively as well.
The nature of some nitrosylchloride addition complexes
Authors: Lewis J. , Sowerby D. B.
Published: September 2010

The nature of the nitrosyl chloride addition compounds of some metallic and non‐metallic chlorides has been investigated. Weak compound formation with metallic chlorides (e.g. ZnCl2) leads to a slow heterogeneous exchange of labelled chloride with liquid nitrosyl chloride and to rapid exchange with the combined nitrosyl chloride. Rapid exchange of chloride occurs when the added chloride even forms a weak compound with nitrosyl chloride e.g. AsCl3. 2 NOCl. The stability of the addition complexes are investigated also in liquid nitrosyl chloride and other solvents by conductometric and spectroscopic methods.
Zur Frage der Bindung in den Cyclopentadienylmetallkomplexen mit Übergangsmetallen: Theoretisches
Authors: Ruch Ernst
Published: September 2010

Die Bindungsverhältnisse in den Cyclopentadienylverbindungen werden auf der Grundlage der molecular orbitals und äquivalenten orbitals auseinandergesetzt. Ein Energieschema auf der Basis berechneter Überlappungsintegrale wird im Vergleich mit einem oktaedrischen Durchdringungskomplex besprochen.

Die Möglichkeiten einer Bindung von aromatischen Systemen an Übergangsmetalle ohne wesentliche Beeinträchtigung der Bindungen innerhalb dieser Systeme wird diskutiert.
Isonitrile complexes of monovalent manganese
Authors: Sacco Adriano
Published: September 2010

The preparation and a number of properties of salts containing the [MnI(RNC)6]+ cation are discussed. The cation appears to be diamagnetic and shows considerable stability.
Crystal field stabilization and tendency towards complex formation of first transition group elements
Authors: Bjerrum Jannik , Jørgensen Chr. Klixbüll
Published: September 2010

The increased affinity towards complex formation exhibited by metal ions with an unfilled d‐shell is related to the crystal field stabilization of such compounds and furnishes an explanation of what is the basis of the so‐called Irving‐Williams rule. The orbital degeneracy of the ground term determines the symmetry of the configuration and is thus responsible for irregularities in the complexity constants.

If the total spin quantum number changes during a set of consecutive complex formation steps, a sudden change of activation energies and formation constants is to be expected, as recently has been verified. The activation energies are then expected and found high only when the crystal field stabilization is large and the orbital degeneracy one. High reaction rates on the other hand are to be expected for complete or half‐complete d‐shells without crystal field stabilization, and for nearly complete d‐shells if the orbital degeneracy is higher than one.
Interpretation of spectra of transition‐group complexes by means of the crystal field theory
Authors: Ballhausen C. J.
Published: September 2010

The crystal field theory, when applied to complexes of the first transition group, is able to describe the “visible” absorption bands of a cubic MA4 complex in terms of a single parameter. A special consequence of the theory is that the splitting of the first band of trans complexes of the Co(III)A4X2 type should be twice the splitting for the corresponding cis complexes, as has been observed.

By means of the crystal field theory it is further possible to account for the existence of magnetically normal (“ionic”) as well as magnetically anomalous (“covalent”) complexes. It is shown that a change in the magnetism does not a priori mean a change of the bond type.
Some new stereochemical arrangements of uni‐ and ter‐valent gold
Authors: Harris C. M. , Nyholm R. S. , Stephenson N. A.
Published: September 2010

The complex compounds formed by uni‐ and ter‐valent gold with a chelating ditertiary arsine group are described. Gold (I) co‐ordinates with two molecules of the chelate group to give four‐covalent, presumably tetrahedral, complex cations. Gold (III) gives rise to a four‐covalent cation with two molecules of the chelate group but on the addition of halide ions one can prepare cations of the formulae [Au(Diarsine)2]X++ and [Au(Diarsine)2X2]+ in which X is a halogen atom. The assigned five‐ and six‐covalency, in nitrobenzene solutions at least, are supported by various physical measurements. The structures of the compounds are discussed in terms of modern valency theory. Preliminary results of an X‐ray crystallographic study of AuI and the [Au(Diarsine)2]+ cation are reported. In each case a tetrahedrally co‐ordinated Au(I) atom is indicated.
The hydrolysis of some tripositive ions
Authors: Biedermann George
Published: September 2010

A review of experimental methods for investigating hydrolysis equilibria by emf measurements is given. Liquid‐junction potentials and the activity factors of the reacting species can be estimated by a suitable combination of cells. An emf method is mentioned for the accurate determination of the analytical hydrogen ion concentration of a solution containing metal ions of appreciable acidity constant.

Of the tripositive ions investigated only TI(III) forms exclusively mononuclear ions, TIOH2+, and TI(OH)2+ (pka1 = 1.14, pka2 = 1.49). The main products of hydrolysis of In(III) are ions of the formula In[(OH)2In]n3+n (for the first step pK = 5.21, for all following steps pK = 4.70).

At low [In(III)]total, InOH2+ and In(OH)2+ become appreciable (pka1 = 4.4, pka2 = 3.9). Similar results were found by Kilpatrick and Pokras for Sc(III) and by Hedström for Fe(III), the main hydrolysis products being Sc[(OH)2Sc]n3+n and Fe[(OH)2Fe]4+; at low metal ion concentration. ScOH2+ and FeOH2+, Fe(OH)2+ are predominant species. Al(III) seems to be an exception; Brosset's emf studies and other available data are consistent with the assumption that Al6(OH)153+ is formed in acid solutions.
The incomplete dissociation of thallous hydroxide
Authors: Bell R. P. , Panckhurst M. H.
Published: September 2010

The thallous ion and silver ions are unique among univalent cations in forming fairly strong complexes with univalent anions. A review of previous evidence (involving measurements of solubilities, conductivities and reaction kinetics) indicates that thallous hydroxide is incompletely dissociated, having a thermodynamic dissociation constant of about 0.15. New data are reported on the effect of thallous ions on the velocity of the fast reaction between nitroethane and hydroxyl ions. These lead to a similar value for the dissociation constant if it is assumed that the species TIOH does not react.

Measurements have also been made of the ultra‐violet absorption of solutions containing thallous and hydroxide ions. The results show clearly the presence of two distinct absorbing species, and although it is not possible to derive unambiguously a dissociation constant for TIOH, the data are consistent with the value given above.

The nature of the binding in TIOH is discussed in the light of the above findings.
The influence of the structure of chelating agents on the complexity and distribution constants of thorium complexes
Authors: Dyrssen David
Published: September 2010

This paper deals with results obtained by the distribution method described in the preceding paper

Margareta Dyrssen, The application of solvent extraction to the study of chelate complexes of thorium, p. 748.

. This work still being in progress and new data may considerably change the present picture. For those interested in the chemistry of coordination compounds the value of the acid dissociation constants pka and the mean complexity constants a of ThA4 are of the greatest interest. For those interested in metal extraction log K is very important

Definitions of the complexity constants ka, a, and K: cf. M. Dyrssen, p. 750, eqs (8), (2), (11) respectively.

.

It has been generally recognised that when comparing the reaction of a series of chelate ligand ions A− with hydrogen ion and with a metal ion MN+ the respective equilibrium constants ka and k1 show the same trend; i.e. there appears to be a correlation between acid strength and chelate stability

H. Rossotti, this volume page 763.

. Furthermore it has been observed that 5‐membered chelate rings are more stable than 6‐ or 4‐membered ones. Such generalisations are however not sufficient to explain the behaviour of so different chelating agents as e.g. oxine, cupferron and acetylacetone. Some properties which at the present time seem relevant to the stability of the chelate‐complexes of H+ and Th4+ will be discussed here.
On the partial molal entropies of complex ions and their conjugate acids in aqueous solution
Authors: George P. , Hanania G. I. H. , Irvine D. H.
Published: September 2010

The partial molal entropies of HFeCN6−3 and HFedipyCN4−1, the conjugate acids of FeCN6−4 and FedipyCN4−2, have been determined relative to FeCN6−3 and FedipyCN4−1 respectively, and are found to be even more negative than the corresponding S° differences for pairs of oxy‐anions where the charge is also the same, e.g. XO2−1 and HXO2−1, etc. The values are examined in relation to an empirical equation for S°, and the possibility that the two conjugate acids have some special structure feature is discussed.
Some relationships among the stabilities of metal complexes
Authors: Rossotti Hazel
Published: September 2010

The stability constant, KML, of the first metal‐ligand complex, ML, can be related to the stability constant, KHL, of the corresponding proton‐ligand complex, and to the partial molar free energies of the various species in solution. The relationship has been modified for application to mixtures of aqueous and organic solvents. For closely related ligands, log KML, will be an approximately linear function of log KHL. Moreover, log KML, is often a linear function of the molar fraction of the organic component of the mixed solvent.

The relationships between the stabilities of very closely related complexes are also discussed, and illustrated with reference to metal complexes of some derivatives of oxine, and to other metal chelates. Steric hindrance to complex formation may cause large deviations from predicted behaviour.
The influence of the composition and the properties of the solvent on complex formation between silver and chloride, bromide, iodide, and thiocyanate ions
Authors: Kratohvil J. , Težak B.
Published: September 2010

In order to obtain some insight into the effect of the dielectric constant of the medium on complex formation, the complex solubilities of silver chloride, silver bromide, silver iodide, and silver thiocyanate in halide or thiocyanate solutions in isodielectric mixtures of water and methanol, ethanol, iso‐propanol, glycerol, dioxane, and acetone have been determined. The complex solubility of the precipitates increased, relative to that in water, with increasing concentration of the organic component in solutions. The lowering of the dielectric constant of the medium caused an increase in the stability of the complex ions present.
Einschlussverbindungen der Cyclodextrine unter Besonderer Berücksichtigung der Blauen Jodverbindungen
Authors: Cramer Friedrich
Published: September 2010

Zunächst wird ein kurzer Überblick über die bisher bekannten Einschlussverbindungen der Cyclodextrine gegeben. Cyclodextrine werden aus Stärke erhalten, sie sind Ringmoleküle, bestehend aus 6, 7 und 8 Glucoseeinheiten. Die freien Durchmesser in der Mitte der Ringe betragen 6, 8 und 10 Å. Die Dextrine bilden unter anderem mit Chlor, Brom und Jod Einschlussverbindungen. Die blaue Jodverbindung ist der Schlüssel zum Verständnis des Jodstärke‐Komplexes. Auf verschieden Weise lässt sich zeigen, dass Jod in Einschlussröhren Ketten der folgenden Struktur ausbilden kann:

magnified image

Die Ausbildung der Struktur In ist jedoch nur in ganz bestimmten Fällen möglich, nähmlich wenn das umgebende Gitter

Kanäle bildet

Elektronen zur obigen Resonanzstruktur beiträgt.

Es wurden eine grosse Zahl von blauen Jodadditionsverbindungen untersucht. Zahlreiche Cumarine und Flavonderivate bilden mit Jod kristallisierte, blaue Komplexe. Bei manchen von ihnen lassen sich unabhängige Jodketten röntgenographisch nachweisen, bei anderen wiederum bildet Jod und Wirtsmolekül eine kristallographische Einheit. Eine interessante Zwischenstellung nimmt das Benzonitril‐Jod‐Addukt ein. Die eindimensionalen Jodketten zeigen Anzeichen einer dreidimensionalen Ordnung. Die energetische Wechselwirkung zwischen Jod und Einschlussgitter ähnelt dem Benzol‐Jod‐Komplex von Mulliken. Das Einschlussgitter tritt als Lewis‐Base auf.

Die Jod‐Einschlussverbindungen sind daher nicht reine Einschlussverbindungen im Sinne eines einfachen räumlichen Festhaltens, sondern bilden einen Übergang zu den charge‐transfer‐Komplexen.

Es wird gezeigt, dass Einschlussverbindungen auch anderweitig als Lewis‐Basen wirken können. An den Cyclodextrinen kann man auch das Verhalten von Einschlussverbindungen in Lösung studieren, in einem Experiment wird dies gezeigt. Auf diese Weise kann man einen Einblick in die energetischen Verhältnisse in derartigen Hohlräumen gewinnen.
Investigations in the vitamin A series. III. Rearrangement of theretro‐system to thenormalsystem of conjugated double bonds in the vitamin A series
Authors: Huisman H. O. , Smit A. , van Leeuwen P. H. , van Rij J. H.
Published: September 2010

A new synthesis of vitamin A essentially based on the almost quantitative rearrangement of theretro‐system to thenormalsystem of conjugated double bonds is described.

This rearrangement is carried out by converting theretroC15acid and theretroC20‐acid respectively, by means of phosphorus trichloride in suitable solvents, into the correspondingretro‐acid chlorides, which thereupon rearrange smoothly to the acid chlorides with thenormalsystem of conjugated double bonds, β‐ionylidene acetic acid chloride and vitamin A acid chloride respectively.

The acid chlorides are reduced with LiAlH4to the corresponding alcohols β‐ionylidene ethanol and vitamin A.

The physical and chemical properties of the intermediates and geometric isomers obtained in the various reaction steps are described.
Complex coacervation. V Experiments on the distribution of salts. Comparison of theory and experiment
Authors: Voorn M. J.
Published: September 2010

The ratio of the salt concentrations (KCl) in the coacervate and the equilibrium liquid has been determined experimentally, for the system gelatinpotassium arabinate. The concentration of KCl was found to be higher in the coacervate.

The theory, developed in previous papers, is compared with existing experimental data.
Application of paper chromatography to the identification of accelerators and antioxidants: II. Detection of some heterocyclic compounds
Authors: Zijp J. W. H.
Published: September 2010

In this paper a detailed procedure is given for the paper‐chromatographic separation and identification of some mercapto‐substituted heterocyclic compounds. The detection of these accelerators in rubber mixes and vulcanisates is also described.
Phenate ion and the Fe3+PhO− ion‐pair complex
Authors: Hush N. S.
Published: September 2010

A value of 120 kcal/mole−1 is derived from available data for the electron affinity (E) of phenoxyl radical plus the solvation energy (S) of phenate ion (). Employing this value of E + S, it is shown that the location of the visible absorption maximum of the Fe3+PhO− ion pair

J. Babko, J. Gen. Chem. U.S.S.R. 33, 963 (1946).

is in good agreement with the interpretation of the spectra of Fe3+X− complexes of this type as charge‐transfer bands. The OH bond strength in phenol employed in this calculation is that recently proposed by Hush

N. S. Hush, J. Chem. Soc. London 1953, 2375.

, and its consistency with the light absorption measurements provides evidence in favour of the value 84 ± 5 kcal/mole−1 for this quantity.

An estimate of S shows the EphO is ca. 1.2 e.v. mole−1; the electron affinity of phenoxyl radical is thus ∼ 1 e.v. mole−1 lower than that of OH radical.
Studies in polarography: Part II reduction of telluric acid at the dropping mercury electrode
Authors: Issa I. M. , Khalafalla S. E. , Issa R. M.
Published: September 2010

The reduction of telluric acid at the dropping mercury electrode is studied in buffer solutions of pH 1‐12, in 0.1 M KCl, and in 0.01‐1 M NaOH. It is found that telluric acid is reduced under all conditions to elementary tellurium. The relation between the diffusion current and the concentration is excellent in 0.1 M KCl and 0.1 M NaOH within the concentration range of 1 × 10−4 −1 × 10−3 M and in ammoniacal buffer of pH 10 within the range of 2 × 10−4 −3 × 10−3 M. Maxima, except in 1 M NaOH, are occasionally met with, which could be suppressed by gelatin.
Breaking of a single CC bond upon reduction with sodium and alcohol in ammonia
Authors: van der Zanden J. M. , ter Borg A. P.
Published: September 2010

The action of sodium and ethyl alcohol in liquid ammonia on allyl and benzyl alcohols in general leads to replacement of the OH group by H

A. J. Birch, Quart. Revs. London 4, 64 (1950).

, i.e. breaking of the COH bond.

With p‐isopropyl benzyl alcohol and p‐tert. butyl benzyl alcohol, however, we found breaking of the CC bond at the OH‐bearing carbon atom.

As appears from the table below, all sorts of structural variations in the above‐mentioned molecule, which do not seem to be very essential to the occurrence or non‐occurrence of the breaking of the CC bond, result in the appearance of the “normal” OH reduction.

We are of opinion that we cannot make any attempt at theoretical interpretation until a larger body of experimental data is available to us.
The action of hydrazine on 1:4‐dianisoylbutane and the reduction of 3,8‐di‐p‐methoxyphenyl‐4,5,6,7‐tetrahydro‐1,2‐diazocine
Authors: Zanden J. M. V. D. , de Vries G.
Published: September 2010

The interaction of hydrazine and 1,4‐dianisoylbutane furnished two cyclic products (I and II). The structures of these compounds were investigated and one of them (I) was treated as usual for a Wolff‐Kishner reduction. The substance was also hydrogenated. The hydrogenated product (VI) when oxidised with mercuric oxide gave VII, which when heated afforded a compound (VIII) synthesised previously.
Determination of the individual cyclic oligomers in equilibrium systems from ϵ‐caprolactam and water
Authors: Heikens D.
Published: September 2010

The content of cyclic dimer, trimer, tetramer in equilibrium polymerisates of ϵ‐caprolactam and water is determined by fractional sublimation of a methanolic extract, freed from the cyclic monomer and linear oligomers.

The proportion of the cyclic dimer, trimer and tetramer in these products is 2/1/2 at 221.5° C and 5/2/7 at 253.5° C.

The stability of the tetramer is tentatively explained on the basis of its molecular structure.
1,2‐Dehydroderivatives of Reichstein's substances U and E
Authors: Szpilfogel S. A. , van Hemert P. A. , de Winter M. S.
Published: September 2010

Aerobic fermentation of cortisone (I) using Fusarium and Calonectria strains gave rise to 17α,20β,21‐trihydroxy‐3,11‐diketopregna‐1,4‐diene (IV) (1,2‐dehydro‐U). IV is also formed by fermentation of prednisone (III) and Substance U (II).

Selenium dioxide dehydrogenation of II and sodium borohydride reduction of III lead also to IV. The last reaction applied to prednisolone (VI) yielded the 1,2‐dehydroderivative of Reichstein's Substance E (VII).
Synthesis of (‐)‐β‐homocystine. A contribution to the problem of the high rotatory power of cystine
Authors: Balenović K. , Jambrešić I. , Gašpert B. , Cerar D.
Published: September 2010

A new cystine homologue IV showing [α]D −260° has been prepared by applying the Arndt‐Eistert reaction to S‐benzyl‐N‐phthaloyl‐l‐cysteine (I). The high [α]D of this compound supports Fredga's explanation of the high rotatory power of cystine.
Paperchromatography of 2,4‐dinitrophenylhydrazones of aliphatic carbonyl compounds
Authors: Klein F. , de Jong K.
Published: September 2010

The separation of 2,4‐dinitrophenylhydrazones of aliphatic carbonyl compounds having 7 or more carbon atoms is possible by means of paper chromatography, employing paraffin oil as immobile phase and dioxan/water (4:1) as mobile phase.
Melting curves (temperature‐heat content curves) as criteria for purity
Authors: Smit W. M.
Published: September 2010

Methods for calculating the purity of a given sample from its melting curve developed thus far have been derived by assuming that the contaminants are immiscible with the main component in the solid phase. These methods may give rise to serious errors when applied to arbitrary samples.

In the present paper a discussion is given of the behaviour of systems with solid solutions (miscibility in the solid phase), and a method is developed, resemblingWichers' “comparative method”, that is applicable to both types of systems.

In addition, errors occurring in the experimental determination of melting curves are briefly discussed.

Cooling curves are considered to be less suitable for the determination of purity than heating curves.

A description of a simple apparatus and procedure for the determination of heating curves is given.

The quantity of substance needed for a determination is about 200 mg. It is shown that the smallest amount of contaminant (s) determinable with this apparatus varies (depending on the system investigated) from 0.1 to 0.01 mol. %. The sensitivity of the method may be improved by using more sensitive thermometers.
Dimerisation under the influence of 43 % sulphuric acid; comparison of the rates of similar dimerisations with propenyl‐ and isopropenylbenzene
Authors: van der Zanden J. M. , Rix Th. R.
Published: September 2010

On boiling with 43 % sulphuric acid isopropenylbenzene (V) dimerises much more rapidly than propenylbenzene (IV). This result is explained in the present paper and compared with the effect previously noted with the corresponding p‐methoxy‐compounds

J. M. van der Zanden and Th. R. Rix, Rec. trav. chim. 75, 1166 (1956).

).
Syntheses of polychloro‐compounds with aluminium chloride. XV. The condensation of chloral with trichloroethene
Authors: Prins H. J.
Published: September 2010

This condensation leads to the formation of an addition compound of α,β,γ,γ,γ‐pentachloro‐n‐butyryl chloride with aluminium chloride and of a small amount of 1,1,1,3,4,4,4‐heptachlorobutanol‐2.

The above mentioned addition‐compound may be decomposed into carbon monoxide, hydrochloric acid and 1,1,2,3,3‐pentachloropropene‐1.

The corresponding acid can be transformed into chlorofumaric acid, α‐hydroxy‐β,γ,γ‐trichlorovinylacetic acid and into α,α‐dihydroxy‐γ,γ‐dichlorovinylacetic acid.

The heptachlorobutanol can be oxidized to the corresponding ketone, which is converted by alkaline hydrolysis into chloroform and trichloroacrylic acid.
A new spectrophotometric method for the evaluation of complex‐stability constants
Authors: Janssen M. J.
Published: September 2010

An exact spectrophotometric method has been devised for the evaluation of stability constants of metal complexes.

This method is developed for complex‐formation in two steps and is especially useful when complex‐formation occurs in acid solutions where the conventional Calvin‐Bjerrum titration method becomes inaccurate. Knowledge of the extinction coefficients of the different species in the solution is necessary.

The method has been successfully applied to the determination of stability constants of the complexes of 8‐hydroxyquinoline and 8‐hydroxyquinoline‐5‐sulphonic acid with copper in ethanol/water mixtures.

The conditions are examined which must be satisfied in order to obtain accurate results by this method [equations (11) and (15)].
New musk odorants: A new synthesis of polyalkylindans II
Authors: Weber S. H. , Stofberg J. , Spoelstra D. B. , Kleipool R. J. C.
Published: September 2010

The reaction of p‐cymene with tert.amyl alcohol, which yields indans, has been extended to other alcohols and homologues of cymene. It has been found that straight chain secondary alcohols yield substituted cymenes, but secondary alcohols containing a tertiary carbon atom, and tertiary alcohols, yield polyalkylindans. Under the conditions of the reaction cumene does not yield indans.
Chemistry of acetylenic ethers. XXII: Reactions of ethoxyacetylene with formaldehyde and amines
Authors: Arens J. F. , Koerts D. H. , Plieger P.
Published: September 2010

Ethoxyacetylene I reacts readily with a mixture of aqueous solutions of formaldehyde and non‐aromatic amines yielding ethyl esters of derivatives of β‐aminopropionic acid III instead of “Mannich bases” II.

Attempts to prepare the true Mannich bases under anhydrous conditions failed.
Investigations on bongkrekic acid, the toxine from Pseudomonas cocovenenans
Authors: Nugteren D. H. , Berends W.
Published: September 2010

Reliable methods for the preparation, isolation and determination of bongkrekic acid, the antibiotic from Pseudomonas cocovenenans, are described.

Bongkrekic acid (C29H40O7) is shown to be a branched olefinic tricarboxylic acid with a tertiary methoxyl group in a δ‐position with respect to one of the carboxylic acid groups. Seven double bonds are present, forming at least two conjugated systems.

A fragment of the structure of the completely hydrogenated bongkrekic acid (C29H54O7) has been elucidated.
Isomerisation of unsaturated fatty acid esters. Part I: The effect of certain catalysts upon the migration of the double bond
Authors: Blekkingh J. J. A. , Janssen H. J. J. , Keppler J. G.
Published: September 2010

An investigation was carried out to study the effect of certain catalysts on the migration of the double bond especially without simultaneous hydrogenation in esters of unsaturated fatty acids. The position of the double bond, before and after isomerisation, was determined by oxidative degradation, followed by chromatographic analysis of the oxidation products.

It was observed, that under the influence of a nickel isomerisation catalyst, migration of the double bond to many positions in the chain occurred.
Dimerisation of allylbenzene under the influence of 43% sulphuric acid: (Dimerisation along with isomerisation and hydration; continued)
Authors: van der Zanden J. M. , Rix Th. R.
Published: September 2010

Propenylbenzene (III), 1‐phenylpropanol‐2 (II) and 1,3‐diphenyl‐2‐methyl‐ 3‐ethylpropene (IV) are obtained on boiling allylbenzene (I) with 43% sulphuric acid.
The formation of pyrimidinols from α‐acylbenzyl cyanides or α‐acylphenylacetamides
Authors: Wajon J. F. M. , Arens J. F.
Published: September 2010

Certain α‐acylbenzyl cyanides are converted into derivatives of pyrimidinol‐4 by heating with a mixture of acetic and sulphuric acids. Scheme A could possibly explain this reaction, but is not entirely satisfactory. According to step 3, the pyrimidinol‐4 is formed by reaction of an α‐acylphenylacetamide with another amide. It is indeed possible to obtain derivatives of pyrimidinol‐4 by such a reaction (scheme B) but only for R′ = phenyl or benzyl. In some cases, a complicated mixture is obtained, due to secondary reactions. One of these, the self condensation of the α‐acyl phenylacetamide, is followed by hydrolytic cleavage of the product to a pyrimidinol‐4 or to a pyrimidine‐diol (scheme C, 2 and 3). Other secondary reactions of a simpler nature occur too. The yields of the derivatives of pyrimidinol‐4 are therefore moderate to low.
The ortho/para distribution of methylol groups in the reaction of phenol and formaldehyde II
Authors: Dijkstra R. , de Jonge J.
Published: September 2010

A potentiometric method is described for the quantitative determination of o‐methylol phenol. The method is based on the acidic properties of the complex formed by o‐methylol phenol and boric acid.

In the reaction of phenol and formaldehyde, leading to the formation of mono‐methylol compounds, 57‐61% ortho substitution takes place. The distribution of the methylol groups over the ortho and para places of the phenolic nucleus was determined with the aid of the potentiometric method mentioned above.
Determination of the surface tension at 20° C of mineral oil fractions from their ultrasonoric sound velocity and density both measured at 20° C
Authors: Cornelissen J. , Waterman H. I.
Published: September 2010

The surface tension of mineral oil fractions has been determined from their ultrasonoric sound velocity and density. Use is made of a graph with the ultrasonoric sound velocity at 20° C and the density at 20° C, both determined experimentally, as coordinates.

For non‐hydrogenated and hydrogenated oil fractions a different graph has to be used, contrary to the determination of the surface tension from kinematic viscosity and density, where one graph was sufficient.
Applications of the Eotvos equation to the study of parachors
Authors: McGowan J. C.
Published: September 2010

The Eötvös equation and the parachor equation of Sugden have been combined with the elimination of the surface tension term. The equation thus obtained has been used for the determination of certain parachors from density measurements.
Preparation of optically‐pure light petroleum
Authors: van der Ven B. , de Jonge A. P.
Published: September 2010

Great care is required in the preparation of optically pure solvents intended for spectrophotometric purposes.

A procedure is described, which enables optically pure light petroleum (having a measuring limit below 200 mμ) to be prepared in larger amounts.
New musk odorants III. Synthesis of several new acetylpolyalkylindans
Authors: Weber S. H. , Kleipool R. J. C. , Spoelstra D. B.
Published: September 2010

The acetyl derivatives of 1,1,2,3,3,5‐hexamethylindan, 1,1,3,3,5‐pentamethylindan and 1,1,3,5‐tetramethyl‐3‐ethylindan prepared previously have been shown to possess musk odour. The hexamethyl compound is the most important of these and has the best properties as a musk substitute. Chloromethylation of the polyalkylindans followed by removal of chlorine by reduction gave a series of methyl‐homologues which were acetylated in the manner described in an earlier publication. These new compounds had less musk odour than the parent ketones.

The acetyl group in the acetylpolyalkylindans, having an alkyl group attached to carbon‐5 was found to occupy position 6 in the benzene nucleus.
Hydrocarbures polycycliques aromatiques. III. Dérivés de substitution de l'anthanthrène
Authors: Buu‐Hoï N. P. , Lavit Denise
Published: September 2010

Il est montré que l'anthanthrène est formylé par la N‐méthylformanilide en 6‐formylanthanthrène, cet aldéhyde pouvant être réduit par la méthode de Kishner‐Wolff en 6‐méthylanthanthrène. Ce dernier corps peut être à son tour converti en 6,12‐diméthylanthanthrène par l'intermédiaire du 12‐formyl‐6‐méthylanthanthrène; la réactivité des 2 positions méso‐anthracéniques dans la molécule de l'anthanthrène a été en outre mise en évidence par l'action du chlorure de sulfuryle, qui conduit au 6,12‐dichloro‐anthanthrène.
Acid anilides: V. Qualitative separation of fatty acid anilides by paper chromatography
Authors: de Jonge A. P. , Verhage A.
Published: September 2010

A new method is described for the qualitative separation and identification of fatty acids in the range C1 to C12 by paper chromatography of their anilides.

The basic principles underlying this method are discussed. Use has been made of one of three closely related systems.

The location of the spots is determined by means of ultra‐violet absorption measurements.

The smallest amount of anilide which can be detected is about 1 μg.
Reactivity of 3,5‐Disubstituted Derivates of Pyridine‐N‐Oxide Towards Sulphuryl Chloride
Authors: den Hertog H. J. , Hoogzand C.
Published: September 2010

The action of sulphuryl chloride on 3,5‐dibromopyridine‐N‐oxide at 120° yields a mixture of chiefly 2‐chloro‐3,5‐dibromopyridine along with a considerable amount of 4‐chloro‐3,5‐dibromopyridine.

The conversion of 3,5‐diethoxypyridine‐N‐oxide by the same reagent at lower temperatures results in the formation of a reaction product from which 2,6‐dichloro‐ and 2,4,6‐trichloro‐3,5‐diethoxypyridine‐N‐oxide were isolated.
Dipole moments of α,ω‐disubstituted alkanes
Authors: Ketelaar J. A. A. , van Meurs N.
Published: September 2010

The dipole moments of terms of three series of α,ω‐disubstituted alkanes have been determined in the liquid phase using several methods of calculation. The measurements included the dibromoalkanes, the glycols and the ethyl esters of the dicarboxylic acids. From the resulting moments of the dibromides it is obvious an alternating effect exists for the first members of this series with regard to the influence of temperature. In the other series no definite temperature effect is shown by the different terms, with the exception of the oxalic esters.
Studies on tautomerism VI.): A preliminary communication on the molecular structures of α‐3‐methyl‐6‐chloroquinone‐4‐oxime and 3‐chloroquinone‐4‐oxime in the solid phase
Authors: Romers C. , Shoemaker Clara Brink , Fischmann E.
Published: September 2010

It follows from an X‐ray determination of the crystal structures of “a”‐3‐methyl‐6‐chloroquinone‐4‐oxime and 3‐chloroquinone‐4‐oxime that in the solid state the molecules of these compounds occur in the quinone‐oxime form and not in the tautomeric nitrosophenol form.
Simultaneous transitions in liquid mixtures
Authors: Ketelaar J. A. A. , Hooge F. N.
Published: September 2010

Simultaneous transitions were observed in the infra‐red absorption spectra of 19 mixtures; experimental details are given. The influence of the temperature, the mixing ratio and dilution on the intensity of the simultaneous band of CS2 + Br2 is investigated and discussed.
Association of fatty acids in the liquid phase
Authors: Sarkadi D. Szabo , de Boer J. H.
Published: September 2010

Using high paraffins as solvent the association of the fatty acids has been investigated in the liquid phase by an infra‐red spectrophotometric method. Firstly, the association of stearic acid was investigated at temperatures between 40° and 220° C and at concentrations from 0.02 mole/kg up to the pure acid. The degree of association and the equilibrium constants were calculated from the relative intensities. From the temperature dependence of the equilibrium constant a heat of dissociation of 13,400 cal/mole and a standard entropy change of 24 cal/mole × degree could be calculated. Measurements with other fatty acids showed that neither the chain length nor the presence of one or two double bonds, nor the branching of the chain influences the association. The relatively high heat of dissociation and entropy indicate that the high paraffins are very indifferent solvents for the polar parts of the molecular; little or no solvation of these parts occurs.
Investigations on agricultural fungicides. III. The reaction between trichloromethanesulphenyl chloride and benzoic acid)
Authors: Uhlenbroek J. H. , Koopmans M. J.
Published: September 2010

A mixed anhydride of trichloromethanesulphenic acid and benzoic acid has been prepared for which we propose the name of benzoic trichloromethanesulphenic anhydride. Some chemical and biological properties of the new compound are described.
Dimerisation ofp‐methylthio‐isopropenyl‐ benzene under the influence of 43 % sulphuric acid
Authors: van der Zanden J. M. , Nieuwenhuis J. , Bos H. J. T.
Published: September 2010

On boiling with 43% sulphuric acidp‐methylthio‐isopropenylbenzene dimerises more slowly than thep‐methoxy‐compound1) and about as rapidly as isopropenylbenzene2) when treated under similar conditions.
Hydrocarbures polycycliques aromatiques. VI. Nouvelles synthèses du 5‐méthylnaphtacène et du dibenzo[a,c]naphtacène
Authors: Buu‐Hoï N. P. , Lavit Denise
Published: September 2010

La réaction de formylation du naphtacène a ét examinée, et une synthèse nouvelle proposée pour le 5‐méthylnaphtacène, consistant en la réduction du 5‐formylnaphtacène. D'autre part, on montre que la ré;action de Friedel‐Crafts entre le triphénylène et le chlorure d′o‐toluoyle conduit au 2‐(2‐méthyl‐benzoyl) triphénylène, et que cette dernière cétone, soumise à la réaction d'Elbs, conduit au dibenzo[a,c]naphtacène.
Investigations on sterols. IX Dihydroderivatives of ergocalciferol
Authors: Westerhof P. , Buisman J. A. Keverling
Published: September 2010

Some partially hydrogenated derivatives of ergocalciferol are described; their structures are discussed, and their activities in raising the serum calcium level of rats are reported.
Electrochemical researches on paraffin membranes I. 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 single salts.
Polarography with a stationary platinum plate electrode. Part II: The anodic waves of iodides and bromides
Authors: el Wakkad S. E. S. , Khalafalla S. E. , el Din A. M. Shams
Published: September 2010

Previous reports on the behaviour of iodide solutions when subjected to anodic oxidation are limited and not in agreement. This has been clarified by carrying out the oxidation in solutions of different pH values using the stationary platinum microelectrode and a special technique which applied the potential to the electrode intermittently. The anodic oxidation of the iodide ion produces two well defined waves. The first wave corresponds to a one electron process and is due to the formation of elementary iodine at its reversible potential. The wave height is proportional to the concentration of the iodide ion in solution. The second wave showed irregularities and corresponds to the irreversible formation of iodous acid HIO2. This was concluded from the fact that the height of the wave was roughly four times that of the first wave, and from its dependence on the pH value of the solution. At fairly positive potentials and prior to evolution of oxygen, the wave was found to lose a part of its height, and a minimum appeared in the current which was interpreted by the interaction between the diffusing iodide ion and hydroxyl radicals formed as intermediaries in the evolution of oxygen.

Investigations on the bromide ion reveal that it is oxidised in a simple one electron wave to yield bromine. This took place with some overvoltage. The wave height was a linear function of the concentration of the bromide ion in solution.
Electric polarisation of hydrocarbon dinegative ions
Authors: Hoijtink G. J.
Published: September 2010

The influence of a homogeneous electric field on the charge distribution in the di‐negative ions of naphthalene, anthracene, phenanthrene, pyrene, triphenylene, tetrahydroanthracene, tetrahydrophenanthrene and tetrahydro‐triphenylene has been calculated with the aid of a variation treatment and a first order perturbation treatment based on the Hückel m.o. wave functions for the ground and excited states of the unperturbed system. Permanent dipole moments and polarisabilities have been roughly estimated.
The temperature variation of orthobaric density difference in liquid‐vapour systems. I: Normal liquids
Authors: Bowden S. T. , Costello J. M.
Published: September 2010

The chief modifications of the Verschaffelt relation are reviewed, and the generally accepted method of applying the equation is criticised.

Analysis of the data for representative non‐associated liquids reveals that the exponent in the equation is specific for each system. Formulated in this way the relation is brought into line with the power laws representing the variation of surface tension and heat of vaporization with temperature and orthobaric density difference, respectively.