bluuebunny/crossref_metadata_2025 huggingface dataset:
Contribution A L'Étude de La Clathration Synthèse et Propriétés des α‐Arylalcoylamines. II
Authors: De Roocker A. , De Radzitzky P.
Published: September 2010

The Leuckart reaction has been applied to the synthesis of 22 α‐arylalkylamines 16 of which are new compounds. An improvement of the Leuckart reaction is described. Physical properties of these amines are tabulated and their pKa have been measured when it was possible. All those amines are of great value for the preparation of clathrating Werner complexes.
Applications de la Spectrographie de Résonance Magnétique Nucléaire (R.M.N.) Dans le Domaine des Dérivés Polycycliques A Caractère Aromatique V. Dérivés Monosubstitués du Phénanthrène
Authors: Martin R. H. , Defay N. , Geerts‐Evrard F. , Figeys H.
Published: September 2010

– N.M.R. spectra of aldehydes, methylketones and esters of phenanthrene, substituted in positions 2, 3 and 9, have been recorded at 60 Mc. In the nine cases examined in this work, it is possible to determine the position of substitution, without ambiguity.

– Introduction of a methyl group in position 4 (angular position) has a deshielding effect on the proton located on carbon 5 (opposite angular position).

– The main results are summarized in table I and figure 1.
Dosage Par Dilution Isotopique du Calcium et du magnésium A L'Échelle du Microgramme
Authors: Delwiche R. , Vosters M.
Published: September 2010

The quantitative analysis of Ca and Mg by isotopic dilution is described. The theory of isotopic dilution is recalled and a description of the apparatus used is given. The concentrations of standard solutions of Ca and Mg have been tested by this method. The results show that it is possible to measure quantities of these elements at the microgram level with an accuracy of 2 to 5% (2σ%). The main limitations of this method are due to contaminations during handling, and moreover, for Ca, to isotopic fractionation.
The Humulinic Acids II. Hydrogenation products. Chemical evidence for the structure of humulinic acids A and B
Authors: Lepoivre A. , Alderweireldt F. , Anteunis M. , Verzele M.
Published: September 2010

Chemical evidence shows that humulinic acids A and B (1) are cis‐trans isomers, corresponding to structure I and II or vice‐versa.
Synthèse de Thio‐ et Séléno‐Phtalides À Partir des Esters Imides Cycliques Correspondants ou de Leur Forme Tautomère
Authors: Renson M. , Collienne R.
Published: September 2010

Nous avons étudié l'équilibre tautomère et la possibilité de cyclisation de l'alcool o‐cyanobenzylique et de ses homologues sulfuré et sélénié. L'existence d'une forme cyclique à fonction iminoester, iminothioester et iminosélénoester a été prouvée et nous a permis d'utiliser celles‐ci pour mettre au point une méthode nouvelle de préparation des thio‐1, thio‐2, séléno‐1, séléno‐2, dithio‐1,2 et séléno‐2 thio‐1 phtalides. Parmi celles‐ci, la séléno‐2 phtalide n'avait pas pu être obtenue jusqu'à présent par d'autres méthodes, tandis que la séléno‐2 thio‐1 phtalide est particulièrement importante car elle constitue le premier exemple d'un ester mixte de soufre et de sélénium connue dans la littérature.
Acylation des Amidoximes Synthèse Nouvelle D'Oxadiazoles 1, 2, 4
Authors: Eloy F. , Lenaers R. , Buyle R.
Published: September 2010

The question of the structure of the acylamidoximes is reviewed. It appears that the acylation of amidoximes invariably occurs on the oxygen atom forming O‐acyl derivatives unless the NOH group is substituted. Until now, N‐acylamidoximes have never been isolated, with the exception of the acylation products of formamidoxime. N‐acylamidoximes, however, are formed as unstable intermediates during some particular methods of synthesis of 1,2,4‐oxadiazoles. A new method of forming derivatives of this heterocycle is described.
Contribution À L'Étude D'Acides de la Série de la Pyridazine I‐Nouvelles Préparations de l'acide chloro‐3 pyridazinoxyacétique‐6 et étude de quelques dérivés
Authors: Rosseels G.
Published: September 2010

Chemical and spectrophotometrical investigations of the structure of the isomeric acids: 3‐chloro 6‐pyridazinoxyacetic and 3‐chloro 6‐pyridazone 1‐acetic. New preparations of these acids have been effected. Some basic esters and amides of these acids and their oxygenated analogous were prepared, especially a structural analogous of centrophenoxine.
La Constante D'Acidité de L'ion Anilinium Dans le Formamide
Authors: Mandel M. , Decroly P.
Published: September 2010

The dissociation constant ka of the anilinium ion in formamide has been determined at several temperatures between 20 and 45°C by two independent methods. The spectrophotometric determination of ka and the potentiometric method using a cell without transference gave results which are in good agreement except at 45°C, although the measurements are difficult due to a secondary transamination reaction between the anilinium ion and formamide. This agreement give additional confirmation to the standard potentials of the Ag; AgCl reference electrodes in formamide as previously determined for the temperature range of 20 to 40°C. Furthermore ka of anilinium ion appears to be a factor four larger in formamide than in water. The slope of the linear plot of ka against T−1 is nearly identical in both solvents.
Étude Cinétique de L'Hydrolyse des Amides XII. Hydrolyse alcaline de l'oxamide, de la malonamide, de la fumaramide et de la maleamide
Authors: Vigneron‐Voortman Mme , Crooy P. , Bruylants A. , Baczynskyj L.
Published: September 2010

L'oxamide, la malonamide et la fumaramide subissent l'hydrolyse en milieu alcalin, suivant le schéma classique: la diamide engendre l'acide amique (VI) qui se transforme ensuite en diacide correspondant (VII). Les auteurs en ont fait l'étude cinétique et déterminé les paramètres suivants (valeurs de k à 65°C):

pour l'oxamide

k = 1,2 10−1 1 m−1 s−1; ΔH≠ = 9,3 Kcal m−1; ΔS≠ = − 37,5 u.e.s.

k = 2,1 10−3 1 m−1 s−1; ΔH≠ = 11 Kcal m−1; ΔS≠ = − 40,6 u.e.s.

pour la malonamide

k = 1,6 10−2 1 m−1 s−1; ΔH≠ = 16,0 Kcal m−1; ΔS≠ = − 21,6 u.e.s.

k = 3,1 10−4 1 m−1 s−1; ΔH≠ = 11,4 Kcal m−1; ΔS≠ = − 43 u.e.s.

pour la fumaramide

k = 8,3 10−3 1 m−1 s−1; ΔH≠ = 15,5 Kcal m−1; ΔS≠ = − 24,4 u.e.s.

k = 1,2 10−3 1 m−1 s−1; ΔH≠ = 10,3 Kcal m−1; ΔS≠ = − 43,6 u.e.s.

L'hydrolyse de la maléamide est plus complexe; elle se déroule en trois étapes consécutives compétitives : la cyclisation de la diamide en imide (VI), l'ouverture du cycle en acide amique (VII) et enfin la transformation de I'acide amique en diacide (VIII), d'aprés les lois suivantes:

VI = k [diamide] [OH−]

VII = k [imide] [OH−] + k [imide] [OH−]2

VIII = k [acide amique] [OH−]

les paramètres correspondants (valeurs de k à 65°C) sont:

k = 5,4 10−1 1 m−1 s−1; ΔH≠ = 6,4 Kcal m−1; ΔS≠ = − 43 u.e.s.

k = 490 1 m−1 s−1; ΔH≠ = 13,4 Kcal m−1; ΔS≠ = − 8,8 u.e.s.

k = 3,2 10−3 1 m−2 s−1; ΔH≠ = 18,7 Kcal m−1; ΔS≠ = + 24,2 u.e.s.

k = 2,15 10−4 1 m−1 s−1; ΔH≠ = 18 Kcal m−1; ΔS≠ = − 24,2 u.e.s.
Mean Amplitudes of Vibration of some Tetrahedral XY4 Type Molecules Part VIII: Silicon tetrahalides
Authors: Nagarajan G.
Published: September 2010

With the recent vibrational and molecular structural data for silicon tetrahalides possessing a tetrahedral symmetry the computed numerical values of mean‐square amplitude quantities, generalized mean‐square amplitude quantities (mean‐square parallel amplitudes, mean‐square perpendicular amplitudes and mean cross products) and mean amplitudes of vibration at the temperatures T=0 and T=298°K have been reported. The paper deals with the relevant discussion over the arrived results. The Bastiansen‐Morino shrinkage effects at these temperatures have been calculated. All the calculations were made by the Cyvin's method using symmetry coordinates. The molar thermodynamic functions have also been calculated for these molecules except silicon tetrafluoride on the basis of a rigid rotator, harmonic oscillator model for the temperature range 50‐2000°K.
Préparation D'Oxadiazoles‐1,2,4 par Addition Dipolaire sur les Oxydes de Nitriles Aliphatiques
Authors: Eloy F.
Published: September 2010

This paper describes the preparation of 1,2,4‐oxadiazoles by condensation of an aliphatic nitrile oxide with a nitrile. The nitrile is formed «in situ» by treating a nitroalkane with an isocyanate in the presence of a tertiary base. The nitrile must be activated by an electron withdrawing substituent.
Force Constants and Mean Amplitudes of Vibration in some XY6 Ions of Group VIIB and VIII Elements
Authors: Nagarajan G.
Published: September 2010

Force constants for the hexafluoroplatinate, hexachlororhenate, hexabromorhenate and hexachloroosmate ions possessing an octahedral symmetry have been evaluated by the Wilson's group theoretical method. Mean amplitudes of vibration at the temperatures T=O and T=298º K have also been calculated by the Cyvin's method. A brief discussion of the results follows.
La Détermination du Sulfate D'Hydrazine par L'Hypobromite
Authors: Campe A. , Pijck J. , Claeys A.
Published: September 2010

Les conditions optimales pour la détermination du sulfate d'hydrazine par l'hypobromite de soude en milieu alcalin ont été déterminées. En employant la méthode de standardisation dite «en milieu identique» le nombre d'électrons échangés (n=2) correspond á la réaction stochiométrique. La précision moyenne de la méthode, contrǒlée par comparaison au titrage direct avec le KBrO3‐indigo, est de l'ordre de 0,2%.
Corrélations Structure‐Réactivité Dans Les Familles de Benzoylacétanilides
Authors: van Brandt P. , Bruylants A.
Published: September 2010

Les auteurs ont étudié la cinétique de condensation de la paranitrosodiméthylaniline avec 16 benzoylacétanilides, de formule générale:\documentclass{article}\pagestyle{empty}\begin{document}$ {\rm X} - {\rm C}_6 {\rm H}_4 - {\rm CO} - {\rm CH}_2 - {\rm CO} - {\rm NH} - {\rm C}_6 {\rm H}_4 - {\rm Y} $\end{document}répartis en trois familles: la famille A où seul le noyau anilide est substitué (X=H, Y≠H), où Y peut être 4‐CH3O, 4‐CH3, H, 4‐Cl, 4‐I, 3‐Cl, 4‐CN et 4‐NO2; la famille B dont le noyau benzoyle seul est substitué (X≠H, Y=H), où X peut être 4‐CH3O, 3‐CH3, 4‐Cl et 3‐NO2; la famille AB où la substitution affecte les deux noyaux (X≠H, Y≠H) avec les couples de substituants suivants (X, Y): 4‐CH3O, 4‐CH3; 4‐CH3, 4‐CH3O; 4‐Cl, 4‐CH3; 3‐NO2, 4‐CH3O.

La corrélation des résultats expérimentaux se fait au moyen de la formule généralisée: logk/k0= ρxσx+ ρyσxoú ρyvaut‐0,508 (k10=20,4.10−3mn−1), mais oú ρxpeut prendre deux valeurs distinctes ρx'=‐1,94 et ρx=‐0,08 suivant le caractère polaire du substituant.
La Détermination de la Thiosémicarbazide Par L'Hypobromite
Authors: Pijck J. , Campe A. , Claeys A.
Published: September 2010

Optimal conditions were determined for the titrimetric determination of thiosemicarbazide with alcaline hypobromite solutions. It appears that the number of electrons exchanged (n=12) corresponds to a stochiometric reaction. Precision is about 0,25% and accuracy, checked by potentiometric titration with CeIV has a mean deviation of 0,15%.
Phosphorus Containing Polymethine Dyes I. Methods of preparation and chemical properties
Authors: Depoorter H. , Nys J. , van Dormael A.
Published: September 2010

On décrit une nouvelle classe de colorants polyméthiniques renfermant dans leur molécule, en tant qu'auxochrome, un groupement –CP≡. Les possibilités et les limitations de la nouvelle méthode de synthèse de matières colorantes sont discutées. La réactivité des phosphoranes utilisés comme produits de départ, ainsi que la stabilité des colorants obtenus sont discutées en fonction des structures chimiques.
Étude du Comportement D'Isomères Géométriques Sous L'Impact Électronique IV. Cyclopropane, méthylcyclopropane et diméthylcyclopropanes gem, cis et trans
Authors: Natalis P. , Laune J.
Published: September 2010

Mass spectra of cyclopropane, methylcyclopropane, 1,1‐dimethylcyclopropane, cis‐1,2‐ and trans‐1,2‐dimethylcyclopropane have been recorded in the electron energy range 50‐10 volts, especially in order to study the effect of isomerism in the three dimethyl compounds.

Surprisingly, only a slight effect of position isomerism shows up in 1,1 and 1,2 isomers and no effect of geometrical isomerism can be detected in cis and trans stereoisomers, contrarily to the published data. The identity of behavior of cis and trans isomers under electron impact seems to be related to the pseudoethylenic character of C‐C bonds in C3 ring which, in the present case, overcomes the expected steric effect observed in larger cyclanic isomers.

Ionization potential of the three isomers and appearance potentials of main fragment ions are found to be the same within experimental uncertainties. Metastable transitions in the three isomers being identical, corresponding types of fragmentation are also the same. Fragment ions have therefore to be produced by a common molecular ion whose most probable structure is an isopentanic chain magnified image. Fragility of C‐C bonds close to substituting alkyl groups in branched hydrocarbons is confirmed by the present study of methylcyclopropane and gem‐dimethylcyclopropane.
Synthesis of 4‐O‐Methyl‐D‐Lyxose
Authors: Piotrovsky J. , Verheijden J. P. , Stoffyn P. J.
Published: September 2010

La synthèse du 4‐O‐méthyl‐D‐lyxose (V) a été réalisé suivant trios schémas différents. La réduction catalytique de ce dérivé fournit le 4‐O‐méthyl‐D‐lyxitol (VI) (2‐O‐méthyl‐arabitol), ce qui confirme sa structure.
A new synthesis of chlorosulfonyl chlorides
Authors: Goethals E. J. , Verzele M.
Published: September 2010

γ‐and ω‐hydroxyalkane‐1‐thiols, in many cases easily accessible over the chlorohydrins, are converted to γ‐and ω‐chloroalkylsulfonyl chlorides by the combined action of chlorine and water. A mechanism is suggested. This new synthesis method provides an easy way to obtain sultams.
Étude Spectroscopique de Molécules Halogénées. IV. Analyse conformationnelle en série cyclooctanique
Authors: Celotti J. C. , Nagels L. , Reisse J. , Chiurdoglu G.
Published: September 2010

The infra‐red solvent‐shift method has been used in order to determine the carbon halogen stretching vibrations (ν (C‐Hal)) in the I.R. spectra of cyclo‐octane chloride, bromide and iodide.

This procedure leads to the attribution of six carbon‐halogen stretching bands in the spectrum of each compound.

The conformational implications of these results are discussed.
Contribution A L'Étude D'Acides de la Série de la Pyridazine. III. — Préparation de Quelques Amides et Hydrazides D'Acides Pyridaziniques et Phtalaziniques
Authors: Rosseels Gilbert
Published: September 2010

Preparation of some amides and hydrazides of pyridazinic and phtalazinic acids, in sight of eventual bacteriostatic activities. These compounds do not present the expected properties.

Synthesis of two isomeric isopropylhydrazides, 3‐chloro‐6‐pyridazin‐oxyacetylisopropylhydrazide and 3‐chloro 6‐pyridazone 1‐acetylisopropylhydrazide, whose one, the O‐substituted compound, is active as inhibitor of the monoamino‐oxydase.
Alcaloides Indoliques. V. Structure de la Voacarpine
Authors: Denayer‐Tournay M. , Pecher J. , Martin R. H. , Friedmann‐Spiteller M. , Spiteller G.
Published: September 2010

Voacarpine, a minor alkaloid obtained from Voacanga chalotiana Pierre ex Stapf (Apocynaceae), is shown to have the tautomeric structure VII ⇆ VIII. The non basic O,N‐diacetyl‐ and O,N‐ditosyl derivatives are true 2‐acyl‐indoles (IX, X).

Isovoacarpine, isomeric with voacarpine, is obtained by acid treatment followed by neutralization; it is also a carbinolamine compound. On acetylation, it gives a monoacetyl derivative.

UV, IR, NMR and mass spectra of voacarpine and derivatives are discussed.
Mean Amplitudes of Vibration, Thermodynamic Functions, and Molecular Polarizabilities of Some Monohaloacetylenes
Authors: Nagarajan G. , Hariharan T. A.
Published: September 2010

A brief survey of the vibrational and structural data for the monohalo‐acetylenes and their deuterated compounds except the higher member of the series possessing a linear asymmetrical structure with the point group C∞ν is given. The symmetry coordinates, G matrix elements and analytical expression for the mean‐square amplitudes of vibration have been given. The mean amplitudes of vibration at the room temperature have been calculated by the Cyvin's method. A brief discussion of the results follows. The molar thermodynamic functions have been calculated on the basis of a rigid rotator, harmonic oscillator model for the temperature range 100‐2000° K. Molecular polarizabilities have been calculated from a semi‐empirical delta‐function model by using a variational method and delta‐function electronic wave functions. The model enables one to obtain very simple expressions for the parallel and perpendicular components and mean molecular polarizabilities. A comparison of the observed and computed molecular polarizabilities shows that a deviation of nearly 10% is quite reasonable.
Electron Irradiation of Hydrocarbons. III. Radical Reactions and Diffusion During Radiolysis
Authors: Claes P. , Rzad S.
Published: September 2010

This work concerns the theoretical study of the influence of tracks expansion on radicals reactions occuring during the radiolysis of hydrocarbons. It is shown that a dose rate effect may occur on the organic products yields. This should be due to the competition between organic radicals recombination and hydrogen abstraction from the solvent by these radicals. Hydrogen atoms, however, react chiefly by hydrogen abstraction from the solvent.
Synthèse des 5‐Méthoxyméthyl et 5‐Éthoxyméthyl‐Desoxyuridines
Authors: Bricteux‐Grégoire S. , Verly W. G.
Published: September 2010

On a préparé, à partir de désoxyuridine, de la 5‐méthoxyméthyl‐désoxyuridine et de la 5‐éthoxyméthyl‐désoxyuridine. La pureté de ces produits a été démontrée par chromatographie sur papier dans deux systèmes différents, par un dosage des groupements alkoxyle, par la mise en évidence du désoxyribose et, enfin, par réduction catalytique en thymidine.
Dosage Polarographique du Molybdene. Application À L'Analyse des Aciers
Authors: Patriarche G. , Gerbaux A. A. , Molle L.
Published: September 2010

The polarographical behaviour of Mo (VI) in a supporting electrolyte composed of citric acid, potassium dihydrogen orthophosphate and potassium chloride was investigated.

At pH 1, 6, Mo (VI) gives two waves with half‐wave electric tensions of ‐0,17 V and — 0,57 V vs S.C.E.

The quantitative determination is based on the height of the second reduction wave which is proportional to the concentration of Mo (VI). Rounded maxima which appeared in certain cases are eliminated by addition of methylene blue or basic fuchsin.

Cu (II), Bi (III), Pb (II), Zn (II), As (V), W, V, Ni (II), Co (II), Mn (II) and Zr (IV) do not interfere.

Fe (III), when present in great quantity, must be eliminated. The wave of Cd (II) interfere.

The method proposed was applied to the determination of Mo (VI) in steel samples.
Alcaloides Indoliques. VI. Réactivité de la Fonction Alcoolique Primaire de la Voachalotine et de L'Affinisine
Authors: Braekman J. C. , Dubois J. , Balikdjian M. , Kaisin M. , Pecher J. , Martin R. H.
Published: September 2010

Methane sulphonyl chloride, thionyl chloride and p‐toluene sulphonyl chloride react with voachalotine (I) to give, in each case, the same cyclised dihydroindole compound: 2α‐hydroxy‐17‐desoxyvincamajine(VI).

At room temperature the same reagents give with affinisine (II) the expected derivatives, but at 115° only one compound is obtained: 16B‐chloromethyl‐voachalotane (VII).

These observations are discussed on the basis of known reaction mechanisms and of the structure of the two alkaloïds (I and II), used in this work.
Dégradation de L'Acide Ribonucléique Microsomal par les Ultrasons
Authors: Burnotte J. , Fredericq E.
Published: September 2010

The action of sonic radiations (20 Kc) on RNA solutions has been studied in relation with structural characterizations. Ribosomal RNA from calf thymus was used; it had two components with molecular weights 1.3.106 and 0.5.106. The content of helical parts was estimated from hypochromic effect as 56%.

Several sonicates were prepared using times of sonication from 2 minutes to 6 hours. Their intrinsic viscosities and sedimentation constants were determined. The minimum molecular weight which could be obtained was 60,000. Optical rotation and ultraviolet absorbancy of native and sonicated RNA samples were the same, indicating that the secondary structure was not modified by sonication. The influence of pH and dilution on absorbancy was also the same for all samples.

The variation of viscosity with ionic strength was used as a means for estimating the flexibility of the molecules. These determinations showed that the sonicated RNA has a smaller degree of flexibility than the undegraded sample.

It was concluded that by sonication the polynucleotide chains of RNA molecules are split mostly in the disordered regions.
The reaction of 2,3‐epoxy‐1‐propanol with 3′(2′)‐uridylic acid
Authors: van Montagu M. , Stockx J.
Published: September 2010

The reaction of 2,3‐epoxy‐1‐propanol with 3′(2′)‐uridylic acid in an anhydrous medium does not result into the formation of glyceryl esters of uridine phosphate, but cyclic 2′,3′‐uridylic acid is formed. No reactivity of the heterocyclic ring was observed.
Recherches sur L'Hétérocyclisation. III. Mécanisme de L'Hétérocyclisation des O. Aminobenzène‐Sulfonamides en Dioxyde‐1,1 de Benzothiadiazine‐1,2,4, en Présence D'Acide Formique
Authors: De Smedt V. , Bruylants A.
Published: September 2010

Le présent travail est consacré à l'hétérocyclisation en dioxyde‐1,1 de benzothiadiazine‐1,2,4 correspondant de six o.aminobenzène‐sulfonamides.

II a été possible de généraliser la méthode spectroscopique de détection du formanilide intermédiate et de confirmer ainsi que le schéma réactionnel comprend deux réactions consécutives non compétitives. L'étude cinétique a conduit á la détermination des constantes de vitesse ainsi que des paramétres d'Eyring et de Hammett relatifs à chaque étape. Par ailleurs, on démontre que les constantes d'acidité des sulfonamides, déterminées au sein de l'acide sulfurique, sont régies par une relation log Ka/Kao ρκ Σσ (ρκ = 3,03; Kao = 1).

Pour la première étape, le mécanisme proposé est celui d'une substitution a nucléophile variable (les différentes sulfonamides) sur support insaturé identique (l'ion formylonium). Tous les résultats expérimentaux peuvent être coordonnés et interprétés sur cette base: en particulier l'existence de deux constantes de réaction (ρI, ρ′I), l'une négative (constante réelle) et l'autre positive (constante apparente).

L'hétérocyclisation elle‐même est une substitution intramoléculaire sur centre insaturé. Elle est peu sensible à l'action des substituants: en fait, la température expérimentale est voisine de la température isocinétique.
Réactions des Diazoalcanes sur les Cyclanones. I. Action du Diazométhane sur la Cyclobutanone
Authors: Jaz J. , Davreux J. P.
Published: September 2010

L'action du diazométhane sur la cyclobutanone conduit à la cyclopentanone. L'emploi du trifluorure de bore comme catalyseur ramène le temps de réaction à une heure au lieu de quelques jours, et favorise la formation des cyclanones homologues; le produit de réaction contient: la cyclopentanone, la cycloheptanone et la cyclooctanone.
Synthèses et Propriétés des Bases de Schiff I. Modes D'Obtention et Spectres U. V. Des α (P, N‐Diméthylamino‐Phényl) Iminobenzoylacétanilides (PIBA)
Authors: De Hoffmann E. , Bruylants A.
Published: September 2010

Les auteurs ont synthétise l'α (p, N‐diméthylamino‐phényl) iminobenzoylacétanilide (PIBA) et deux familles de substitution: la famille PIBAX, où X est le substituant du noyau benzoyle, et la famille PIBAY, avec Y dans le groupe anilide(Y = X = 4‐CH3O,4‐Cl,3‐NO2 et 4‐NO2; en outre, X = 3‐CH3, Y = 4‐CH3). Deux modes d'obtention ont été essayes: l'un, par condensation en milieu alcalin des benzoylacétanilides correspondants avec la p‐nitrosodiméthylaniline, donne de meilleurs rendements que le second, par oxydation au ferricyanure de potassium de la N‐diméthyl p‐phénylènediamine, en présence du benzoylacétanilide approprié.

Les spectres U. V. ont été enregistrés et les fréquences d'absorption (νmax en cm−1) mises en corrélation avec les sigmas des substituants: dans la famille PIBAY, il y a une relation linéaire, tandis que dans la famille PIBAX les variations ne sont pas systématiques.

Le terme PIBAX4 (X = 3 NO2) a été isolé sous deux variétés différentes.
Triesters of tris‐(hydroxymethyl) phosphine oxide
Authors: Anteunis M. , Verzele M. , Dacremont G.
Published: September 2010

A series of tri‐acylated and tri‐arylated tris (hydroxymethyl) phosphine oxide derivatives was prepared either from tris‐(hydroxymethyl) phosphine oxide or from tris‐(iodomethyl) phosphine oxide.
Étude par Diffraction de Rayons X de Complexes D'Halogénures Alcalins et de Molécules Organiques. V. Structure du Complexe Chlorure du Lithium. Dioxanne‐1,4.
Authors: Durant F. , Gobillon Y. , Piret P. , van Meerssche M.
Published: September 2010

La structure du complexe LiCl. O‐CH2‐CH2‐O‐CH2‐CH2 a été déterminée par l'étude tridimensionnelle du spectre de diffraction X. Système orthorhombique, groupe spatial P2121; a = 8.03, b = 11.32, c = 7.14 Å, Z = 4. Elle a été résolue par la méthode de l'atome lourd et affinée par séries de Fourier et moindres carrés. Le coefficient de désaccord final établi à partir des 648 facteurs de structure des zones hk0 à hk5 (réflexions inobservées incluses) est de 0, 148.

L'ion lithium est lié a 2 ions chlore et à 2 atomes d'oxygéne provenant de 2 molécules organiques distinctes; le chlore et le dioxanne sont reliés chacun à 2 cations Li+. Les distances principales sont : Li‐O, 1.88 et 1.95; Li‐Cl, 2.39 et 2.42; C‐C, 1.54 et 1.57; O‐C, 1.44, 1.44, 1.45 et 1.46 Å.
Étude Théorique de Molécules Conjuguées. III. Les fondements théoriques des procédés de Pariser et Parr
Authors: Leroy G.
Published: September 2010

The nature of the Pariser and Parr “atomic orbitals” in their non empirical and semiempirical procedures is briefly discussed. It appears that the Pariser and Parr approximations are generally valid if the overlap matrix can be calculated using Slater atomic orbitals and if the Mulliken approximation remains valid when empirical Coulomb integrals are used.
Triterpenes V. Spectroscopie de Résonance Magnétique Nucléaire de Composés Triterpéniques. Les Groupes Méthyles en Série Oléanénique
Authors: Tursch B. , Savoir R. , Chiurdoglu G.
Published: September 2010

Attribution of the methyl resonance peaks in the oleanene series has been derived from the comparison of the N. M. R. spectra of 26 derivatives.
Suggested Semiempirical Molecular Orbital Schemes for Xenon Tetroxide
Authors: Yeranos Walter A. , Winter Nicholas W.
Published: September 2010

Using recently published approximate SCF wave functions for Xenon, the one‐electron molecular orbital energies of xenon tetroxide have been determined in three approximations and within the general formalism of the semi‐empirical Mulliken‐Wolfsberg‐Helmholtz molecular orbital method. The bonding and symmetry‐allowed electronic transitions have been discussed qualitatively.
Studies of Models of Indole Alkaloids. IV. Solvent effect in IR and NMR spectroscopy of methoxy derivatives of 1, 2, 3, 4‐tetrahydrocarbazole
Authors: van Binst G. , Danheux C. , Martin R. H.
Published: September 2010

La différenciation de la position des substituants méthoxy sur le noyau indolique a été effectuée par l'étude des spectres IR (entre autre par effets de solvant) et par l'étude en spectroscopie de résonance magnétique nucléaire des hydrogènes aromatiques et du proton de la fonction NH de différents dérivés méthoxylés du 1, 2, 3, 4‐tétrahydrocarbazole. En spectroscopie IR, les effets de solvant sur les fréquences des vibrations de déformation CH aromatiques, des vibrations de valence C‐O‐C du groupe méthoxy et sur la fréquence de vibration vnh sont discutés. Les déplacements chimiques des hydrogènes aromatiques, du groupe méthoxy et du proton fixé sur l'azote sont étudiés. Une corrélation avec les alcaloïdes indoliques est envisagée.
On the dimerization of 5,5‐dlmethyl‐2‐cyclohexenone
Authors: Schamp N. , De Bundel E. , Delarue E.
Published: September 2010

In alkaline medium 5,5‐dimethyl‐2‐cyclohexenone forms a dimer, which is shown to be 2‐(3′‐keto‐5′,5′‐dimethyl‐cyclohexyl)‐ 5,5‐dimethyl‐2‐cyclohexenone. The dimerization can be explained as an abnormal Michael addition.
Evaluation of ΔF*, ΔH* And ΔS* for the diazotization of m‐chloroaniline
Authors: Aboul‐Seoud A.
Published: September 2010

The results of a kinetic study of the diazotization of m‐chloroaniline (1), are combined with equilibrium and thermodynamic studies of m‐chloroaniline and its hydrochloride (2), in order to evaluate ΔF*, ΔH* and ΔS* for the nitrosation of m‐chloroaniline, which is the rate‐determining reaction in the diazotization of this amine.
Une Synthèse Simple des Sélénochromones et Sélénoflavones
Authors: Ruwet A. , Renson M.
Published: September 2010

Nous décrivons une méthode simple et rapide de préparation des sélénochromones et sélénoflavones. Cette méthode est une extension de la réaction de Simonis aux dérivés séléniés.
Clathration of aromatic compounds by coordination complexes of the type dithiocyanato tetrakis (α‐arylalkylamine) nickel(II). IV. Thermodynamics of the clathration of o‐xylene, p‐xylene and p‐dichlorobenzene by the complex of α‐phenylbutylamine
Authors: Hanotier J. , Brändli J. , de Radzitzky P.
Published: September 2010

La clathration des composés aromatiques par les complexes dithio cyanatotetrakis(α‐phénylbutylamine) nickel(II) est un processus réversible qui peut être considéré comme une réaction chimique. Les grandeurs thermodynamiques ΔG, ΔH et ΔS associées à la clathration de l'o‐xylène, du p‐xylène et du p‐dichlorobenzène par ce complexe ont été déterminées et leur comparaison confirme que les sélectivités de clathration sont régies à la fois par des facteurs stériques et énergétiques. Les valeurs obtenues pour les chaleurs de réaction ΔH sont compatibles avec l'intervention de forces par transfert de charge au niveau des noyaux aromatiques des deux constituants des clathrates.
Acylcyclopentanones. V. The reduction of 3‐alkylcyclopentane‐1, 2, 4‐triones and the acylation of the resulting 4‐alkylcyclopentane‐l, 3‐diones
Authors: Vandewalle M. , Compernolle F.
Published: September 2010

A specific reduction of the 2‐carbonylfunction of 3‐alkylcyclopentane‐l, 2, 4‐triones is described. The 4‐alkylcyclopentane‐l, 3‐diones, obtained in this way, can be acylated to 2‐acyl‐4‐alkylcyclopentane‐l, 3‐diones.
The preparation of 5‐substituted 1, 2, 4‐triazoline‐3‐thiones and of alkylene and arylene 5, 5'‐bis‐l, 2, 4‐triazoline‐3‐thiones
Authors: Willems J. F. , Vandenberghe A.
Published: September 2010

A method has been developed for the preparation of 5‐substituted 1. 2. 4‐triazoline‐3‐thiones and of alkylene and arylene 5. 5'‐bis‐1. 2. 4‐triazoline‐3‐thiones starting from carboxylic acid esters or dicarboxylic acid esters and thiosemicarbazide in sodium alcoholate medium.
The influence of spatial orientation of free orbitals in pmr spectroscopy influence of vicinal orbitals on3J and2J
Authors: Anteunis M.
Published: September 2010

In accordance with recent literature data, it is proposed that an increment of + 2.3 cps and + 1.8 cps is to be added to the vicinal (3J) and gem (2J) coupling values respectively, each time an α‐oxygen (or α‐nitrogen) atom has one of its free electron pairp‐orbitals parallel with the carbon hydrogen bond of one of the protons involved in the coupling under consideration. An influence on3J coupling values in three membered rings (epoxides) is however not to be considered. Molecular deformations which disturb the parallelity (i.e. in the rigid half chair form of pentacyclic compounds or in the twist form of hexacyclic compounds) nullify this effect. The Karplus rule and the electronegativity rule have regained a great amount of their reliability with this supplementary effect.
A re‐examination of the selectivity in the Friedel‐crafts chalcone synthesis
Authors: Rasschaert A. , Janssens W. , Slootmaekers P. J.
Published: September 2010

On a réexaminé la synthèse de chalcones à partir de chlorures de cinnamoyle (substitués) en présence du chlorure d'aluminium: cette réaction, effectuée d'après les données de la littérature, donne de très mauvais rendements en chalcone désirée. Dans la présente étude on démontre que le rendement en chalcone est quantitatif, à condition que la réaction est effectuée en solution homogène. La pureté du produit ainsi obtenu, déterminée par chromatographie en phase gazeuse, est de l'ordre de 99,9%, la principale impureté étant la 3, 3‐diphényl‐propiophénone.
Chaleurs D'Interaction de Complexes par Liaison Hydrogène. II. — Complexes Phénol — Pyridine Substituée
Authors: Neerinck D. , Lamberts L.
Published: September 2010

Enthalpies of hydrogen bond formation between phenol and substituted pyridines are measured by calorimetry. The obtained energies are compared with the base ionization constants in water and the σ values of the pyridine substituents. The relation formation energy to infrared frequency shift is the same as for alcohols or phenols‐pyridine complexes. Distances between O and N atoms linked by the hydrogen bond are related to the infrared frequency shift: it is then concluded that a linear relation exists, for the complexes studied, between the heat of formation and the bond distance. Influence of steric hindrance on the bond distance is discussed.
Studies in organic mass spectrometry. I. — Acyclic 1, 3‐diketones
Authors: Schamp N. , Vandewalle M.
Published: September 2010

The mass spectra of 18 1, 3‐diketones are discussed. Next to the normal α‐cleavage of ketones, the most important fragmentations are the McLafferty rearrangement with the second carbonyl function in the ring, the expulsion of carbon monoxide and a specific σ‐cleavage of the side chain. The fragmentation seems to depend strongly on the enol content of the compound, enol molecules giving mainly α‐cleavage with loss of an alkyl radical, expulsion of carbon monoxide and σ‐cleavage of the side chain, while diketo‐molecules undergo in the first place the McLafferty rearrangement with the carbonyl function in the ring.
Détermination Par Résonance Magnétique Nucléaire de la Position des Atomes D'Hydrogène dans la Kröhnkite
Authors: van Tiggelen P. J.
Published: September 2010

The fine structure of the proton magnetic resonance line in a single crystal of Kröhnkite (Na2Cu(SO42 2H2O) has been investigated in order to fix the position of the hydrogen atoms in the lattice. From the results of the Pake's curves, one of the possibilities for hydrogen bonding can be eliminated. This conclusion is also supported by a thorough study of the paramagnetic influence of the copper atom upon the spectra. The interproton distance (1.57 A) in the water molecule is similar to what has been found in other hydrates. The deviation from the linearity of the hydrogen bonds is respectively 11° and 3°. The water molecule keeps the same angle as in the gaseous state. Furthermore the proposed structure accounts for the perfect cleavage parallel to (010).
Acylcyclopentanones. VI. Halogen derivatives of 2‐acylcyclopentane‐1, 3‐diones
Authors: Vandewalle M. , Schamp N. , De Wilde H.
Published: September 2010

2‐Acyl‐2‐halogenocyclopentane‐1, 3‐diones are obtained in high yield, starting from 2‐acylcyclopentane‐1, 3‐diones. Their degradation and isomeration products are described.
The solubilities of current purines, pyrimidines and their nucleosides in urea and sucrose solutions
Authors: Stockx J. , van Aert A. , Clauwaert J.
Published: September 2010

The solubilities of the heterocyclic bases adenine, guanine, cytosine, uracil and the corresponding nucleosides adenosine, guanosine, cytidine and uridine were determined at room temperature in function of urea and sucrose concentration. Although urea exerts a solubilizing effect on adenine, guanine, cytosine, adenosine, guanosine, cytidine and uridine, strong individual differences in behavior emerge.

Uracil shows a maximum in solubility around 12% urea.

Sucrose solutions promote to a lesser extent the solubilities of adenine, cytosine, adenosine and guanosine; they show no effect on uracil solubility but depress that of the pyrimidine nucleosides.

In urea solutions the influence of the ribosyl substituent shows up by enhanced solubility increments of the purine nucleosides and diminished ones for cytidine, uridine taking an intermediate position. In sucrose solutions the attachment of the ribosyl group to the bases results into a negative slope for the relation nucleocide solubility: base solubility ratio vs sucrose concentration for adenosine, cytidine and uridine.
Azoic dyestuffs from α‐bromonaphtylamines colour and constitution
Authors: Bassilios H. F. , Salem A. Y. , Shawky M.
Published: September 2010

The properties of seven new azoic dyestuffs prepared from the possible 1‐bromonaphthylamine isomers, are determined and compared; the best conditions of their development on cotton fabrics are found, their fastness properties are assessed and their absorption spectra in the visible region are determined.
Triterpènes VII. Épimérisation en C‐21 au Cours de L'Hydrolyse Basique de Dérivés Oxydes de la Coriacéolide et de L'Acide Machaerinique
Authors: Daloze D. , Tursch B. , Chiurdoglu G.
Published: September 2010

Epimerisation of the C–21 substituent has been observed during methanolic sodium hydroxyde hydrolysis of acetoxy‐12, 19‐dioxo‐Δ9(11), 13(18‐coriaceolide and diacetoxy‐12, 19‐dioxo‐Δ9(11), 13(18‐methyl machaerinate.
Contribution to the Knowledge of the Electrochemistry of Uranium in Molten LiCl‐KCl Eutectic: I. The redox potential of the couple U(IV)/U(III)
Authors: Caligara F. , Martinot L. , Duyckaerts G.
Published: September 2010

Careful measurements of the redox potential of the system U(IV)/U(III) in molten LiCl‐KCl eutectic have been carried out in glove‐boxes with dry and inert atmosphere. The cell used was the following:

magnified image

whose e.m.f. have been measured by a high impedance electronic voltmeter.

Our efforts have been directed to prevent even the slightest oxidation of the Uranium species involved in the measurements.
Contribution to the Knowledge of the Electrochemistry of Uranium in Molten LiCl‐KCl Eutectic: II. Chronopotentiometric study of the reaction U(IV) + e⇆U(III) and measurement of the diffusion coefficient
Authors: Caligara F. , Martinot L. , Duyckaerts G.
Published: September 2010

The reaction U(IV)+e⇆U(III) in molten LiCl‐KCl eutectic has been investigated by means of chronopotentiometry. The diffusion coefficient of U(IV) passes from 4.46 . 10−6 to 12.15 . 10−6 cm2/sec. when the temperature increases from 400°C to 500°C.

The diffusion coefficient of U(III) passes from 4.14 . 10−6 to 13.62 . 10−6 cm2/sec. when the temperature increases from 400°C to 550°C.

The mechanism of diffusion is discussed and the hypothesis is put forward that for each ion there is a temperature at which the diffusion takes place according to the viscous flow mechanism.

Some aspects of the kinetics of the reaction are also clarified.
Contribution to the Knowledge of the Electrochemistry of Uranium in Molten LiCl‐KCl Eutectic: III. The kinetics of the reactions U(IV)⇆U(III) and U(III)⇆U(O)
Authors: Caligara F. , Martinot L. , Duyckaerts G.
Published: September 2010

The kinetics of the reactions U(IV)+e⇆U(III) and U(III)+3e⇆U(O) in molten LiCl‐KCl eutectic are investigated by means of Tafel lines.

For the first reaction, the slope of the line is RT/F, both for reduction and oxidation, which indicates that the electron‐transfer is not the rate determining step. The rate determining step is the rearrangement of the solvation shell, which follows the electron‐transfer. The slope of the Tafel line, for the second reaction, is nearly zero; it is suggested that the great exchange current does not allow the attainment of the Tafel zone.
Solubility and Complex Formation of Some Silver Halides in Dimethylsulfoxide
Authors: Rumbaut N. A. , Peeters H. L.
Published: September 2010

The solubility of AgCl, AgBr and AgI in a dimethylsulfoxide solution of ammonium nitrate has been determined by a potentiometric method.

At 25°C the solubility products in terms of molarities are 2 × 10−10, 9 × 10−11 and 3 × 10−12 resp. in a 0.1 M NH4NO3 solution.

The stability constants of the complexes AgCl2− AgBr2− and Ag2I3−, which are formed with excess halide ions are 4 × 1010, 4 × 1010 and 9 × 1023 resp., under the same conditions of temperature and inert salt concentration.

Extension of the measurements to other temperatures supports the view of a “structural change” of the solvent at higher temperatures, affecting the solution equilibria.
Addition Des Sulfènes Sur Les Nitrones Et Les Nitriles Oxydes. Synthèse Et Propriétés Des Benzoxathiazépines
Authors: Eloy F. , van Overstraeten A.
Published: September 2010

A new class of heterocyclic compounds, benzoxathiazepines, has been synthesized by condensing aromatic nitrones with sulfenes. Their chemical and spectral properties have been studied. Attempts to form oxathiazoles by adding sulfonyl chlorides to nitrile oxides led to the formation of sulfonyl derivatives of chloroximes.
Studies in Organic Mass Spectrometry III 1, 3‐Cyclohexanediones
Authors: Vandewalle M. , Schamp N. , De Wilde H.
Published: September 2010

The mass spectra of 1, 3‐cyclohexanedione and its 2, 4 and 5 substituted derivatives are discussed.

Most fragmentation patterns can be rationalised starting from the diketo form, through initial 1.2 and 1.6 bond cleavages. Evidence is advanced that ionised enol‐molecules mainly yield retro Diels‐Alder type degradations. Ring bond cleavage processes are strongly dependent on the position and size of the substituents.
Studies in Organic Mass Spectrometry IV. Fragmentation of 2‐Alkyl‐ 1, 3‐cyclohexanediones
Authors: Vandewalle M. , Schamp N. , De Wilde H.
Published: September 2010

In 2‐propyl‐ and 2‐butyl‐1, 3‐cyclohexanediones, fragmentations in the side chain carry most of the total ionisation. Exact mass measurements and deuterium labeling led to mechanistic interpretations for the formation of the principal fragment ions.
Spectres De Masse De Quelques Dérivés De La Dimédone
Authors: Maquestiau A. , Lejeune P.
Published: September 2010

The mass spectra of dimedone, 2‐methyldimedone, 2‐ethyldimedone (mixture of tautomers, type A), of 2,2‐dimethyldimedone (pure ketonic form, type B) and of (3‐keto‐5,5‐dimethyl‐cyclohexenyl) ethyl ether (pure “enolic” form, type C), as well as these of deuterated analogues, have been recorded. Examination of the spectra showed, besides some common features, sufficient specificity of the fragmentation patterns to distinguish between the dimedone derivatives of either type A, B or C, and to yield information about the size and position of substituents on the ring.
Association of the Carboxylic Acids and Viscosity
Authors: Meeussen E. , Debeuf C. , Huyskens P.
Published: September 2010

Nous avons étudié l'influence de l'autoassociation des acides carboxyliques sur leur viscosité dans des solutions où le solvant avait approximativement la même masse moléculaire que l'acide. A partir de l'acide propionique l'élévation relative de la viscosité avec la fraction molaire de l'acide, dη/η.dX2, est assez semblable pour les différents homologues étudiés. La variation de la viscosité avec la fraction volumique est, dans ces cas, analogue, aux basses concentrations, à celle des solutions dans les mêmes solvants d'un hydrocarbure saturé de masse moléculaire double. A forte concentration elle devient plus élevée. Cette comparaison est en accord avec les mesures de moments dipolaires qui indiquent une forte prédominance des dimères cycliques dans un large domaine de concentration. Dans le cas de l'acide acétique les écarts aux fortes concentrations et à l'état pur sont beaucoup plus importants, ce qui suggère un degré moyen d'association plus élevé dans ces conditions.
NMR Experiments on Ketals IX 1, 3‐Dioxanes with axial Alkyl Substituents
Authors: Tavernier D. , Anteunis M.
Published: September 2010

PMR Spectroscopic evidence has been advanced (3) to prove that the fundamental conformation of 4‐t. Bu‐4‐Me‐1, 3‐dioxane (Ia) is the stretched boat form (Ib). This paper discusses the PMR spectra of trans‐4, 6‐dialkyl‐1, 3‐dioxanes, including trans‐4, 6‐di‐t. Bu‐1, 3‐dioxane a genuine boat conformation model. It is concluded that the features, which have led to the boat form Ib, are not characteristic of stretched forms, but may be found in some chair form 1, 3‐dioxanes.

It is shown that stretched forms do not contribute significantly to the properties of trans‐4, 6‐dialkyl‐1, 3‐dioxanes.
The Diazotisation of Aniline and of the Chloroanilines in Dilute Sulphuric Acid Solutions: A Kinetic Study
Authors: Aboul‐Seoud A.
Published: September 2010

The rate of diazotisation of aniline, o‐, m‐, and p‐, chloroaniline, in 0.1 mol/l sulphuric acid, was determined at different temperatures. The values of the specific reaction rate, free energy, enthalpy, entropy, and energy, of activation, for the rate‐determining reaction, viz, the nitrosation of the free amine by nitrosyl sulphuric acid, were calculated and compared. Relations were drawn between each of the specific reaction rate, and the free energy of activation, for the rate‐determining reaction, and base strength. The effect of the chlorine atom, in the different positions of the benzene nucleus, of the chloroanilines, on the reaction rate, is discussed.
Propriétés Physico‐Chimiques De Composés À Caractère Aromatique X (). Réduction polarographique de composés monoaza‐aromatiques N‐oxydés
Authors: Anthoine G. , Nasielski J. , Vander Donckt E. , Vanlautem N.
Published: September 2010

Seven aza‐aromatic‐N‐oxides have been reduced polarographically. It is suggested that the mechanism involves an intermediate (V) having the structure of an unsaturated cyclic hydroxylamine which partially dehydrates to the corresponding deoxygenated base. The half‐wave potentials of the first reduction wave correlate reasonably well with the energy of the lowest vacant orbital as calculated by various refinements of the HMO method.
The Proton Magnetic Resonance Spectra of Ethyltin Compounds
Authors: Verdonck L. , van Der Kelen G. P.
Published: September 2010

Les spectres de R.M.N. des protons dans les composés organostanniques (C2H5)nSnX4‐n (X = Cl, Br, I, OCH3, C6H5) ont été étudiés. L'analyse de ces spectres du type A3B2X a été faite. Le déplacement chimique, tant pour les protons CH3 que pour les protons CH2, est déterminé conjointement par l'effet inductif et par l'anisotropie diamagnétique de la liaison Sn–X. Il est démontre que les couplages spin‐spin indirects Jsn117/119‐‐A et Jsn117/119‐‐B entre les atomes d'étain (Sn117 et Sn119) et les protons du groupe éthyle sont principalement déterminés par le terme de contact de Fermi. En second lieu ces couplages dépendent de la polarité des liaisons et de l'anisotropie magnétique des liaisons Sn–X et C–H.
Spread Mixed Monolayer of Senegin and Seneginin with Cholesterol at the Air‐Water Interface
Authors: Joos P. , Ruyssen R.
Published: September 2010

Door spreidingsproeven van gemengde monolagen werd aangetoond dat tussen Seneginine (het aglucon van Senegine) en cholesterol geen interactie optreedt aan het grensvlak. Bij het systeem Senegine‐cholesterol daarentegen werd een duidelijke interactie vastgesteld. Terwijl bij de meeste vroeger onderzochte systemen, die interactie vertonen, een contractie‐effect optreedt, werd hier een expansie‐effect gevonden. Dit expansie‐effect duidt op een chemische interactie. Ook werd een tijdseffect waargenomen. Deze feiten zijn een bevestiging van vroegere resultaten (geadsorbeerde gemengde filmen en penetratieproeven).
Application of the Average Potential Model to Simple Liquid Mixtures
Authors: Bellemans A. , Vilcu R.
Published: September 2010

The excess free energies and volumes of the five following liquid mixtures: CH4‐Kr, N2‐CH4, A‐Kr, N2‐CO and CO‐A, are compared with the theoretical predictions of the Average Potential Model of Solutions, developed by Prigogine and his coworkers.