bluuebunny/crossref_metadata_2025 huggingface dataset:
Potential Constants and Thermodynamic Properties of Some X Y3 Z Type Molecules
Authors: Nagarajan G.
Published: September 2010

A general potential function containing thirteen constants seems to be necessary for the molecules of the type XY3Z, but since the latter has only six frequencies all the constants cannot be determined. Making use of an assumption of Voge and Rosenthal that the forces remain constant within certain molecular group in passing from one molecule to another, the frequencies of the molecules SnBrCl3, SnClBr3, TiBrCl3 and TiClBr3 have been calculated, using the most general potential function. The potential constants have been calculated on the basis of Wilson's group theoretical method. Using the observed fundamental frequencies the thermodynamic properties have also been calculated for these molecules.
Études Conformationnelles. VIII. Équilibration des 2‐, 3‐ et 4‐Méthylcyclohexanols et des 3,3,5‐Triméthylcyclohexanols Stéréoisomères
Authors: Chiurdoglu G. , Masschelein W.
Published: September 2010

The equilibration of cis and trans isomers of 2‐3‐ and 4‐methylcyclohexanols is performed by the action of Raney Nickel in the presence of hydrogen. Conformational equilibrium between the two chair conformations possible for each alcohol explains the results. Also cis‐ and trans‐3,3,5‐trimethylcyclohexanols are equilibrated. It may be possible that the trans‐3,3,5‐trimethylcyclohexanol is not present entirely in the chair conformation.
Potential Constants of Iodine Heptafluoride
Authors: Nagarajan G.
Published: September 2010

A vibrational analysis has been made for the XY7 type molecules and radicals which have the pentagonal bipyramidal structure belonging to the symmetry point group D5h. An orthonormalized set of symmetry coordinates satisfying the transformation properties has been constructed for XY7 type molecules. The elements of F and G matrices have been worked out and from these matrices the secular equations for the various irreducible representations have been deduced by means of Wilson's group theoretical method. A potential function consisting of the ordinary valence force terms and central force terms has been adopted for the evaluation of potential constants for Iodine heptafluoride.
Potential Constants and Thermodynamic Properties of Some XY4 Type Molecules
Authors: Nagarajan G.
Published: September 2010

Potential constants of eleven molecules and eleven ions of the XY4 type with the symmetry point group Td have been evaluated on the basis of Wilson's group theoretical method. The thermodynamic properties for the eleven molecules have also been calculated for a rigid rotator, harmonic oscillator approximation.
Étude de la Structure et des Propriétés du Chlorure D'Ortho Mésitoylbenzoyle et de Quelques Homologues
Authors: Golstein‐Golaire J. , Renson M.
Published: September 2010

Dans ce travail nous montrons que contrairement à la plupart des chlorures d'acides ortho cétoniques aromatiques, le chlorure d'ortho mésitoylbenzoyle possède une structure entièrement normale. De plus, tous ses dérivés présentent également une structure normale non cyclique. Ainsi en présence du diphénylcadmium il donne l'ortho benzoylmésitoylbenzène, dérivé dicétonique, alors que la substance isomère cyclique, la mésityl‐3 phényl‐3 phtalide, peut être obtenue simplement en inversant les radicaux organiques. Nous montrons que la présence des deux groupements méthyles en ortho est nécessaire pour obtenir une structure normale. Enfin nous discutons les interprétations possibles de cette réactivité particulière.
Complexes Métalliques de Polyaminés, Complexes de la NN1‐Di‐(3‐Aminopropyl) Propylènediamine
Authors: Teyssié P. , Anderegg G. , Schwarzenbach G.
Published: September 2010

The formation constants of polyamine complexes with six‐membered chelation rings were measured and compared to those of similar five‐membered chelates; the hexaatomic ring chelates are proved to be much less stable, which reduces the formation of hydrogen complexes.
Stéroides CXC: Préparation de Stéroides Aminés
Authors: Crabbé Pierre , Durazo M. J. , Saloma R. M. , Holton P. G.
Published: September 2010

The synthesis of certain 3‐amino, 6‐amino and 17‐amino steroids as well as of 3,17‐ and 3,20‐bis‐amino‐steroids is described.
Mean Amplitudes of Vibration of Sulphur Trioxide and Aluminium Trichloride Molecules
Authors: Nagarajan G.
Published: September 2010

The theoretical treatment of the planar symmetrical XY3 molecular model for the mean‐square amplitude quantities has been given. Mean‐square amplitude quantities as well as mean amplitudes of vibration for the sulphur trioxide and aluminium trichloride molecules have been computed. The values of the generalized mean‐square amplitudes (mean‐square parallel amplitudes, mean‐square perpendicular amplitudes and mean cross products) in terms of the Σ matrix elements have been reported.
Mean Amplitudes of Vibration and Thermodynamic Functions of the Difluorides of Oxygen and Silicon
Authors: Nagarajan G.
Published: September 2010

The developments in the vibrational assignment and molecular parameters of the difluorides of oxygen and silicon have been reported. The theory of mean‐square amplitude matrices has been applied to the bent symmetrical XY2 molecular model. Four valence force constants have been evaluated on the basis of Wilson's group theoretical method for these two molecules. Numerical values of the ten mean‐square amplitude quantities have been given at the temperatures T=O and T=298°K. The corresponding mean amplitudes of vibration for O – F, Si – F and F – F distances have also been given at these temperatures. The observed fundamental frequencies have been utilized for the calculation of molar thermodynamic functions assuming a rigid rotator, harmonic oscillator approximation for the temperature range from 100° to 1700°K.
Studies on Halogenated Aliphatic Compounds VII. Dipole Moments and Infrared Spectra of Halogenated Acetonitriles
Authors: van Der Kelen G. P.
Published: September 2010

Les moments dipolaires électriques des nitriles CH3CN, CH2ClCN, CHCl2CN, CCl3CN, CH2FCN, CHF2CN et CH2(CN)2 ont été déterminés en solution dans le benzène. Le moment du CF3CN a été observé en phase gazeuse. Les spectres infrarouges de ces substances à l'état pur ont été déterminés. Des calculs vectoriels fournissent les valeurs du moment partiel du groupe CN. Il est démontré, tant par ces valeurs du moment partiel du groupe, que par l'intensité de la bande CN dans l'infrarouge, que le groupe CN subit des influences inductives très prononcés par les atomes d'halogène. D'autre part il est mis en évidence que les moments partiels des liaisons C‐X (X=F,C) ne sont nullement constantes dans ces composés.
Structure des Cyanostilbènes VI. Détermination radiocristallographique de la structure du dibromo‐2,6, α‐cyanostilbène
Authors: Bois D'Enghien H. , van Meerssche M.
Published: September 2010

Le dibromo‐2‐6, α‐cyanostilbène est triclinique, Pl, a=9,63, b=9,69, c=7,21 Å; α=90o, β=99,5o, γ=90o Z=2 La structure a été résolue en appliquant la méthode de l'atome lourd aux réflexions hko, hkl, hhl. Elle a été affinée par moindres carrés. La molécule est cis et les deux cycles sont presque perpendiculaires l'un à l'autre.
Synthèse des Sélénosemicarbazides Substituées I. Synthèse des esters isosélénocyaniques
Authors: Collard‐Charon C. , Renson M.
Published: September 2010

Nous recherchons systématiquement et discutons les méthodes d'obtention des esters isosélénocyaniques en vue de la préparation ultérieure de sélénosemicarbazides substituées.

Les méthodes principales de préparation des esters isothiocyaniques ne sont généralement pas applicables à leurs isologues séléniés, et nous devons utiliser des procédés d'obtention moins directs et plus délicats. Les esters isosélénocyaniques sont des substances peu stables, non distillables et done difficilement purifiables.
Furo [3,2‐C] et Thiéno [3,2‐C] Pyridines Ainsi Que Leurs Dérivés DI‐ET Tétra‐Hydrogénés
Authors: Descamps M. , Binon F.
Published: September 2010

New 4‐aryl and 4‐alkyl‐6,7‐dihydrofuro [3,2‐C] or thieno [3,2‐C] pyridines have been synthesized by making use of the Bischler‐Napieralski reaction with the corresponding amides of 2‐(2‐furyl) or 2‐(2‐thienyl)‐ethylamine. This reaction may also be used with the amides of 2‐(2‐benzofuryl)‐éthylamine. The reaction does not appear to be applicable to the amides of furfurylamine.

In the case of the 6,7‐dihydrofuro [3,2‐C] and thieno [3,2‐C] pyridines, the corresponding dehydrogenated or tetrahydrogenated derivatives have been obtained. The I.R. and U.V. spectra of some of these derivatives are compared.
Substitution Électrophile Aliphatique II. Influence de l'effet stérique dans la bromo et l'iododemétallation de dérivés alcoylés de l'étain (1)
Authors: Gielen M. , Nasielski J.
Published: September 2010

The rates of the reactions of tetraalkyltins (R4Sn) with bromine in dimethylformamide and acetic acid solutions and with iodine in acetic acid are found to depend on steric effects (kMe> kEt > knPr), caused by the R3Sn leaving group. Trialkyltin bromides (R3SnBr) are cleaved by bromine in acetic acid in a reactivity sequence (kMe < kEt > knPr) which is best explained by an increasing importance of inductive effects.
Quaternisation de Dérivés Monohalogénés de la Pyridine Par L'Iodure de Méthyle
Authors: Coppens G. , Declerck F. , Gillet C. , Nasielski J.
Published: September 2010

The reactivity of six monohalogenated pyridines with methyl iodide has been determined conductimetrically in nitrobenzene. The results are: (k25∘ EA; log PZ):2‐chloropyridine (0,204.10‐5; 16,5; 6,41) 3‐chloropyridine (3,0.10‐5; 15,1; 6,56); 4‐chloropyridine 7,3.10‐5; 14,7; 6,66), 2‐bromopyridine (0,11.10‐5; 16,9; 6,44) 3‐bromopyridine (3,5.10–5; 15,2; 6,7), 4‐bromopyridine (16,9.10‐5; 14,2; 6,63).

Combining these figures with data from the literature, one obtains a good Hammett plot yielding ρ=‐2,5.

The relation between the activation energies and the pKas gives a value of 4.6 for the pKa of 4‐bromopyridine and suggests the following values for the compression energies of ortho substituents Cl:0,17, Br:0,65 and CH3:0,50 Kcal/mole.

Side reactions, such as polymerization of the reactants or the products, did not interfere with kinetic measurements, suggesting that the instability of 4‐halogenopyridines has been somewhat exaggerated.
Stéroides CCXXXIII(1) Préparation et Stéréochimie de la 16β‐Hydroxyméthyl Isoprogestérone
Authors: Crabbé Pierre , Romo J.
Published: September 2010

The synthesis of 16β‐hydroxymethyl‐17α‐Δ5‐pregnene‐3β‐ol‐20‐one (IV) and 16β‐hydroxymethyl‐isoprogesterone (IXa) is described. The configuration assigned to these substances and their derivatives is based on rotatory dispersion, nuclear magnetic resonance and circular dichroism considerations.
Oxidation of Cholesterol II. Influence of The Nature of The 3β‐Ester Group on The Yield of 17‐Ketosteroid
Authors: Maas S. P. J. , van Dam M. J. D. , De Heus J. G. , Mulder D.
Published: September 2010

An improved method of oxidation with chromic (VI) oxide of dibromocholestanyl esters has been developed. Application of this technique to both pure 5β, 6α‐dibromocholestanyl acetate and benzoate, as well as to mixtures resulting from mutarotation of several laevorotating dibromocholestanyl esters gave yields of 17‐ketosteroid which were considerably higher than those mentioned before.
Mean Amplitudes of Vibration and Thermodynamic Functions of the Hydro and Deutero Sulphides and Selenides
Authors: Nagarajan G.
Published: September 2010

Regarding the molecular structure and vibrational spectral studies of the hydro and deutero sulphides and selenides, a brief survey of the work done so far has been narrated. The computed numerical values of (1) mean‐square amplitude quantities, (2) generalized mean‐square amplitudes (mean‐square parallel amplitudes, mean‐square perpendicular amplitudes and mean cross products) and (3) mean amplitudes of vibration for the temperatures at T=0 and T=298°K have been given for hydrogen sulphide, deuterium sulphide hydrogen selenide and deuterium selenide. Using the vibrational fundamental frequencies the molar thermodynamic functions have been calculated on the basis of a rigid rotator, harmonic oscillator approximation for the temperature range from 200° to 2000°K.
Étude du Comportement D'isomères Géométriques Sous L'impact Électronique. II. Les Cis et Trans Hexahydroindanes
Authors: Natalis P.
Published: September 2010

The influence of geometrical isomerism on the behaviour of cis and trans hexahydroindanes under electron impact appears in two different ways.

Firstly, mass spectra, although qualitatively identical, show important differences between abundances of several main fragment ions, especially C5H7+ and C6H9+. Relative abundances of molecular ions also differ, by about 15%, and indicate a greater stability of ionized trans isomer.

Secondly, from the standpoint of energetics, two results are to be noticed. (a) Ionization potentials of cis and trans hexahydroindanes are the same within experimental uncertainties, which means that an effect due to isomerism appears in both ionized molecules. (b) Appearance potentials of the main fragment ions show that a lower energy is required to dissociate ionized cis hexahydroindane into fragments, which has to be related to the energy provided by steric conformation in this molecule.

These results are in perfect agreement with those previously obtained in a study of cis and trans decalines.
New bivalent sulfur derivatives of pentaerythritol
Authors: Goethals E.
Published: September 2010

Several new bivalent sulfur derivatives of pentaerythritol amongst them a member of the new class of the “thiosultones” are described.
Chromatographie Sur Couche Mince De Quelques Alcaloides Des Légumineuses
Authors: Ramaut J. L.
Published: September 2010

According to several experiments, it is stated that thin layer chromatography of Leguminosae alkaloids yields very good results with the following technique:

Adsorbent: Kieselgel G‐Plates dried at 110°C for 30 minutes. Colour reagent: Dragendorff modified by Munier. Solvent: Cyclohexanol‐Cyclohexane‐Hexane (1:1:1+5% in vol. diethylamine).

After chromatographying, the plates were dried at 100°C for 1 h and sprayed afterwards.

The majority of alkaloids appeared red orange (coloured); Orensin, Adenocarpin and Santiaguin were yellow or yellow‐orange (coloured); Lupinin was beige.
Potential Field and Force Constants of Antimony Pentafluoride and Niobium Pentachloride
Authors: N'agarajan' G.
Published: September 2010

For the 'XY'5 type molecules possessing the trigonal bipyramidal Structure with the symmetry point group 'D'3'h' an orthonormalized set of symmetry coordinates satisfying the transformation properties has been constructed. The potential and kinetic energy matrices have been derived. For the antimony pentafluoride and niobium pentachloride molecules the potential energy constants have been evaluated.
La Dégradation Enzymatique de L'Acide Désoxyribonucléique. IV.‐Mise au Point et Application D'Une Méthode D'Adsorption
Authors: Hacha R. , Fredericq E.
Published: September 2010

Calf thymus deoxyribonucleic acid (DNA) was hydrolyzed by pancreas and by spleen deoxyribonucleases (DNases I and II). The hydrolysates were adsorbed on Ecteola cellulose and eluted by successive amounts of 0.1, 0.2 and 0.3 M NaCl. Oligonucleotides of increasing sizes were present in the eluates and were determined spectroscopically. This provided a simple method for following the whole course of the enzymic hydrolysis. Moreover it was possible to estimate the percentage and the average degree of polymerization of the oligonucleotides produced.

The enzymic action of DNase I was studied in varied conditions of temperature and in the presence of several activating cations. It was confirmed that there were two phases: a rapid one mostly activated by Mg ions and by Mn2+ and Co2+, a slow one activated by Ca2+. The highest rate was obtained with mixtures of Mg2+ and Ca2+. These results were interpreted by supposing the existence of a second enzyme in the DNase preparation, an oligonucleotidase.

With DNase II, higher oligonucleotides were produced.

Native DNA, DNA denatured by heat or by desionization and DNA degraded by ultrasonic waves were submitted to the action of both DNases. Their behaviour was very similar. It seems that the intact structure of native DNA is not an important requirement for the enzymic action.
Substitution Nucléophile Sur L'Atome D'Étain. Mise en Évidence de Complexes Pentacovalents du Type R3SnBr I−.
Authors: Gielen M. , Nasielski J. , Yernaux R.
Published: September 2010

Trialkyltin bromides are found to act as Lewis acids towards iodide ions. Equilibrium constants for the complexation in acetone solution are reported.
The Calculation of the Stability Constants of Some Lanthanide‐α‐Hydroxy‐Carboxylate Complexes Using a High Speed Digital Computer
Authors: Deelstra H. , Vanderleen W. , Verbeek F.
Published: September 2010

The four successive stability constants and their standard deviations have been determined for the α‐hydroxy‐isobutyrate and lactate complexes of the lanthanide elements and yttrium. A least squares treatment of the experimental data obtained by the Calvin‐Bjerrum potentiometric titration method using an I.B.M. 1620 high speed digital computer is described.
Sur Une Nouvelle Méthode de Synthése Des Oxadiazoles‐1,2, 4 Disubstitués
Authors: Eloy F. , Lenaers R.
Published: September 2010

A new one‐step synthesis of disubstituted 1, 2, 4, oxadiazoles is described. The process consists in condensing a hydroxamyl chloride with an iminoether at relatively low temperature.
Halogen Substituted 1,3‐Cyclohexanediones I. Reaction of 2,2‐dichlorodimedone with bases
Authors: Schamp N. , Verzele M.
Published: September 2010

The reaction of 2,2‐dichlorodimedone with bases gives complex mixtures, but with silver oxide a straightforward reaction leads with high yield to 6,6‐dichloro‐4,4‐dimethyl‐5‐oxohexanoic acid and/or to 4,4‐dimethyl‐5‐chloroacetyl‐2‐tetrahydrofuranone. Identical reactions occur with 2,2‐dichloro‐1,3‐cyclohexanedione.
Substitution Électrophile sur Carbone Saturé IV. Oxydation chromique de tétra‐alkylétains
Authors: Deblandre C. , Gielen M. , Nasielski J.
Published: September 2010

Symmetrical tetraalkyltins react with chromic anhydryde to yield aldehydes and acids. The rates have been measured, and the kinetic results suggest a five‐membered transition state for this bimolecular electrophilic substitution on a saturated carbon atom.
Humulinone
Authors: Meheus J. , Alderweireldt F. , Verzele M.
Published: September 2010

Chemical evidence shows that humulinone has the five membered ring‐structure I.
The Theoretical Treatment of Ionized Molecules
Authors: Hall G. G.
Published: September 2010

The calculation of molecular ionization potentials and of the structure of ions is reviewed and some extensions of the theory to enable it to include inductive effects are discussed. The status of some theories of the unimolecular dissociation is considered critically in relation to experimental facts and to theoretical requirements. A new theory of this dissociation is presented which uses some of the ideas of quantum mechanical scattering theory and provides a proper foundation for further investigations.
The Ionization and Dissociation Energies of the Hydrides and Fluorides of the Elements
Authors: Price W. C.
Published: September 2010

Plots of the bond dissociation energies of the hydrides and fluorides are presented together with those for the corresponding isoelectronic ions derived from ionization potential data. These show the dependence of the energies on the closed shell configurations appropriate to the shape of the radical or ion. The curves are also used to derive certain proton affinities and to explain the feasibility of ion‐molecule reactions.

All the processes to be considered in the present article refer to the monomeric species and the bond dissociation energies are with reference to the lowest states of the atoms, radicals or ions. Exceptions to the latter statement occur for NH, HF and Ne+F where the removal of a pπ electron does not lead to the lowest state of the ion.
Recherches Dans la Série Des Benzofurannes XI‐Synthèse de pyrazoles et d'isoxazoles a partir de composés céto‐3 benzofuranniques
Authors: Descamps M. , Binon F. , Van Elst J. Der
Published: September 2010

It is shown that hydrazine and methyl hydrazine react with 3‐keto benzofurans to yield trisubstituted pyrazoles having a phenolic character. Several pyrazole compounds have been prepared. R. Royer and E. Bisagni have shown that phenolic trisubstituted isoxazoles are formed by the action of hydroxylamine on the 3‐keto benzofurans; we have prepared other phenolic isoxazoles, thus showing how very general the reaction is.

Finally we have synthesised β‐N‐diethylaminoethylether derivatives of all phenolic pyrazoles and isoxazoles.
Préparation et Propriétés de la Sélénochromannone‐4 et de la Sélénochromone
Authors: Renson M.
Published: September 2010

Nous décrivons une méthode nouvelle et pratique de préparation de la sélénochromannone. Cette substance constitue le point de départ d'un travail dont nous décrivons quelques réactions dans ce premier article.
Réactions du Sulfoxyde de Diméthyle I — Synthèse des halogénures de diméthyl‐hydroxyaryl‐sulfonium et pyrolyse de ces corps en méthyl‐hydroxyaryl thioethers
Authors: Goethals E. , De Radzitzky P.
Published: September 2010

15 dimethyl‐hydroxyaryl‐sulfonium chlorides have been prepared by condensing dimethylsulfoxide on hydroxyaromatic compounds with hydrochloric acid. The structure of the sulfonium salts and the mechanism of their formation are discussed. The pyrolysis of those sulfonium chlorides gives a quantitative yield of the corresponding methyl‐hydroxyaryl‐thioethers. The combination of those two reactions provides a very convenient way to introduce a methylthio‐group on an aromatic nucleus already carrying an hydroxyl group.
Isomérie de Position et Spectres de Masse I‐Diméthylcycloalcanes à cycle en C3, C5 et C6
Authors: Natalis P.
Published: September 2010

Correlation rules of mass spectra with molecular structure of branched hydrocarbons have been checked for all position isomers of dimethylcyclopropane, dimethylcyclopentane and dimethylcyclohexane, by examining relative abundances of molecular ions P+ and two fragment ions (P‐CH3)+ and (P‐C2H4)+, corresponding to loss of CH3 or C2H4 groups from molecular ion.

It turns out that correlation rules concerning abundance of molecular ions, nature of side‐chains, location of some C‐C breakdowns, and metastable transitions can be applied to the dimethylcycloalkanes examined, with some restriction for cyclopropane derivatives.

Relative abundances of fragment ion (P‐C2H4)+ in various position isomers can only be explained in a satisfactory manner by a ring opening process involving a C‐C bond close to a side‐chain.
Synthèse de L'Amino‐2‐Hydroxy‐4‐Triazine‐1,3,5
Authors: Flament I. , Promel R. , Martin R. H.
Published: September 2010

2‐Amino‐4‐hydroxy‐1,3,5‐triazine (VI, VIa), an analog of cytosine, has been prepared from 2,4,6‐trichloro‐1,3,5‐triazine by a four or five step synthesis (cf. scheme). Its U.V. spectra, apparent dissociation constant and activity against three experimental tumors are also reported.
Determination of Serum Glyceride Glycerol
Authors: Christophe A. , Matthus F.
Published: September 2010

A suitable method for the routine determination of serum glyceride glycerol, was developed.

The procedure consists of 3 steps: the separation of the phospholipids, hydrolysis of the glycerides and determination of the glycerol formed.
Isolation of Some Organic Acids in the Presence of Pyruvic Acid
Authors: Demeyer D. , Henderickx H.
Published: September 2010

Lower volatile fatty acids, formic acid and lactic acid were isolated by partition chromatography in the presence of pyruvic acid. It appeared that previous conversion of pyruvic acid to acetic acid was necessary. Acetic acid could then be determined in a second sample.

A detailed description of the method is given.
Acylcyclopentanones III‐The synthesis of 2‐acetylcyclopentane‐1,3‐diones
Authors: Vandewalle M.
Published: September 2010

2‐Acylcyclopentane‐1,3‐diones and 2‐acyl‐4‐carboethoxy‐cyclopentane‐1,3‐diones are obtained by Dieckmann condensation of 1,4‐dicarboethoxyhexane‐3,5‐diones. They exist in a monoenolic form and are monobasic acids.
Mean Amplitudes of Vibration and Thermodynamic Functions for the Trioxides of Xenon and Rhenium
Authors: Nagarajan G.
Published: September 2010

The mean amplitudes of vibration for the trioxides of xenon and rhenium possessing a pyramidal structure with the symmetry point group C3V have been evaluated on the basis of the principle postulated by Cyvin for the temperatures T=0 and T=298°K, respectively. The molar thermodynamic functions also have been calculated for these molecules with an assumption of a rigid rotator, harmonic oscillator model for the temperature range 100‐2000°K.
Electron Irradiation of Hydrocarbons I. Radiolysis of Liquid N‐Pentane
Authors: Claes P. , Rzad S.
Published: September 2010

Ce travail a pour objet l'étude de l'action d'électrons d'une énergie de l'ordre de 30 KeV sur le pentane n liquide. Nous avons mis au point une méthode d'analyse des différents gaz formés au cours de la radiolyse. Nous nous sommes attachés surtout à étudier l'influence de l'intensité d'irradiation et de la dose totale cédée au système. L'étude de ces effets nous a permis de mettre en évidence les réactions qui prennent une part prépondérante aux effets chimiques observés.
Les Constantes D'Acidité des Benzoylacétanilides Mono‐Et Polysubstitués
Authors: van Brandt P. , De Hoffmann E. , Bruylants A.
Published: September 2010

Les auteurs ont déterminé la constante d'acidité du benzoylacétanilide et de ses dérivés de substitution:

Trois familles de dérivés ont été choisies; la première (X=H et Y≠H) comporte quatorze termes, Y pouvant être: 4‐N (CH3)2; 4‐CH3O; 4‐CH3; H; 4‐F; 4‐Cl; 4‐Br; 4‐1; 3‐Cl; 3‐NO2, 4CH3; 3‐NO2; 4‐CH3CO; 4‐CN; 4‐NO2; la deuxième (X=H et Y≠H) comprend six corps, X étant: 4‐CH3O; 3‐CH3; 4‐Cl; 3‐No2; 4‐NO2; 3,5‐(NO2)2.

Les constantes d'acidité (Ka) sont reliées entre elles par la corrélation classique: log Ka/Ka0=ρσ(Ka0=1,1.10−9 à 20°C); toutefois, en raison de la dissymétrie de la structure, les valeurs de ρ sont différentes. Dans la première famille, σν=0,79, tandis que dans la deuxième ρx=1,83.

La troisième famille comprend vingt‐trois termes, avec des couples de substituants (X,Y): 4‐CH3O, 4‐CH3; 4‐CH3, 4‐CH3O; 4‐CH3O, 4‐Br; 4‐CH3O, 3‐Cl; 4‐Cl, 4‐N(CH3)2; 4‐CH3, 4‐Br; 4‐CH3, 3‐Cl; 4‐CH3O, 3‐NO2; 4‐Cl, 4‐CH3O; 4‐CH3, 3‐NO2; 4‐Cl, 4‐CH3; 4‐Cl, 4‐Br; 4‐Cl, 3‐Cl; 3‐NO2, 4‐N(CH3)2; 4‐Cl, 3‐NO2; 3‐NO2, 4‐CH3; 4‐NO2, 4‐N(CH3)2; 3‐NO2, 4‐Br; 3‐NO2, 3‐Cl; 3‐NO2, 4‐CH3O; 4‐NO2, 4‐CH3; 4‐NO2; 4‐Br; 3,5‐(NO2)2, 4‐N(CH3)2.

Toutes les valeurs expérimentales se placent sur un droite: log Kaxy / Ka0 = ρx ρv (σx/ρv + σy/ρx) calculée au moyen des constantes de réaction, ρx et ρy, caractéristiques des deux premières familles.

En fait, au moyen de cette corrélation nous avons pu coordonner entre elles les valeurs des constantes aussi bien pour la troisième famille que pour les deux premières.
Mean Amplitudes of Vibration and Thermodynamic Functions of Aluminum Suboxide
Authors: Nagarajan G.
Published: September 2010

A brief vibrational analysis of aluminum suboxide, Al2O, possessing a bent symmetrical structure with the symmetry point group C2v has been made. The computed numerical values of (a) mean‐square amplitude quantities, (b) generalized mean‐square amplitude quantities (mean‐square parallel amplitudes, mean‐square perpendicular amplitudes and mean cross products) and (c) mean amplitudes of vibration for the bonded as well as nonbonded atom pairs at the temperatures T=0 and T=298° K are reported. Discussion of the results is made. The calculated values of the statistical thermodynamic functions on the basis of a rigid rotator, harmonic oscillator model for the temperature range 100‐2000°K are also given.
Anharmonic Constants and Thermodynamic Functions of the Germyl Halides
Authors: Nagarajan G.
Published: September 2010

Anharmonic constants for the germyl halides possessing a C3ν symmetry have been calculated by the Dennison's method. The molar thermodynamic functions have also been calculated with the assumption of a rigid rotator, harmonic oscillator model for the temperature range 200°‐2000°K using the zero‐order frequencies.
Potential constants of some inorganic hexahalides
Authors: Yeranos W. A.
Published: September 2010

Using recently published Infrared and Raman data, the Urey‐Bradley constants of ReCl2−6, ReBr2−6 and OsCl2−6 have been determined. The treatment has been carried within the formalism of WILSON'S F‐G matrix method, and the force constants have been calculated by a computer routine which refined approximate values in the least square sense.
Phosphorus‐containing polymethine dyes. II. The absorption spectra and electronic structure of symmetric cationic dyes derived from cyclopentadienylenetriphenylphosphorane
Authors: Depoorter H. , Nys J. , van Dormael A.
Published: September 2010

La méthode théorique dite du “modéle métallique” est appliquée aux phosphinines symétriques décrites dans la première partie. Les résultats des calculs permettent l'énoncé d'une hypothèse relative à la structure électronique de ces édifices.
Studies on the grignard reaction. IX. Autocatalytic aspects of the reaction on ketones
Authors: D'Hollander R. , Anteunis M.
Published: September 2010

In the Grignard reaction, magnesium bromide and alcoholates (e.g. reaction products) greatly reduce the reaction velocity of either the addition or the reduction with ketones. Magnesium bromide and α‐unbranched alcoholates favour however the addition over the reduction reaction. Complex (α‐branched) alcoholates on the contrary favour reduction, and this can be prevented by adding magnesium bromide. The mechanism proposed by Hamelin (14) can be adopted by supposing a nucleophilic attack of the Grignard reagent on the ketone, assisted by ketone/magnesium bromide or ketone/alcoholate complexation.
Étude Spectroscopique de Molécules Halogénées. V. Analyse Conformationnelle en Série Cyclopentanique
Authors: Reisse J. , Nagels L. , Chiurdoglu G.
Published: September 2010

The infra‐red spectra of halogenocyclopentanes were recorded in liquid and solid phase. The behaviour observed was compared with literature data. The results were discussed in terms of cyclopentane conformations and pseudorotation of this ring.
L'Iturine. I. Préparation, Purification et Poids Moléculaire
Authors: Delcambe L.
Published: September 2010

L'iturine, antibiotique antifongique de nature peptidique, a été concentrée, dépigmentée, puis séparée de peptides inactifs par chromatographie d'adsorption sur alumine suivie d'une chromatographie de partage sur cellulose. La préparation obtenue se comporte comme une substance homogène à l'électrophorèse, l'ultracentrifugation et la chromatographie sur papier tandis que les courbes de solubilité indiquent une substance pratiquement pure. Le poids moléculaire mesuré en solution alcoolique, par thermoosmométrie, par diffusion au travers d'une cloison poreuse ou par ultracentrifugation est de l'ordre de 1.000. En solution aqueuse on obtient des valeurs beaucoup plus élevées (38.500) attribuées à un important phénomène d'agrégation.
L'Iturine. II. Composition en Acides Aminés, Spectre Ultraviolet et Structure Cyclique
Authors: Delcambe L.
Published: September 2010

Par hydrolyse acide totale on a mis en évidence dans l'iturine 3 Asp (NH2), Glu (NH2), Pro, Ser, Tyr. L'enchaînement de ces acides, qui forment un cycle, a été déterminé par l'étude des peptides obtenus par hydrolyse partielle. Leur forme optique a été déduite de Faction des L — et D — aminoacide‐oxydases. L'iturine diffère des autres antibiotiques antifongiques, dont la structure est connue, par sa composition en acides aminés et par ses propriétés.
The proton magnetic resonance spectra of phenyltin chlorides
Authors: Verdonck L. , van Der Kelen G. P.
Published: September 2010

Les spectres de résonance magnétique nucléaire des phénylchlorostannanes (C6H5)3SnCl, (C6H52SnCl2, C6H5SnCl3 ont été étudiés. Les satellites dus au couplage des noyaux Sn117 et Sn119 avec les protons en position ortho sont enregistres. II résulte de l'analyse des spectres que les déplacements chimiques relatives des signaux sont moins importantes pour les protons ortho que pour l'ensemble des protons méta et para. Les données des constantes de couplage indiquent la possibilité de liaisons multiples par l'interaction entre les orbitales d supérieures de l'atome d'étain et les électrons π du noyau benzénique.
Normal coordinate analysis of XeOF4 in the Urey‐Bradley field
Authors: Yeranos W. A.
Published: September 2010

Using published infrared and Raman data, the Urey‐Bradley force constants of XeOF4 have been determined, the analysis has been carried with in Wilson's G‐F matrix method and the constants evaluated by the use of a computer program which refined the differences of the experimental and calculated frequencies in the least‐squares sense. The G and F matrix elements, in both the GVFF and UBFF, of any molecule of the type MYX4 and of C4v symmetry have been reported (α = γ = 90°). Finally, the normal coordinates as well as the potential energy distribution matrix of XeOF4 in the field force determined by us has been given.
Studies on organogermanium compounds. II. The raman and infrared spectra of the methylgermanium chlorides (CH3)n GeCl(4‐n)
Authors: van De Vondel D. F. , van Der Kelen G. P.
Published: September 2010

Les spectres Raman et les spectres d'absorption infra rouge de la série de composés (CH3)nGeCl 4‐n (n = 1, 2, 3) ont été étudiés. L'attribution des fréquences observées aux vibrations fondamentales est faite. Cette attribution a été facilitée par les mesures du facteur de dépolarisation de plusieures fréquences Raman. Les calculs théoriques des fréquences fondamentales confirment cette attribution.
Studies on organogermanium compounds. III. The raman and infrared spectra of the methylgermanes
Authors: van De Vondel D. F. , van Der Kelen G. P.
Published: September 2010

Les spectres Raman et les spectres d'absorption infra rouge de la série de composés (CH3)nGeH4‐n (n = 1, 2, 3) ont été étudies. L'attribution des fréquences observées aux vibrations fondamentales est faite. Cette attribution a été facilitée par les mesures du facteur de dépolarisation de plusieurs fréquences Raman. Les calculs théoriques des fréquences fondamentales confirment cette attribution.
Étude Physico‐Chimique de Modèles D'Alcaloïdes Indoliques. III. Détermination de la Structure des Isomères Géométriques Du 3‐Éthylidène‐1‐Azabicyclo [2,2,2] Octane Préparés Par la Réaction de Wittig et Corrélation Avec les Alcaloïdes Indoliques. Étude des Couplages À Longue Distance
Authors: van Binst G. , Nouls J. C. , Stokoe J. , Danheux C. , Martin R. H.
Published: September 2010

1‐azabicyclo [2,2,2] octan‐3‐one (3‐quinuclidone) treated with triphenyl‐ethylphosphonium bromide in dimethylsulfoxide and sodium hydride gives pure 3‐ethylidene‐1‐azabicyclo [2,2,2] octane in high yield. Evidence for the existence of cis and trans isomers, whose structures were determined by study of long range coupling, is given by N.M.R. spectroscopy. A correlation with sarpaginelike indole alkaloids has been established and a simple rule for the determination of the configuration of the ethylidene side chain in such alkaloids is given.
Physico‐chemical properties of coordinating compounds. V. Hydrolysis of N‐salicylidenealkylamines as monomeric models of poly‐N‐salicylidenevinylamine
Authors: Charette J. , Decoene C. , Faltlhansl G. , Teyssié Ph.
Published: September 2010

L'hydrolyse de bases de Schiff monomériques et polymériques de la famille des N‐salicylidenealcoylamines a été étudiée par spectroscopie dans l'ultraviolet dans différentes conditions de concentration, force ionique, température et pH. Une relation est établie entre la vitesse d'hydrolyse d'une base de Schiff et la basicité de l'amine de départ; cette relation s'étend même à la base polymérique. Dans certains cas, la présence d'ions métalliques catalyse l'hydrolyse.
Alcaloides Indoliques. VII. Structure de la Voacoline
Authors: Lhoest G. , De Neys R. , Defay N. , Seibl J. , Pecher J. , Martin R. H.
Published: September 2010

Voacoline, a new minor alkaloid from Voacanga chalotiana Pierre ex Stapf (apocynaceae) is shown to have structure I. This structure contains two unusual features : a Na‐CH3 indolic group and a hemiketal function. This last feature accounts for the very easy formation of O‐methyl II and O‐ethyl‐voacoline HI. A correlation with voachalotine IV, the major alkaloid of the same species, has been achieved by degradation of I to dihydrodeshydroxymethylvoachalotine XIV. UV, IR, NMR and mass spectra of I and some of its derivatives are discussed.
Dosimétrie Chimique dans les Irradiations À Haute Densité D'Énergie. I. Solutions Aqueuses
Authors: Lutgen P. , Claes P.
Published: September 2010

In this work, air‐free aqueous solutions of ferrous sulfate and oxalic acid were tested as dosimeters in the case of irradiations at high dose rates and non homogeneous energy repartition. The extend of reaction is strongly dose‐rate dependent. It seems that diffusion of the solute to the irradiated zone is the rate determining step. The tested solutions are thus no accurate dosimeters for the irradiations used in the present work.
Constantes D'Acidité de Quelques Phenyl‐2, Acridines
Authors: D'Souza J. , Bruylants A.
Published: September 2010

Les auteurs ont déterminé la constante d'acidité des acides conjugués de la phényl‐2, acridine et de deux dérivés de substitution azotés: magnified image.

Ils ont montré, en outre, que, dans le cas de (2), la première ionisation affectait l'azote du noyau, dans le cas de (3), la première ionisation concernait l'azote du noyau, tandis que la deuxième ionisation était imputable à l'azote terminal de la fonction hydrazinée, la dernière affectant l'azote restant.
Contribution à L'Étude D'Acides de la Série de la Pyridazine IV. ‐ Nouvel alcaloïde de synthèse, L'«aza‐2 nicotine»
Authors: Rosseels Gilbert
Published: September 2010

An exhaustive study of the different methods of synthesis of pyridazine 3‐carboxylic acid has been undertaken and two new preparations of this acid have been realized, one by carbonatation of 6‐chloro 3‐pyridazinyllithium, the other by permanganic oxidation of 6‐chloro 3‐pyrrolo pyridazine.

The α‐(3‐pyridazinyl)‐N‐Methyl pyrrole or «2‐aza‐nicotine» is obtained from N‐methyl‐2‐pyrrolyllithium and 3,6‐dichloropyridazine.
Oxydation des Bases Monoaza‐Aromatiques Par L'Acide Perbenzoïque
Authors: Foucart J. , Nasielski J. , Vander Donckt E.
Published: September 2010

The reactivity of a series of monoaza‐aromatic bases towards perbenzoïc acid in dioxane‐water has been determined. The results are (k2 25°): pyridine (5,3.10−3), isoquinoline (5,8.10−3), quinoline (5,9.10−3), 9‐azaphenanthrene [phenanthridine] (3,3.10−3), 1‐azaphenanthrene (4,4.10−3), 4‐azaphenanthrene (0,14.10−3), 9‐aza‐anthracene[acridine] (317.10−3). This reaction appears to be much less sensitive to steric effects than the CH3I quaternisation. The high reactivity of acridine suggests a relation between the nucleophilicity of the nitrogen atom and its π electron density, as calculated by LCAO MO.
Triterpenes 11. Les Sapogénines J et L de Stryphnodendron Coriaceum
Authors: Tursch B. , Daloze D. , Tursch E. , Chiurdoglu G.
Published: September 2010

Sapogenins J et L from Stryphnodendron coriaceum have been identified as maslinic acid and machaerinic acid, respectively.
Synthèse du Sélénopheno [2′, 3′: 5, 6] Benzo [B] Thiophène
Authors: Vafai M. , Renson M.
Published: September 2010

Nous passons en revue les méthodes susceptibles de conduire au sélénophéno [2′, 3′: 5, 6] benzo [b] thiophène, hétérocycle dans lequel un noyau benzénique est condensé à la fois à un noyau thiophène et un noyau sélénophène. La préparation de cette substance doit obligatoirement se réaliser en construisant le cycle thiophéne sur le benzo [b] sélénophène, le procédé inverse n'ayant pas pu être réalisé expérimentalement.
Sélénochromannones et sels de Séléna‐1 Naphtalénium
Authors: Danze J. M. , Renson M.
Published: September 2010

Nous étudions la préparation des sélénochromannones méthylées, par cyclisation des acides β‐phénylsélénopropioniques méthylés dans les différentes positions. Les sélénochromannones ainsi obtenues sont, d'une part déshydrogénées en sélénochromones, d'autre part transformées par une série de réactions en sels de séléna‐1 naphtalénium correspondants.
Étude du Comportement D'Isomères Géométriques sous L'Impact Électronique. VI. Les Cis‐ et Trans‐1, 2‐Di‐Terbutyl‐Éthylènes
Authors: Natalis P. , Franklin J. L.
Published: September 2010

Mass spectrometry investigation of cis and trans di‐t‐butylethylenes has been carried out by the study of the effect of electron energy on mass spectra, measurement of ionization and appearance potentials and examination of metastable transitions.

It is shown that the geometrical isomerism strongly influences the behavior of these compounds under electron impact: (1) relative abundance of the molecular ion from cis isomer is much smaller than that of trans, especially for low energy electrons; (2) the ionization potentials of both isomers are the same, but the appearance potentials of main fragment ions are smaller in the cis isomer, indicating that less energy is required to break down the ionized cis molecule; and (3) for several processes, the probability of decomposition of metastable ions is larger in cis isomer. This difference of behavior of cis and trans di‐t‐butyl‐ethylenes under electron impact has to be interpreted as a result of an effect of conformational energy (10 kcal/mole) in the cis isomer, which is nonexistant in the trans.

Molecular ions of di‐t‐butyl‐ethylenes, either cis or trans, undergo rearrangement by H migration due to the double bond and the quaternary carbon atoms. Calculation of the heat of formation of main fragment ions leads to the same values in both isomers, indicating that a common ionic intermediate (or a set of intermediates) is involved in the dissociation process. It can also be shown from such data that main fragment ions have a rearranged structure.
Halogen substituted 1, 3‐cyclohexanediones. III. A new preparation of 2‐bromoresorcinol
Authors: Schamp N. , De Pooter H.
Published: September 2010

A procedure for the synthesis of 2‐bromoresorcinol (III), with cyclohexane‐1, 3‐dione as the starting material, is described. Cyclohexane‐l, 3‐dione (VIII), prepared by the catalytic hydrogenation of resorcinol (VII), is readily brominated to 2, 2‐dibromocyclohexane‐l, 3‐dione (IX). This compound is isomered to 2, 4‐dibromocyclohexane‐l‐, 3‐dione (X), which, by dehydrobromination, yields 2‐bromoresorcinol (III).
The Friedel‐crafts acylation reaction. III. The Friedel‐crafts chalcone synthesis from substituted trans‐cinnamoyl chlorides and toluene
Authors: Slootmaekers P. J. , Rasschaert A. , Janssens W. , Verhulst J.
Published: September 2010

Dans le cadre de l'étude de la corrélation structure‐réactivité dans la réaction d'acylation du toluène par des chlorures d'acide, catalysée par le chlorure d'aluminium, on a étudié le comportement de divers chlorures de cinnamoyle, substituées en méta ou en para.

La réaction se présente comme une réaction de deuxième ordre, d'un ordre un part rapport à chacun des réactifs. Les réactivités relatives sont corrélées d'une manière satisfaisante par l'équation de Hammett, avec une constante de réaction égale à + 1,656. La série de réactions est essentiellement isoentropique, comme on démontre par application rigoureuse de la relation isocinétique. La distribution des isomères dans la réaction sur le toluène, est constante dans toute la série de réactions étudiée, c'est‐à‐dire indépendante de la nature du substituant dans le chlorure d'acide. Ce résultat (d'ailleurs aussi observé dans la réaction de benzoylation du toluène par des chlorures de benzoyle substitués) est discuté en fonction des facteurs qui déterminent la distribution des isomères dans les réactions électrophiles en chimie aromatique.

On pourrait s'attendre à une analogie très marquée entre la série de réactions étudiée et celle de la benzoylation du toluène. Si l'on exprime cette comparaison d'une manière quantitative, notamment par le facteur d'atténuation de l'effet de substituant, on constate que les deux réactions sont nettement différentes: le facteur de transmission prendrait ici la valeur exceptionelle de 0,827, contrastant fortement avec le valeur théorique d'environs 0,5.
α‐fluoronitronaphthalenes and α‐fluoronaphthylamines
Authors: Bassilios H. F. , Shawky M. , Salem A. Y.
Published: September 2010

Direct nitration of 1‐fluoronaphthalene by fuming nitric acid leads to a good yield of l‐fluoro‐4‐nitronaphthalene. Other 1‐fluoronitronaphthalenes, formerly unknown, have been prepared from the corresponding nitro‐1‐naphthylamines. Their reduction to the corresponding 1‐fluoronaphthylamines is also described.
A kinetic study of the diazotization of aniline in dilute sulphuric acid
Authors: Aboul‐Seoud A.
Published: September 2010

The results of kinetic measurements of the diazotization of aniline in 0.1 mol/l sulphuric acid, were combined with equilibrium data of the dissociation of the anilinium ion, and of nitrosyl—sulphuric acid. The specific rates for the rate‐determining reaction, and the quantities ΔG≠, ΔH≠ and ΔS≠ were calculated. These were compared with the corresponding data for the nitrosation of aniline by nitrosyl chloride. From the values of k′, of the activation energy, and of ΔH≠, it was concluded that the diffusion of the reactants is of importance as a rate‐determining process.
Préparation de Nouveaux bis (Thiazolyl‐4)‐Benzènes
Authors: De Roocker A. , De Radzitzky P.
Published: September 2010

Eight new bis‐(4‐thiazolyl) benzenes substituted on the 2‐position of both thiazole rings by the groups –CH3, –C6H5, –NH2 or –NHC6H5 have been prepared in high yield by reacting a bis‐x‐halogeno‐acetyl‐benzene with a thioamide. These compounds are models for some heat stable polymers containing the thiazole ring in the chain.
Enthalpy, free energy, entropy and heat capacity of cyclohexane and acetaldehyde
Authors: Lippincott E. R. , Nagarajan G. , Katon J. E.
Published: September 2010

On the basis of the recent vibrational and structural data, enthalpy, free energy, entropy and heat capacity of cyclohexane and acetaldehyde have been computed for the temperature range 200‐2000°K by the statistical‐mechanical treatment. The calculated values of heat capacities are in good agreement with the experimental ones. This agreement provides confirmatory evidence for the validity of the vibrational assignments of these two molecules, especially in low frequency regions.
Etude du Comportement Électrochimique des Organomagnésiens dans les Éthers Anhydres
Authors: Martinot L.
Published: September 2010

Nous avons étudié la cinétique électrochimique de l'oxydation et de la réduction d'une série d'organomagnésiens aliphatiques dans l'éther éthylique et le tétrahydrofuranne.

La réaction anodique donne naissance aux hydrocarbures éthyléniques et paraffiniques correspondant au radical organique du magnésien et à l'hydrocarbure paraffinique de doublement. Un dépôt de magnésium constitue la réaction cathodique.

L'étape cinétiquement déterminante est le transfert électronique à l'anode et l'électrocristallisation du dépôt métallique à la cathode.
Triterpènes VI. L'Oxydation de la Coriacéolide par le Dioxyde de Sélénium
Authors: Tursch B. , Daloze D. , Chiurdoglu G.
Published: September 2010

Selenium dioxide oxidation of acetoxycoriaceolide (Stryphnodendron coriaceum sapogenin B) leads to compounds exhibiting abnormal ultraviolet absorption. These have been identified as acetoxy‐12, 19‐seleno‐Δ coriaceolide (XIV) and acetoxy‐12, 19‐dioxo‐Δcoriaceolide (XII).