bluuebunny/crossref_metadata_2025 huggingface dataset:
Obtention D'un Benzile Substitué Par Dégradation D'une Isoflavone
Authors: Crabbé Pierre
Published: September 2010

The benzil (VI) has been obtained by alkaline degradation of isoflavone. (I). A mechanism for the formation of (VI) is discussed.
Études Spectroscopiques Des Molécules Hydroxylées I. Localisation Des Bandes ν(CO) D'Une Série D'Alcoylcyclohexanols Secondaires Par L'étude Des Effets De Solvant Sur Le Spectres Infrarouges
Authors: Chiurdoglu G. , Masschelein W.
Published: September 2010

Solvent effects on ν(CO) frequencies provide a new experimental method for the localisation of ν(CO) bands of substituted secondary cyclohexanols.
Études Spectroscopiques des Molécules hydroxylées. II. Analyse des érythro‐ et thréo‐butane‐2,3‐diols, ‐pentane‐2,3‐diols, et hexane‐3,4‐diols. Spectres des sulfites correspondants
Authors: Chiurdoglu G. , Groote R. De , Masschelein W. , Risseghem Melle H. Van
Published: September 2010

It has been possible to assign by infrared spectroscopy relative conformation to a number of stereomeric 1,2‐alkanediols. Spectra of the cyclic sulfites obtained from these diols are given, and it is shown that on subsequent acid hydrolysis the recovered diols entirely retain their initial configuration.
Synthèses Dans Le Domaine Des Composés Polycycliques Aromatiques XXII. 1,3‐Diméthyl‐4,5‐Méthylènephénanthrène (1,3‐Diméthyl‐4H‐Cyclopenta[def]Phénanthrène)
Authors: Martin R. H. , Binst G. Van
Published: September 2010

1,3‐dimethyl‐4,5‐methylenephenanthrene has been synthesized in two different ways, starting from 1‐acenaphtylsuccinic anhydride. A stereochemical interpretation of anomalous reactions is proposed.
Étude de L'Oxydation des Sulfocyanures par L'Hypobromite de Soude
Authors: Claeys A. , Campe A. , Thun H.
Published: September 2010

L'influence de l'alcalinité dans l'oxydation des sulfocyanures par l'hypobromite de soude a été étudiée à l'aide d'une méthode générale où le nombre d'électrons échangés (n) dans l'oxydation du composé réducteur a été déterminé.

Les résultats obtenus indiquent que l'alcalinité de la solution originale n'a pas d'influence notable dans la détermination des sulfocyanures de potassium, où n = 8.

Par contre, pour la détermination des sulfocyanures d'ammonium, la teneur en hydroxyde de soude ne peut varier qu'entre des concentrations limitées. Le nombre d'électrons échangés est de n = 11 pour des solutions de légère alcalinité et diminue de façon progressive en augmentant la quantité d'hydroxyde de soude: dans les milieux de forte alcalinité, l'oxydation devient perturbée et ne répond plus à une réaction stochiométrique.

Pour les deux cas, la teneur en hypobromite a été déterminée par la méthode graphique.
Alcaloides Indoliques III. Structure de la Voachalotine
Authors: Defay N. , Kaisin M. , Pecher J. , Martin R. H.
Published: September 2010

Voachalotine, the major alkaloid of Voacanga Chalotiana (Pierre ex Stapf), has been shown to have structure (A).
Propriétés Physico‐Chimiques de Composés A Caractère Aromatique II. Application de la Méthode des Orbitales Moléculaires Aux Spectres électroniques et a la Réduction Polarographique D'Esters Dérivés D'Acides Aromatiques Polycycliques Alternants et non Alternants
Authors: Klopman G. , Nasielski J.
Published: September 2010

The electronic energy levels of a series of ethyl esters derived from aromatic polycyclic carboxylic acids have been computed by the LCAO method.

A good correlation with polarographic half‐wave potentials and with UV absorption spectra is obtained.
Le Rôle des Complexes A Liaisons Hydrogène “Homéotopiques” Dans Les échanges Rapides Entre Protons
Authors: Huyskens P. , Zeegers‐Huyskens Th.
Published: September 2010

In some hydrogen‐bonded complexes, the bonding proton can occupy two positions, such as the motion from the first to the latter does not modify the general aspect of the complex. To this class belong, for instance, the ammonium‐amine complexes, the four‐centers transition complexes between OH and NH groups discussed by Brodskii, the cyclic dimers of carboxylic acids and so on. Quite generally the presence of such complexes with “homeotopous” bonds leads to a very fast exchange of the protons. The exchange rate is given by νexch=k[complex] wherekis the rate constant for the rupture of the hydrogen bond, with an order of magnitude of 109sec−1and [complex], the equilibrium concentration of the complex obeys, in first approximation to the law of mass‐action. The knowledge of the equilibrium constant can given information about the exchange rate. For the exchange between amines and alcohols, for instance, one can deduct from our experimental complexation constants, caracteristic exchange‐times of 10−8to 10−7sec. Alternatively one can predict the order of magnitude of complexation constants from experimental values of the exchange rate. From the rate constants of proton exchange between methyl ammonium salts and water, determined by Grunwald, Loewenstein, Meiboom and coworkers, one can deduct a order of magnitude of 0,1 to 1 M−1for the complexation constants between ammonium ions and amine. On the other hand, the exchange rates through such complexes appear to be little temperature dependent because the complexation energy acts in opposite sense onkand on the complexation constant. The only term that remains is the activation energy for the formation of the H‐bond, that may be very small. Experimental results of Conner and Loewenstein seem fit with this prediction.
Étude de La Position de la Bande CS des Thione‐Esters en Spectrographie Infra‐Rouge
Authors: Renson M. , Bidaine J.
Published: September 2010

Nous avons étudié les conditions les meilleures d'obtention des thione‐esters, et nous avons mis au point une méthode modifiée de préparation et de purification de ces substances.

Nous avons ensuite étudié leurs spectres infra‐rouges et nous avons tenté d'y localiser la vibration CS. Celle‐ci se trouve avec certitude entre 1200 et 1270 cm−1; toutefois deux alternatives s'offrent à l'intérieur de ce domaine très encombré, et les arguments respectifs en faveur de chacune d'elles sont discutés.

La position la plus probable est cependant 1205‐1218 cm−1 pour les thione‐esters aliphatiques, 1227 cm−1 pour les thione‐esters aromatiques.
Dosage Titrimétrique de la Thio‐Acétamide
Authors: Claeys A. , Sion H. , Campe A. , Thun H.
Published: September 2010

Les conditions optimales pour la détermination de la thio‐acétamide par l'hypobromite de soude ont été déterminées. En travaillant dans un milieu de faible alcalinité, et en employant la méthode de standardisation en milieu identique, le nombre d'électrons échangés (n = 8) correspond à la réaction stochiométrique.

Un contrǒle a démontré que la méthode proposée a une précision moyenne de 0,25%, et permet ainsi des titrages de solutions de thio‐acétamide d'une concentration de 0.01 molaire.
Polymorphism in Monobromoacetic Acid and the Diagram of State of Dichloroacetic Acid at Elevated Pressures
Authors: Glasgow Augustus R. , Timmermans Jean
Published: September 2010

Piezometric measurements to 5000 atmospheres have shown that dichloroacetic acid occurs in only one crystalline form; monobromoacetic acid exists in three forms with triple points at about 50.5°C and 120 kg/cm2(liq, C I, C II) and 53°C and 260 kg/cm2(liq, C II, C III). The transitions C I to C II and C II to C III have negative temperature‐pressure coefficients (dT/dP) and occur only at elevated pressures. No example has been previously reported of an organic compound which has two successive solid transitions with negativedT/dP coefficients such as were observed for monobromoacetic acid.

Values ofdT/dP, ΔH, and ΔS, calculated from the piezometric data are given for the fusion of dichloroacetic acid and for the two solid transitions and the fusion (C III, liq) of monobromoacetic acid. An evaluation of purity of the acids from time‐pressure data is discussed.
Dosage du Fluor II Composition du Chlorofluorure de Plomb en Fonction du Mode D'Addition du Réactif
Authors: Winkler P. Ed
Published: September 2010

A method allowing, with an accuracy of one per thousand, the determination of chlorine and lead in the leadchlorofluoride precipitate, has been worked out. The precipitate, previously collected in filtring crucible and weighed, is then dissolved in an aqueous solution of aluminium nitrate, thus avoiding any deterioration of the glass material.

Application of this method to the analysis of precipitates obtained in various conditions has shown the influence of the mode of introduction of the lead nitrate solution, producing the precipitation of the lead chlorofluoride. The modes only, for which the addition is very progressive and extremely slow, can give precipitates corresponding to the formula PbClF. The relative error in the determination of fluorine may thus be reduced to two per thousand for a quantity of fluorine present of about 50 mg. If the reagent is added too quickly, the precipitate has a composition which may be represented, by grouping the ions, in the form of a mixture of PbClF, PbCl2and PbClOH.
Études Conformationnelles VII. Sur L'épimérisation Des 4‐Tertiobutylcyclohexanols et Des 4‐Cyclohexylcyclohexanols Stéréoisomères
Authors: Chiurdoglu G. , Masschelein W.
Published: September 2010

The epimerisation of cis and trans isomers of 4‐tertiobutylcyclohexanol and of 4‐cyclohexylcyclohexanol is studied. The equilibration of these alcohols by catalytic methods may be interpreted by the thermodynamics of the conformational equatorial‐axial equilibrium of the hydroxyl group. This is not the case for the equilibration by the alcoholates of the corresponding alcohols.
Ionization and Dissociation of Molecules by Monoenergetic Electrons V. Acetylene and Ethylene
Authors: Collin Jacques E.
Published: September 2010

L'étude détaillée des processus d'ionisation des molécules d'acétylène et d'éthylène a été entreprise au moyen d'un spectromètre de masse équipé d'une source d'électrons monoénergétiques. Certains processus d'apparition d'ions fragmentaires ont été également examinés.

La discussion des résultats sur la base des structures électroniques des molécules considérées a permis de déduire un certain nombre de potentiels d'ionisation correspondant à des états excités des ions considérés.
Substitution Électrophile Aliphatique. Mécanisme et Vitesse de la Réaction D'Iododémétallation des Tétraméthyl, Éthyl, nPROPYL, nBUTYL et Allylétains
Authors: Gielen M. , Nasielski J.
Published: September 2010

The reactivity of a series of tetraalkyltins towards iodine has been determinated. The rate equation has been found to be v=k2. SnR4. I2 and the rate constant is not affected by added I‐. The reaction is an electrophilic substitution at a saturated carbon atom. The following rate constants have been observed: R=CH3, k2=6,81.m−1. sec−1; R=C2H5, k2=0,8; R=nC3H7, k2=0,1; R=nC4H9, k2=0,04.

The CH3<C2H5<nC3H7<nC4H9 sequence is interpreted as being due to an increasing steric repulsion between the incoming and leaving groups.

Tetraallyltin has further been found to react 300 million times faster than tetrapropyltin towards I2. An SE2′ mechanism, free from steric effects, is suggested to explain this very large difference.
Thermodynamic Properties of Some Metal Hexafluorides
Authors: Nagarajan G.
Published: September 2010

The thermodynamic properties such as heat content, free energy, entropy and heat capacity have been calculated for the molecules MoF6, WF6, IrF6, UF6, NpF6 and PuF6 for the ideal gaseous state at one atmospheric pressure up to a rigid rotator, harmonic oscillator approximation. The values have been calculated for the temperature range from 50° to 1600° K by using the observed fundamental frequencies for the above molecules.
Potential Field and Force Constants of Symmetrical Tetrazine
Authors: Nagarajan G.
Published: September 2010

An orthonormalized set of symmetry coordinates satisfying the transformation properties has been constructed for the planar s‐tetrazine molecule having the symmetry point group D2h. The F and G matrices have been deduced for both planar and nonplanar vibrations. With the existing infrared absorption fundamental frequencies the secular equations have been formed and solved to obtain a set of symmetry force constants.
Chaleurs de Combustion de Dérivés Cyclopropaniques et Pouvoir de Conjugaison du Groupe Cyclopropyle
Authors: Fierens P. J. C. , Nasielski J.
Published: September 2010

The heats of combustion of vinyl‐, ethyl‐, phenyl‐ and cyclohexylcyclopropane have been found to be respectively 772,8, 808,8, 1213,3 and 1317,8 Kcal/mole. These results clearly indicate that the ground state of “conjugated” cyclopropane derivatives is not stabilized by resonance; this is supported by HLSP quantum mechanical calculations, which give a resonance energy of 0,6 Kcal/mole in the case of vinylcyclopropane. The synthesis of phenylcyclopropane has been improved; a new compound, cyclohexylcyclopropane, has been prepared.
Phase Relations Involving Brochantite and Antlerite at Pressures to 100 Kilobars
Authors: Pistorius Carl. W. F. T.
Published: September 2010

The phase boundary representing the reaction brochantite ⇋ antlerite + tenorite + water has been followed to a pressure of 100 kilobars in the simple squeezer high‐pressure apparatus. The critical point brochantite (antlerite + tenorite + ice VII) antlerite + tenorite + vapour is situated at 65 ± 5 kilobars, 290 ± 10°C.
Potential Constants and Thermodynamic Functions of Isotopic Oxides of Nitrogen
Authors: Nagarajan G.
Published: September 2010

By using the observed zero‐order frequencies of isotopic oxides of nitrogen, the evaluation of potential constants on the basis of Wilson's group theoretical method and the calculation of molar thermodynamic functions for the temperature range from 200° to 2000°K on the basis of a rigid rotator, harmonic oscillator model have been carried out.
Potential Constants and Thermodynamic Properties of some Germanium Haloforms
Authors: Nagarajan G.
Published: September 2010

Using the observed Raman fundamental frequencies of GeHCl3 and GeHBr3 the potential constants on the basis of Wilson's group theoretical method and the thermodynamic properties upto a rigid rotator, harmonic oscillator approximation were calculated.
Étude, Par la Théorie du Champ Cristallin, de la Structure des Solutions Aqueuses des Éléments de Transition. I Scission des Termes dn Dans des Champs Faibles
Authors: Michielsen‐Effinger Janine
Published: September 2010

A point dipole model is used to calculate the electronic energies of the first transition‐series ions when four, five or six coordinated. The calculation of energy levels is made for the ions of configuration 3dn in weak crystal fields of tetrahedral, square planar, square pyramidal and octahedral symmetries. A first‐order perturbation calculation is carried out on the free ion terms of the highest multiplicity arising from the ground state configuration. Russel‐Saunders zero order n‐electrons wave functions are calculated by the method of the angular momentum operators. The calculation yields energy levels expressed in terms of adjustable parameters depending on the nature of the cation, the nature of the solvent and the symmetry of the point charge distribution around the metal ion. The energy eigenvalues obtained will be used subsequently to determine the structure of the aqueous solutions.
Extraction des Lanthanides et des Actinides au Moyen D'Acide Dibutylphosphorique. II
Authors: Duyckaerts G. , Dreze P. H.
Published: September 2010

Le mécanisme de l'extraction par l'acide dibutylphosphorique des lanthanides et des actinides trivalents est établi en tenant compte du partage du complexant et de sa dimérisation dans les diluants organiques. Les constantes de stabilité des dibutylphosphates de lanthanides et de certains actinides trivalents ont été calculées et l'extraction est discutée en fonction du nombre atomique.
Thermodynamic Functions of some Trigonal Bipyramidal Pentahalides
Authors: Nagarajan G.
Published: September 2010

The importance of the spectroscopic method of calculating the thermodynamic functions over that of the calorimetric method and the detailed procedure for the calculation of these functions have been given. By using the observed fundamental frequencies and molecular parameters, the thermodynamic functions have been calculated for the pentafluoride of stibium and the pentachloride of niobium molecules on the assumption of a rigid rotator, harmonic oscillator approximation for the temperature range from 100° to 1700°K.
Mean Amplitudes of Vibration of Some Tetrahedral XY4 Type Molecules‐Part I
Authors: Nagarajan G.
Published: September 2010

The general theory of mean‐square amplitude matrices has been briefly applied to the tetrahedral XY4 type molecule. The expressions for the twelve mean‐square amplitude quantities as linear combinations of the symmetrized mean‐square amplitude matrix elements have been given. The secular equations for the normal frequencies involving symmetry force constants and symmetrized mean‐square amplitude matrix elements have been obtained. The expressions for 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 given. For the molecules SiF4, OsO4, RuO4, CH4, CD4, CD4 and Cl4, the computed values of (1) mean‐square amplitude quantities, (2) generalized mean‐square amplitudes and (3) mean amplitudes of vibration at the temperatures T=O and T=298°K have been reported.
Préparation D'Isochromannones‐3 A Partir des Chlorures D'(o‐Acétyl‐ Eto‐Benzoyl‐Phényl) α, α Diméthylacétyle
Authors: Renson M. , Christiaens L.
Published: September 2010

Nous nous sommes efforcés sans succès de préparer les chlorures des acideso‐acétyl eto‐benzoyl‐phénylacétiques, et nous montrons que cet échec est lié à la présence d'hydrogènes mobiles sur le groupement–CH2–.

Nous préparons en conséquence les acideso‐acétyl eto‐benzoyl‐phényl α, α diméthylacétiques ainsi que leur chlorure d'acide, afin d'en étudier la structure et les propriétés notamment par comparaison avec les chlorures d'acides homologues inférieurs.

Nous montrons par spectrographie infra‐rouge que toutes les substances dérivant de ces chlorures d'acides possèdent la forme cyclique et appartiennent à la classe des isochromannones‐3.
Étude, Par Spectrométrie Infrarouge, de L'Association de L'Acide Mono‐n‐Butylphosphorique
Authors: Winand L. , Drèze Ph.
Published: September 2010

Infrared spectroscopy has been used in order to obtain information about the structure of mono‐n‐butylphosphoric acid polymers (H2MBP) which exist in the liquid state.

The spectra are compared with those of phosphoric acid, di‐n‐butylphosphoric acid (HDBP) and tri‐n‐butyl phosphate.

Discussion of the results give evidence that two molecules of H2MBP associated in a polymeric unit are generally linked together by only a hydrogen bond and that each P=O group is linked by two hydrogen bonds.

Tri‐n‐butylphosphine oxide associates with H2MBP and HDBP through its P=O groups. In the case of HDBP, it is easy to show that such interactions induce the breaking of the dimers.
Études Conformationnelles IX. Epimérisation des 4‐tertiobutylcyclohexanols stéréoisomères par le potassium dans du benzène. Analyse par la loi d'action des masses
Authors: Chiurdoglu G. , Gonze Melle H. , Masschelein W.
Published: September 2010

The epimerisation of the cis and trans isomers of 4‐tertiobutylcyclohexanol is studied quantitatively in the case of potassium in benzene as an agent. A general theory is formulated for the epimerisation of conformationally homogeneous cyclohexanols by monovalent agents. It has been shown that, in such conditions there is a linear relationship between the equilibrium titres of the trans derivative and the titre of the cyclohexanolate present. By extrapolation one may obtain experimental values of the conformational equatorial axial equilibrium of both the free alcohol and the corresponding alcoholates.
L'Effet des Radiations Électromagnétiques sur les Protéines I. Hydrolyse enzymatique de sérumalbumine aprés irradiation gamma en solution aqueuse
Authors: Colson C. , Fredericq E.
Published: September 2010

Bovine serumalbumin has been irradiated in aqueous solutions by gamma rays from a 60Co source, at dose rates varying between 5,000 and 60,000 rad per hour. An increase in absorbancy is brought about in the absorption band of aromatic aminoacids.

A moderate increase in asymmetry is evidenced by viscosity measurements at total doses below 100,000 rad. For high doses, asymmetry strongly increases and precipitation takes place.

The hydrolysis of irradiated samples by pepsin, trypsin and chymotrypsin has been measured by titration with a pH‐stat or by precipitation with trichloracetic acid. It was found that the rate of hydrolysis by pepsin and chymotrypsin decreased in proportion to the time of irradiation. This was attributed to the modifications produced in aromatic rings by irradiation, since the enzymes used are specific for bonds neighboring such aminoacids. On the contrary, trypsin, which does not have these requirements, is more active on irradiated samples. This could be related, partly at least, to the partial denaturation brought about in serumalbumin by gamma rays.
Synthèse des Sélénosemicarbazides Substituées III. Synthèse des sélénosemicarbazides substituées en 1
Authors: Collard‐Charon C. , Renson M.
Published: September 2010

Nous étudions la préparation de sélénosemicarbazides uniquement substituées en position 1; ces substances encore inconnues ne peuvent pas être préparées par la méthode générale utilisée dans le travail précédent; nous avons pu obtenir, par des méthodes particulières, des aryl‐1 sélénosemicarbazides.

La préparation d'alcoyl‐1 sélénosemicarbazides n'a cependant pas pu être réalisée.
Essais de Synthèse de Substances Non Azotées Renfermant Une Liaison Sélénocarbonyle Localisation de la Vibration C=Se des Sélénone‐Esters en Spectrographie Infra‐Rouge
Authors: Collard‐Charon C. , Renson M.
Published: September 2010

Parmi les substances non azotées possédant une liaison double C=Se, nous avons réussi à préparer deux sélénone‐esters aromatiques. L'étude de leurs spectres infra‐rouges, comparée à celle des esters et thione‐esters, nous a permis de localiser vraisemblablement la position de leur vibration C=Se.
Potential Constants and Thermodynamic Functions of Iodine Pentafluoride
Authors: Nagarajan G.
Published: September 2010

An orthonormalized set of symmetry coordinates satisfying the transformation properties has been constructed for the iodine pentafluoride molecule having the tetragonal pyramidal structure with the symmetry point group C4v. Utilizing these symmetry coordinates and a potential function consisting of the ordinary valance force terms and central force terms, the elements of potential and kinetic energy matrices have been obtained. From the observed Raman and infrared fundamental frequencies the potential constants and thermodynamic functions such as heat content, free energy, entropy and heat capacity have been calculated for a rigid rotator, harmonic oscillator approximation.
The Complex of Humulone and 1,2‐Diaminobenzene
Authors: Anteunis M. , De Borger L.
Published: September 2010

The crystalline complex between humulone (I; R = CH2CH (CH3)2) and 1, 2‐diaminobenzene is completely dissociated in solution.

It is shown that the complexation involves the alcohol group of the asymmetric carbonatom and a neighbouring carbonylfunction.
Équilibre Acide‐Base du Diméthylamino‐4′, α‐Cyanostilbène et de ses Dérivés de Substitution
Authors: Jerumanis S. , Bruylants A.
Published: September 2010

Les auteurs ont étudié les variations de basicité du groupe diméthylaminé en fonction des divers substituants X sur un certain nombre de dérivés du N‐diméthylamino‐4′, α‐cyanostilbéne de formule générale:magnified imageEn milieu acide, en effet, les stilbènes colorés (B) fixent un proton et se transforment ainsi en ions aniliniums correspondants (BH+).

Les mesures ont été effectuées sur une série de vingt N‐diméthylamino‐4′, α‐cyanostilbénes, comprenant le terme non substitué ainsi que ses dérivés monofluorés (2,3 et 4), monochlorés (2,3 et 4), monobromés (2,3 et 4), monoiodé (4), monométhyléthylés, 2, et 4), difluorés (2, 4 et 2, 6), dichlorés (2, 4 et 2, 6), dibromés (2, 4 et 2, 6) et diméthylé (3, 5).

Les résultats montrent que la constante d'acidité varie avec le caractére polaire des substituants. En particulier, pour les dérivés méta et para, la corrélation de Hammett, log KαKαo=ρσ, est vérifiée dans les limites habituelles de précision. (Kαo=1,43. 10–2; ρ=0,515). Les données obtenues permettent en outre de chiffrer l'effet polaire (σ) du groupe cyanostyrilique (σ=0,529).
Studies on the Grignard Reaction IV. The Quantitative Determination of Grignard Reagent Concentration
Authors: D'Hollander R. , Anteunis M.
Published: September 2010

It is shown that the methods used to evaluate Grignard reagent concentration (acidimetry, argentometry, iodometry) give to high results. Two new methods are proposed, one based on the estimation of unreacted excess acetone (with hydroxylamine) and one upon a photometric determination of benzophenone excess. The latter only gives good results with aliphatic non‐tertiary derivatives.

The methods can be extended to dialkyl magnesium compounds when enough magnesium bromide is added.
A Practical General Formula for the Calculation of Hydrogen‐ion Concentration of Aqueous Solutions of Acids and Bases
Authors: Claeys A.
Published: September 2010

A general formula is proposed for the calculation of the hydrogen‐ion concentration of aqueous solutions of acids. This formula, containing the dissociation constant K and the analytical concentration No, and taking into account the dissociation of the acid (correction factor C) as well as the interaction with the solvent (correction factor X) is useful over the whole range of concentration and strength, and permits a rapid calculation in a simple way.

An analogous formula is proposed for the calculation of the hydroxylion concentration of aqueous solutions of bases.
Contribution À La Spectrométrie Raman V. Etude De La Raie Raman Du Carbonyle:LA Mesure Du Coefficient De Diffusion
Authors: Michel Gilbert
Published: September 2010

The Raman bands of a large number of esters, ketones and aldehydes are investigated photoelectrically with a view of studying the intensity‐molecular structure correlation.

Particular attention is drawn to the corrections of the observed intensities considered to obtain by the external and the internal standard methods the relative scattering coefficients able for this purpose.

The relative scattering coefficient related to the CO, CC and C‐Carom. stretching bands and to the aromatic cycle breathing band are calculated from the maximum intensities.

Some preliminar remarks are pointed out about the agreement of our values with those previously published by other authors.

The intensity‐molecular structure correlation will be extensively discussed in further papers.
Étude Infra‐Rouge Des Substances Possédant une Liaison C=SE Adjacente à un ou Plusieurs Atomes D'azote
Authors: Sélénourées I. , Collard‐Charon C. , Renson M.
Published: September 2010

Nous avons étudié les spectres infra‐rouges d'une sélénouréea progressivement substituées, dont certaines ont dû être synthétisées pour la première fois.

Nous y avons localisé la bande CSe dans les limites extrêmes 1083–1109 cm−1; nous discutons également les positions et l'identification des autres bandes principales, par comparaison notamment avec les spectres de sélénourées deutérées et d'une isosélénourée.
Étude De L'isomérie Géométrique Dans Les Cis‐et Trans‐1,2‐Dialcoylcyclopentanes Par Spectrométrie D'absorption Dans L'infrarouge
Authors: Natalis P.
Published: September 2010

The infrared spectra of cis and trans 1,2‐dimethyl‐, 1,2‐diethyl‐, 1,2‐methylethyl‐and 1,2‐methylpropylcyclopentane isomers have been recorded in the frequency range from 400 to 3000 cm–1. Assignments of some fundamentals are possible in a few cases when comparison of the spectra with those of cycloalkanes and other paraffinic hydrocarbons is straightforward. Cis and trans isomers are distinguishable by specific low frequency bands and corresponding combination bands. Other important differences between the infrared spectra of these isomers have been pointed out, mainly vibrations of methyl groups.
Contribution a L'Étude de la Clathration: Synthése et Propriétés des α‐Arylalcoylamines I
Authors: De Roocker A. , De Radzitzky P. , Labofina S. A.
Published: September 2010

The Leuckart reaction has been applied to the synthesis of 59 α‐arylalkylamines 38 of which are new compounds. Physical properties of those amines are tabulated and their pKa is shown to be related to their structure and to the polarity of their substituants. All those amines are of great value for the preparation of clathrating Werner complexes.
The Synthesis of Biologically Important Organic Compounds from Abiologic Systems
Authors: Berger Rainer
Published: September 2010

L'étude présentée est une discussion sur la synthèse d'importants composés organiques dérivés de systèmes abiologiques. De nouvelles méthodes de synthèse de composés de ce genre ont été récemment rapportées. Dans le cadre de l'étude du problème de l'origine de la vie, ces méthodes nouvelles ont été appliquées dans une grande variété de conditions dont certaines existent dans l'univers et dont d'autres peuvent s'être réalisées sur la terre à son origine. Cette étude est une présentation abrégée de la synthèse de purines, pyrimidines, monosaccharides, nucléosides, nucléotides, acides aminés, polypeptides, etc.….
Étude du Comportement D'isoméres Géométriques Sous L'impact Électronique I. Les cis et Trans Décalines
Authors: Natalis P.
Published: September 2010

Mass spectrometric investigation of cis and trans decalines shows an influence of geometrical isomerism on the behavior of these two compounds under electron bombardment. Qualitatively mass spectra are identical, but quantitatively differences appear between relative abundances of molecular ions and most important fragment ions as well as between appearance potentials determined for the two fragment ions first produced.

Greater stability of ionized trans decaline parallels its greater thermodynamic stability with respect to the cis isomer. Ionization potential has been measured for both isomers and found to be the same, 9.61 ±.02 ev, within experimental uncertainties, which means that an effect due to geometrical isomerism appears in both compounds in the ionized state. As shown by ionization potential and appearance potential data, lower energy is required to dissociate ionized cis decaline into fragments. This has to be related to the energy provided by steric conformation which is released in cis isomer when fragmentation occurs.

In mass spectra of decalines and several other pairs of stereoisomers containing a cyclohexane ring it is possible to distinguish H atoms according to their axial or equatorial position.
Étude Infra‐Rouge Des Substances Possédant Une Liaison C=Se Adàjacente à un ou Plusieurs Atomes D'azote II. Sélénosemicarbazides
Authors: Collard‐Charon C. , Renson M.
Published: September 2010

Nous étudions les spectres infra‐rouges des sélénosemicarbazides progressivement substituées, dont la synthèse a été donnée dans un article précédent. Nous y fixons la bande CSe à 990–1070 cm−1, et nous discutons les attributions pour les autres bandes principales.
Chromatographie sur couche mince des despsides et des depsidones
Authors: Ramaut J. L.
Published: September 2010

After separating and identifying β‐orcinol depsidones by thin layer chromatography, a technique permitting the chromatographic study of depsides and depsidones derived from orcinol is presented.

Using Stahl's Kieselgel HF. 254 and Pastuska's phase, a good separation of both depsides and depsidones mixtures is obtained.

This technique should be very valuable for the chemist interested in the lichenic acids as well as for the chimiotaxonomist using them for taxonomic purposes.
Potential constants and thermodynamic functions of the tetrachlorides of titanium and vanadium
Authors: Nagarajan G.
Published: September 2010

Using the observed Raman and infrared absorption fundamental frequencies of gaseous and liquid tetrachlorides of titanium and vanadium, the potential constants on the basis of Wilson's group theoretical method and the molar thermodynamic functions on the basis of a rigid rotator, harmonic oscillator approximation have been calculated.
Preparaton of 6‐oxo‐and 6‐thioxo‐5, 6‐dihydrobenzimidazo [1,2‐c] quinazolines
Authors: Poot A. L. L. , Willems J. F. , Heugebaert F. C.
Published: September 2010

Substituted 6‐oxo‐and 6‐thioxo‐5, 6‐dihydrobenzimidazo [1,2‐c] quinazo‐lines were prepared by cyclization of 5(6) and 4(7) substituted 2‐(o‐aminophenyl) benzimidazoles with chloroethyl formate respectively with carbon disulphide.

The 5(6) and 4(7) substituted 2‐(o‐aminophenyl) benzimidazoles were prepared by reductive cyclization of the 4′ and 6′ substituted 2, 2′‐dinitroben‐zanilides which in their turn were obtained from o‐nitrobenzoyl chloride and 4 or 6 substituted o‐nitroanilines.
Étude du Comportement D'Isomères Géométriques Sous L'impact Électronique III. Corrélations Entre Les Spectres de Masse et la Structure Moléculaire Dans Une Série de 1,2‐DIALCOYLCYCLOHEXANES.
Authors: Natalis P.
Published: September 2010

Correlations between mass spectra and molecular structure are attempted in a series of cis and trans 1,2‐dialkylcyclohexanes previously investigated. Rather large differences appear between abundances of main fragment ions, especially (P‐R1)+ (parent ion having lost the R1 group) and (P‐R1‐H)+, some of which can be related to the different stability of the two kinds of stereoisomers. Metastable transitions indicate that an important fragmentation process is given by a sequence of the type P+→ (P‐R1)+→ (P‐R1‐R2)+.
Mécanisme D'Apparition D'Un Domaine Fermé de Démixion Dans Un mélange Binaire
Authors: Bellemans A.
Published: September 2010

Le diagramme de phase d'une solution binaire associée: A+B+AB, est discuté en détail. On montre que, pour un choix particulier des paramètres d'interactions moléculaires, ce système présente un domaine fermé de démixion, symétrique par rapport au titre 0.5.
The Effect of Dissolved Electrolytes on the High Frequency Raman Band of Water
Authors: Lauwers H. A. , Van Kelen G. P. Der
Published: September 2010

Les spectres Raman des solutions des halogénures des métaux alcalins dans l'eau ont été étudiés à diverses concentrations. L'intensité de la bande Raman dans la région de la vibration de valence OH est augmentée par la dissolution d'électrolytes dans l'ordre F−Cl−Br−I−. L'ion fluorure exerce une influence négative, opposée à celui des autres.

L'analyse des spectres de mélanges binaires à concentration d'halogénure constante, nous a montré que l'effect de l'ion positif se manifeste dans l'ordre K+Na+Li+.

En général on admet que la bande de vibration de valence OH peut être résolue en trois bandes de Gauss. De plus on attribue en grande partie la variation de l'intensité totale à une interaction de Fermi entre 2v2 et v1. La critique de ces deux hypothèses est faite À la lumière des données nouvelles.
The Practical pH‐Calculation of Acids or Bases
Authors: Claeys A.
Published: September 2010

Two basic formulas are given for the practical pH‐calculation of aqueous solutions of acids or bases.
The Determination of Glycerides in Human Serum
Authors: De Mets M.
Published: September 2010

A method is described for the routine determination of glycerides in human serum. After isolation and saponification, the glycerol is oxidized to formaldehyde, and a colour reaction with chromotropic acid is developed.
Mean Amplitudes of Vibration and Thermodynamic Functions of the Dioxides of Chlorine, Sulphur and Selenium
Authors: Nagarajan G.
Published: September 2010

An elaborate discussion of the various methods regarding the molecular structure and vibrational spectral studies of the dioxides of chlorine, sulphur and selenium has been reported. The computed numerical values of (1) meansquare amplitude quantities, (2) generalized mean‐square amplitudes (meansquare 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 these molecules. Using the fundamental frequencies as well as normal frequencies the molar thermodynamic functions have been calculated on the basis of a rigid rotator, harmonic oscillator approximation for the temperature range from 100° to 1700°K.
Mean Amplitudes of Vibration of Some Octahedral XY6 Type Molecules
Authors: Nagarajan G.
Published: September 2010

A brief survey on the vibrational analyses of the octahedral XY6 type molecules belonging to the symmetry point group Oh has been presented. For this type of molecules, the general theory of mean‐square amplitude matrices has been applied. The analytical expressions for the sixteen meansquare amplitude quantities as linear combinations of the symmetrized meansquare amplitude matrix elements have been obtained. The secular equations for the calculation of normal frequencies involving the symmetrized meansquare amplitude matrix elements have been given. For the twelve molecules namely, SF6, SeF6, TeF6, MoF6, WF6, UF6, NpF6, PuF6, ReF6, OsF6, IrF6 and PtF6, the computed values of (1) mean‐square amplitude quantities and (2) mean amplitudes of vibration at the temperatures T=0 and T=298°K.
La Substitution Nucleophile Activée en Série Aromatique. VI. Étude du Rapport Ortho‐Para. Réactivité Des 2 et 4‐Chloro‐Pyridines, Chloropyridinoxydes et Cloronitrobenzènes Avec la Pipéridine Dans la Méthanol.
Authors: Coppens G. , Declerck F. , Gillet C. , Nasielski J.
Published: September 2010

The 2‐ and 4‐chloro derivatives of pyridine, pyridine‐N oxyde and nitrobenzene have been reacted with molar piperidine in methanol. The results suggest an increased built‐in solvation in the case of 2‐chloropyridine‐N oxyde, and favour the electrostatic interpretation for this particular interaction.

The “meta” substituted chlorides have almost identical reactivities; this points to the similarities of the inductive effects for the three activating groups.
Equilibre Acide‐Base de la N‐Diméthylamino‐4′, Diphényl, α‐Cyanazométhine et de Ses Dérivés de Substitution
Authors: Feytmans‐De Medicis Mme E. , Bruylants A.
Published: September 2010

Les dérivés de substitution de la N‐diméthylamino‐4′, diphényl, α‐cyanazométhine (B): magnified image sont transformés en milieu acide en ions ammonium (anilinium) (BH+) correspondants dont la constante d'acidité (Ka) peut être déterminée par la méthode spectroscopique.

La série étudiée comporte huit termes, caractérisés par les substituants (X‐) respectifs: NO2‐4, CN‐4, CN‐3, Cl‐3, Br‐4, Cl‐4, F‐4, CH3‐4; leurs constantes d'acidité sont liées entre elles par corrélation log Ka/KaO=ρσ, oú ρ=0,549. La valeur relative au terme non substitué a été déterminée par interpolation (KaO=0,26. 10−2). En outre, l'effet polaire (σ) du groupe α'‐phényl, α‐cyanazométhinique a été calculé (σ=0,351).
The Ionization Constant of α‐Hydroxy‐Isobutyric Acid
Authors: Deelstra H. , Verbeek F.
Published: September 2010

The apparent ionization constants of α‐hydroxy‐isobutyric acid were determined with and without added sodium perchlorate. The data were extrapolated to zero ionic strength to give the corresponding thermodynamic constant, pKT=4.00 (25°C).
Séparation de Flavonoïdes Par Chromatographie Sur Échangeur D'Ions du Type Carboxylique
Authors: Vancraenenbroeck R. , Rogirst A. , Lemaître H. , Lontie R.
Published: September 2010

La séparation chromatographique de flavonoïdes sur colonne d'Amberlite CG‐50 T1 ou T2 a été mise au point. La (+)‐catéchine et la (‐)‐épicatéchine, de même que plusieurs flavonols peuvent ainsi être séparés quantitativement par élution au moyen d'isopropanol en concentration croissante.
Propriétés physico‐chimiques de composés à caractère aromatique VI. Association par lien H entre le méthanol et quelques bases monoazaaromatiques dans le Tétra chlorure de carbone (1)
Authors: Coppens G. , Nasielski J. , Sprecher N.
Published: September 2010

The equilibrium constant for the hydrogen‐bond association aromatic base + methanol ⇋ complex in carbon tetrachloride has been determined by I.R. spectroscopy. The compounds examined are (K in 1.mole−1): pyridine (3,1), quinoline (3,5), isoquinoline (3,8), 1‐azaphenanthrene (4,7), 2‐azaphenanthrene (3,9), 4‐azaphenanthrene (1,6), 9‐azaphenanthrene (4,7), 9‐azaanthracene [acridine] (4,9), 1‐azafluoranthene (3,3) and 7‐azafluoranthene (4,5). The low value found for 4‐azaphenanthrene is attributed to steric hindrance. The other values are much too close together to allow any interpretation on the basis of electronic charges calculated by LCAO.
Mean Amplitudes of Vibration of Some Tetrahedral XY4 Type Molecules‐Part IV
Authors: Nagarajan G.
Published: September 2010

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 at the temperatures T=0 and T=298°K have been reported for the molecules PbF4, PbCl4, ZrCl4, HfCl4 and GeBr4 respectively. Besides these, the potential constants on the basis of Wilson's group theoretical method have been evaluated for the GeBr4 molecule.
Effet de la Longueur de la Chaîne Aliphatique Sur L'Association Des Alcools
Authors: Huyskens P. , Gillerot G. , Zeegers‐Huyskens T. H.
Published: September 2010

The curves of the dipole moments μ of the primary aliphatic alcohols in function of the concentration in CCl4 present a minimum that increases with the length of the hydrocarbon chain, as showed by R. Mecke. We have determined these μ values for several primary alcohols from methanol to octanol at 25, 35, 45, and 55°C. Assuming that the minimum is due to the presence of cyclic hydroxylic chains. it is possible to calculate from the curves the ratio r of alcohols molecules implicated in cyclic structures. The variation of r with the concentration C seems more similar to these of C1/2/C, where C1 is the monomer concentration, than to these of C3/1/C, C4/1/C, etc. One concludes to a predominance of trimeric cycles in the cyclic species, although it seems that the importance of higher cycles increases with the molecular weight in the alcohol. The theory of Mecke and Kempter, with the correction for the dimerisation constant, introduced by Coggeshall and Saier, is only applicable on the open species. The length of the aliphatic chain of the alcohol seems to have a rather moderate effect on the dimerisation and polymerisation constants of the open species. This factor has a greater influence on the closing of the open hydroxylic polymers, the cyclisation being more important when the molecular weight of the alcohol increases.
On the Metal Catalyzed Deposition of Carbon from Carbon Monoxide
Authors: Henry J. F.
Published: September 2010

A set of equations describing the process of carbon deposition from carbon monoxide on a metal catalyst is proposed. Solutions valid for high and low concentrations of CO are obtained and compared to experimental results. In the high concentration limit, the calculated cumulative curve for the amount of carbon deposited is in good agreement with the experimental data, whereas in the low concentration case the agreement is very good.
2,2‐Bis(Aminométhyl)Propane‐1, 3‐Disulfonic Acid Disultam and its N,N′‐Diphénylderivative
Authors: Goethals E.
Published: September 2010

The synthesis and properties of 2,2‐bis (aminomethyl) propane‐1,3‐disulfonic acid disultam are described. It is a new pentaerythritol derivative and can be isolated in two isomeric forms which are probably the tautomers of the N‐S‐O triad system.
Studies on the Grignard Reaction‐VI. Steric Effects in the Grignard Addition Reaction on Ketones
Authors: van Schoote J. , Anteunis M.
Published: September 2010

The reactivity in the normal Grignard addition reaction is greatly reduced when the ketone is branched in the α‐position. Alkylation in β‐position has only slight effect and in the γ‐position there is no effect at all.
Studies on the Grignard Reaction‐VII (1) on the Mechanism of the Grignard Reagent Formation and the Wurtz Side Reaction in Ether
Authors: Anteunis M. , van Schoote (2) J.
Published: September 2010

In contradiction with accepted views about Wurtz coupling reactions during the preparation of Grignard solutions, the highly accurate Volhard titrimetric and the complexometric method show no difference. Checking the amount of coupling product by direct GLC the obtained results are discussed on the basis of a new mechanistic scheme, which assumes the formation of univalent magnesium radicals. These either disproportionate after preparation, or stay bonded as subhalide.
N.M.R. Experiments on Ketals Part I. Reaction Heat and Entropy of the Methyl Ketal Formation of Cyclohexanone, Cyclopentanone and Cyclobutanone
Authors: Anteunis M. , Alderweireldt F. , Acke M.
Published: September 2010

The methyl ketal formation is strongly exothermic (‐14,6 Kcal/mole) with cyclohexanone and moderately so with cyclopentanone (‐3,5 Kcal/mole) and with cyclobutanone (‐2,5 Kcal/mole). An exceptional low reaction entropy is noted for cyclohexanone (‐59 E.U.) and this is partly ascribed to the occurence of a high proportion of the twist conformation in cyclohexanone.
Physical Properties and Chemical Reactivity of Alternant Hydrocarbons and Related Compounds VII. The polarographic reduction of pyridine‐like heterocycles
Authors: Párkányi C. , Zahradník R.
Published: September 2010

The polarographic reduction of pyridine‐like heterocycles in 5.10−2 M tetraethylammonium iodide in 95% dimethylformamide gives well pronounced two‐electron waves. Half‐wave potentials of seven heterocyclic compounds have been determined in this medium. The data have been found to fit the correlation with energies of the lowest free π‐molecular orbitals in the HMO approximation. A similar correlation has also been obtained for half‐wave potentials of some heterocycles taken from the literature.
Halogen Substituted 1,3‐Cyclohexanediones II. New Chlorinated Cycloalkanones from 2, 2‐Dichlorodimedone
Authors: Schamp N. , Verzele M.
Published: September 2010

A number of new substances obtained from 2,2‐dichlorodimedone are described. The most interesting features of the reactions are: a) the ring contraction to a 2‐cyclopentenone derivative with simultaneous carbon monoxide elimination, b) the isomerization procedure of halogenated ketones in dimethylformamide and hydrogen chloride, c)the aromatization to some new resorcinol derivatives. The high yields give most of the procedures a distinct preparative interest.
Vector Methods in the Theory of Molecular Vibrations III. Application to a Linear Molecule Model
Authors: Cyvin S. J. , Brunvoll J.
Published: September 2010

The s‐, ρ, and ρº vectors are developed for the linear symmetrical X2Y2 molecule model.
Mathematical Techniques in the Study of Coriolis Coupling in Tetrahedral XY4 Molecules
Authors: Cyvin S. J. , Brunvoll J. , Cyvin B. N.
Published: September 2010

Relations between Coriolis coupling coefficients in tetrahedral XY4 molecules are evaluated, using the method of Cα and related matrices. It appears that the Coriolis coupling may be studied in terms of two independent Coriolis coefficients, e.g. ζ24 and ζ44. For these two quantities explicit equations are deduced, containing atomic masses, vibrational frequencies (in terms of λ values), and force constants of the molecule.
Étude Théorique des Molécules Conjugées I. Description d'une méthode SCF‐LCAO semi‐empirique
Authors: Leroy G.
Published: September 2010

La méthode de Roothaan n'est pas rigoureusement applicable à l'étude des molécules polyatomiques conjuguées. Pour tourner cette difficulté, on propose un procédé semi‐empirique basé sur les approximations de Pariser‐Parr‐Pople.

On y tient compte d'une correction d'effet de charge et certaines intégrales sont évaluées à partir de données de spectroscopie atomique.

La méthode ainsi obtenue permet d'étudier les molécules polyatomiques conjuguées contenant les atomes C,N,O ou S.