bluuebunny/crossref_metadata_2025 huggingface dataset:
Photochimie de Dérivés Aromatiques: III [1] Propriétés Acido‐Basiques de Dérivés Aromatiques non Substitués dans les États Électroniques Excités Singulet et Triplet
Authors: Vander Donckt E. , Lietaer D. , Nasielski J.
Published: September 2010

The acidity constants of protonated naphthalene, anthracene, phenanthrene, chrysene, triphenylene and 1,2,5,6‐dibenzanthracene in their lowest singlet and triplet excited states have been estimated by application of the Förster cycle to the electronic spectra of the neutral and protonated species prepared in 96% sulfuric acid or in trifluoroactic‐boron trifluoride mixtures.

With the exception of 1,2,5,6‐dibenzanthracene, the basicity of these hydrocarbons is increased in the S1 state compared to the ground state. Except chrysene and 1,2,5,6‐dibenzanthracene, a similar trend is observed for the lowest triplet state although the ΔpK(T1‐So) values are smaller than the ΔpK(S1‐So) values. Solutions of naphtalene, anthracene and phenanthrene in CH3COOD were irradiated. It is shown that the positions of H/D exchange are the same for naphthalene in the ground state and in the excited state (position 1 or equivalent). Phenanthrene is photodeuterated essentially on positions 4,5, although in dark condition, deuteration occurs on positions 9, 10.
Synthèse des Thiénopyridines
Authors: Eloy F. , Deryckere A.
Published: September 2010

Des thiénopyridones isomères ont été obtenues par cyclisation d'isocyanates de (β‐thiényl)vinyle, puis transformées en thiénopyridines correspondantes.
Binary Diffusion Coefficients of Lower Alkanes in Nitrogen and Argon
Authors: Jacobs T. , Peeters L. , Vermant J.
Published: September 2010

A recently described technique for determining diffusion coefficients in binary gas mixtures was improved and the diffusion of methane, ethane, propane and n‐butane in nitrogen and argon studied.

The experimental D12 values, most of which unpublished untill now, were compared with theoretical values derived from classical kinetic theory (to a first approximation), and from a more advanced treatment describing the interaction between non‐polar molecules in terms of a Lennard‐Jones potential function.
Synthèses de Ditellurures Aromatiques et de Telluroéthers Arylaliphatiques
Authors: Piette J. L. , Renson M.
Published: September 2010

La réaction de condensation entre les organolithiques aromatiques et le tellure commercial permet de préparer des ditellurures aromatiques (Ar‐Te‐Te‐Ar) et des telluroéthers arylaliphatiques (Ar‐Te‐C4H9) suivant que l'organolithique est préparé par réaction directe du lithium métallique ou par réaction d'interconversion au moyen du butyllithium sur un dérivé halogéné aromatique. À partir des telluroéthers du type butylique il est possible de préparer les ditellurures aromatiques correspondants par réaction de déquaternisation dans la pyridine des sels de telluronium Ar‐TeX2‐C4H9.

La réduction des ditellurures aromatiques en tellurophénolates de sodium correspondants et la condensation de ces derniers avec un dérivé halogéné R‐X constituent une méthode particulièrement souple pour la préparation de substances du type Ar‐Te‐R dans lesquelles la nature du groupement R peut être choisie en fonction de la destination finale de la molécule.
Synthèses de tellurolesters
Authors: Piette J. L. , Renson M.
Published: September 2010

Nous décrivons une méthode de préparation des tellurolbenzoates d'aryle et des tellurolbenzoates d'alcoyle différemment substitués en vue d'étudier en spectrographie infrarouge la position du carbonyle de ce groupement fonctionnel. La synthèse mentionnée est basée sur la condensation de tellurophénolates soit avec des chlorures d'acides aromatiques soit avec des anhydrides d'acides aliphatiques. La transposition du principe de la méthode à des telluroalcoolates n'a pu être réalisée avec succès.
Determination of the Dissociation Constant of Monothiooxamide and Some of its Derivatives
Authors: van de Cappelle G. L. , Herman M. A. , Eeckhaut Z.
Published: September 2010

The dissociation constant of monothiooxamide and four of its derivatives has been determined by a spectrophotometric method at various wavelengths and ionic strengths. Values of the thermodynamic dissociation constant were obtained by graphical extrapolation and by the Debye‐Hückel equation.
The Stereochemical Requirements for Long Range Coupling Between Protons in α‐Halocyclohexanones
Authors: Jefford C. W. , Waegell B.
Published: September 2010

The pitfalls of assigning a stereospecific arrangement to protons coupled through four sigma bonds have been assessed for some α‐bromocyclohexanones, in particular, 2‐bromo‐3,3,5,5‐tetramethylcyclohexanone. Despite apparent exceptions, it is seen that the arrangement of four sigma bonds, which satisfactorily accounts for the observed couplings, is that of a W.
Étude de Complexes Accepteur‐Donneur par Spectrométrie Infrarouge: II. Influence de la Nature du Solvant sur les Complexes Formés Entre L'Acétophénone et SbCl3
Authors: Lecl Nedden G. Ère‐Zur , Duyckaerts G.
Published: September 2010

Infrared intensity measurements of the free CO band have been used to investigate the complex formation between antimony trichloride and a cetophenone in various solvents. The dissociation constants of the acceptor‐donor complexes with a 1:1 stoichiometry are compared with different parameters of the solvents.
Oxidation Products of Isohumulones
Authors: Vanhoey M. , Vandewalle M. , Verzele M.
Published: September 2010

Humulone is oxidised in conditions which parallel the hops treatment conditions in brewing. A number of products can be isolated from the reaction mixture by counter current distribution. These are oxidation products of isohumulones; this paper is about their preparation, isolation and identification.
NMR Experiments on Acetals: XXIX. The Ease of Acetonide Formation of Some Glycols
Authors: Anteunis M. , Rommelaere Y.
Published: September 2010

The ease of acetonide formation for some 1,2‐ and 1,3‐glycols is measured and in the discussion of the equilibrium data (tables I and II), obtained by quantitative evaluation as a function of temperature, emphasis is placed upon the pronounced entropy decrease, and its consequence in the interpretation. All cyclizations are found to be favoured by enthalpy decreases but are governed by entropy changes.
Chlorination of Olefins in Dimethylformamide with Intermediate Formation of Immonium Chlorides
Authors: de Roocker A. , de Radzitzky P.
Published: September 2010

Well defined intermediate immonium chlorides were isolated during the chlorination of olefines in N, N‐dimethylformamide. These immonium chlorides of general formula (CH3)2 [X‐CH(CHYCl)‐O‐CH=] N+.Cl− react to 1,2‐dichloroalkane derivatives by thermal decomposition, to l‐chloro‐2‐alkyl formate deriatives by hydrolysis and to chlorohydrins by alcoholysis.

The 1‐chloro‐2‐alkyl formate derivatives are easily transformed into epoxy compounds.

The chlorination of styrene into 1,2‐dichloro‐l‐phenylethane gives a higher yield and a better selectivity in N, N‐dimethylformamide than in other solvents.

When bromine is used instead of chlorine, corresponding intermediate immonium bromides can also be isolated but with lower yields.
Contribution à L'Étude Stéréochimique de la Décomposition des Pyrazolines‐1
Authors: Bourmanne J. C. , Deleux J. P. , Leroy G. , Weiler J.
Published: September 2010

On décrit la synthèse et la décomposition de pyrazolines‐1 obtenues par addition de diazoalcanes sur les isomères cis et trans de l'acide p‐nitro α‐phénylcinnamique et de l'α,α′‐dicyanostilbène.

On constate que les facteurs stéréochimiques (configuration et conformation) influencent considérablement le schéma de décomposition des pyrazolines‐1 considérées dans ce travail.
The Vibrational Spectra of Difluorophenylphosphine
Authors: Green J. H. S. , Harrison D. J. , Lauwers H. A.
Published: September 2010

The infrared (3650‐50 cm−1) and Raman spectra of difluorophenylphosphine are reported and interpreted, and the fundamental frequencies are correlated with those proposed for phenylphosphine, dichloro‐ and dibromophenylphosphine.
Méthode Nouvelle et Générale de Synthèse des Cycles Benzo(b) Thiophène et Benzo(b) Sélénophene
Authors: Ruwet A. , Renson M.
Published: September 2010

Bromine addition to o‐methylselenocinnamic acid, followed by pyridine action, leads to the heterocyclic compound: benzo(b) selenophene 2‐carboxylic acid. This new way is a very general one. Every styrene, when having selenoether in ortho position and H, COOH, or COOAlk in β, reacts in the same conditions to give benzo(b) selenophene and derivatives with good yields. Benzo(b) thiophene and derivatives are also easily available by this procedure when using sulfuryl chloride instead of bromine. The reaction is discussed.
Action de Dérivés Maloniques sur les Thio et Sélénophénols
Authors: Ruwet A. , Pourveur A. , Renson M.
Published: September 2010

Malonic esters and other derivatives, with thio or selenophenol in polyphosphoric acid, lead to unexpected Simonis reaction. Instead of 4‐hydroxy 1‐thio or 1‐selenocoumarines they give 2‐phenylthio‐1‐thio chromones or 2‐phenylseleno 1‐seleno chromones. Several intermediates are considered. The most probable one seems to be an acrylic compound formed via the thiophenyl or selenophenyl ethyl malonate (or malonic acid). «Mixed» chromones are indeed obtained from these thiolesters or thiolacids and selenophenols and reciprocally.
Organometallic Compounds. XXIII (). Matrix representation of octahedral and prismatic stereoisomers and of their interconversion reactions
Authors: Gielen M.
Published: September 2010

Matrix representations are given to describe how octahedral and trigonal prismatic stereoisomers are converted into one another.
Tautomérie Dans la Série des Pyrazolinones: I. Influence du Solvant Sur L'Équilibre Prototropique de la 1,3‐Diméthylpyrazoline‐5‐one
Authors: Maquestiau A. , van Haverbeke Y. , Jacquerye R.
Published: September 2010

The tautomerism between CH, NH and OH forms of 1,3‐dimethylpyrazoline‐5‐one has been investigated by use of I.R., N.M.R. and U.V. spectroscopy. In non polar solvents only the CH form is observed. In aprotic solvents, a linear relationship is obtained between the percent of the CH form and the basicity of the solvents, the decrease of CH form being in favor of the OH structure.

In protic solvents it is difficult to discern the effect of acidity and dielectric constant in the appearance of the NH form.
The Isomeric Sulfo‐2‐Methylbenzothiazoles and their Use in the Synthesis of Sensitising Polymethine Dyes
Authors: Libeer J. , Depoorter H. , Nys J.
Published: September 2010

Les 4‐, 5‐, 6‐ et 7‐amino‐2‐méthylbenzothiazoles (1) furent transformés en sulfo‐chlorures correspondants 2. Par hydrolyse ceux‐ci fournissent les acides sulfoniques 3 et par ammonolyse les sulfonamides 4 (Schéma I). Un mode de préparation du 2‐méthyl‐7‐nitrobenzothiazole ne laissant plus aucun doute quant à la structure du produit obtenu fut élaboré (Schéma VI). Enfin, les auteurs décrivent la synthése de colorants polyméthiniques en partant des bases mentionnées et de plusieurs de leurs dérivés et étudient l'effet des substituants sur les propriétés optiques.
Kinetics of the Oxidation of n‐Butyl Alcohol with Aqueous Bromine
Authors: Kudesia V. P.
Published: September 2010

A kinetic study of the oxidation of n‐butyl alcohol with aq. bromine has been made. The order of reaction with respect to molecular bromine, n‐butyl alcohol and [H+] ion is found to be first, first and half at all hydrogen ion concentrations. The various activation parameters have been determined between 25° to 55°C. Effect of salts on the oxidation rates have been studied. A possible mechanism involving a rate determining proton transfer is suggested.
Stability of Alkaline‐Earth Citrate Complexes
Authors: Rumbaut N. A.
Published: September 2010

The stability constants of the Ca, Sr and Ba complexes with citrate ion have been determined as a function of the temperature, in the presence of 0.2 M NH4Cl. There is also evidence for 1: 2 complexes, the constants of which are reported. The stability constants for the Sr and Ba monocomplexes show a minimum at 30°C. Above this temperature, there exists a linear relationship between the enthalpy and the entropy of complex formation, the isokinetic temperature being 104°C.
Structure Cristalline de Dérives D'Acides Aminés: III. LiBr. Glylcyglycine et CaCl2. 2 Glycylclycine
Authors: Meulemans Réginald , Piret Paul , van Meerssche Maurice
Published: September 2010

The crystal structures of LiBr. glycylglycine and CaCl2. 2glycylglycine have been determined by X‐ray diffraction. Unit cells are triclinic P1, with a = 5.068, b = 7.620, c = 10.380 Å, a = 101.48°, β = 88.99°, γ = 95.10° for LiBr. GG (Z = 2) and a = 7.216, b = 11.325, c = 4.487 Å, α = 90.05°, β = 103.96°, γ = 97.25° for CaCl2. 2GG (Z = 1).

Atomic positions, bond lengths and coordinations are given.
Effect of Thiocompounds on the Electrodeposition of Copper
Authors: Lahousse G. , Heerman L.
Published: September 2010

The effect of different thiocompounds in the concentration range 4.10–7–2,5.10–4 M on the electrodeposition of copper from 0,63 M CuSO4/2,04 M H2SO4 solution at 50°C was investigated.

Almost no influence was observed with thiazol. Thiourea, N,N'diethylthiourea, cystine and methionine strongly influence the current/overvoltage characteristics and the structure and surface roughness of copper electrodeposits. With these compounds a depolarisation was found at low concentrations while at higher concentrations an increase of the overvoltage is observed. Addition of thiocompounds decreases the surface roughness of deposits obtained at 50 mA/cm2 with respect to those deposited from the pure solution and generally results in a grain size refinement of the crystallites. Results are discussed in terms of the strong interaction of the thiocompounds with the electrode.

It is proposed that at low concentrations thiourea and N,N'‐diethylthiourea are desulfurated in preferred sites on the surface while at higher concentrations more uniform adsorption over the whole surface is predominant.
Determination of Nitrate Ion in Marine Biotopes with High Nitrate Content by Ultraviolet Spectrophotometry
Authors: Mertens J. , Massart D. L.
Published: September 2010

A simple and rapid method for the determination of nitrate in seawater of high nitrate content (> 1 ppm) is proposed.

The absorption of the nitrate ion is measured at 210 and 220 mμ. The sample is treated with a measured quantity of hydrochloric acid to eliminate the carbonate and bicarbonate interferences and measured against a nitrate free blank prepared by reduction of the nitrate to ammonia with Raney nickel. The addition of HCl permits also storage of the sample without special precautions and the use of the blank eliminates the most serious of the interferences (bromide) expected in sea‐water. The interference of organic matter limits however the applicability of the method to concentrations higher than 1 ppm.
Organometallic Compounds: 26. Halogen cleavage of group IV B Hexaalkyldimetals: A Kinetic Study
Authors: Gielen M. , Nasielski J. , Vandendunghen G.
Published: September 2010

Iodine cleavage of the metal‐metal bond in hexasubstituted dimetals of the fourth group has been studied kinetically. The reactivities of disiliciums, digermaniums, ditins and mixed dimetals are discussed in function of the substituents and of the metals involved in the metal‐metal bond.
Organometallic Compounds: 28 NMR and mass spectra of benzyltin derivatives
Authors: Gielen M. , Barthels M. R. , de Clercq M. , Nasielski J.
Published: September 2010

The J(Sn‐CH2) coupling constants in a series of benzyltin derivatives are examined as a function of the substituents. A J vs Σσ* graph shows three equidistant and parallel lines.

The mass spectra of these compounds confirm the fragmentation rules described before.
Humulinic Acids: IX. Formation and Isomerization
Authors: van Boven M. , Verzele M.
Published: September 2010

This paper discusses the formation and isomerization of humulinic acids and the origin of positive and negative optically active trans humulinic acid in humulone hydrolysis mixtures. The separation of the cis humulinic acid stereoisomers is described.
Essais De Chloration Dirigée: XVI. Effet Mésomère et Réactivité Dans Les Réactions De Chloration Radicalaire
Authors: Soumillion Ph. J. , Gouverneur P. , Burton T. , Bruylants A.
Published: September 2010

From their results concerning mainly radical chlorinations of substituted alkanes and from other literature data dealing with this subject, the authors discuss about mesomeric effects of substituents in relation with medium and reactants modifications.

With the aid of a properly modified structure‐reactivity correlation, it can be demonstrated that changes in reactivity of chlorinating agents or in structure of aliphatic substrates result in quantitative variation in the importance of mesomeric effects of substituents.
Organophosphorus Chemistry. Part II. The Electric Dipole Moments of Some Tertiary Arylphosphines
Authors: de Ketelaere R. F. , Claeys E. G. , van der Kelen G. P.
Published: September 2010

The dipole moments of a series of tertiary arylphosphines were measured: R3P, R2PC6H5, RP(C6H5)2 (R = 4‐FC6H4, 4‐ClC6H4, 3‐FC6H4, 3‐ClC6H4), 2‐ClC6H4P(C6H5)2, 3‐FC6H4P(4‐FC6H4)2 and 4‐FC6H4P(3‐FC6H4)2.

The preparation of these phosphines, some of which are reported for the first time, is briefly outlined. The identity and the purity of these substances were certified by molecular weight measurements and for some by C–H analysis.
Évaluation des Potentiels D'Ionisation et des Grandeurs Connexes au Moyen Du modèle de L'Électron Libre (F.E.M.). II. Dérivés Substitués des Hydrocarbures Conjugués et Hétérocycles Correspondants
Authors: Puttemans J. P.
Published: September 2010

Nous utilisons dans le cadre du modèle de l'électron libre, à la fois une méthode de perturbation limitée au premier ordre, un modèle inductif et le théorème de Koopmans. Nous évaluons les potentiels d'ionisation et les grandeurs connexes des dérivés substitués des oléfines conjuguées, des hydrocarbures aromatiques et des hétérocycles correspondants. Nous comparons principalement les résultats du calcul et les valeurs expérimentales dans la série du benzène.
Radiolyse a 77°K de Verres Composés de Cyclopentane et de Diméthyl‐2,3‐Butane
Authors: Tilquin B. , Claes P.
Published: September 2010

Des mélanges vitreux de cyclopentane et de diméthyl‐2,3‐butane ont été irradiés aux rayons gamma à 77°K, à des doses de 2,06 à 2,08 Mrads.

Les rendements des principaux produits de la radiolyse ont été déterminés en fonction de la composition du mélange.

Le rendement en pentène‐1 est insensible à la présence d'oxygène et varie linéairement en fonction de la fraction électronique du cyclopentane. Les rendements de tous les autres produits de radiolyse étudiés sont réduits de 40 à 60% en présence d'oxygène et se caractérisent par une dépendance plus complexe vis‐à‐vis de la composition du mélange.

Cette dépendance peut être expliquée par un transfert de l'activation chimique du diméthyl‐2,3‐butane vers le cyclopentane. Aux faibles concentrations en diméthyl‐2,3‐butane, le sens du transfert serait inversé.
Propriétés et Caractéristiques Des Complexes de Chélation Formes Entre les Lanthanides Trivalents et L'Acide Hydroxyéthyléthylénediaminetriacetique
Authors: Merciny E. , Duyckaerts G.
Published: September 2010

Different properties of the complexes Me Y formed between the trivalent lanthanides and HEDTA have been studied: the solubilities at 20°C and 100°C, the degree of hydration and the temperature of dehydration.

Extremely high solubility of certain complexes and other unexpected properties at high temperature are interpreted by the formation of aggregates in concentrated aqueous solutions.
Activités Catalytiques Simultanées D'Un Porteur D'Oxygène Dans L'époxydation Directe
Authors: Rouchaud J. , Mawaka J.
Published: September 2010

Propylene dissolved in benzene has been oxidised by molecular oxygen at 150°C under a total pressure of 45 atm. The oxidation is eventually catalised by a soluble chelate of the MoO2+2 cation. The relationships existing between the selectivity in epoxypropane, the conversion of propylene and the concentration of the catalyst show that the chelate has a double catalytic activity: 1° it carries and activates molecular oxygen; the oxygenated catalyst epoxidises selectively the olefinic bond. 2° It catalises the consecutive oxidation of the produced epoxypropane. The relative intensities of the two simultaneous catalysis are measured for the different experimental conditions.
On the Hydroxyl Group—PMR Signals in 2‐ and 4‐Acylresorcinols and the Structure of Humulone
Authors: De Keukeleire D. , Vanheertum R. , Verzele M.
Published: September 2010

At room temperature the intramolecular hydrogen bridge in 2‐acyl resorcinols flip‐flops rapidly back and forth between the two possible positions. N.M.R. experiments prove that this is a “coalesced state “which can be “frozen out”.
Alternant Molecular Orbitals In Butadiene
Authors: LASKOWSKI B. , VAN Leuven P.
Published: September 2010

The ground state energy of butadiene is studied by means of the alternant molecular orbital method. Two possible ways for coupling molecular orbitals to form alternant molecular orbitals are investigated. It is found that when the molecular orbitals are taken from a SCF calculation the traditional coupling scheme gives lowest energy. Another choice of molecular orbitals is presented for which the alternative pairing scheme yields the lowest energy.
Dosimétrie Des Radiations Avec La Dithizone En Solution Dans Différents Solvants Organiques
Authors: Dejehet F. G. , Apers D. J. , Capron P. C.
Published: September 2010

On a déterminé les facteurs G de transformation de la dithizone, en solution dans des solvants organiques, par irradiation aux σ du 60Co.

Dans le chloroforme, aux concentrations de 10−5, 2.10−5 et 10−4 mol.l−1 on trouve respectivement G(–dith.) = 13,3 ± 0,6; 13,6 ± 0,5 et 15,4 ± 2,1.

Dans le dichlorométhane, à 2.10−5 mol.1−1. G(–dith.) = 11,5 ± 0,9 et, en présence de 1 % d'éthanol, G(–dith.) = 9,4 ± 0,6.

Enfin, dans le cyclohexane, à 3.10−5 mol.1−1, G(–dith) = 5,9.

Toutes ces valeurs ont été déterminées en présence d'oxygène. Le système Dithizone‐Chloroforme à 2.10−5 mol.1−1 peut servir de dosimètre entre 0 et 600 rads, domaine dans lequel il présente une réponse linéaire à la dose.
Confirmation de la Structure Cristalline et Moléculaire du Complexe Guanine. CuCl2.Hcl.H2O
Authors: Declercq J. P. , Debbaudt M. , van Meerssche M.
Published: September 2010

The crystal data and the results of two independent X‐ray structure determinations of a guanine‐copper chloride complex are compared. This two analyses, carried out with Cu and Mo radiation and involving 1403 and 1868 observed reflections respectively account for the high accuracy: the parameters could be refined to an R‐index of 0.052 and 0.038. The bond lengths of the guanine moiety as found in the two determinations agree well, the mean difference is 0.011 Å.
Ab Initio Wave Functions For Ground State Of Hydrocarbons
Authors: AndrÉ J. M. , Degand Ph. , Leroy G.
Published: September 2010

All‐electrons SCF‐LCAO‐MO computations for methane, ethane, propane, n‐butane, i‐butane, ethylene, propene, 1‐butene, trans‐2‐butene and acetylene are presented. The basic functions are contracted gaussian orbitals. Theoretical results are discussed and related to available experimental data.
Infrared Study of the Association Between Phenol and 1‐Azabicyclo(4,4,0)Decane (Quinolizidine) Derivatives
Authors: van Binst G. , Nouls J. C.
Published: September 2010

The following values of the thermodynamic functions for the association by H bonding of phenol with 1‐azabicyclo(4,4,0)decane (quinolizidine) derivatives in tetrachlorethylene solution, have been determined from infrared measurements: 1‐azabicyclo(4,4,0)decane (I): ‐ΔH°: 9.8 ± 0.5 kcal/mole, ‐ΔG°: 2.5 ± 0.5 kcal/ mole, ‐ΔS°: 24.6 ± 2 e.u.; 3(a)‐methyl‐l‐azabicyclo(4,4,0)decane (II): ‐ΔH°: 6.2 ± 0.5 kcal/mole, ‐ΔG°: 1.6 ± 0.5 kcal/mole, ‐ΔS°: 15.3 ± 2 e.u.; 3(e)‐methyl‐l‐azabicyclo(4,4,0)decane (III): ‐ΔH°: 9.4 ± 0.5 kcal/mole, ‐ΔG°: 2.4 Δ 0.5 kcal/mole, ‐ΔS°: 23.4 ± 2 e.u.; 3‐ethylidene‐2‐azabicyclo(4.4,0)decane (IV): ‐ΔH°: 9.6 ± 0.5 kcal/mole, ‐ΔG°: 2.4 ± 0.5 kcal/mole, ‐ΔS°: 24.3 ± 2 e.u. These values show a large decrease in the enthalpy of formation of the H bond complex in the case of 1,3‐diaxial interactions between the lone pair of nitrogen atom and a methyl or methylene group.
Some Constituents from Lycopodium Carolinianum L. Var. Affine Carolinianine a New Lycopodium Alkaloid
Authors: Miller N. , Hootele C. , Braekman‐Danheux C. , Braekman J. C.
Published: September 2010

Three alkaloids: lycocernuine [II], anhydrolycocernuine [III] and carolinianine [IV] have been isolated from Lycopodium carolinianum L. var. affine together with the triterpene α‐onocerine [I]. The structure of the new alkaloid carolinianine is established and is shown to be [IV].
Organometallic Compounds. 34. A Convenient Method Of Synthesis For Haloalkyltin Compounds
Authors: Gielen M. , Topart J.
Published: September 2010

The reaction of organotin alcohols ϕR2Sn(CH2)n,CR'R”;OH (n = 1; R= ϕ R', R”; = H, H – n = 2; R = ϕ R', R”; = H, H; H, CH3; CH3, CH3; R = Me, ϕ R', R”; = H, CH3) with CCl4 or CBr4 in the presence of triphenylphosphine yields the corresponding halides, ϕR2Sn(CH2)n,CR'R”;X, which may readily be converted into triorganotin halides R2XSn(CH2).,CR'R”;X, good precursors of stannacyclo‐propanes and ‐butanes.
Preparation of Dideguanylstreptomycylamine and Bis‐N,N′‐(Dideguanylstreptomycyl)‐p‐Xylylene Diamine
Authors: Claes P. , Vanderhaeghe H. , Verlooy L.
Published: September 2010

Two dideguanyl derivatives of streptomycin were synthesized. The first compound, dideguanylstreptomycylamine, was obtained by alkaline degradation of streptomycylamine. The second, bis‐N,N′‐(dideguanylstreptomycyl)‐p‐xylylene diamine, is a “distreptomycin”; derivative prepared by catalytic reduction of the Schiff base of streptomycylamine and terephthalic aldehyde followed by alkaline deguanylation.
Long range phenomena. XIII [I]. Atypical Long Range Coupling In 1,3‐Dioxolanes. The Sign Of 2J(O2Ch2) And Differentiation In 2J(13C2–H)
Authors: Anteunis M. , Anteunis‐De Ketelaere F. , Borremans F.
Published: September 2010

It is found that long range phenomena involving H‐2 atoms in 1,3‐dioxolanes are “atypical”. The sign of 2J(CH2–2) is restated to be positive. Both coupling values, 2J and 4J follow a non‐monotonous series in bicyclic 4,5‐cyclano‐1,3‐dioxolanes. Finally 2J(13C2–H) was found to depend slightly on remoted substitution.
Chloration, Dégradation Chlorante et Pyrolyse Compétitives D'Alcanes en Présence de Tétrachlorure de Carbone I. L'exemple du Néopentane
Authors: Philardeau Yves , Dzierzynski Marjan , Martin René , Niclause Michel
Published: September 2010

En utilisant le symbolisme classique «β, μ» introduit par P. Goldfinger et al. en 1947 et par analogie avec le mécanisme «μH, YH» examiné au laboratoire en 1966, on suggère un schéma général «μH, YB» pour représenter, à l'instant initial, la réaction thermique homogène d'une substance organique μH en présence d'un corps YB, possédant au moins un atome «mobile» B (autre qu'un atome d'hydrogène).

Pour éprouver la validité de ce nouveau mécanisme radicalaire en chaînes, on étudie expérimentalement, par chromatographie gazeuse, la réaction thermique du néopentane (μH) en présence de CCl4 (YB), à faible avancement, vers 450 °C et dans un réacteur «vide» en pyrex.

On montre que les caractéristiques chimiques et cinétiques de la réaction, à l'instant initial, sont compatibles avec un mécanisme, qui apparaît comme un exemple particulier du schéma général «μH, YB».
Discussion of the mechanism of free‐radical pyrolyses of chloroethanes
Authors: Huybrechts G. , Katihabwa J. , Martens G. , Nejszaten M. , Olbregts J.
Published: September 2010

The mechanism usually proposed for the pyrolysis of 1,2‐C2H4Cl2 is discussed in terms of existing data on elementary rate constants and using the value
equation image
measured in this work for the rate constant of the reaction
equation image
This discussion is extended to the free‐radical pyrolysis of other chlorinated ethanes using recent literature data. The usual Rice‐Herzfeld mechanism is questioned in view of the discrepancy between experimental results and values predicted from the knowledge of elementary rate constants of this mechanism.
Molecular Modulation Mass Spectrometry Kinetic Study of the ClO Free Radical
Authors: Wu Ching‐Hsong , Johnston Harold
Published: September 2010

In complex photochemical reactions the effective mechanism may be different at low and at high light intensities, since the ratio of radicals to reactants may approach unity at high light intensities and may be 10−4 or less at low light intensities (such as sunlight). The method of flash photolysis has been highly successful in measuring the spectra and kinetics of free radicals in systems of high light intensities. In this laboratory a method named “molecular modulation spectrometry” has been developed, which measures the spectra and lifetimes of free‐radicals in lowintensity photochemical systems. Previous versions have utilized infrared and ultraviolet spectrometry. In this article the method is extended to ion‐counting mass spectrometry. The molecular‐modulation mass spectrometer was used to re‐investigate the kinetics of the CIO radical at low pressure and at low light intensities. Studies by flash photolysis have shown that the CIO radical decays by simple, second‐order kinetics

magnified image

This study confirms the previous result found in low intensity photolysis of CI2 and O2 that the decay process is complex and dependent on inert gas

magnified image

The change in rate law between high and low light intensities and trends exhibited by the parameters, k′ and k″, show that we still do not have a complete understanding of the mechanism of this reaction.
Les sulfates basiques mixtes de Nickel et de Zinc
Authors: Frias Rocha M. Ferreira Da , Glibert J.
Published: September 2010

The stable basic sulfates of nickel and zinc, precipitated at 20° by NaOH, are tetrabasic and tribasic respectively.

Experiments with mixed NiSO4‐ZnSO4 solutions, over a wide concentration range (500 Zn+ +/1 Ni+ + to 0,002 Zn+ +/1 Ni+ +), have evidenced the formation of solid solutions.

In the case of high Zn+ +‐concentrations in the initial solution, a 3 Zn(OH)2. ZnSO4‐type compound is formed, in which Zn‐atoms progressively have been replaced by Ni‐atoms within the sulfate layers. Saturation is attained at (Ni+ +/Zn+ +)lattice = 1/3. When the Zn+ +‐concentration is low, a 4 Ni(OH)2. NiSO4‐type compound is formed, in which Zn‐atoms have taken the place of some Ni‐atoms in the hydroxide layers, up to a ratio (Zn+ +/Ni+ +)lattice = 1/4.

In the intermediate range, there is a progressive evolution of the basicity index. The distribution factor F, characterizing equilibrium between precipitate and final solution, (Zn+ +/Ni+ +)lattice = F(Zn+ +/Ni+ +)sol., is about 4 when Zn is in the majority, but is about 1000 when Ni is predominating. This means that there exists a highly selective incorporation of Zn into the basic sulfate of Ni.
Sélénazolidines II. Alcoylation, Acylation, et Tautomérie Anneau‐Chaîne Ouverte des Sélénazolidines
Authors: Draguet C. , Renson M.
Published: September 2010

La N‐acylation des sélénazolidines peut se réaliser par un chlorure d'acide dans la pyridine. Si on travaille en présence de soude aqueuse, il y a hydrolyse du cycle avec formation de N‐Se dibenzoylcystéamines.

Un barbotage d'air supplémentaire forme des N‐N′ dibenzoyl séléno cystamines.

L'alcoylation des sélénazolidines est une Se‐alcoylation.

La tautomérie anneau‐chaîne ouverte de ce cycle est discutée.
Sélénazolidines III. Synthèse de Sélénazolidines À Partir D'Aziridines Asymétriques. Méthyl‐4 et Diméthyl‐4,4 Sélénazolidines
Authors: Draguet C. , Renson M.
Published: September 2010

Nous décrivons la synthèse de sélénazolidines à partir d'aziridines asymétriques. Nous obtenons ainsi des monométhyl‐4 ou diméthyl‐4, 4 sélénazolidines. Le sens d'ouverture du cycle aziridine est prouvé par des méthodes chimiques sûres.
La Décomposition Thermique du Chlorochromate de Potassium
Authors: Mahieu B. , Ladriere J. , Cambier J. , Apers D. , Capron P.
Published: September 2010

The slow thermolysis of potassium chlorochromate is studied by means of thermogravimetric and differential thermal analysis. The nature of intermediate compounds is determined by X‐ray diffraction and labelling by radioactive tracers. Effluent gases are analysed by potentiometric titrations. In this way, the overall reaction
equation image
is verified and the different decomposition steps are elucidated.
Stability Constants of the Ag(I) Complexes of Some Amino‐Alcohols
Authors: Poucke L. C. Van , Eeckhaut Z.
Published: September 2010

The stability constants of the Ag(I) complexes of nine amino‐alcohols have been determined at 25.0±0.1 ° and in an ionic medium of 0.5 M KNO3. Because of the high values of k2/k1 the formation curves are very steep and it was preferable to calculate the stability constants from pH and pAg measurements. No relationship was found between the acidity constants of the ligands and the stability constants of the Ag(I) complexes.
Anodic Dissolution of Lithium in LiClO4‐Ethylene Carbonate Electrolytes
Authors: Heerman L. , Baelen J. Van
Published: September 2010

The anodic dissolution of lithium in LiClO4‐ethylene carbonate solutions is complicated by the formation of a film on the electrode effecting a decrease of its activity. This film is not the normal product of the anodisation of lithium metal but is the product of a chemical reaction with the solvent or traces of water in the electrolyte. Anodic dissolution at higher current densities results in a partial breakdown of the film which accounts for an increase of the standard exchange current density from 1,47±0,25 mA/cm2 to 3,28±0,64 mA/cm2 at 40°.
The Electrical Resistivity of Hexagonal Ni1‐xS
Authors: Pauwels L. J. , Maervoet G.
Published: September 2010

Electrical resistivity measurements are carried out from 4.2° to 800 °K on sintered hexagonal Ni1‐xS powder compacts. All samples appear to be metallic at room temperature. Ni1.00S and Ni0.98S exhibit a sudden resistivity increase that shifts towards lower temperature with increasing non‐stoichiometry; the transition no longer occurs for No0.96S and Ni0.94S. After the transition, the resistivity has a constant value down to 4.2 °K. By means of the energy level diagram an explanation is proposed for this remarkable phenomenon, which results from the combination of a constant carrier concentration and a constant mobility. It is concluded that only in the case of extremely stoichiometric NiS, an actual metal‐to‐semi‐conductor transition will occur. In the presence of even a very slight non‐stoichiometric deviation, the magnetic ordering gives rise to a metal‐to‐semimetal transition. The occurrence of a transformation into rhombohedral NiS, when heating the samples, depends on the amount of non‐stoichiometry.
The Hg 6(3P1) photosensitized reactions of 3‐methylcyclohexene
Authors: Maré George R. De
Published: September 2010

The major products of the reaction at 26° are H2, CH4, C2H4, cis‐ and trans‐1,3‐pentadiene, methylcyclohexane and an isomer of the substrate. Two modes of quenching of the Hg 6(3P1) atoms are presumed to occur: paraffinic type quenching into the C‐H bonds of the molecule and quenching into the CH bond to form vibrationally excited triplet molecules which undergo allylic C‐C and C‐H bond cleavage. Under initial conditions the ratio of trans‐ to cis‐1,3‐pentadiene formed is ≥ 2.0. This can be explained by assuming that the 1,3‐pentadiene is formed in its s‐cis triplet state.
Differential Cryoscopy in Ternary Systems, System Cl(Li‐Cs) + H2O and Associated Binaries
Authors: Vilcu Rodica , Irinei Florica
Published: September 2010

The cryometric depressions determined of the LiCl + H2O and CsCl + H2O binary, solutions as well as the LiCl + CsCl + H2O ternary solution, at several concentrations, up to the 3 molality, through a process of rigourous differential cryometry. From the experimental data, the activity coefficients of the dissolved electrolytes were deduced in the binary systems, as well as in the ternary systems. The deviation from additivity of the global activity coefficients of the two ternary system electrolytes in regard to the activity coefficients of the binary systems, were attributed to specific effects of the system under study.

By means of the deviation functions, the excess free energies of the ternary system were computed, at the freezing point of the solutions, as well as the Harned coefficients of the system.
Étude de Complexes Accepteur‐Donneur par Spectrométrie Infrarouge IV. Comparaison des Complexes SbCl3‐Acétophénone et SbCl3‐Benzophénone Formés en Solution dans Quelques Solvants
Authors: Lecl Nedden G. Ère‐Zur
Published: September 2010

Infrared intensity measurements of the free C = 0 band have been used to investigate the complex formation between antimony trichloride and benzophenone in various solvents. The dissociation constants of the SbCl3. acetophenone complexes are plotted versus those of the SbCl3. benzophenone complexes in the same solvents and a straight line is obtained.
Vibrational Spectra of Mono‐ and Polymethylene Diphosphonic Acids
Authors: van Haverbeke L. , Desseyn H. O. , Herman M. A.
Published: September 2010

The Raman and Infrared spectra of H2O3P‐(CH2)n‐PO3H2, n being 1, 2, 3, 4 and 6 have been recorded.

The vibrational assignments of PO3H2 were studied, together with their behaviour in different aggregational states.

Attention was given to the v(P‐C) assignment. Both a symmetric and an asymmetric one arise when the two phosphorus atoms are attached to the same carbon, while in the higher homologues they are fairly close to one another, giving a single band.
Sulfuration du Cuivre par le Soufre Dissous en Milieu Benzénique
Authors: Labar Ch. , Breckpot R.
Published: September 2010

The sulphidation of copper by Sa dissolved in benzene has been studied in the concentration range 0.1‐5.0 Sa g liter−1 and in the temperature range 283‐313 °K. The continuous films observed have a composition varying with the progression of the reaction; the cristallographic study has shown that these films are constituted successively by the different phases: Cu1.97S (II) and (III), Cu2‐xS (II) (x varying from 0.18 to 0.45) and CuS (I). The variation of the cristallographic parameter of the C. F. C. digenitoïde phase, Cu2‐xS (II), has made it possible to follow the progression of the sulphidation by XR analysis.

The kinetic study has been made by the radioactive tracer method. The sulphidation is a succession of different reaction mechanisms: initiation period (1), diffusion in the liquid phase (2), mixed diffusion (3), diffusion in the solid phase (4) (through the sulfides film itself). A systematic study of the main processus (2) and (4) has made it possible to define the fundamental parameters of the reaction (velocity constants: K (2) (298°K) = 73.3 γ cm−2 min−1. g−1 liter; K (4) (298 °K) = 4.7 10−7 cm Cu1.80S (II). 10−4 sec; activation energies: ΔK = −4.7 kcal. mole Cu1.80S (II)−1 for mechanism (2); ΔH= ‐11.2 keal. mole Cu1.80S (II)−1 for mechanism (4)). The diffusion in the solid phase follows an inverse logarithmic kinetic relationship and can be explained by the formation mechanism of thin corrosion films (Mott and Cabrera's theory).
The Molar Heat of Reversible Adsorption at the Air‐Solution Interface in Correlation with Biological Activity
Authors: Vochten R. , Pétré G.
Published: September 2010

Aus Messungen von der Oberflächenspannung in Funktion der Temperatur, wird für wässerige Lösungen von einige normale Alkohole, die molare reversible Adsorptionswärme bestimmt.

Für einige biologische Experimenten in vitro ist eine bedeutungsvolle Korrelation nachgewiesen worden zwischen die Adsorptionswärme und die Alkoholkonzentration für 50% inhibition der biologische Experimenten.
Synthesis of 2‐amino‐4‐mercapto‐s‐triazine (5‐aza‐thiocytosine)
Authors: De Lannoy J. , Nasielski‐Hinkens R.
Published: September 2010

2‐Amino‐4‐mercapto‐s‐triazine (IV), an analog of cytosine, has been prepared from cyanuric chloride by a three steps synthesis and by cyclisation of guanylthiourea with ethyl formate.

The mass spectra of compounds III, IV and V have been investigated and fragmentation patterns are presented which account for most of the major ions. Preliminary biological tests are reported.
Étude de la Formation de Lactones Penta‐Atomiques sur les Positions 2,3 des Benzo(B)Furanne, Benzo(B)Thiophène et Benzo(B)Sélénophène
Authors: Christiaens L. , Renson M.
Published: September 2010

La déshydratation des acides hydroxyméthylés sur les positions 2,3 ou 3,2 du benzo(b)sélénophène conduit aux deux lactones isomères. Dans le benzo(b)thiophène, seule la lactone dont le groupement carbonyle est en position 3 a pu être obtenue par cette méthode.

La lactone isomère a cependant pu être synthétisée à partir du nitrile alcool correspondant par l'intermédiaire d'un iminoester interne. Dans le cas du benzofuranne, aucune des deux lactones n'a pu être obtenue quelle que soit la méthode employée. Nous discutons les raisons de cette différence de comportement.
The Acid‐Catalysed Reaction of Cyanogen Chloride with Aliphatic Alcohols. A General Synthesis of Aliphatic Carbamates
Authors: Fuks Robert , Hartemink Marinus A.
Published: September 2010

A general synthesis of aliphatic carbamates has been worked out starting from 1 mole of cyanogen chloride and 2 moles of an aliphatic alcohol giving 1 mole of the corresponding carbamate and 1 mole of the alkyl chloride in yields ranging from 75 to 98%. The reaction is catalysed with 1 to 10 moles % of dry HCl as catalyst and takes place at room temperature.

The reaction of cyanogen chloride with 1,6‐hexanediol yields 60% 1,6‐hexamethylenedicarbamate and 1,6‐dichlorohexane and 40% ω‐chlorohexylcarbamate.
Spectral and Chemical Evidence for the Structure of C‐Nor‐D‐Homoconessine
Authors: van De Woude G. , van Hove L.
Published: September 2010

The rearranged product resulting from the action of lithium aluminium hydride upon holarrhenine tosylate (IV) in ether solution has been tentatively formulated by Uffer as C‐nor‐D‐homoconessine (V).

We found that holarrhenine mesylate (III) is converted into the same rearranged product on reacting with sodium borohydride in refluxing alcohol. The spectroscopic analysis of the rearranged product confirms the proposal of Uffer and gives results which completely parallel those obtained by Lukacs et al. in their study on the product of the reaction of the sulfonic esters of 12β‐hydroxyconanine

Conanine = 3‐dedimethylamino‐5, 6‐dihydroaonessine, cf. conessine (II) in chart I.

with aluminium dichlorohydride. Further converging data are afforded by a reaction sequence involving consecutive Hofmann degradations of the rearranged product (V).
I. Les Sulfates Basiques Mixtes de Nickel et de Cobalt
Authors: Frias Ferreira Da Rocha M. , Glibert J.
Published: September 2010

When precipitated by NaOH, the basic mixed nickel‐cobalt sulphates form at 20°C a solid solution ranging from 4 Ni (OH)2. NiSO4 to 4 Co(OH)2. CoSO4.

X‐ray diffraction and I.R.‐absorption permit to follow the Ni/Co substitution process. The results are brought together in a distribution curve: (Ni++/Co++)prec. against (Ni++/Co++)final sol..

A change in the slope of the curve corresponds to the saturation of the basic nickel sulphate with cobalt and to the transition to a solid solution with the characteristics of the basic cobalt sulphate.

The distribution factor remains close to unity, cobalt exhibiting a preference to occupy the sulphated layers.
Influence du pH Sur L'adsorption de L'ion Manganeux
Authors: Roy R. , Cogneau M. A. , Debuyst R. , Apers D. J.
Published: September 2010

L'ion manganeux présente des variations du taux d'adsorption en fonction du pH de la solution et en fonction du temps de contact entre le Mn(II) et l'adsorbant (Al2O3).

Ces phénomènes sont contrôlés par voie chimique grâce à l'utilisation de traces de manganèse radioactif (54Mn) ainsi que par résonance paramagnétique électronique (R.P.E.).
Vibrational Assignments and Normal Co‐Ordinate Analysis of Dichloro‐, Dibromo‐ and Monobromomalononitrile
Authors: van Haverbeke L. , Desseyn H. O. , van Der Veken B. J.
Published: September 2010

The infra‐red and Raman spectra of C12C(CN)2, Br2C(CN)2, and HBrC(CN)2 have been recorded.

The fundamentals were assigned and a normal co‐ordinate analysis has been made using the method of BECHER and MATTES.
II. Les Sulfates Basiques Mixtes de Nickel et de Cobalt
Authors: Da Rocha M. Frias Ferreira , Glibert J.
Published: September 2010

The basic sulphates of nickel and cobalt, precipitated at 40°C, have a basicity index of 4, just as at 20°C, and form a continuous solid solution.

At 75°C, the index remains 4 for the basic cobalt sulphate, whereas the nickel salt is degraded to reach a composition of approximately 20 Ni(OH)2. NiSO4. At first amorphous, this compound presents afterwards, By aging, a structure very near to Ni(OH)2. This transformation affects the mixed nickel‐cobalt basic sulphates in the nickel‐rich range and influences the evolution of the distribution curve, which is obtained from the (Ni++/(Co++) ratios in the precipitates and the final solutions.
Essais de Chloration Dirigée. XX: Etude des Réactivités Relatives Dans la Photochloration de Chloroalcanes
Authors: Gouverneur Par P. , Bruylants A.
Published: September 2010

The propyl, isopropyl, butyl, isobutyl, amyl, isoamyl and hexyl‐chlorides were submitted to photochlorination in the liquid phase at ordinary temperature in pure phase as wel in solvents. The relative reactivities (r. r.) observed in the presence of CS2 clearly shown that the influence of this solvent increases when the inductive effects on the reaction centers decrease. Furthermore, these r. r. permit to estimate how far in the aliphatic chain the influence of the chlorine substituent is extended. Finally, these r. r. are quantitatively analysed by means of the relationship:

.

This latter takes into account the inductive, hyper conjugative and mesomeric effects.

The results obtained at higher temperatures on the propyl, butyl, butylidène, amyl, isoamyl and hexylchlorides confirm that the bêtachloroalkyl radicals decompose by “vicinal effect” and that differences of activation energies between different positions are not important. Finally, the structure‐reactivity correlation obtained at 40° C is compared with the results observed at room temperature.
Tautomérie dans la Série des Pyrazolinones II. Influence Du Milieu Sur L'équilibre Prototropique Des Pyrazoline‐5‐Ones N1 Substituées
Authors: Maquestiau A. , van Haverbeke Y. , Jacquerye R.
Published: September 2010

The influence of solvent on the tautomerism on N1 substituted pyrazolin‐5‐ones has been investigated.

As a general rule, the percentage of CH form is always bigger in apolar solvents and decreases in aprotic solvents with increasing basicity, probably in favour of the OH form.

In protic solvents, the concentration of NH form is related with hydroxylic solvents acidity.
Cyclopentanones. VII on the synthesis of the rethrolones
Authors: Madeleyn E. , Vandewalle M.
Published: September 2010

In a previous paper a new synthesis of (±) allethrolone was described starting from 2‐methyl‐3,5,5‐triethoxy‐2‐cyclopentene‐l‐one. The applicability of this method for the synthesis of the natural rethrolones has now been investigated. The method is only suitable for the synthesis of (±) jasmololone.
Synthesis of α, β‐Unsaturated Ortho‐Hydroxy Aromatic Ketones by Fries Rearrangement of α, β‐Unsaturated Para‐Cresylesters
Authors: van De Sande C. , Vandewalle M.
Published: September 2010

The Fries rearrangement of α, β‐unsaturated para‐cresyl esters is reinvestigated. Spectroscopic data are included.