bluuebunny/crossref_metadata_2025_split huggingface dataset:
The interaction of free radicals and aromatics. I. Reaction of anthracene and of pyrene with 2‐cyano‐2‐propyl radicals
Authors: Bickel A. F. , Kooyman E. C. 
Published: September 2010

Abstract2‐Cyano‐2‐propyl radicals (R) generated by decomposition of 2,2′‐azo‐isobutyronitrile were found to add on to anthracene (A) at one of the reactive 9,10 positions, yielding radicals R—A with a free valence at the other meso‐position. The latter combine to a dimer (R—A—A—R) in 22.5% yield and, with R, form cis and trans R—A—R in 49% and 13.5% yield. Under the same conditions, pyrene gave little reaction.Thermal decomposition of both R—A—A—R and R—A—R produces anthracene and 2‐cyano‐2‐propyl radicals in high yields, while H—A—A—H (9,9′,10,10′‐tetrahydrodianthranyl‐9,9′) gives anthracene and 9,10‐dihydroanthracene.The significance of these results relative to the formation of substitution products from aromatics and highly reactive radicals is discussed.
Steric effects on mesomerism VIII : Benzoquinuclidine, an aromatic amine without mesomeric interaction between the benzene ring and the amino group
Authors: Wepster B. M. 
Published: September 2010

AbstractThe spatial configuration of benzoquinuclidine (I) is such as to justify on theoretical grounds the assumption that the mesomeric interaction between the amino group and the benzene ring is at a minimum. The experimental work reported here proves that this interaction is in fact essentially zero, and hence that, in general, elimination of mesomerism by steric factors is possible. This result was obtained by a study of ultraviolet absorption spectra and of the ability to couple with diazonium compounds.
Steric effects on mesomerism IX : The basic strength of benzoquinuclidine and its bearing on the basic strength and the mesomeric energy of aromatic amines
Authors: Wepster B. M. 
Published: September 2010

AbstractIn this paper it is shown that the low basic strength of aromatic amines as compared with aliphatic amines is equally due to the inductive and the mesomeric effect; each of these is responsible for a decrease of about three pKa units. On this basis the (extra) mesomeric energy of aromatic amines is calculated as 4 kcal/mol.
The synthesis of 4‐hydroxy‐6‐amino‐isophthalic acid and related compounds: Chemotherapy of tuberculosis II
Authors: Beyerman H. C. , Wielaert G. L. G. 
Published: September 2010

AbstractIn connection with the tuberculostatic and pharmacological properties of 4‐hydroxy‐6‐amino‐isophthalic acid (4‐hydroxy‐6‐aminobenzene‐1,3‐dicarboxylic acid) a synthesis with 4,6‐dinitro‐m‐xylene (1,3‐dimethyl‐4,6‐dinitrobenzene) as starting material is described. Other alternate routes are discussed.A convenient procedure for preparing 4,6‐dinitro‐m‐xylene from technical grade xylene is given.
Sur la Chimie du Sec.‐Dodécylbenzène
Authors: Buu‐Hoï Ng. Ph. , Royer R. , Bizzini B. 
Published: September 2010

AbstractDans ce travail, on dêcrit un certain nombre de dérivés du sec.‐dodecylbenzène ‐ (1′ ‐ méthyl ‐ undécylbenzène) (cétones, hydrocarbures, dérivés azotés), préparés au cours d'une étude sur la réactivité de cet hydrocarbure aromatique.
Structure of α,ω‐diphenylpolyenes.: I. crystal data of 1,4‐diphenyl‐1,3‐butadiene, 1,6‐diphenyl‐1,3,5‐hexatriene and 1,8‐diphenyl‐1,3,5,7‐octatetraene
Authors: Drenth W. , Wiebenga E. H. 
Published: September 2010

Abstract1,4‐Diphenyl‐1,3‐butadiene, 1,6‐diphenyl‐1,3,5‐hexatriene and 1,8‐diphenyl‐1,3,5,7‐octatetraene have each both a monoclinic and an orthorhombic modification of which lattice constants and some optical data are given.
Influence of the solvent on the action of ammonia on halogeno‐derivatives of pyridine and nitrobenzene
Authors: Den Hertog H. J. , Jouwersma C. 
Published: September 2010

AbstractThe reactivity of 2,4,6‐tribromopyridine‐towards dilute solutions of ammonia in water and butanol is described. The rate of the substitution reaction is higher in water than in the less polar butanol. In water the reagent attacks chiefly the bromine atom at the 4‐position, where the nucleus carries the highest positive electrical charge. In butanol the replacement of the bromine atoms at the 2‐ and 6‐positions is preponderant. Together with 2‐amino‐4,6‐dibromopyridine and 4‐amino‐2,6‐dibromopyridine, which compounds were known, 2,4‐diamino‐6‐bromopyridine was isolated as a reaction product.In agreement with the above‐mentioned results 2,4‐dichloronitrobenzene reacts more quickly with ammonia in water than in ethanol. While in the latter solvent during a reaction at 140° exclusively the ortho chlorine atom is replaced, in water, in addition to 2‐amino‐4‐chloronitrobenzene, some 4‐amino‐2‐chloronitrobenzene is formed.
The relation between the stability of metal complexes in solution and the ionization potential of their metal component
Authors: van Panthaleon Van Eck C. L. 
Published: September 2010

AbstractThe relation between the stability (log k) of a metal complex in solution and the ionization potential (I) of the metal component is ascertained for a number of systems described in the literature. There proves to be a linear relation of the following form: log k = p. (I − q). The value of q is found to depend on the functional group(s) of the ligand, that of p on the number of the functional groups in the ligand and the polarizability of the ligand molecule.
The Raman spectrum of liquid and solid gallium trichloride
Authors: Gerding H. , Haring H. G. , Renes P. A. 
Published: September 2010

AbstractThe Raman spectra of solid and liquid gallium trichloride are communicated. From the number of frequency shifts found and from the frequency values it is probable that gallium trichloride is present as double molecules Ga2Cl6 in the solid and in the liquid. The structure of these double molecules is probably that of the ethylenic (bridge) model as was formerly concluded for Al2Cl6 etc., although the absence of polarization measurements makes this conclusion less conclusive. The result is in agreement with the crystal structure determination of Ga2Cl6 as given in the Thesis of Renes. A comparison is made between experimental and calculated frequency values for the “ethane” and the “ethylenic” models.
On electro‐osmosis and streaming‐potentials in diaphragms: III. Electrokinetic effects in networks of capillaries
Authors: Overbeek J. Th. G. , van Est W. T. 
Published: September 2010

AbstractElektrokinetic effects in diaphragms are treated with the aid of a model consisting of a network of capillaries. With negligible surface conductance or when all capillaries have equal cross‐sections the streaming‐potential E/P and the electro osmotic flow V/I are both equal to ϵζ/4πη. R. C where R and C are the resistance and the capacity of conductance of the network. In the presence of surface conductance, and for unequal cross‐sections of the capillaries, the proportionality constant between E/P or V/I and RC may be either smaller or greater than ϵζ/4πη depending on the detailed structure of the diaphragm. The first case is the usual one. For a value larger than ϵζ/4πη rather exceptional conditions have to be fulfilled.
Sulfones DI‐α‐Oléfiniques: (Propriétés du groupe sulfonyle XXXII)
Authors: Backer H. J. 
Published: September 2010

AbstractEn faisant réagir des aldéhydes sur l'acide sulfonyldiacétique et sur ses esters en présence d'acétate de pipéridine, on parvient à obtenir des sulfones di‐α‐oléfiniques. Celles‐ci sont à même de fixer sur leurs doubles liaisons des réactifs nucléophiles.
Kinetics of the reaction between mono‐methylolurea and methylene diurea
Authors: de Jong J. I. , de Jonge J. 
Published: September 2010

AbstractThe reaction between monomethylolurea and methylene diurea appeared to be bimolecular and the rate constants were found to be directly proportional to the concentration of the hydrogen ions. An influence of the buffer concentration was not observed. The activation energy was found to be 15 kcal/mol.
Etude physico‐chimique de la vagotonine: II. Ultracentrifugation
Authors: Michel G. F. 
Published: September 2010

AbstractNos premiers essais de fractionnement de la vagotonine isolée du pancréas par Santenoise1) nous ont amenés à séparer par précipitation fractionnée au sulfate de lithium deux fractions de solubilités différentes 2). Nous avons par la suite fractionné de nouveau la portion la plus soluble, et dans une précédente communication 3), nous avons décrit leur comportement électrophorétique. Ces substances se sont révélées non homogènes à L'électrophorèse et renferment trois composés principaux accompagnés d'autres protéines en proportions plus faibles. Nous avons voulu vérifier si cette hétérogénéité se manifestait également lors de la sédimentation à L'ultracentrifugeuse.
Stability of oil‐in‐water emulsions II: Mechanism of the coagulation of an emulsion
Authors: van den Tempel M. 
Published: September 2010

AbstractThe colloidal stability of an oil‐in‐water emulsion can be correlated with the well‐known behaviour of the hydrophobic sols of solid particles if the rate of coagulation is expressed in terms of a decrease in particle concentration.Coagulation of an emulsion occurs in two stages, called flocculation and coalescence. Flocculation is assumed to occur according to the second order reaction process applied by Von Smoluchowski to the similar phenomenon in the hydrophobic sols of solid particles. Coalescence is a first order reaction and will only occur between adjacent drops in an aggregate.An equation is derived in which the particle concentration is expressed as a function of both the rate of flocculation and the rate of coalescence, and the time of coagulation. The rate of coagulation appears to depend upon the particle concentration, in such a way that the rate of increase of 1/n increases with decreasing initial particle concentration. Approximations are given which may be applied to cases of practical importance.
Stability of oil‐in‐water emulsions III: Measurement of the rate of coagulation of an oil‐in‐water emulsion
Authors: van den Tempel M. 
Published: September 2010

AbstractDilute oil‐in‐water emulsions stabilised with anionic soaps were coagulated by the addition of salt. After a predetermined time coagulation was stopped by diluting with a solution of a nonionic surface active agent. The rate of coagulation was measured by counting, after varying times of coagulation, the number of oil drops under a microscope.The rate of coagulation increases with increasing salt concentration. An upper limit in the rate of coagulation, where “rapid” flocculation occurs, was observed when salts with polyvalent cations were used as the coagulating electrolyte.Increasing the concentration of Aerosol OT caused a higher rate of coagulation in dilute salt solutions and a lower rate at higher salt concentrations. Variation of the concentration of the more soluble soaps had little effect on the rate of coagulation.The influence of the valency of the coagulating cation was investigated in emulsions stabilised with a soap giving no insoluble compounds with the cations used. A behaviour as predicted by the rule of Schulze and Hardy was observed. Variation of the anion in the coagulating electrolyte had no effect on the rate of coagulation.The rate of coagulation decreases with increasing initial particle concentration. This is explained by considering coagulation as caused by flocculation followed by coalescence. From experiments in which the initial particle concentration was varied, estimations could be made of both the rate of flocculation and of coalescence. The rate of coalescence had a value of the order of 0.001 per second. For the rate of flocculation a higher value was found than that predicted by Von Smoluchowski's theory for “rapid” flocculation. Several effects are present which operate simultaneously to increase the measured rate of flocculation; the influence of these effects is discussed.
Syntheses with the aid of γ‐picolyllithium II: Preparation of oxygen‐containing derivatives
Authors: Hey J. W. , Wibaut J. P. 
Published: September 2010

Abstractβ‐(Pyridyl‐4′)‐propionaldehyde‐diethylacetal (II) is obtained in a yield of 39% by the action of bromoacetal on γ‐picolyllithium (I). By allowing I to react with acetyl bromide or with ethyl acetate, a 34% yield of (pyridyl‐4′)‐propanone (III) is obtained. By the action of carbon dioxide on I, (pyridyl‐4′)‐acetic acid is prepared, which is isolated as the ethyl ester (IV) (yield 34%).
Preparation of thio‐orotic acid labelled with S35
Authors: Ernsting M. J. E. , Nauta W. Th. 
Published: September 2010

AbstractIt was found that condensation of thiourea with ethyl ester of oxalacetic acid in an alkaline milieu yields a higher quantity of thio‐orotic acid than the methods described in the literature. This method of condensation was applied to the preparation of thio‐orotic acid labelled with S35.
Nouvelle synthese d'esters thiolsulfoniques: Reaction d'anhydride sulfureux sur le diphenyldiazomethane en presence de mercaptannes: (Propriétés du groupe sulfonyle XXXVII
Authors: Kloosterziel H. , Boerema J. S. , Backer H. J. 
Published: September 2010

AbstractLa réaction conduit à des thiolsulfonates (“disulfoxydes”) de la formule (C6H5)2CHSO2SR. On peut admettre une fixation des mercaptannes sur la double liaison d'un “sulfène” formé intermédiairement.
The synthesis of p‐guanidino‐salicylic acid and some related compounds
Authors: Beyerman H. C. , Bontekoe J. S. 
Published: September 2010

AbstractThe syntheses of 4‐guanidino‐salicylic acid, 4‐(N′‐cyanoguanidino)‐ salicylic acid, and some related compounds are described.Intermolecular coupling of the diazonium salt of ρ‐amino‐salicylic acid and of its methyl ester yielded products which are in all probability 2,4,3′‐trihydroxy‐5,4′‐dicarboxy‐azobenzene and the methyl ester thereof.These and some related compounds were prepared in order to examine their possible growth‐inhibiting properties for Mycobact. tuberculosis.
A theoretical treatment of Hammett's sigma constants
Authors: Sixma F. L. J. 
Published: September 2010

AbstractA theoretical treatment is given of the connection between the structure and the position of a substituent S and the value of σs, from the Hammett equation: log ks/ko = ρ · σs. The theory is based on a wave mechanical calculation of the effect of S on the localisation energy of a reaction. The equations derived make it possible to calculate σs, for a large number of substituents from known values of bond lengths and bond moments.The calculations are carried out for a number of different reaction types, which are representative of a large number of reactions. The mean deviation of the theoretical values of σ from the experimental values amounts to ±0.07; the agreement reached is of the same order, therefore, as the experimentally found deviations from Hammett's equation.
Vinylogie chez les composés de sulfonyle I: (Propriétés du groupe sulfonyle XXXIX)
Authors: Backer H. J. , Strating J. , Hazenberg J. F. A. 
Published: September 2010

AbstractLe 1,2‐dichloro‐1‐tertiobutylsulfonyl‐éthène, qui peut être regardé comme vinylogue d'un sulfochlorure, dispose d'un atome de chlore qui est extrêmement actif. Tout comme un sulfochlorure, ce composé réagit avec les alcools, les mercaptannes etc. Les produits se comportent comme les vinylogues des simples composés sulfonylés correspondants.
Synthesis of polychloro compounds with aluminium chloride XIII. The condensation of formaldehyde, symm.‐dichlorodimethyl ether, and chloromethyl methyl ether with trichloroethene and with tetrachloroethene
Authors: Prins H. J. 
Published: September 2010

AbstractThe condensation of formaldehyde (paraformaldehyde or trioxane) with trichloroethene in the presence of aluminium chloride gives a mixture of 2,3,3,3‐tetrachloropropanol‐1, the di‐ether of this alcohol (2,3,3,3,2′,3′,3′,3′‐octochloro‐di‐n‐propylether), and αβ‐dichloropropionyl chloride.The same di‐ether is obtained by the condensation of symm.‐dichlorodimethyl ether with trichloroethene.Condensation of chloromethyl methyl ether with trichloroethene gives the methyl ether of 2,3,3,3‐tetrachloropropanol‐1.Tetrachloroethene yields, by condensation with formaldehyde, 2,2,3,3,3‐pentachloropropanol‐1 and the di‐ether of this alcohol (2,2,3,3,3,2′,2′,3′,3′,3′‐decachloro‐di‐n‐propylether).The same ether results from the condensation of tetrachloroethene with symm.‐dichlorodimethyl ether.At temperatures above 50°, cleavage and dehydrohalogenation of the di‐ether of 2,2,3,3,3‐pentachloropropanol‐1 occurs, with formation of 1,1,2,3,3‐pentachloropropene‐1 as well as 2,2,3,3,3‐pentachloropropanol‐1.Condensation of chloromethyl methyl ether with tetrachloroethene is accompanied by cleavage of the ensuing methyl ether of 2,2,3,3,3‐pentachloropropanol‐1, and yields 2,2,3,3,3‐pentachloropropanol‐1.The mechanism of these reactions is discussed.
The binary system of nitrosyl chloride with aluminium chloride
Authors: Houtgraaf H. , de Roos A. M. 
Published: September 2010

AbstractThe fusing point diagram of NOCl with AlCl3 has been investigated.The curves show a well defined maximum at a composition of 1 mole of NOCl and 1 mole of AlCl3. The congruent melting point of the compound NOCl · AlCl3 has been determined as 180° C. In high vacuum this compound can be sublimed almost undecomposed.Another compound with an incongruent melting point has been found. containing 2 moles of NOCl and 1 mole of AlCl3 (transformation point 17.5° C).Moreover there exists a two liquid layer region extending from about 84 mole % of AlCl3 to about 99 mole % of AlCl3. (The temperature of the three‐phase equilibrium S + L1 + L2 is about 195.2° C).Some attention is paid to the difficulties encountered in the determination of the exact melting point temperature of solid AlCl3 and to their explanation.
Synthesis of potential chemotherapeutics in bile duct infections (II)
Authors: van Kampen E. J. 
Published: September 2010

AbstractIn a previous publication1) the synthesis was described of 3′,3″‐disulphanilylamino‐phenolphthalein as a potential chemotherapeutic for combating infected bile ducts.Below the synthesis is described of mono‐sulphanilylamido‐phenolphthalein, α‐phenyl‐β‐(3‐sulphanilylamido‐4‐hydroxyphenyl)‐propionic acid, and 2‐carboxy‐3′‐sulphanilylamido‐4′‐hydroxybenzophenone. An investigation for informative purposes of the latter two compounds has been made as regards their bacteriological and pharmacological properties.
Über das Verhalten einiger α,α′‐Iminosäuren als Substratkomponenten in biologischen Systemen: Untersuchungen in Beziehung zu Eiweissproblemen. II
Authors: Kögl F. , de Flines J. 
Published: September 2010

AbstractZur Prüfung der Frage ob α,α′‐Iminosäuren im Sinne der Hypothese von Karrer als Zwischenprodukte bei der enzymatischen Transaminierung eine Rolle spielen, wurde ein mit C14, D und N15 markiertes Präparat von L‐α‐L‐α′‐Imino‐propionsäure‐glutarsäure neben α‐Ketoglutarsäure und Alanin zu einem Homogenat von Rattenmuskel gefügt. Die nach der enzymatischen Umsetzung isolierte L‐Glutaminsäure war nicht radioaktiv, was im Prinzip gegen eine intermediäre Rolle der α,α′‐Iminosäure spricht. Die gebildete L‐Glutaminsäure zeigte jedoch eine geringfügige Erhöhung der N15‐Konzentration. Ein Erklärungsversuch hierfür wird diskutiert.Weiterhin wurde untersucht, ob die verschiedenen Stereoisomeren von α,α′‐Imino‐propionsäure‐bernsteinsäure und von α,α′‐Imino‐propionsäure‐glutarsäure imstande sind, Alanin und Asparaginsäure bzw. Glutaminsäure als Substratkomponenten von Leuconostoc dextranicum, Leuconostoc mesenteroïdes P60 oder Lactobacillus arabinosus zu ersetzen. Dies war nicht der Fall.
Biphenyl derivatives III: Basic esters of biphenyl‐2‐carboxylic acid and a number of its partially or totally hydrogenated analogues
Authors: Veer W. L. C. , Oud P. J. A. 
Published: September 2010

AbstractThe synthesis of the hitherto unknown 2‐phenyl‐cyclohexene‐l‐carboxylic acid and 2‐cyclohexyl‐cyclohexene(1 or 6)‐carboxylic acid is described. These acids, as well as 2‐phenylbenzoic acid, trans‐2‐phenyl‐cyclohexane carboxylic acid, 2‐cyclohexyl benzoic acid, 2‐cyclohexyl‐cyclohexane carboxylic acid and biphenyl‐2‐acetic acid were converted into their tertiary aminoalkyl esters. These esters exhibit various pharmacological properties, the antispasmodic activity being most pronounced. In this respect (2‐dimethylaminoethyl)‐2‐phenyl‐cyclohexene‐l‐carboxylate and (2‐diethylaminoethyl)‐trans‐2‐phenyl‐cyclohexane carboxylate are the most powerful compounds of the series.
Cis‐ and trans‐quinonedichloride
Authors: ter Borg A. P. 
Published: September 2010

AbstractContrary to the results of earlier investigators it is found that the reaction of chlorine with quinone is a cis‐addition. Conditions are studied for the conversion of cis‐quinonedichloride into the trans‐isomer and subsequently into 2,3‐dichloroquinol.The course of the reaction between sulphuryl chloride and quinol is elucidated.
The dipole moments of 2,2′‐dipyridyl and of 4,4′‐dipyridyl
Authors: Goethals C. A. , Wibaut J. P. 
Published: September 2010

AbstractIn a paper entitled “The configuration of 2,2′Dipyridil” Fielding and Le Fèvre) point out some errors occurring in a publication) by one of the present authors (G), entitled: “Electric Moments of Pyridine Derivatives”. These errors, which the British authors kindly consider to be “probably clerical errors”, are very annoying, so that we think it useful to correct them as yet.
The separation and identification of normal aliphatic aldehydes and methyl ketones
Authors: Kramer P. J. G. , van Duin H. 
Published: September 2010

Abstractn‐Aliphatic aldehydes and n‐methyl ketones up to and including C18 are separated by partition chromatography of the 2,4‐dinitrophenylhydrazones on silica‐gel with light petroleum as mobile and nitromethane as immobile phase. Identification is possible by means of the retention volumes.
The separation and identification of normal aliphatic alcohols
Authors: van Duin H. 
Published: September 2010

AbstractWith the aid of 4‐dialkylamino‐3,5‐dinitrobenzoyl chloride primary normal aliphatic alcohols and normal methyl‐carbinols up to ca. C14 are practically quantitatively converted into coloured esters, which can be separated by partition chromatography. Identification is possible by means of the retention volumes, while a quantitative determination can be made by measuring the UV absorption.The theory of partition chromatography is extended and it is shown that the logarithms of the true retention volumes for terms of a homologous series plotted against the number of C‐atoms must give a straight line, provided the behaviour of the solutions and chromatographic system is ideal. The slope of this line is determined exclusively by the partition system and the nature of the homologous series. The significance of this relationship for the identification of homologues is discussed.
Investigation of the alkaloids of Punica Granatum L. by partition chromatography
Authors: Wibaut J. P. , Beyerman H. C. , Enthoven P. H. 
Published: September 2010

AbstractIn recent literature doubts are expressed about the accepted structure of the anthelmintic substance pelletierine, one of the four alkaloids said to occur in the bark of the pomegranate tree (Punica granatum L.) It has been suggested that the “pelletierine” of the literature is in reality isopelletierine, which would reduce the number of alkaloidal components to three.The present investigation reports on the analyses by means of partition chromatography on paper of two samples of commercial “pelletierine sulphate” and of an extract made of pomegranate bark. Four (or five) spots were found, three of which had RF‐values identical with those of synthetic pseudopelletierine, d,l‐isopelletierine and d,l‐methylisopelletierine. This is a convenient way of establishing the presence of these three compounds in pharmaceutical “pelletierine” preparations and of establishing the presence of one (or two) more substances not yet identified.