bluuebunny/crossref_metadata_2025 huggingface dataset:
A Facile New Method for the Preparation of Aromatic Diisothiocyanates
Authors: Garín J. , Meléndez E. , Merchán F. , Merino P. , Tejero T.
Published: September 2010

In the present communication we describe a new facile method for the preparation of aromatic diisothiocyanates. The main advantage of this method is a one‐pot procedure from bis(dithiocarbamates) compared with the methods described in the literature.
Synthesis of Large‐Sized Sapo‐5 Crystals With Silicon Occupying Predominantly Phosphorus‐T‐Sites
Authors: Finger G. , Jahn E. , Zeigan D. , Zibrowius B. , Szulzewsky K. , Richter‐Mendau J. , Bülow M.
Published: September 2010

Silicoaluminophosphates of type SAPO‐5 with low content of silicon have been synthesized forming single hexagonal prisms up to 100 micrometers. By 29Si MAS NMR technique it is proved that in these samples silicon predominantly occupies framework sites which should give rise to catalytic activity.
Determination Voltamperometrique Des Ions Bi3+ A L'Aide D'Une Electrode Tournante a Renouvellement Constant De La Surface
Authors: Stoytcheva Margarita , Noninski Christo
Published: September 2010

On a étudié l'influence de différents facteurs‐vitesse de rotation de l'électrode, concentration de l'électrolyte indifférent (KCl, KBr, NaF, NH3+NH4Cl), concentration du dépolarisant, température, etc. sur le courant de diffusion et le potentiel de demi‐vague, enregistrés lors de la réduction des ions Bi+3 sur une électrode tournante à renouvellement constant de la surface. On a démontré que cette électrode peut être employée pour la détermination qualitative et quantitative du dépolarisant cité.
Synthesis of 1‐Amino‐5‐(Substituted)Amino‐1,2,3‐Triazoles
Authors: L'abbé Gerrit , Bruynseels Maria , Beenaerts Linda , Vandendriessche Anna , Delbeke Pieter , Toppet Suzanne
Published: September 2010

1‐Amino‐5‐(substituted)amino‐1,2,3‐triazoles (3) are directly produced by heating 1‐aryl‐5‐chloro‐1,2,3‐triazoles (1) with hydrazine. The 5‐hydrazinotriazoles 2 are presumably formed first, but rearrange spontaneously under the reaction conditions. The structures of the products were established principally on the basis of 13C NMR analyses.
Thermal Characterization of Liquid Crystalline Materials
Authors: van Ende P. , Groeninckx G. , Reynaers H. , Leuven K. U.
Published: September 2010

During the last years, there has been a significant interest in the field of liquid crystalline components, polymers in particular.[1,2] There is a definite need to use a wide range of methods to characterize these materials. Thermal properties need to be examined properly in order to obtain the glass‐transition temperature, melting, clearing and crystallization temperatures.

The first part of this paper will give an introduction to the basic principles of the liquid crystalline state. The outstanding properties as well as the required chemical structure will be discussed. The second part deals with the characterization of these materials by means of optical, thermal and scattering techniques available in our laboratory.
α‐Arylation of Aldehydes Via α‐Chloroaldimines
Authors: Kimpe Norbert De , Zi‐Peng¶ Yao , Schamp Niceas
Published: September 2010

α‐Chloroaldimines are arylated at the α‐position under Friedel‐Crafts conditions via the presumptive intermediacy of α‐imidoylcarbenium ions. Aluminium (III)chloride in arenes cleanly converted α‐chloro‐α‐phenylaldimines into α‐aryl‐α‐phenylaldimines. Aliphatic α‐chloroaldimines could only be converted into the corresponding α‐arylaldimines in low to moderate yields due to a lower reactivity and a competitive side reaction, i.e. dehydrochlorination into 1‐aza‐1,3‐dienes. α‐Bromo‐and α‐iodoaldimines were also evaluated under the given Friedel‐Crafts conditions but the results appeared to be negative. The formation of all reaction products (i.e. α‐arylaldimines, 1‐aza‐1,3‐dienes and indolines) from the reaction of α‐chloroaldimines with arenes in the presence of Lewis acids could be explained by the intermediacy of α‐imidoylcarbenium ions, the chemistry of which is discussed to some extent.
Photo‐Oxidation of Some DI‐2‐Benzothiazolymethane Derivatives
Authors: Ramos M. Teresa , Avendaño Carmen , Elguero José , Jimeno M. Luisa
Published: September 2010

We report the photo‐oxidation of some di‐2‐benzothiazolylmethane derivatives and discuss the structure of the isolated methanols and ketones.
Synthesis of Imines From N‐(1‐Halogenoalkyl)Heteroarylium Salts
Authors: Maquestiau A. , Anders E. , Eynde J.‐J. Vanden , D'Orazio P. , Mayence A.
Published: September 2010

A comparison is established for the reactivity of benzaldehyde, N‐(1‐chlorobenzyl)pyridinium chloride or N‐(1‐chlorobenzyl)pyrimidinium chloride with several poorly nucleophilic and/or poorly soluble primary amines under mild experimental conditions.
Synthèse Dans La Chimie Des Phenanthridines. II. Préparation D'Une Nouvelle Série D'ω‐(Phenanthridinyl‐6) Alcanoates De Méthyle Ou D'Éthyle
Authors: Lion C. , Boukou‐Poba J. P. , Charvy C.
Published: September 2010

A new series of methyl and ethyl w‐(6‐phenanthridinyl) alkanoates is easily synthesised from the acid chloride‐esters ROCO(CH2)nCOCl (n=0,3 to 8; R=Me or Et). Reaction of these with o‐aminobiphenyl leads to the expected amide‐esters which are cyclised to phenanthridines quaternised to the corresponding phenanthridinium salts.
Polyphosphazenes: Synthèse, Propriétés Et Développements Récents
Authors: Potin Philippe , Jaeger Roger De
Published: September 2010

The two step preparation of polyphosphazenes‐polydichlorophosphazene synthesis and later substitution‐allows design of tailor‐made structures. For the past few years, a new route to polydichlorophosphazene and a large range of structures have been disclosed leading to many potential applications.
Synthesis and Properties of Novel Polyetherketones and Polyethersulphones
Authors: Staniland P. A.
Published: September 2010

Nucleophilic polycondensation procedures developed for the synthesis of ICI's polymers Victrex PES, PEEK and PEK have been utilised to prepare novel polymers whose properties are in some respects superior.

Three basic groups of polymers have been examined based on Isophthaloyl, sulphonyl terphenylene and oxyterphenylene units which together yield a spectrum of thermal properties. Glass transition temperatures range from 160°C‐260°C and crystal melting points from 300°C‐400°C.

The crystallinity developed in selected examples gives rise to excellent chemical resistance as observed in PEEK and PEK but in many cases the synthetic chemistry is such that the new polymers could be cheaper to produce than these existing resins.
Characterization and Chemical Nucleation of a Polyaryletherether Ketone (Peek)
Authors: Devaux J. , Leblanc D. , Daoust D. , Legras R. , Nield E.
Published: September 2010

19NMR spectroscopy has been performed on PEEK samples in sulphuric acid, revealing that most chain ends are fluorine. Different chemical shifts have been observed on sulphonated samples due to already demonstrated long range shielding effects. The method appears suitable for Mn determination.

Substitution of F chain ends, followed by 19NMR, appeared feasible leading to alkaline sulphonate end groups. Ionic chain ends associations act as seeds for nucleation. Fast crystallizing PEEK and PEK are thus obtained. This is a new demonstration of the concept of Chemical Nucleation.
Realisation of a Bioartificial Pancreas Using a New Performant Asymmetric Membrane
Authors: Schué F. , Aoumar A. Ben , Clarotti G. , Sledz J. , Orsetti A. , Paleirac G.
Published: September 2010

The results of this work show a new asymmetric membrane very performant, characterized by an exceptional deformability, a good pressure strength, a high permeability and a satisfactory permselectivity.

Its interesting specific anticoagulant activity is a contribution to the realization of a “new bio‐artificial pancreas”.
Possibilités Offertes Par Le Traitement Par Plasma Pour Augmenter L'Hémocompatibilité Des Membranes D'Ultrafiltration
Authors: Clarotti G. , Schué F. , Sledz J. , Ait Aoumar A. Ben , Geckeler K. , Orsetti A. , Paleirac G.
Published: September 2010

Ce travail est financé par la bourse nº ST2*35I du programme Stimulation de la Commission des Communautés Européennes
Proprietes Electriques Du Metavanadate De Potassium
Authors: Pouchards M. , Theobald F. , Theobald J. G. , Ammari M.
Published: September 2010

We measure the piezoelectric (d=65.10−12 m V−1) and pyroelectric (P=2,5 10−6 Cb m−2 °K−1) properties of K2 V3 O8. We try to obtain a coherence between these results, using the structure of K2 V3 O8 previously determined.
Complexes of Group IIb Metals With Dithiooxamides V‐Vibrational Spectra And Thermal Analysis of the CdLX2 Complexes
Authors: Geboes Peter , Plakatouras John , Desseyn Herman O.
Published: September 2010

In acid media, CdX2 forms non‐electrolyte CdLX2 (L=DTO, NN′DMDTO, TMDTO; X=Cl, Br, I) complexes with dithiooxamides. The ligands act as bidentates with S,S coordination.

A thorough vibrational analysis (i.r. and Raman) has been performed for the Cd(H2NCSCSNH2)X2 (X=Cl, Br, I), the Cd(CH3NHCSCSNHCH3)X2 (X=Br, I) and the Cd[(CH3)2NCSCSN(CH3)2]X2 (X=Cl, Br, I) complexes, by NH/ND and CH3/CD3 isotopic substitution. Stereochemistries varying from tetrahedral to octahedral structures are proposed based on spectroscopic evidence and the positions of the metal‐ligand vibrations can be explained in terms of the HSAB principle.

The thermal behaviour of the complexes has been studied, using isothermal as well as non‐isothermal techniques.
Cyclic Voltammetric of the 4,NO2 Pyrazolepentacyanoferrate and 4,Br Pyrazole‐Pentacyanoferrate Complexes at Different pH Values. The Ko and α Values
Authors: López Fernández V.
Published: September 2010

Cyclic voltammetric studies of the oxidation of the 4,NO2 pyrazole‐pentacyanoferrate and 4,Br pyrazole‐pentacyanoferrate complexes were carried out in a platinum rotating electrode at different pH values. For these complexes the ko and α values have been determined. Average values of ko=0.58 10−1 cm/s and ko=0.98 10−1 cm/s respectively are obtained.
Chemical Analysis of Zairian Coastal Seawater
Authors: Mulenga M. , Monama O. , Kabungu Y. , Kalala K. , Yowa K. , Dorebaba R.
Published: September 2010

Salt composition of seawater along Zairian coast between 4,5° and 6° S was determined by volumetric and photometric methods. The concentration of NaCl per litre was found to be approximately 18 g/l.
Captodative Substituent Effects. ‐ Part 491 ESR Study of Carbon Centered Transient Radicals Using α‐Tert.Butylthioacrylonitrile as Radical Trap
Authors: Merényi Robert , Janousek Zdenek , Viehe Heinz G. , Mignani Serge
Published: September 2010

A method for trapping of transient carbon centered radicals is proposed. The ESR spectra of radical adducts 4 deriving from α‐tert.butylthioacrylonitrile 3a give more information concerning the scavenged radical 2 than the other known radical traps.
Synthese Et Etude De La Reactivite Dipolarophilique De L'Oxyde De 1‐Ethoxyphosphindole
Authors: Sedqui Ahmed , Lakhlifi Tahar , Laude Bernard , Amaudrut J.
Published: September 2010

A new and efficient synthesis of 1‐ethoxyphosphindole oxide 1 is reported. The dipolarophilic activity of this heterocycle towards three class of 1,3‐dipoles was tested. The cycloaddition reactions are regio‐and stereospecific. Nmr data (1H and 13C) allow us to determine the regio and the diastereochemistry of the cycloadducts.
On the Emission of BaCl2‐Tl Single Crystals
Authors: Tabakova Veneta , Stoicheva Margarita , Trifonova Roumiana
Published: September 2010

The emission of the crystalphosphor BaCl2‐Tl is studied. All the measurements are performed at 53 and 279 K. The emission is excited with photons with different energies in the region of the activator's absorption. Two bands are observed in the spectrum the intensities of which depend on the temperature and the excitation energy. The symmetry of the centres‐associates (Tl+V+) the formation of which is possible in the crystalphosphor is determineda.
Etude D'Electrodes Bifonctionnelles (Electrolyse De L'Eau Et Reduction De L'Oxygene) A Base De Charbons Impregnes De Naphtalocyanine De Molybdene‐Role Du Nickel Superficiel
Authors: Dieng M. , Savy M. , Aaron J. J.
Published: September 2010

The electrolysis of water in alkaline medium has been investigated on electrodes consisting of molybden naphthalocyanine (NPcMo) supported on carbon blacks. The catalyst role of nickel metal incorporated in the carbon black supports in the process of evolution of hydrogen and oxygen has been examined using cyclic voltammetry. The analysis of the peaks of oxidation and reduction at ambient temperature shows an enhancement of activity for the oxygen reduction in the case of NPcMo impregnated electrodes. The state of the chelated nickel depends of the type of electrode used. Thus the existence of nickel naphthalocyanine can be assumed.
Complex Hydride Reductions of 12‐Oxosteroids. Influence of Remote Substituents
Authors: Biesemans M. , Van Woude G. De , van Hove L.
Published: September 2010

A number of 12‐oxosteroids with both 5α‐ and 5β‐configuration and with variable side chain are reduced with LiAlH4, NaAlH4 and Li[Al(Ot‐Bu)3H] in THF and diethylether. The ratio of the epimeric 12‐alcohols obtained, exhibits a remarkable dependence on the type of A/B ring fusion and on the C‐17 substitution. An evaluation of these effects is made in the light of generally accepted rationalizations on the mechanism of ketone reductions by hydride reagents.
Potentiometric Measurements in Water/Ethanol Medium
Authors: Abdel‐Rahman L. H. , Herman G. G. , Goeminne A. M. , Mahmoud M. R.
Published: September 2010

A glass electrode calibration method is described for potentiometric pH‐measurements in a water‐ethanol solvent mixture. The method is checked by determining the protonation constants of glycine, β‐alanine, L‐tryptophane, L‐methionine and DL‐ethionine in water/ethanol (43% weight ethanol) (I=0.1 M KNO3) at 25°C. The binary complex formation of these amino acids with Co(II), Ni(II), Cu(II) and Zn(II) has also been investigated, together with the ternary complex formation with 2,2′‐bipyridyl as second ligand. The solvent effect is discussed.
New Polymers by Olefin Polymerization with Aluminoxane Containing Catalysts
Authors: Kaminsky Walter , Möller‐Lindenhof Nico
Published: September 2010

Highly active catalysts for the polymerization of olefins are formed by combination of metallocenes and methylaluminoxane. Both components are soluble in hydrocarbons. An unusually wide field of syntheses of different polyolefins is opened up by the mere variation of the ligands coordinated to the transition metal.
2,2,4‐Trichlorobutanal: An Invitation to the Synthesis of Heterocyclic Compounds
Authors: De Buyck L. , Menke N. , Schamp N.
Published: September 2010

The title aldehyde (1) was obtained in 69% isolated yield by chlorination of 4‐chlorobutanol in the presence of dimethylformamide. 3,3‐Dichloro‐2‐hydroxytetrahydrofuran (3a) or the 2‐alkoxyderivatives 3b and 3c were produced by treating the hydrate 2a or the hemiacetals 2b and 2c resp. with base. With aqueous ammonia 1 rapidly formed the hemiaminal which then slowly afforded 3,3‐dichloro‐σ1‐pyrroline (4). In a rapid reaction with primary alkylamines 1 was converted to N‐alkyl‐3,3‐dichloro‐2‐hydroxypyrrolidines (5). The 2‐hydroxyl group in 5 was reversibly exchanged in the presence of alcohols or amines. 5 Were converted to N‐alkyl‐3,3‐dichloro‐σ1‐pyrrolinium salts by an excess of trifluoroacetic acid.
1,3‐Dipolar Cycloadditions of some Azomethine Ylides to Thioketones
Authors: Mloston Grzegorz , Skrzypek Zuzanna
Published: September 2010

Reactions of the azomethine ylides generated from cis‐1‐substituted‐2,3‐diphenylaziridines 1a‐b or from 1,2,3‐triazoline 5 with thiobenzophenone, adamantanethione and 2,2,4,4‐tetramethyl‐3‐thioxocyclobutanone are described.
The Dependence of Endopeptolysis on the Sequential Chirality Exemplified by a Simplified Preparation of the |D‐MePhe−4| ‐Epimer of Virginiamycin s.
Authors: Anteunis M. J. O. , Van Auwera C. Der , Sharma N. K.
Published: September 2010

The 4‐epimer of Virginiamycin S (VS‐epi4) containing the heterochiral triad L‐Pro−3‐D‐MePhe−4‐L‐(γOxo) Pec−5 is found to be resistant against acidic hydrolysis in contrast to the native VS possessing the L−3, L−4, L−5‐sequence. This allows a simplified protocol for its isolation, and exemplifies previous findings (ref. 1) about the easy endopeptolysis of homochiral triads.
Preparation and Properties of Zirconocene Complexes with Ferrocenylcarboxylate Ligand
Authors: Yong‐Xiang Ma , Zheng‐Zhi Zeng , Guo‐Sheng Huang , Chun‐Lin Ma
Published: September 2010

Some zirconocene complexes containing ferrocenylcarboxylate ligands, [(RC5H4)2ZrCl]nY, R = H or CH3; n = 1, Y = ferrocenylcarbonyloxy, 2‐ferrocenylacetoxy, 4‐ferrocenylbutanoyloxy, 4‐ferrocenyl‐4‐oxobutanoyloxy, and 3‐(ferrocenylcarbony)lbicyclo[2,2,1]hept‐5‐ene‐2‐carbonyloxy; n = 2, y = bis[(3‐carboxypropionyl)cyclopentadienyl]iron, have been prepared. Their IR, −1H NMR, UV, and other determinations show that the carboxyl groups are bidentate ligands in these complexes.
Copper(II) Ion Transport Through Mono and Binary Liquid Membranes
Authors: Szpakowska Mariola , Fizycznej Zaklad Chemii , Nagy Ottó B.
Published: September 2010

The influence of membrane material and water phases acidity on coupled active copper transport by Acorga 5100 used as carrier has been examined. It was found that the efficiency of copper ion flux depends not only on proton concentration gradient across the membrane but also on the viscosity of the membrane solvent. However, both dependencies show saturation effects. Diffusion through the membrane phase turns out to be the rate determining step as shown by the accumulation of copper ions in the membrane and confirmed by partitioning measurements. Facilitated passive transport experiments showed that both the nature of the carrier and the composition of binary membranes influence strongly the transport rate. Varying membrane composition may even increase transport efficiency more than the use of better carrier. It was also found that the presence of surfactants have a favourable effect on the transport rate.
New Vertex Indices and their Applications in Evaluating Antileukemic Activity of 9‐Anilinoacridines and the Activity of 2′,3′‐Dideoxy‐Nuclosides Against HIV
Authors: Raychaudhury C. , Klopman G.
Published: September 2010

A newly developed graph‐theoretical artificial intelligence program has been used to evaluate qualitatively the antileukemic activity of 9‐anilino‐acridines and the activity of 2′,3′‐dideoxy‐nucleosides against HIV. The idea behind the approach is to predict the biological activity of any chemical compound on the basis of already identified pharmacologically/toxicologically relevant components of the molecules exhibiting the same kind of activity. A family of new graph‐theoretical (topological) vertex indices called distance exponent indices (Dx) of molecular graph have been proposed and used in the present study. Two previously used information‐theoretical topological indices viz., vertex distance complexity (Vd) and normalized vertex distance complexity (Vdn) have also been used. However, some distance exponent indices have produced the most significant results. These indices appear to identify biologically relevant molecular components (vertices in our case) quite effectively. Subsequently, an experiment of cross‐validation has been carried out to analyze the predictive power of the present approach. The possible application of the vertex indices, considered here, in different databases has also been discussed.
Vibrational Analysis of New Macrocyclic Imine‐Carbinolamine Complexes of Nickel(II)
Authors: Amer S. A. , El‐Hefnawy G. B. , Saleim G. W. , Desseyn H. O.
Published: September 2010

The new macrocyclic imine‐carbinolamine complexes of nickel(II) have been prepared by reaction of 2,3‐diformylfurane and aliphatic diamines in ethanol in the presence of nickel(II) acetate or by simple addition reaction of the tetraaza‐macrocyclic ligand and NiX2 (X = chloride or acetate) in ethanol. The mode of coordination of these complexes has been studied through the vibrational analysis (i.r. and Raman) using the −58Ni/−62Ni isotopes technique.
Spectrophotometric Determination of CD(II) and Zn(II) with 1,2,3‐Cyclohexanetrione‐1,3‐Dioxime‐2‐Thiosemicarbazone. Simultaneous Determination by first and Second Derivative
Authors: Murillo José A. , Lemus José M.
Published: September 2010

1,2,3‐Cyclohexanetrione‐1,2‐dioxime‐3‐thiosemicarbazone (CTDT), produces coloured complexes with zinc and cadmium ions in basic medium. The yellow colour obtained has been used to develop spectrophotometric methods for zinc and cadmium in the concentration range 1.30‐8.50 μg ml−1 of zinc and 1.20‐6.50 μg ml−1 of cadmium.

A new method for the determination of zinc and cadmium in mixtures is proposed for concentrations between 0.5‐6.0 μg ml−1 and 0.8‐5.5 μg ml−1 by first derivative spectrophotometry and between 0.5‐6.0 μg ml−1 and 0.8‐5.5 μg ml−1 by second derivative spectrophotometry.
Selective Cleavage of the Ether and Amide Bonds in N‐(2,4‐Difluorophenyl)‐2‐[3‐(Trifluoromethyl)‐Phenoxy]‐3‐Pyridinecarboxamide (Diflufenican)
Authors: Rouchaud Jean , Gustin Fabrice , Moulart Claude , Herin Marc
Published: September 2010

Heated to reflux in water containing 8 g% KOH, the herbicide diflufenican [N‐(2,4‐difluorophenyl)‐2‐[3‐(tri‐fluoromethyl)‐phenoxy]‐3‐pyridinecarboxamide, 1] was selectively transformed into 2‐[3‐(trifluoromethyl)‐phenoxy]‐3‐pyridinecarboxylic acid (2) plus 2, 4‐difluoroaniline (5); after 60 hr of heating, 27% of the initial diflufenican was transformed, yielding 21% (mole% relative to initial diflufenican) of compound 2. Heated to reflux in a mixture of acetic acid + concentrate hydrochloric acid, diflufenican was transformed into a mixture of N‐(2,4‐difluorophenyl)‐2‐hydroxy‐3‐pyridinecarboxamide (3) and 2‐hydroxy‐3‐carboxypyridine (4) plus 2,4‐difluoroaniline (5) and 3‐trifluoromethylphenol (6); after 48 hr of heating, diflufenican was completely transformed, yielding 28% (mole% relative to initial diflufenican) of compound 3, and 57% of compound 4. The base catalyzed hydrolysis thus selectively yielded compound 2; the acid catalyzed one yielded compounds 3+4: diflufenican first was transformed into compound 3, which thereafter was transformed into compound 4.
Characterisation by 2D Proton Nuclear Magnetic Resonance Methods of Z/E Isomeric States of the Linear Pentapeptide Pic(3′‐Oh)‐THR‐D‐Abu‐PRO‐Mephe‐Oh Derived From Virginiamycin S1
Authors: Jacob Elly M. F. , Anteunis Marc J. O. , Borremans Frans A. M.
Published: September 2010

The four Z/E isomeric states of the linear pentapeptide Pic(3′‐OH)‐Thr‐D‐Abu‐Pro‐MePhe‐OH are characterized by two‐dimensional proton NMR methods and some of their conformational features are discussed.

The title compound as obtained from Virginiamycin S1 contains less than 5% of its epimer Pic(3′‐OH)‐Thr‐D‐Abu‐Pro‐D‐MePhe‐OH.
Synthesis of Rare Carbohydrates and Biomolecules from Furan
Authors: Vogel Pierre
Published: September 2010

Zinc iodide‐catalyzed cycloaddition of furan to 1‐cyanovinyl (1′S)‐camphanate or 1‐cyanovinyl (1′R)‐camphanate led to optically pure (1R,2S,4R)‐2‐exo‐cyano‐7‐oxabicyclo[2.2.1]‐hept‐5‐en‐2‐yl (1S')‐camphanate and (1S,2R,4S)‐2‐exo‐cyano‐7‐oxabicyclo[2.2.1]hept‐5‐en‐2‐yl (1R')‐camphanate, respectively. Saponification afforded (1R,4R)‐ and (1S,4S)‐7‐oxabicyclo[2.2.1]‐hept‐5‐en‐2‐one, respectively, and allowing recovery of the chiral auxiliaries (1S)‐ and (1R)‐camphanic acid, respectively. The 7‐oxabicyclo[2.2.1]hept‐5‐en‐2‐yl derivatives (”naked sugars“) so‐obtained can be substituted at C(3), C(5) and C(6) by direct techniques with high stereoselectivity. The methods exploit the exo‐facial selectivity of the reactions of these bicyclic systems and the regiochemical control exerted by the remote substituents at C(2) in electrophilic attack at C(5) and C(6). The polysubstituted 7‐oxabicyclo[2.2.1]heptan‐2‐ones so‐obtained are chirons that can be converted into D‐ or L‐hexose derivatives and analogues, into 2,5‐anhydrohexonic acid derivatives (precursors for C‐nucleosides and C‐glycosides), or into polysubstituted cyclohex‐1‐ones. Moreover, conditions have been found under which the bicyclic ethers can transformed into (+) and (−)‐methyl 8‐epinonactate and (+)‐ and (−)‐methyl nonactate (precursors of nonactine), into octoses, into branched carbohydrates such as calditoses and calditols, and into (+)‐castanospermine. Compared with natural carbohydrates, the ”naked sugars“ are chirons with the following advantages: (1) the problem of selective protection and deprotection of polyalcoholic systems does not exist; (2) the functional moieties are grafted onto C(3), C(5), and C(6) of the 7‐oxabicyclo[2.2.1]heptane systems together with the appropriate protective groups; (3) since both enantiomeric forms of the ”naked sugars“ an available, either enantiomers of a targeted compound can be reached with the equal ease.
The Sampling of Ions from an Atmospheric‐Pressure Flame into a Vacuum Chamber
Authors: Axford S. D. T. , Hayhurst A. N.
Published: September 2010

One atmospheric‐pressure flame of H2 + O2 + N2 has been burnt with a final temperature of 2400 K. Small amounts of caesium were added to the burner supplies, which resulted in free electrons and Cs−+ ions being formed in the flame. The burnt gases were continuously sampled through a tiny (diam. 80 ‐ 200 μm) orifice at the tip of a hollow conical nozzle. Subsequently the gases pass inside the nozzle and down a conical expansion duct into a vacuum chamber. A pointed needle is located axially inside the hollow sampling nozzle and collects either the positively or negatively charged species which had passed through the inlet hole to the vacuum chamber. It was found that, for optimal sampling of negative ions, the sampling nozzle should be at a positive potential with respect to the burner. However, the sampling of positive ions from a flame is best achieved when the burner and nozzle are at the same potential. The effect of varying the inlet orifice's diameter is also investigated. All the observations can be explained in terms of there being either an ion or an electron sheath adjacent to the sampling nozzle. Moreover, the thickness of such a sheath varies inversely with the square root of the electron density in the flame. One important conclusion is that when the electron concentration is low, it is usually impossible for electrons to pass through the inlet hole; instead they are collected by the sampling nozzle. However, for large electron densities (∼ 10−10/ml) and a big orifice, electrons can pass through the sampling hole into the vacuum chamber. By contrast the losses of positive or negative ions, whether atomic or molecular, are almost negligible.
Effect of Temperature on the Fragmentation Pattern of Hydrocarbons Under Electronic Impact
Authors: Walravens B. , Vandooren J. , Tiggelen P. J. Van
Published: September 2010

The study shows the change induced by the temperature of sampling on the fragmentation pattern of n‐butane and isobutane when a molecular beam sampling technique is used coupled with a mass spectrometric analysis. A decrease of the parent peak signal of both butane isomers is observed when the sampling temperature increases. Furthermore, sampling temperature effects on the parent peak of some hydrocarbons from C1 up to C4 have also been investigated.
Étude expérimentale de flammes méthane oxygène dopées avec de l'ammoniac ou du monoxyde d'azote comparaison avec les résultats des modèles
Authors: Garo A. , Puechberty D.
Published: September 2010

In order to simulate the formation of NO from fuel Nitrogen and to have a better understanding of the interaction between nitric oxide with hydrocarbon radicals, NH3 and NO have been added to methane oxygen premixed flame established under low pressure.

Formation and destruction of NO have been studied from experimental results obtained using mass spectrometry, U.V. optical absorption spectroscopy and L.I.F. measurements. Modeling of these flames is performed with Miller s kinetic mechanism and with a modified one. Thus it is possible to deduce the relative importance of NO reactions with hydrocarbon radicals in the first millimeters of the flame.
The Solubility of Calcium Hydrogen Phosphate Dihydrate and Magnesium Hydrogen Phosphate Trihydrate and Ion Pair Formation in the System M(OH)2‐H3Po4‐H2O (M = Ca or Mg) at 37°C
Authors: De Bruyne Peter A. M. , Verbeeck Ronald M. H. , Verbeek Frans
Published: September 2010

The solubility of CaHPO4·2H2O and MgHPO4·3H2O is determined in the system M(OH)2‐H3PO4‐H2O at 37°C with M = Ca or Mg and in the range 4.1 < pH < 6.3 and 4.9 < pH < 7.2 respectively. The solubility behaviour of both solids can be described consistently only by taking into account the formation of the ion pairs MH2PO4+ and MHPO4. The thermodynamic solubility product of CaHPO4·2H2O and the thermodynamic association constants for CaH2PO4 + and CaHPO4 with their standard error are determined as (2.06 ± 0.05)×10−7 mol2/L2, 8.4 ± 1.7 L/mol and 542 ± 46 L/mol. The corresponding constants for MgHPO4·3H2O, MgH2PO4 + and MgHPO4 are (1.15 ± 0.07)×106 mol2/L2, 43.0 ± 6.7 L/mol and 1004 ± 89 L/mol.
Mechanism of the Polarographic Reduction of Anti‐5‐Nitro‐2‐Furaldoxime
Authors: López Fonseca J. M. , García Monteagudo J. C. , Crespo M. A. , Lois B.
Published: September 2010

The electroreduction of the radiosensitizer anti‐5‐nitro‐2‐furaldoxime (nifuroxime) was studied by conventional, normal pulse and reversed pulse polarography in aqueous buffers containing 0.75% dimethylformamide. In acid media were obtained four cathodic waves, namely I (related to the reduction with 4 electrons of the nitro group), II and III (both linked to the reduction of the oxime group with 4 electrons) and IV (corresponding to the reduction of the hydroxylamino group formed in the reaction yielding wave I). As the pH increased, IV disappeared, II and III overlapped and I was split into waves I' and I“. Mechanisms accounting for the electrode processes of the waves are proposed. The presence of sodium laurylsulphate decreased the limiting current of I' to 1/4 of that of I; under these conditions, wave I' corresponded to the reversible reduction of the nitro derivative to its radical‐anion.
One Pot N‐Protection of Amino Acids
Authors: Becu Chr. , Reyniers M.‐F. , Anteunis M. J. O. , Callens R.
Published: September 2010

Attention is called on the extreme simple procedure for N‐protection of amino acids mediated through previous silylation. Although the methodology is known, it has rather scarcely been used. Some examples show the versatility of a one‐pot procedure. Selective Boc and Z‐ Nα‐protections of His were also worked out.
Synthesis and Characterization of DMSO and HMPA Adducts of R′OCOCHRCH2SnCl3
Authors: Fu Fangxin , Tian Laijin , Pan Huade , Willem Rudolph , Gielen Marcel
Published: September 2010

The synthesis and characterization of complexes of R'OCOCHRCH2SnCl3 with DMSO and HMPA by means of elemental analysis, IR, Mössbauer, 1H and 13C NMR spectroscopy are described.
Crystal Structure of 2,3‐Diamino‐2,3‐Diphenylbutane
Authors: Bracke B. , Volckaerts E. , Lenstra A. T. H. , Geise H. J.
Published: September 2010

C16H20N2, M = 240.35, monoclinic, P21/n, a = 6.800(1), b = 6.833(2), c = 14.427(2)Å,β = 97.55(1)°, V = 664.5(4)Å)−3, Z = 2, Dx = 1.202 g cm−3, μ = 1.33 cm−1, λ(Mo‐Kα) = 0.71073Å, F(000) = 520, room temperature, R = 0.079, wR = 0.080 for 113 variables and 499 observed [I ≥ 3σ(I)] reflections of 1575 measurements.

The structure of this new compound is proved and its configuration established as meso. The large sterical hindrance in the central part of the molecule is reflected in an unusually long central C‐C bond (1.635(7)Å). It explains why in the mass spectrum under electron impact the molecular ion peak [M+] is missing and the peak at half the molecular weight [1/2M+] has a high abundance.
Synthesis of Soluble Poly(Divinylbenzene) with an End‐Functional Group
Authors: Nagasaki Yukio , Kato Masao , Kato Norikiyo , Mitsuhata Yoshio , Nishizuka Hiroaki , Tsuruta Teiji
Published: September 2010

Synthetic methods of end‐functional soluble poly(divinylbenzene) [poly(DVB)] and A‐B‐A type block copolymers having soluble poly(divinylbenzene) segments were investigated. Lithium N,N′‐bis(trimethylsilyl) ethylenediamine was found to initiate an anionic polymerization of 1,4‐divinylbenzene (DVB) to form soluble polymer having one N,N′‐bis (trimethylsilyl) ethylenediamine moiety at the end of polymer chain almost quantitatively. The polymer was easily converted to primary‐amino‐ended soluble poly(DVB) by treating with tetrabutylammonium fluoride. Lithiated trimethylallylsilane also had an initiation ability for DVB polymerization. When the polymerization was carried out by lithiated trimethylallylsilane, in the presence of diisopropylamine, a soluble polymer was formed. The polymer obtained had one terminal organosilyl group and reactive pendent vinyl group in each monomeric unit. A‐B‐A Type tri‐block copolymer was synthesized through reactions between primary‐amino‐ended soluble poly (DVB) and α,ω‐bis‐primary‐amino‐ended silicone using 4,4′‐diphenylmethanediisocyanate as coupling agent. The resulting polymer was a multi‐functional polymer having poly (DVB) segments and silicone segments.
Hydrophobic ‐ Hydrophilic Copolymers from Functional Organosiloxane Oligomers
Authors: Simionescu C. I. , Harabagiu V. , Giurgiu D. , Hamciuc V. , Simionescu B. C.
Published: September 2010

Hydrophobic ‐ hydrophilic siloxane containing copolymers were synthesized by two different methods, namely a) radical polymerization of methacrylic acid or N‐vinylpyrrolidone initiated by azo containing polydimethylsiloxanes, and b) radical polymerization of methacrylic acid in the presence of glycidoxypropyl functional polydimethylsiloxanes with simultaneous ring opening reaction by the carboxylic groups.
Contribution of Block Copolymers to the Control of Polymeric Surfaces
Authors: Petitjean S. , Ghitti G. , Fayt R. , Teyssie Ph. , Jerome R.
Published: September 2010

Diblock copolymers of polystyrene and polydimethylsiloxane, and polystyrene end‐capped with a fluorinated group have been prepared by anionic polymerization. Polymethylmethacrylate end‐capped with the same fluorinated group has been synthesized by a telomerization technique. Surface activity of all these compounds has been studied in solution by tensiometry and in a polymeric matrix by various methods: XPS and measurements of wettability and contact angle. The relative interactions of the dispersion medium with each component of the additive are of a prime importance in the control of the surface energy.
Thermal Analysis and Small‐Angle X‐Ray Scattering of Homogeneous Copolymers of Ethene and 1‐Octene
Authors: Peeters Marleen , Reynaers Harry
Published: September 2010

Homogeneous copolymers of ethene and 1‐octene with a random distribution of comonomer units and the same comonomer/ethene ratio exhibit a double melting behaviour which is ascribed to a slight sample heterogeneity. On crystallization part of the material is segregated and crystallizes on aging of the samples. The results of small‐angle X‐ray experiments allow to correlate the morphological changes and the melting behaviour with the chain microstructure of the copolymer.
Synthetic Approaches for Thymopentin (TP‐5) Using the “in Situ” Silylation Strategy with Trimethylsilyl Cyanide
Authors: Becu Fr. , Becu Chr. , Anteunis M. J. O.
Published: September 2010

The synthesis of the pentapeptide TP‐5 has been considered as a test case for the “in situ” silylating strategy, using trimethylsilyl cyanide, because of the nature of the involved residues. Thus orthogonal lateral protections for Arg, Lys & Asp are needed even using our earlier developed “PERSIL” strategy (5). The best approach was found in a Head‐to‐Tail assemblage of Boc‐Asp(Bzl)‐Val‐Tyr and after Nα deprotection followed by segment condensation with Boc‐Arg(NOG2)‐Lys(Z)‐OPiv and a final two‐step deprotection (SCHEME I). The total yield (38 %) is modest but the relative simplicity for isolation and high quality of the end product (with no detectable epimerization) is noteworthy.
Action Des Composes β‐Dicarbonyles Sur Le Diamino‐5,6 Indazole
Authors: Benchidmi M. , Essassi E. M.
Published: September 2010

The condensation of β‐dicarbonyl compounds with 5,6‐diaminoindazole in hot butanol leads to pyrazolo[4,5‐f]benzimidazole, 5(1‐phenylvinyl)pyrazolo[4,5‐f]benzimidazolone‐6 and 4‐phenyl pyrazolo[3,4‐h][1,5]benzodiazepin‐2‐one.
Collective Cohesion Forces in Polymers
Authors: Huyskens P. , Vandevyvere P. , Colemonts‐Vandevyvere Ch.
Published: September 2010

Collective cohesion forces are a set of normal cohesion forces the origins of which exhibit a regularity in their spatial distribution. Atoms, molecules or segments that undergo their action display collective coupled motions where the neighbours do not change or identity. Such particular kind of motion can be called “rigidity”. The repetitive character of the polymeric chain renders the segments particularly susceptible to generate collective cohesion forces but this tendency is not the same for each of them. Rigid segments have a lower chemical potential than fluid segments. This is the case for the crystalline parts of the semi‐crystalline polymers. The tendency of some sequences to generate collective cohesion forces is so great that in most cases rigid domains are spontaneously formed where the spatial regularity does not extend to the three dimensions, what makes them less detectable by diffraction methods. But these rigid domains being connected with other zones deprive the last ones from macroscopic mobility and no crystallization can take place. Moreover, as evidenced by dipolar measurements, even in true solutions given sequences of segments are regularly involved in ephemeric rigid domains, and have therefore a lower chemical potential. Phase separation occurs when, as a consequence of the change of solvent or temperature, some rigid domains become permanent. As a consequence of this inherent inequality between the segments, the criterion of phase separation in polymer solutions is the existence of two states α and β in which the lowest chemical potential or the segments is the same. This fundamentally differs from the liquid‐liquid treatment of Flory.
Synthèse De Peroxydes Allyliques Dissymétriques
Authors: Chiron‐Charrier Muriel , Campagnole Monique , Bourgeois Marie‐Josèphe , Montaudon Evelyne
Published: September 2010

Une synthèse de peroxydes allyliques dissymétriques est décrite à partier des mésylates convenables. La nature du solvant est un facteur déterminant de la régiosélectivité de la réaction.
Photolyse De HI Dans Une Matrice Hydrocarbonée Vitreuse à 77 K
Authors: De Laet M. , Tilquin B.
Published: September 2010

Stable products from the photolysis of HI in methyl‐3 pentane (3 MP) or dimethyl‐2,3 butane (23 DMB) quenched solid at 77 K are analyzed by capillary gas chromatography. Selective formation of a tertiary radical is proposed for the 23 DMB/HI system; in 3 MP/HI, C‐H bond rupture is also localized at the weakest tertiary bond, however the scission is not selective.
Détermination Bioélectrocatalytique Du Glucose Dans Le Sérum Sanguin
Authors: Nankov Nanko , Stoytcheva Margarita , Mladenova Emilia , Zlatev Rumen
Published: September 2010

A bioelectrocatalytical method with a chronoamperometric registration for glucose determination in blood serum was proposed. It satisfies the criterions for evaluation of the results' quality of the quantitative analyses. It presents certain advantages in comparison with the actually adopted clinical methods and in comparison with some other bioelectrocatalytical methods.
Polyoxadiazoles and Polytriazoles as New Heat and Solvent Resistant Membrane Materials
Authors: Hensema E. R. , Gebben B. , Mulder M. H. V. , Smolders C. A.
Published: September 2010

Polyoxadiazoles and polytriazoles belong to the class of thermally stable and chemically resistant polymers. Both polymers are prepared out of a processable polyhydrazide. The kinetics of the cyclo dehydration reaction which converts a polyhydrazide into a polyoxadiazole was studied and the gas separation properties of a polytriazole and its thermal behaviour were investigated.
Synthèse Et Étude De La Dégradation Photochimique De Tensio‐Actifs Cationiques Photoclivables
Authors: Strub‐Leconte M. P. , Riess G.
Published: September 2010

A homologous series of photocleavable cationic surfactants was prepared. These aryl‐alkyl‐ketone type surfactants have the following structure chemical structure image

Their critical micelle concentration in water was determined. The photodegradation study has shown that the cleavage occurs with a high quantum yield by a Norrish II mechanism with formation of alkene, substituted acetophenone and cyclobutanols. The photochemical yield of cleavage reaches 75% with formation of a hydrophilic (substituted acetophenone) and a hydrophobic derivative (alkene).
Linear Dispiro Decanes and Tetrazolines from Organic Azides and Heavy Diamino Carbene Analogues R2M, M = Ge, Sn
Authors: Neumann Wilhelm P. , Obloh Ronald C.
Published: September 2010

Azides R‐N3 (R = aryl, acyl, cyclohexyl), react at ‐30°C spontaneously with the diaminostannylene 1 to give the distannadispiro[3.1.3.1]decanes 2 and 3, or with the diaminogermylene 4 to give the digerma analogues 5. The dispiro[3.1.3.1]decane systems, with an unusual linear combination of three four‐membered rings, were fully characterized by X‐ray and other spectroscopic methods. 4 gives, with 2 mol phenyl azide, the germatetrazoline 6, whose structure is also evidenced by X‐ray spectroscopy.
Synthese Chiraler Phosphinoxide Und Phosphine Durch Michaelis‐Arbuzov‐Umlagerung
Authors: Brunner H. , Zettlmeier W.
Published: September 2010

Several phosphinites and phosphites, derived from chiral alcohols, were synthesized. The phosphinites were subjected to a I2‐catalyzed Michaelis‐Arbuzov rearrangement. Phosphinites derived from primary alcohols give satisfactory yields of the corresponding phosphineoxides. Phosphinites synthesized from secondary alcohols also undergo the rearrangement but numerous byproducts appear in the reaction mixtures. Optical resolutions of chiral phosphineoxides by crystallization with optically active acids were not successful. The corresponding phosphines can easily be prepared by reduction of the oxides with trichlorosilane.
Enantioselektive Katalyse, 63 [1] Optisch Aktive Phosphine Aus Dicarbonsäuren Und Ihr Einsatz in Der Enantioselektiven Hydrierung
Authors: Brunner H. , Zettlmeier W.
Published: September 2010

Two optically active bident phosphine ligands were synthesized from derivatives of succinic acid as starting materials. The optical resolution of the acids was carried out with cinchonidine and (S)‐α‐phenylethylamine. In the Rh‐catalyzed enantioselective hydrogenation of α‐acetamidocinnamic acid, the bisphosphine with a phenyl substituent in the 2‐position of the four‐carbon chain gave an enantiomeric excess of 17%. The enantiomeric excess was twice as high with the corresponding thienyl substituted bisphosphine.
Structures of Two Planar Flavones: 4′‐Methoxyflavone and 3′,4′‐Dimethoxyflavone
Authors: Wallet J. C. , Gaydou E. M. , Tinant B. , Declercq J. P. , Baldy A.
Published: September 2010

(I): C16H12O3, Mr=252.27, monoclinic, P21/n, a=16.446(3), b=3.887(1), c=19.565(4)Å, ß=106.59(l)°, V=1198.5(4)Å3, Z=4, Dx=1.40g·cm−3, MoKα, λ=0.71069Å, μ=1.04cm−1, F(000)=528, T=291K, R=0.046 for 1904 observed reflections. (II): C17H14O4, Mr=282.30, monoclinic, C2/c, a=30.844(7), b=4.073(2), c=26.119(4)Å, ß=124.25(1)°, V=2713(1)Å3, Z=8, Dx=1.38g·cm−3, MoKα, λ=0.71069Å, μ=1.06 cm−1, F(000)=1184, T=291K, R=0.043 for 1515 observed reflections. Both molecules are essentially planar with dihedral angles between the benzopyran and the aromatic ring least squares mean planes of 2.1(5)° for (I) and 6.2(5)° for (II).
Synthesis, Spectroscopic Characterization and Antitumour Activity of Diorganotin(IV) Derivatives of N‐Substituted Ortho‐Aminobenzoic Acid
Authors: Meriem Abdelkader , Biesemans Monique , Willem Rudolph , Mahieu Bernard , de Vos Dick , Lelieveld Peter , Gielen Marcel
Published: September 2010

Four compounds of the type [(o‐RNH‐C6H4COO)(CH3CH2CH2CH2)2Sn]2O and [(o‐CH3NH‐C6H4COO)(CH3)2Sn]2O have been prepared, characterized by 1H, 13C, 119Sn NMR, and by Mössbauer and mass spectrometry. They have been tested in vitro against two human tumour cell lines, nl. MCF‐7 (mammary tumour) and WiDr (colon carcinoma), and found to score slightly better than cis‐platin but markedly less than other cytostatic agents.
Reduction of Acetals with CpTiCl3‐LiAIH4
Authors: Shaozu Wu , Yin Chen , Yulan Zhang
Published: September 2010

The reduction of cyclic acetals and ketals derived from aromatic or aliphatic aldehydes and ketones with CpTiCl3‐LiAlH4 system in diethyl ether at 30°C affords the corresponding hydroxyethyl ethers and the corresponding alkyl benzene or aliphatic hydrocarbons.
Étude Théorique de Réactions de Couplage de Radicaux Libres
Authors: Leroy G. , Sana M. , Espinosa‐Garcia J.
Published: September 2010

Ab initio quantum mechanical methods are used to calculate the thermodynamic and kinetic parameters for the reactions of NH2O with NH2 and NHOH. It is found that these dissymetrical coupling involving a highly stabilized radical are both characterized by a non‐negligible activation energy.
Reactivity of YBa2Cu3O7‐x Towards Water and Humid Air
Authors: Vlaeminck H. , Hoste S.
Published: September 2010

Detailed XPS studies with emphasis on special characteristics of the Ols and Cu2p3/2 core‐levels, thermogravimetry, X‐ray diffraction, infrared spectroscopy and scanning electron microscopy have been used to study the degradation of the superconducting phase YBa2Cu3O7‐x in contact with water under various conditions.

It is shown that the superconducting YBa2Cu3O7‐x phase in contact with water or humid air decomposes into CuO, Ba(OH)2, Y2BaCuO5 and oxygen and also yields BaCO3 by reaction with atmospheric CO2. A Br2‐EtOH etching solution removes surfacial BaCO3. Furthermore, this treatment may yield a passivation layer inhibiting further decomposition.
Hydrogénation du Monoxyde de Carbone II ‐ Influence du support et du cesium sur les propriétés du Nickel‐Molybdène
Authors: Ghazi M. , Barrault J.
Published: September 2010

The selectivity for alcohols formation in the carbon monoxide hydrogenation reaction on nickel molybdenum catalysts increased when zinc oxide was used as a support, where it reached 50%. The same trend was observed when an alkaline metal such as cesium was added to the catalyst. Moreover when the surface area of the zinc support was increased from 10 to 80 m2·g−1 the selectivity was multiplied by 20 with a selectivity for alcohol formation still greater than 70% after 20 hours time on stream.
A Reexamination of the Retro‐fries Rearrangement of Some o‐Hydroxyketones
Authors: Martin Robert , Lafrance Jean Ronald , Demerseman Pierre
Published: September 2010

The retro‐Fries rearrangement, catalyzed by protic and Lewis acids, was studied for some o‐hydroxyketones. The results are consistent with the mechanism of an heterolytic cleavage and rearrangement. It appears that, in general, Lewis acids do not induce the retro‐Fries rearrangement of o‐hydroxyketones. However, in certain cases, it may be brought about by the presence of a protic acid generated in situ, from a solvent‐catalyst interaction.
Destruction du Paraoxon par une Nouvelle Série de Sels de N‐Alkyl Hydroximinomethylpyridinium
Authors: Lion Claude , Despagne Bruno , Delmas Gérard , Fosset Laurent
Published: September 2010

The facile hydrolysis of toxic organophosphorus compounds is of interest since these compounds have been used as insecticides or potent chemical warfare agents. The high reactivity of oximate ions associated with micelle forming molecules against Paraoxon (O,O‐diethyl O‐paranitrophenylphosphate) is tested with new N‐alkyl hydroximinomethylpyridinium salts. The position of the hydroximinomethyl function (ortho, meta or para), the length of the alkyl chain and the nature of the anion are discussed.