bluuebunny/crossref_metadata_2025_split huggingface dataset:
Facile synthesis of furobenzothiazepines
Authors: Ogawa Masayuki , Koyanagi Jyunichi , Sakuma Katsuya , Tanaka Akira , Yamamoto Katsumi 
Published: March 2009

AbstractThe reaction of methyl 5‐(2‐isocyanatophenylthio)‐2‐furancarboxylate 2 with N‐methylpiperazine gave 5‐(2‐N‐piperazinocarbamoylphenylthio)‐2‐furancarboxylate 3a. Furthermore, 4‐N‐methylpiperazinyl‐2‐methoxycarbonylfuro[2,3‐b][1,5]benzothiazepine 4a was obtained by the Bischler‐Napieralski reaction of 3a with phosphorus oxychloride in the present of phosphorus pentoxide. Three furobenzothiazepines could be obtained using the same method. Based on the pharmacological studies of these compounds, it was found that 4‐morpholinyl‐2‐methoxycarbonylfuro[2,3‐b][1,5]benzothiazepine 4b had anti‐inflammatory activity similar to flufenamic acid.
Synthesis and X‐ray structure of a novel 1,2,4‐trithiolane
Authors: Bryce Martin R. , Lay Alexander K. , Batsanov Andrei S. , Howard Judith A. K. 
Published: March 2009

AbstractPhotolysis of 1,2‐dithiole‐3‐thione derivative 1 results in the formation of the 1,2,4‐trithiolane derivative 2, the structure of which was established by single crystal X‐ray analysis. Interesting bond delocalisation is observed in the molecular structure. A mechanism involving dimerisation of 1 followed by loss of sulfur is proposed.
Synthesis of 5‐chloro‐2‐methyl‐3‐(5‐methylthiazol‐2‐yl)‐4(3H)‐quinazolinone and related compounds with potential biological activity
Authors: Párkányi Cyril , Schmidt Duran S. 
Published: March 2009

AbstractEight new 2‐methyl‐4(3H)‐quinazolinones (8a‐8d, 9c, 9d, 10c, 10d) with one or two chlorine atoms in the benzene ring and a 5‐methyl‐1,3‐thiazol‐2‐yl, 4‐methyl‐1,3‐thiazol‐2‐yl, and 5‐ethyl‐1,3,4‐thiadiazol‐2‐yl substituent in position 3 of the heterocyclic ring were synthesized and characterized. The two step procedure (Scheme 1) utilizes chlorosubstituted anthranilic acids (3a‐3d) and acetic anhydride as the starting materials, with the respective chlorosubstituted 2‐methyl‐4H‐3,1‐benzoxazin‐4‐ones (4a‐4d) as the intermediates. The quinazoline derivatives were characterized by their melting points, elemental analyses and the mass, ultraviolet, infrared, and 1H and 13C nmr spectra. The new compounds are expected to be biologically active.
Ring enlargement reactions of tetramic acid derivatives
Authors: Poschenrieder Hermann , Eckl Eduard , Stachel Hans‐Dietrich , Windt Andreas , Polborn Kurt 
Published: March 2009

AbstractThe 4‐hydroxypyridones7and 3‐hydroxypyridones8/9(azagrevellins) were prepared by reaction of the pyrrolidinetrione4and diazoalkanes. The ring enlargement proceeded by anionotropic [1,2]‐rearrangement introducing carbon between C‐3 and C‐4 or, to a lesser extent, between C‐2 and C‐3 due to the different migration aptitudes of the two acyl groups involved. In a cognate manner ring expansion between C‐2 and C‐3 occured by the interaction of diazomethane and the pyrrolidinetrione hydrazone15, to give the spiroe‐poxide16as the final product. From the reaction of trione4and diazomethane, however, the diepoxide14was obtained. In this case ring homologation must have taken place by insertion of carbon between C‐4 and C‐5. In a two step ring expansion the pyridones21and22were obtained from the maleineimides17.
Conformational properties of thiophene oligomers
Authors: Millefiori Salvatore , Alparone Andrea , Millefiori Arcangelo 
Published: March 2009

AbstractThe molecular geometries and the torsional potentials about the inter‐ring C‐C bond in α‐oligothiophenes (α‐nTh, n=2–4) have been calculated by means of conventional ab initio and density functional theory (DFT) calculations employing the hybrid B3LYP and BH&HLYP functionals. The position and the energetics of the critical points in the potential energy curve generated by rotation about the inter‐ring CC bond are shown to be dependent on the computational method. DFT calculations, in comparison with MP2 calculations, favour conjugative interactions, while steric and coulombic interactions are equally treated by both methods. On oligomerization the electron delocalisation increases slightly, the p‐charge being preferentially confined within the rings, although it is sufficient to move the molecular structure towards co‐planarization and to increase the barrier through the perpendicular conformation. The IR and Raman spectra on the relevant rotamers of α‐2Th have been computed at HF/6–31G* and B3LYP/6–31G* levels. The comparison with the experiment is excellent. It has been found that small twisting from the planar conformation has no apparent effects, while 90° twisting and isomerization to the syn‐gauche form produce significant frequency and intensity variations which could be useful probes in conformational studies. The simulated IR and Raman spectra of the α‐2Th rotamers are consistent with a smallπ‐electron delocalisation between the rings.
Ab initio study of azolides: Energetic and spectroscopic properties
Authors: Claramunt Rosa MarÍA , Sanz Dionisia , Alkorta Ibon , Elguero JosÉ , Foces‐Foces ConceptiÓN , Llamas‐Saiz Antonio L. 
Published: March 2009

AbstractWe report the ab initio study of twenty‐four azolides derived from pyrrole, imidazole, pyrazole, both triazoles, tetrazole, pentazole, indole and carbazole bearing at the nitrogen atom the groups COMe, CHO, COCF3 and CO2Me. Theoretical values (isomerism, barriers, dipole moments, C=O stretching) are compared with experimental ones, when available, and also internally compared. A special effort has been devoted to the calculation of the absolute shieldings for the different nuclei present in azolides. At the level of calculation used (RHF/6‐311G**) the results are satisfactory. To complete the nmr data from the literature, some 1H, 13C, 15N, 17O and 19F chemical shifts have been determined.
The synthesis and nucleophilic substitution of haloxanthones
Authors: Sharghi Hashem , Tamaddon Fatemeh 
Published: March 2009

AbstractAcylation reaction of m‐cresol with 2,6‐dihalobenzoic acid in the presence of methansulfonic acid and subsequently, cyclization of the obtained o‐hydroxybenzophenones with K2CO3/dimethyl formamide, afforded haloxanthones 4 and 5 in high yields. Aromatic nucleophilic substitution of the resulted haloxanthones with O‐, N‐ and S‐nucleophiles are studied in a comparative manner, and various new O‐, N‐ and S‐substituted xanthones have obtained.
Studies with enaminones: synthesis of new coumarin‐3‐yl azoles, coumarin‐3‐yl azines, coumarin‐3‐yl azoloazines, coumarin‐3‐yl pyrone and coumarin‐2‐yl benzo[b]Furans
Authors: El‐Taweel Fathy Mohamed Abel Aziz , Elnagdi Mohamed Hilmy 
Published: March 2009

Abstract3‐Acetylcoumarine was condensed with dimethylformamide dimethylacetal (DMFDMA) to yield the enaminone, which reacts readily with hydroxylamine and with hydrazines to yield coumarin‐3‐ylisoxazoles and coumarin‐3‐ylpyrazoles respectively. Reaction of the enaminone with benzamidine hydrochloride and 3‐amino‐1,2,4‐1H‐triazole affords the pyrimidine and triazolo[3,4‐b]pyrimidine. The enaminone reacts with hippuric acid and with the dithiocarboxylic acid to yield pyranones. The reaction of the enaminone with 3‐amino‐1H‐1,2,4‐triazole gives the triazolo[3,4‐b]pyrimidine. The enaminone underwent self dimerization on reflux in acetic acid ammonium acetate to yield the coumarinyl pyridines and reacted with ketone under the same conditions to yield the pyridine. The reaction of the enaminone with 1,4‐benzoquinone and 1,4‐naphthoquinone gives benzofuryl coumarine derivatives.
Synthesis of polycyclic nitrogen‐containing heterocyclic: One pot formation of 1,6‐naphthyridine ring system by reaction of amino‐cyano‐methylthio‐heterocycles with dialkyl acetyeledicarboxylates
Authors: Tominaga Yoshinori , Nomoto Kenichi , Yoshioka Noriko 
Published: March 2009

AbstractReaction of 3‐amino‐3‐methylthio‐2‐cyanoacrylonitrile (1) with excess dimethyl acetylenedi‐carboxylate(DMAD) in the presence of potassium carbonate in dimethyl sulfoxide gave a novel tricyclic heterocycle, hexamethyl lH‐1,4,7‐triazaphenalene‐2,3,5,6,8,9‐hexacarboxylate (5a). When one equivalent of DMAD was used in this reaction, dimethyl 4‐amino‐3‐cyano‐2‐methylthiopyridine‐5,6‐dicarboxylate (3a), a key intermediate of5a, was obtained.
A short synthesis of 5,7‐bis(dialkylamino)‐2‐methyl‐ 8 ‐hydroxyquinolines
Authors: Okide George B. 
Published: March 2009

AbstractThe bromine atoms of the title compound were replaced by the requisite amino compound to afford the desired derivatives in high yields. Thus, six target compounds viz‐ bis(diethylamino)‐, bis(dibutylamino)‐, bis(dicyclohexylamino)‐, dipyrrolidino‐, dipiperidino‐, and dipiperazino‐derivatives were obtained and characterized by spectral and elemental analyses.
Synthesis and application of 2‐styryl‐6,7‐dichlorothiazolo[4,5‐b]‐quinoxaline based fluorescent dyes: Part 3
Authors: Sonawane N. D. , Rangnekar D. W. 
Published: March 2009

AbstractA new efficient synthesis of 2‐styryl‐6,7‐dichlorothiazolo[4,5‐b]quinoxaline based fluorescent dyes was achieved by the condensation of 2‐methyl‐6,7‐dichlorothiazolo[4,5‐b]quinoxaline with selected 4‐N,N‐dialkylaminoarylaldehydes and heteroarylaldehydes in the presence of piperidine. The coloristic, fluo‐rophoric, and dyeing properties of these dyes were studied.
Synthesis of imidazoles as novel emivirine and S‐DABO analogues
Authors: Loksha Yasser M. , Jørgensen Per T. , Pedersen Erik B. , El‐Badawi Mahmoud A. , El‐Barbary Ahmed A. , Nielsen Claus 
Published: March 2009

Abstract5‐Alkyl‐4‐benzyl‐1,3‐dihydroimidazol‐2‐ones (3a‐d) and 5‐alkyl‐4‐benzyl‐1,3‐dihydroimidazole‐2‐thiones (7a‐d) were prepared via Dakin West reaction on DL‐phenylalanine with the appropriate aliphatic acid anhydrides followed by hydrolysis and reaction with potassium cyanate or potassium thiocyanate. Compounds 3a‐d were alkylated with ethoxymethyl chloride to give the alkylated imidazoles 5a‐d which were considered analogues of Emivirine with deletion of carbonyl group at the 4‐position. Alkylation of 7a‐d afforded the corresponding S‐alkylated derivatives 8a‐p which in a similar way were considered analogues of S‐DABO. However all the imidazole derivatives were devoid of activity against HIV.
Research on heterocyclic compounds. XLIII. Synthetic studies on 1,4‐dihydropyridine derivatives
Authors: Rimoli Maria Grazia , Avallone Lucia , Zanarone Serena , Abignente Enrico , Mangoni Alfonso 
Published: March 2009

AbstractIn order to obtain N‐benzyl‐3,5‐dicarbethoxy‐2,6‐dimethyl‐4‐phenyl‐1,4‐dihydropyridine 1 as a lead compound of pharmacological interest, the classical Hantzsch synthetic method and the modified Collie procedure were used. However, only a very low yield of 1 was obtained in a mixture with larger amounts of some by‐products (2, 3, 4). Compound 1 was then synthesized in satisfactory yield via a different method, together with another by‐product (9). The structures of all by‐products were elucidated and possible mechanisms leading to the formation of such compounds are described.
A convenient synthesis of 2‐Arylidene‐5H‐thiazolo[2,3‐b]quinazo‐line‐3,5[2H]‐diones and their benzoquinazoline derivatives
Authors: Khodair Ahmed I. 
Published: March 2009

AbstractVarious 5H‐thiazolo[2,3‐b]quinazoline‐3,5[2H]‐diones (7a,b), 2‐arylidene‐5H‐thiazolo[2,3–b]quin‐azoline‐3,5[2H]‐diones (9a‐o) and 2‐arylidene‐5H‐thiazolo[2,3‐b]benzoquinazoline‐3,5[2H]‐diones (12a,b) have been synthesized via simple and efficient methods.
Synthesis and reactions of 11H‐benzo[b]pyrano[3,2‐f]indolizines an pyrrolo[3,2,1‐ij]pyrano[3,2‐c]quinolines
Authors: Kappe Thomas , Roschger Peter , Schuiki Birgit , Stadlbauer Wolfgang 
Published: March 2009

Abstract2‐Methyl‐3H‐indoles 1 cyclize with two equivalents of ethyl malonate 2 to form 4‐hydroxy‐11H‐benzo[b]pyrano[3,2‐f]indolizin‐2,5‐diones 3, whereas 2‐mefhyl‐2,3‐dihydro‐1H‐indoles 9 give under similar conditions regioisomer 8‐hydroxy‐5‐methyl‐4,5‐dihydro‐pyrrolo[3,2,1‐ij]pyrano[3,2‐c]quinolin‐7,10‐diones 10. The pyrone rings of 3 and 9 can be cleaved either by alkaline hydrolysis to give 7‐acetyl‐8‐hydroxy‐10H‐pyrido[1,2‐a]indol‐6‐ones 4 or 5‐acetyl‐6‐hydroxy‐2‐methyl‐1,2‐dihydro‐4H‐pyrrolo‐[3,2,1‐ij]quinolin‐4‐ones 11, respectively. Chlorination of 3 and 9 with sulfurylchloride gives under subsequent ring opening 7‐dichloroacetyl‐8‐hydroxy‐10H‐pyrido[1,2‐a]indol‐6‐ones 5 or 5‐dichloracetyl‐6‐hydroxy‐2‐methyl‐1,2‐dihydro‐4H‐pyrrolo[3,2,1‐ij]quinolin‐4‐ones 12. The dichloroacetyl group of 5 can be reduced with zinc to 7‐acetyl‐8‐hydroxy‐10H‐pyrido[1,2‐a]indol‐6‐ones 7. Treatment of the acetyl compounds 4, 7 and 11 with 90% sulfuric acid cleaves the acetyl group and yields 8‐hydroxy‐10H‐pyrido[1,2‐a]‐indol‐6‐ones 6 and 8, and 6‐hydroxy‐2‐methyl‐1,2‐dihydro‐4H‐pyrrolo[3,2,1‐ij]quinolin‐4‐ones 13. Reaction of dichloroacetyl compounds 12 with sodium azide yields 6‐hydroxy‐2‐methyl‐5‐(1H‐tetrazol‐5‐ylcarbonyl)‐1,2‐dihydro‐4H‐pyrrolo[3,2,1‐ij]quinolin‐4‐ones 14 via intermediate geminal diazides.
An efficient synthesis of 3,5‐dimethoxyhomophthalic acid, a key intermediate for synthesis of natural isocoumarins
Authors: Saeed Aamer , Rama Nasim H. , Arfan M. 
Published: March 2009

Abstract3,5‐Dimethoxyhomophthalic acid was prepared efficiently in three steps, from 3,5‐dimethoxybenzyl bromideviarhodium‐catalyzed direct carbonylation to 3,5‐dimethoxyphenylacetic acid followed by successiveo‐formylation and oxidation. Isocoumarins related to agrimonolide and achlisocoumarin 1 were prepared in single step by condensation of the homophthalic acid with appropriate acid chlorides.
Synthesis of acrimarins from 1,3,5‐trioxygenated‐9‐acridone derivatives
Authors: Herath H. M. T. B. , Müller K. , Diyabalanage H. V. K. 
Published: March 2009

Abstract1,3,5‐Trihydroxy‐9(10H)‐acridinone (1) was prepared from 3‐hydroxyanthranillic acid with phloroglucinol. 1,3‐Dihydroxy‐5‐methoxy‐9(10H)‐acridinone (2) was prepared from 3‐methoxyanthranillic acid and phloroglucinol. Methylation of 1 under different conditions gave 1‐hydroxy‐3,5‐dimethoxy (3), 1‐hydroxy‐3,5‐dimethoxy‐10‐methyl (4), 1‐hydroxy‐3,5‐dimethoxy‐4‐methyl (5), 1,3,5‐trimethoxy‐10‐methyl (6) and 1,3,5‐trimethoxy‐4,10‐dimethyl (7) analogues. Demethylation of 4 afforded the 1,3,5‐trihydroxy‐10‐methyl analogue 8. Condensation of acridones 1, 2, 3 and 4 individually with E‐suberenol (9) gave four novel acrimarins (acridone‐coumarin dimers) 10, 11, 12 and 13 respectively, while the acridone 8 gave previously reported acrimarin‐G (14).
Synthesis of original benzo[g]quinoxaline‐5,10‐diones by bis‐SRN1 methodology
Authors: Remusat Vincent , Terme Thierry , Gellis Armand , Rathelot Pascal , Vanelle Patrice 
Published: March 2009

AbstractA new heterocyclic bioreductive bis‐alkylating agent, 2,3‐bis(chloromethyl)benzo[g]quinoxaline‐5,10‐dione, was prepared in a four‐steps synthesis. It was shown to react under electron transfer conditions with 2‐nitropropane anion by an bis‐SRN1 mechanism to give three C‐alkylation products in excellent yields. Extension of this bis‐SRN1 reaction to various nitronate or malonate anions and S‐centered anions led to a new class of potentially active benzo[g]quinoxaline‐5,10‐dione derivatives.
Water‐soluble pH‐sensitive 2,6‐bis(substituted ethylidene)‐cyclohexanone/hydroxy cyanine dyes that absorb in the visible/near‐infrared regions
Authors: Strekowski Lucjan , Mason J. Christian , Lee Hyeran , Say Martial , Patonay Gabor 
Published: March 2009

AbstractThree methods were used to synthesize a series of the title compounds. The ketones absorb in the visible region, and upon protonation (pH<6) they are converted to hydroxy‐substituted heptamethine cyanines that show an intense absorption in the near‐infrared region (>700 nm). The conversion is reversible and depends solely on pH conditions.
Synthesis and fluorescent properties of 2‐(1H‐benzimidazol‐2‐yl)‐phenol derivatives
Authors: Ouyang Jie , Ouyang Chenguang , Fujii Yuki , Nakano Yoshiharu , Shoda Takuji , Nagano Tetsuo 
Published: March 2009

AbstractA high yield one pot synthesis of 2‐(2‐hydroxyaryl)‐1H‐benzirrndazole derivatives by 2‐hydroxy aromatic aldehydes with aromatic 1,2‐diamines in the presence of manganese(III) acetate at room temperature was developed. Nine fluorescencers 2‐(2‐hydroxyaryl)‐1H‐benzirrndazoles with substituent(s) X (X = H, CH3, CH3O, Cl) and two fluorescencers 2‐(2‐hydroxyaryl)‐1H‐naphth[2,3‐d]imidazoles with substituent of H or Cl were prepared in 38–87% yield and the ultraviolet absorption and fluorescent spectra of the eleven compounds synthesized were measured in methanol. The fluorescent characteristics of the 2‐(2‐hydroxyaryl)benzimidazole derivatives prepared were investigated on the basis of excited‐state intramolecular proton transfer mechanism, Stokes' shift, quantum yield, and the relationship between fluorescent intensity and the substituents were derived.
Recent development in preparation reactivity and biological activity of enaminoketones and enaminothiones and their utilization to prepare heterocyclic compounds
Authors: Negri Giuseppina , Kascheres Concetta , Kascheres Albert J. 
Published: March 2009

AbstractEnaminoketones and esters are gaining increased interest, particularly cyclic‐β‐enaminoesters, which are known as important intermediates for the synthesis of heterocycles and natural products, because the enantioselective preparation of highly functionalized compounds is of central importance in synthetic chemistry. Enaminones are versatile synthetic intermediates that combine the ambident nucleophilicity of enamines with the ambident eletrophilicity of enones. Enaminoketones and enaminonitriles have proven to be versatile building blocks for the synthesis of various heterocycles such as pyridine, pyrimidine and pyrrole deriva tives. Enaminones systems have “enone” character, and may act as acceptors in both 1,2 and 1,4‐additions. In this way the enaminone serves as a scaffold for annulation, and can gain access to systems such as pyrroles indolizidines, quinolizidines and perhydroindoles, all of which are common motifs in alkaloid structures. Enaminones are frequently employed as building blocks for the preparation of a variety of bicyclic compounds of biological interest and have been recently recognized as potential anticonvulsant compounds. Since a large number of developments in the use of enaminones in heterocyclic synthesis have occurred, a review of the recent developments in the synthetic approaches, covering the literature since 1995 until 2004, to these interesting molecules and their useful chemical transformations and biological activity can be considered of considerable value.
Thermal transformation of arylamidoximes in the presence of phosphorus ylides. Unexpected formation of 3‐aryl‐5‐arylamino‐1,2,4‐oxadiazoles
Authors: Nicolaides Demetrios N. , Litinas Konstantinos E. , Vrasidas Ioannis , Fylaktakidou Konstantina C. 
Published: March 2009

AbstractThe unexpected formation of 3‐aryl‐5‐arylamino‐1,2,4‐oxadiazoles took place, when arylamidoximes reacted thermally with ethoxycarbonylmethylene(triphenyl)phosphorane. Furoxans, nitriles, ureas were also isolated suggesting aryl cyanide oxides as intermediates. 3‐Aryl‐5‐arylamino‐1,2,4‐oxadiazoles were formed via an aryl migration from the carbon atom to the nitrogen atom of the amidoxime, and the structure was further proved from the X‐ray crystal structure of the N‐(4‐bromobenzoyl) derivative.
Atomic force microscopy study of the antimicrobial activity of aqueous garlic versus ampicillin against Escherichia coli and Staphylococcus aureus
Authors: Perry Christopher C , Weatherly Monique , Beale Tiffany , Randriamahefa Alexandrine 
Published: March 2009

AbstractBACKGROUND: In this study the effects of ampicillin and aqueous garlic extract on Escherichia coli (ATCC 9637) and Staphylococcus aureus (ATCC 25923) were compared. Atomic force microscopy (AFM) was used to study the possible mechanisms of membrane disruption.RESULTS: Ampicillin disrupted the cell membrane of E. coli, inducing pores and cell leakage. Aqueous garlic extract also induced leakage from the cell membrane in E. coli, but no pores were observed. The trend in Young's modulus for E. coli was Enative ≈ Eage > Eamp. In contrast, S. aureus incubated with low ampicillin (≤50µg mL−1) and garlic (≤50 mg mL−1) concentrations showed no significant changes in surface morphology compared with the untreated bacterium. The trend in Young's modulus for S. aureus was Enative ≈ Eage ≈ Eamp.CONCLUSION: The trend Enative ≈ Eage for E. coli and S. aureus supports the hypothesis that the compounds in garlic show intracellular activity. This proof‐of‐concept study of the aqueous crude isolate of garlic points to the feasibility of further AFM investigations to compare the antimicrobial properties of various pure thiosulfinate isolates found in garlic. Copyright © 2009 Society of Chemical Industry
Preparation of solid alkaline fuel cell binders based on fluorinated poly(diallyldimethylammonium chloride)s [poly(DADMAC)] or poly(chlorotrifluoroethylene‐co‐DADMAC) copolymers
Authors: Valade David , Boschet Frédéric , Roualdès Stéphanie , Ameduri Bruno 
Published: March 2009

AbstractA membrane or an electrode binder to be used in a solid alkaline fuel cell (SAFC) needs to (i) be insoluble in both aqueous solutions and the required fuels, and (ii) exhibit an hydroxide ion conductivity. To achieve these goals, two pathways were employed: (i) one consists of the radical copolymerization of diallyldimethylammonium chloride (DADMAC) with chlorotrifluoroethylene (CTFE) while (ii) the other one is based on the counter‐ion exchange of a poly(DADMAC) by fluorinated anions. First, the radical copolymerization of CTFE with DADMAC under various experimental conditions was achieved in yields up to 85%, and DADMAC percentages in the copolymers were higher than those in the feed compositions. To obtain insoluble copolymers, high CTFE feed contents (>70 mol %) were required. The other route consisting in the partial replacement of the Cl− counter‐ions in the water‐soluble poly(DADMAC) by bistrifluoromethanesulfonimide (TFSI−) did confer the starting material insolubility in water while maintaining its conductivity. When the fluorinated poly(DADMAC) was obtained from concentrated solutions of fluorinated surfactant, it was observed that the amount of counter‐ions exchanged was difficult to control, which limits optimization. Nevertheless, under diluted conditions, membranes with ion exchange capacity up to 0.7 meq g−1, and conductivities close to 1 mS cm−1 were obtained. Although their conductivities were low, these membranes fulfill the requirements for a SAFC membrane in terms of solubility in DMSO, water insolubility, and thermal stability (Td,10% > 320 °C). When used in a fuel cell, as a binder in the membrane‐electrode assembly (MEA), significant improvements were noted (+50% of the open circuit voltage, +580% in current density, and +540% in accessible power). © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2043–2058, 2009
Solid acid clay mediated copolymerization of methyl acrylate and 1‐octene: 2D NMR substantiation of predominant alternating comonomer sequence
Authors: Kaur Sukhdeep , Singh Gurmeet , Gupta Virendra K. 
Published: March 2009

AbstractMontmorillionite K10 powder presence during radically initiated copolymerization of methyl acrylate (M) and 1‐octene (O) gave copolymers with higher incorporation of alkene unit. Highly viscous and transparent copolymers showed alternation irrespective of the copolymer composition. Increasing the amount of K10 powder increased the total percentage conversion, as well as 1‐octene incorporation. The monomodal curves obtained in gel permeation chromatography (GPC) substantiated that true copolymers were formed. The alternation in the copolymers was authenticated through Heteronuclear Multiple Quantum Correlation (HMQC) experiments in conjugation with Total Correlated Spectroscopy (TOCSY). © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2156–2162, 2009