bluuebunny/crossref_metadata_2025_split huggingface dataset:
Unidirectional cis–trans photoisomerization of cis‐3,3′‐bis(diphenylhydroxymethyl)stilbene in inclusion complex crystals
Authors: Tanaka Koichi , Hiratsuka Takaichi , Ohba Shigeru , Naimi‐Jamal M. Reza , Kaupp Gerd 
Published: October 2003

AbstractWhen a 1:1 complex of cis‐3,3′‐bis(diphenylhydroxymethyl)stilbene (1) with acetone was irradiated in the solid state at room temperature using a high‐pressure mercury lamp with a Pyrex filter for 6 h, a 1:1 complex of the trans‐isomer (2) with acetone was obtained without losing the guest acetone molecules. Similar results were obtained without a guest or in the presence of other guests. Internal rotation around the double bond bearing the very large triphenylhydroxymethyl substituent is hardly imaginable in the confinement of the crystal. Therefore, the geometrically easier ‘hula‐twist’ (HT) mechanism with its movements primarily in the molecular plane provides a viable mechanistic alternative for the cis–trans isomerization. The solid‐state mechanism of the reaction was studied by x‐ray and atomic force microscopy (AFM) analyses. Face‐selective efflorescence formed a protective cover on (100) and can be related to the crystal structure. Further molecular migration was not detected with the sensitivity of AFM and the crystal of 1ċacetone did not lose its clarity and microscopic shape. The cis–trans conversion profits from cages that are present in the crystal lattice. X‐ray structural analysis confirmed a strong loss of crystallinity upon the photochemical conversion of 1ċacetone which precludes a definitive conformational proof of HT by x‐ray diffraction. The formation of the amorphous phase excludes a topotactic reaction. Copyright © 2003 John Wiley & Sons, Ltd.
Photocationic and radical polymerizations of epoxides and acrylates by novel sulfonium salts
Authors: Takahashi Eiji , Sanda Fumio , Endo Takeshi 
Published: October 2003

AbstractNovel sulfonium salts [methyl‐, 2‐indany‐, or 1‐ethoxycarbonylethyl methyl‐2‐naphthylsulfonium hexafluorophosphate and 2‐indany‐, 1‐ethoxycarbonylethyl‐, 2‐methyl‐2‐phenylpropyl‐, 2‐phenylpropyl‐, 2‐phenylethyl‐, 2‐(4‐methoxyphenyl)‐ethyl‐, or 3‐(4‐methoxyphenyl)‐2‐propyl methylphenylsulfonium hexafluorophosphates] were synthesized by the reaction of dimethylsulfate and the corresponding sulfides followed by anion exchange with KPF6. These sulfonium salts could polymerize epoxy monomers at lower temperatures than previously reported for benzylsulfonium salt initiators. In particular, sulfonium salts with naphthyl groups showed higher photoactivity than already reported for di(4‐tert‐butylphenyl)iodonium and triphenylsulfonium hexafluorophosphates. These sulfonium salts showed higher activity in photoradical polymerization and photocationic polymerization. The photopolymerization was accelerated by the addition of 4‐methoxy‐1‐naphthol, N‐ethylcarbazole, 2,4‐dimethylthioxanthone, phenothiazine, and 2‐ethyl‐9,10‐dimethoxyanthracene as photosensitizers. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3816–3827, 2003
Synthesis and characterization of novel hyperbranched poly(imide silsesquioxane) membranes
Authors: Liu Chunqing , Naismith Nathaniel , Huang Yongqing , Economy James 
Published: October 2003

AbstractA new family of hyperbranched polymers with chemical bonds between the hyperbranched polyimide and polysilsesquioxane network was synthesized by the reaction of an amine‐terminated aromatic hyperbranched polyimide with 3‐glycidoxypropyl trimethoxysilane, followed by hydrolysis and polycondensation in the presence of an acid catalyst. The hyperbranched poly(imide silsesquioxane) membranes were fabricated by the casting the aforementioned polymer solution onto a NaCl optical flat, which was followed by heating at 80 °C for 24 h. The membranes were characterized by Fourier transform infrared, X‐ray diffraction, thermogravimetric analysis, scanning electron microscopy, N2 adsorption and desorption, and CO2 adsorption and desorption. The presence of covalent bonds between the hyperbranched polyimide and polysilsesquioxane segments had a significant effect on the properties of the membranes. N2 adsorption–desorption isotherms for these membranes showed surface areas of 6–16 m2/g, whereas CO2 adsorption–desorption isotherms showed much higher surface areas in the range of 106–127 m2/g. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3736–3743, 2003
Anionic iron(II) alkoxides as initiators for the controlled ring‐opening polymerization of lactide
Authors: McGuinness David S. , Marshall Edward L. , Gibson Vernon C. , Steed Jonathan W. 
Published: October 2003

AbstractHetero‐bimetallic Fe(II) alkoxide/aryloxides were evaluated as initiators for the ring‐opening polymerization of rac‐lactide. [(THF)NaFe(OtBu)3]2 (1) and [(THF)4Na2Fe(2,6‐diisopropylphenolate)4] (2) (THF = tetrahydrofuran) both polymerized lactide efficiently at room temperature, with complex 1 affording better control over the molecular weight parameters of the resultant polymer. At conversions below 70%, a linear increase in molecular weight with conversion was observed, indicative of a well‐controlled polymerization process. Complex 2 is the first example of a dianionic Fe(II) alkoxide and has been structurally characterized to reveal a distorted square planar FeO4 array in which both Na counterions bridge two aryloxide ligands and are further complexed by two THF ligands. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3798–3803, 2003
Ethylene polymerization over transition‐metal supported catalysts. II. Cr on zeolite, silica, and charcoal: Characterization and activity studies
Authors: Zhang Y. , Matos I. , Lemos M. A. N. D. A. , Freire Filipe , Nunes Teresa G. , Botelho do Rego A. M. , Henriques R. T. , Fonseca I. F. , Marques M. M. , Lemos F. 
Published: October 2003

AbstractCr catalysts supported on silica, zeolite NaY, and charcoal were prepared with two different methods. They were characterized and examined in the polymerization of ethene. Cyclic voltammetry, electron spin resonance, X‐ray photoelectron spectroscopy and silicon‐29 magic‐angle spinning nuclear magnetic resonance spectroscopy were used to characterize them, demonstrating that Cr is not in a single oxidation state, that the distribution among the various oxidation states depends on the history of the sample, and that even for a single oxidation state a variety of different environments can occur. In the polymerization of ethene, the supported Cr catalysts exhibited activity values varying from 103 to 105 gPE · molCr−1 · [M]−1 · h−1, depending on the choice of the support and on the method by which the Cr is placed on it. Silica seemed to be the most efficient support for Cr for this reaction. However, the zeolite‐supported catalysts also showed reasonable activity values (Ap ≅ 104 units) and presented the advantage of having a strong interaction between the Cr and the support, which may prevent leaching of the cation into the surrounding environment. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3768–3780, 2003
Modification of the microstructure of emulsion polymers
Authors: Ilundain Pedro , Alvarez Daniel , Da Cunha Louis , Salazar Rafael , Barandiaran María J. , Asua José M. 
Published: October 2003

AbstractThe effect of treating several commercially important emulsion polymers with different initiator systems was investigated. The initiator system producing highly reactive tert‐butoxyl radicals was able to cause polymer modification. This represented an opportunity to extend the range of properties achievable with a given emulsion polymer. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3744–3749, 2003
Biodegradable/biocompatible ABC triblock copolymer bearing hydroxyl groups in the middle block
Authors: Gadzinowski Mariusz , Sosnowski Stanislaw 
Published: October 2003

AbstractNew biodegradable/biocompatible ABC block copolymers, poly(ethylene oxide)‐b‐poly(glycidol)‐b‐poly(L,L‐lactide) (PEO‐PGly‐PLLA), were synthesized. First, PEO‐b‐poly(1‐ethoxyethylglycidol)‐b‐PLLA was synthesized by a successive anionic ring‐opening copolymerization of ethylene oxide, 1‐ethoxyethylglycidyl ether, and L,L‐lactide initiated with potassium 2‐methoxyethanolate. In the second step, the 1‐ethoxyethyl blocking groups of 1‐ethoxyethylglycidyl ether were removed at weakly acidic conditions leaving other blocks intact. The resulting copolymers were composed of hydrophilic and hydrophobic segments joined by short polyglycidol blocks with one hydroxyl group in each monomeric unit. These hydroxyl groups may be used for further copolymer transformations. The PEO‐PGly‐PLLA copolymers with a molecular weight of PLLA blocks below 5000 were water‐soluble. Above the critical micellar concentration (ranging from 0.05 to1.0 g/L, depending on the composition of copolymer), copolymers formed macromolecular micelles with a hydrophobic PLLA core and hydrophilic PEO shell. The diameters of the micelles were about 25 nm. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3750–3760, 2003
Biodegradable polycaprolactone–polyanhydrides blends
Authors: Ben‐Shabat Shimon , Abuganima Elias , Raziel Aliza , Domb Abraham J. 
Published: October 2003

AbstractBiodegradable polymers based on a blend of polycaprolactone (PCL) and aliphatic polyanhydrides with various monomer lengths were prepared to obtain desired polymer blends for use as drug carriers. The physicochemical, mechanical, and drug‐release properties of these blends were investigated by various techniques to evaluate the uniformity degree of the polymer blends to establish their potential applications in drug delivery. The results demonstrated that the heat of fusion (ΔH) of the polyanhydride or the blend is increased in relation to the length of the aliphatic chain. However, the blends had different properties than pure polyanhydride, and the crystallization degree of the blends, as expressed by the ΔH, decreased in relation to the ΔH of the pure polyanhydride. Drug‐release studies from blends of PCL and aliphatic polyanhydrides demonstrated first‐order kinetics of the release rate. Polymer degradation was independent at the polyanhydride monomer length. On the basis of theoretical calculation of the interaction factor, a blend of PCL and poly(dodecanedeoic anhydride) was chosen for further elucidation of its thermal, mechanical, and degradation properties. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3781–3787, 2003
S. Kumaresan and P. Kannan, "Substituent effect on azobenzene‐based liquid‐crystalline organophosphorus polymers" Journal of Polymer Science Part A: Polymer Chemistry (2003) 41(20) 3188–3196
Authors: Kumaresan S. , Kannan P. 
Published: October 2003

AbstractThe original article to which this Erratum refers was published inJournal of Polymer Science Part A: Polymer Chemistry (2003) 41(20) 3188–3196No abstract.
Degradation of the sulfonylurea herbicide LGC‐42153 in flooded soil
Authors: Kim Jin , Liu Kwang‐Hyeon , Kang Seung‐Hun , Koo Suk‐Jin , Kim Jeong‐Han 
Published: October 2003

AbstractLGC‐42153, 2‐fluoro‐1‐[3‐(4,6‐dimethoxypyrimidin‐2‐ylcarbamoylsulfamoyl)pyridin‐2‐yl]propyl methoxyacetate, is a new sulfonylurea herbicide for use in rice. Its breakdown and metabolism were studied in soil under flooded condition using radioactive tracers labelled at either the propyl group or the pyrimidine ring. The half‐life of LGC‐42153 was approximately 3.0 days. The mass balance over 120 days ranged from 94.0 to 104.2% of applied radiocarbon, and no significant amount of volatiles or [14C]carbon dioxide were observed. Solvent non‐extractable radiocarbon reached 11 ∼ 14% of applied radiocarbon at 120 days after treatment. The major metabolic reaction was the cleavage of the carboxyl ester bond to give 1‐(4,6‐dimethoxypyrimidin‐2‐yl)‐3‐[2‐(1‐hydroxy‐2‐fluoropropyl)pyridine‐3‐sulfonyl]urea, which underwent hydrolysis of the sulfonylurea bridge giving 2‐(1‐hydroxy‐2‐fluoro)propyl‐3‐pyridinesulfonamide and 4,6‐dimethoxy‐2‐aminopyrimidine. Copyright © 2003 Society of Chemical Industry
Addition of a monovalent cationic pesticide to improve efficacy of bipyridyl herbicides in Hulah valley soils
Authors: Rytwo Giora , Tavasi Mordechai 
Published: October 2003

AbstractBipyridyl herbicides are widely used in agriculture and gardening for non‐selective weed control. Since they are toxic and relatively expensive, it is ecologically and economically desirable to reduce the amounts applied. A decrease in efficacy of these herbicides is caused by dust accumulated on leaves of weeds. This inactivation arises from the adsorption of the herbicides on dust particles, mainly made of clay minerals, lime and soil organic matter. In order to improve the efficacy and so lower the amounts applied, formulations were developed which include cationic pesticides approved for agricultural use, such as mepiquat or difenzoquat. Such addition restored the efficacy of the bipyridyl herbicides by reducing their binding to dust particles. The proposed formulations, which were tested on a number of different dust‐covered plants, allowed the amounts of herbicide applied to be reduced to 50% of the minimum recommended rate. Neither mepiquat or difenzoquat had any herbicidal activity when sprayed alone at the added rates. The results suggest a procedure that may lower the required rates of contact herbicides, reducing costs and toxicity. This procedure, which can be applied immediately, may have broad implications in farming and gardening. Copyright © 2003 Society of Chemical Industry
Fungicidal potential of methoxylated flavones from citrus for in vitro control of Colletotrichum gloeosporioides, causal agent of anthracnose disease in tropical fruits
Authors: Almada‐Ruiz Ernestina , Martínez‐Téllez Miguel Ángel , Hernández‐Álamos Maria M , Vallejo Socorro , Primo‐Yúfera Eduardo , Vargas‐Arispuro Irasema 
Published: October 2003

AbstractFour polymethoxylated flavones (3,5,6,7,3′,4′‐hexamethoxyflavone, 3,5,6,7,8,3′,4′‐heptamethoxyflavone, 5,6,7,8,4′‐pentamethoxyflavone and 5,6,7,8,3′,4′‐hexamethoxyflavone) were isolated and characterized from cold‐pressed orange oil. Their antifungal activities were evaluated against Colletotrichum gloeosporioides (Penz) Penz & Sacc, a major plant pathogen of fruits that causes significant damage to crops in tropical, sub‐tropical and temperate regions. Methoxylated flavones were effective in inhibiting mycelial growth of the fungus. As flavone concentration increased, mycelial growth decreased. 5,6,7,8,3′,4′‐Hexamethoxyflavone completely inhibited the growth of C gloeosporioides at a concentration of 100 µg ml−1. Copyright © 2003 Society of Chemical Industry
Influence of a short exposure to teflubenzuron residues on the predation of thrips by Iphiseius degenerans (Acari: Phytoseiidae) and Orius laevigatus (Hemiptera: Anthocoridae)
Authors: Scott Brown Alison S , Simmonds Monique SJ , Blaney Wally M 
Published: October 2003

AbstractA short duration (24 h) leaf‐disc bioassay was used to determine the effects of teflubenzuron residues on the predation levels of two predators, Iphiseius degenerans (Berlese) and Orius laevigatus (Fieber), foraging on nymphs of two species of thrips, Frankliniella occidentalis (Pergande) and Heliothrips haemorrhoidalis (Bouché), on a range of different species of plant. Teflubenzuron did cause thrips mortality during the 24‐h bioassay; it was more active against H haemorrhoidalis than F occidentalis. Teflubenzuron did not cause significant mortality to either species of predator, although on some plants the effectiveness of both predators was reduced in the presence of teflubenzuron. Copyright © 2003 Society of Chemical Industry
Inhibition of egg development by phosphine in the cosmopolitan pest of stored products Liposcelis bostrychophila (Psocoptera: Liposcelididae)
Authors: Nayak Manoj K , Collins Patrick J , Pavic Hervoika , Kopittke Rosemary A 
Published: October 2003

AbstractPhosphine‐induced delay in development of eggs was investigated as a mechanism of resistance to this fumigant in Liposcelis bostrychophila Badonnel. One‐day‐old eggs of a susceptible and a strongly resistant strain of L bostrychophila were exposed to a range of phosphine concentrations for 6 days at 30 (±1) °C and 70 (±2)% RH. Delay in mean hatching period occurred in both susceptible and resistant eggs, although it was more pronounced in the latter. A maximum delay of 2.65 days was recorded for eggs of the susceptible strain at 0.01 mg litre−1 (the highest concentration at which eggs survived) and 13.39 days for the resistant strain at 1 mg litre−1 (the highest concentration tested). Delay in egg development time was positively correlated with increasing phosphine concentration. Our results reveal that the most successful strategy to control resistant L bostrychophila is to apply relatively low concentrations of phosphine for extended exposure times (eg 0.05 mg litre−1 for 16 days) that allow all eggs to hatch to the much less tolerant nymph stage. Copyright © 2003 Society of Chemical Industry
Toxicity and kinetics of methoxyfenozide in greenhouse‐selected Spodoptera exigua (Lepidoptera: Noctuidae)
Authors: Smagghe Guy , Pineda Samuel , Carton Bert , Estal Pedro Del , Budia Flor , Viñuela Elisa 
Published: October 2003

AbstractMethoxyfenozide (RH‐2485) was found to be 7.5‐fold less toxic in terms of LD50 values against last‐instar larvae of a greenhouse‐selected strain of the beet armyworm Spodoptera exigua (Hübner) that was collected in July 2001 in an experimental greenhouse for resistance at Murcia in southern Spain, in comparison with a laboratory susceptible strain. To date, the compound is the newest member of this new group of moulting hormone accelerating IGRs to reach the marketplace against Lepidoptera. To understand this different potency in the greenhouse‐selected S exigua, oxidative metabolism and acetylcholinesterase activities were measured in last‐instar larvae and adults. In addition, we determined, by the use of 14C‐labelled methoxyfenozide, the pattern of absorption in body tissues and excretion via faeces in last‐instar larvae of the greenhouse‐selected strain and compared the results with those from the laboratory susceptible strain. It was striking that the rate of excretion was about twice as high in the greenhouse‐selected strain, resulting in a more rapid clearance of insecticide amounts from the insect body. Data are discussed in relation to mechanisms of lower toxicities for this new group of IGRs. Copyright © 2003 Society of Chemical Industry
Herbicide resistance in Aster squamatus conferred by a less sensitive form of acetolactate synthase
Authors: Osuna Maria D , Fischer Albert J , De Prado Rafael 
Published: October 2003

AbstractA biotype of Aster squamatus (Sprengel) Hieronymus with suspected resistance to the ALS‐inhibiting herbicide imazapyr was detected in a chicken farm in the province of Seville, Spain, which had been treated once a year with imazapyr for 10 years. Resistance to imazapyr in this biotype was studied using dose–response experiments, absorption and translocation assays, metabolism studies and ALS activity assays. The rate of imazapyr required to inhibit A squamatus growth by 50% (ED50) was 15 times higher for the R (resistant) than for the S (susceptible) biotype. Cross‐resistance existed for the ALS‐inhibitors imazamox, imazethapyr, amidosulfuron, nicosulfuron, rimsulfuron, triasulfuron and tribenuron, but not for bensulfuron. Control of A squamatus using alternative herbicides was poor with clopyralid, intermediate with quinclorac, amitrole and MCPA, and excellent with 2,4‐D, glufosinate and glyphosate. Absorption of [14C]imazapyr increased over time for both the R and S biotypes, and translocation from the treated leaf to shoots and roots was similar in both biotypes, with most of the radioactivity remaining in the treated leaf. No metabolites of imazapyr were detected in either biotype. Sensitivity of the ALS enzyme (target site) to imazapyr was lower for the R biotype (I50(R) = 4.28 × I50 (S)). The mechanism of imazapyr resistance in this R biotype appears to be an altered ALS conferring decreased sensitivity to imazapyr at the whole‐plant level. Copyright © 2003 Society of Chemical Industry
Persistence of the fungicides thiabendazole, carbendazim and prochloraz‐Mn in mushroom casing soil
Authors: Grogan Helen M , Jukes Andrew A 
Published: October 2003

AbstractThe persistence of the fungicides thiabendazole, carbendazim and prochloraz‐Mn in mushroom casing soil was determined following their application at rates commonly used in the UK mushroom industry. Following drench applications, the concentration of all active ingredients was always higher in the top half of the casing soil layer than in with the bottom half. When carbendazim and prochloraz‐Mn were applied using half the recommended volume of water per unit area, there was a tendency for carbendazim concentrations to be even higher in the top half of the casing soil, compared with the standard treatment, while concentrations of prochloraz‐Mn were similar, irrespective of the volume of water used. Carbendazim and prochloraz‐Mn concentrations in the top half of the casing layer decreased to ≤13 mg kg−1 by day 28/29, following different applications, whereas the thiabendazole concentration was consistently high during the course of the crop, being ≤83 mg kg−1 at day 31. Fungicides that do not persist at high concentrations in mushroom casing soil for the duration of the crop may not give good control of mushroom pathogens, particularly if the fungicide concentration falls to a level which is close to the EC50 value. Copyright © 2003 Society of Chemical Industry