bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interfacial polycondensation reactions of the new monomer 1,1′‐bis(β ‐aminoethyl)ferrocene
Authors: Gonsalves K E , Lenz R W , Rausch M D 
Published: January 2005

AbstractCondensation polymerizations of several ferrocenecontaining monomers have been investigated, using low temperature interfacial and solution techniques. 1, 1′‐bis(β‐aminoethyl)ferrocene was synthesized via a 6‐step process starting with ferrocene. This monomer was then copolymerized with various aromatic and aliphatic diacid chlorides as well as with diisocyanates, leading to ferrocene‐containing polyamides and polyureas having moderately high to low viscosities. Using the interfacial method, film formation occurred for the polyamides. The related monomer 1,1′‐bis(β‐hydroxyethyl)ferrocene reacted with diacid chlorides and diisocyanates to form ferrocenecontaining polyesters and polyurethanes, respectively, using the solution method. The ferrocenecontaining condensation polymers were characterized by IR spectroscopy and examined for possible liquid crystalline behavior.
Recovery of all species from photolytic degradation of tributyltin compounds TBTX (X = Cl, OSn Bu3)
Authors: Duhamel K , Blanchard G , Dorange G , Martin G 
Published: January 2005

AbstractMalformations in shellfish have been reported by many authors. They attributed the cause of the deformity to the presence in water of organotin compounds used in the formulation of antifouling paints, for example bis(tributyltin) oxide (TBTO) and tributyltin chloride (TBTC). The behaviour of these compounds has been examined under abiotic laboratory conditions. The influence of many parameters such as sunlight, pH, oxygen, salinity have been examined. The degradation compounds obtained have been identified: (1) In the gas phase two major products, butene‐1 and buetene‐2, are observed with consumption of oxygen; (2) In the liquid phase, three main products are obtained, butanol‐1, butanol‐2 and butanone 2. The identified products represent a small part of the total concentration, suggesting a competing process such as formation of butyltin polymers; (3) In fresh water an amorphous solid phase is observed while in seawater a white cristalline precipitate appears.
Organotin compounds in agriculture since 1980. Part I. Fungicidal, bactericidal and herbicidal properties
Authors: Crowe Alan J 
Published: January 2005

AbstractThe object of this review paper is to provide a guide to agrochemical research involving organotin compounds which has been performed since 1980. The information is presented in tabular form and Part I is divided into main sections as indicated by the title. Each section is then subdivided to cover the various commercial organotin compounds. A final subsection lists investigations involving novel compounds. A table of the contents has been provided to enable ease of reference.
Preparation of trimethyl‐2‐hydroxyethylarsonium (arsenocholine) compounds
Authors: Irgolic Kurt J , Junk Thomas , Kos Carlo , McShane William S , Pappalardo Giuseppe C 
Published: January 2005

AbstractTrimethyl‐2‐X‐ethylarsonium salts (X=OH, Cl, Br, CH3COO; anion=Br) and trimethyl‐2‐diethoxyethylarsonium bromide were prepared from trimethylarsine and the appropriate organic bromides in sealed tubes at elevated temperatures or by refluxing the neat reagents. The yields ranged from 33 to 85%. Anion exchange reactions produced the arsonium iodides, nitrates, acetates, tosylates, tetraphenylborates, picrates, hydroxides, and carbonates. Arsenocholine bromide (X=OH) was phosphorylated with concentrated phosphoric acid. The product was isolated as the barium salt. Treatment of the barium salt with sulfuric acid yielded trimethyl‐2‐(dihydrogen phosphato)ethylarsonium bromide. These substances were synthesized to serve as precursors for arsenic‐ containing phospholipids and as standards for the chromatographic identification of arsenocholines. The synthesized compounds were characterized by elemental analyses and 1H and 13C NMR spectroscopy. The shifts of the arsenic compounds were compared with those of the corresponding nitrogen compounds and found to be sufficiently different to be used for the identification of these compounds in their mixtures.
The synthesis and reactivity of polysilylacetylenes: Diels—Alder reactions to give bis (silyl) benzenes
Authors: Jones Paul Ronald , Albanesi Todd E , Gillespie Ralph D , Jones Priscilla C , Ng Seik Weng 
Published: January 2005

AbstractSix bis(silyl)acetylenes (XMe2SiCCSiMe2X) with the following varied silicon substituents X were prepared: 1 (Me, Me); 2 (H, H); 3 (C1, H); 4 (CI, CI); 5 (MeO, H); 6 (MeO, MeO). While 1 and 2 may be prepared by the reaction of dilithio‐ or bis(bromomagnesium)‐acetylide with the appropriate chlorosilane, similar reactions designed to give 3–6 yielded oligomers, XMe2Si(CCSiMe2)nX, 7, X=CI, MeO, as the major products, indicating that the acetylenic functionality on silicon activates the chlorosilane towards nucleophilic substitution. Compounds 3 and 4 were prepared by free radical chlorination of 2. Methanolysis of 3 and 4 gave quantitative yields of 5 and 6 respectively.Compounds 1–6 undergo a Diels–Alder reaction with α‐pyrone to produce, after loss of carbon dioxide, bis(silyl)‐substituted benzene derivatives. The order of reactivity has been determined to be: 4=6>3=5>1>2, indicating that chloro or alkoxy substituents favor the cycloaddition with 2‐ pyrone. The adducts formed by compounds 3–6 undergo an unusually facile hydrolysis or elimination to give 1,1,3,3‐tetramethyl‐1,3‐disila‐2‐oxaindane.
Palladium(II)‐catalysed H/D allylic exchange in alkenes: An intermediacy of palladium(IV)?
Authors: Ryabov Alexander D , Eliseev Alexey V , Yatsimirsky Anatoly K 
Published: January 2005

AbstractEvidence is presented that the dimeric π‐allylic species [(η3‐allyl)PdCl]2is not intermediate in the Li2Pd2Cl6‐catalysed allylic H/D exchange in alkenes. Neither H/D exchange in α‐methylstyrene, nor enrichment of [(η3‐2‐PhC3H4)PdCl]2, was observed when the latter complex was incubated at 100°C in D3CCOOD either in the presence or in the absence of PhC(CH3)CH2, respectively. The kinetics of H/D exchange in α‐methylstyrene catalysed by Li2Pd2Cl6were studied in some detail. The exchange proceeds at highest rates when reduction of palladium(II) takes place and is much slower in the presence of 1,4‐benzoquinone as a palladium reoxidant. The exchange rate is directly proportional to the alkene and catalyst concentrations and independent of the reoxidant concentration. It is suggested that the palladium(II)‐catalysed exchange involves an intermediate hydrid‐allyl species where palladium has a formal oxidation state of IV.
Environmental bioremediation for organometallic compounds: Microbial growth and arsenic volatillization from soil and retorted shale
Authors: Sanford R A , Klein D A 
Published: January 2005

AbstractNutrient effects on microbial growth and arsenic volatilization from retorted oil shale and soil were evaluated in a laboratory study. Dimethylarsinic acid (DMAA), methanearsonic acid (MAA) and sodium arsenate amendments were used with added nutrients, or with retort process water added to simulate possible co‐disposal conditions. In experiments with soil and retorted shale, dimethylarsinic acid showing the highest cumulative arsenic releases, in comparison with added inorganic sodium arsenate (SA). Low but detectable amounts of innate arsenic present in retorted shale could be volatilized with added organic matter. In soil, arsenic volatilization showed a direct relationship to nutrient levels and microbial growth. With shale, in comparison, a threshold response to available nutrients was evident. Distinct increases in fungal community development occurred with nutrients available at a level of 2.5% w/v, which also allowed incresed arsenic volatization. Codisposal of retort process waters with shale allowed arsenic volatilization without the addition of other nutrients. The presence of retort process water limited arsenic volatilization from the added organometallic compounds DMAA and MAA, but not from SA or innate arsenic. These differences should be useful in the definition of permissive and non‐permissive environmental conditions for arsenic volatilization in bioremediation programs.
Ionic alkylleads in avian tissues from aquatic and terrestrial environments
Authors: Forsyth D S , Marshall W D , Collette M C 
Published: January 2005

AbstractIonic alkyllead concentrations in soft tissues of pigeons from urban Montreal and environs were appreciably different from the variety and concentrations of alkyllead analytes which characterized mallard ducks culled from a sanctuary in eastern Ontario. The major toxicant in pigeons, triethyllead (Et3Pb+) reflected the exclusive use of tetraethyllead as a gasoline additive in both regions. Urban colonies of pigeons were characterized by significantly greater concentrations of Et3Pb+ than were specimens from a suburban/rural colony. In contrast, the major toxicant in ducks was trimethyllead although six other alkyllead analytes were also observed. An environmentally mediated methylation of Pb2+ which is more active in (but not restricted to) aquatic environments is postulated to account for the ubiquity of trimethyllead in ducks.
Polyureidoborazines
Authors: Gonsalves Kenneth E , Agarwal Radha 
Published: January 2005

AbstractPolyureidoborazines were synthesized by the reaction of tri‐isocyanato‐trimethylborazine with linear aliphatic diamines. The insoluble oligomers were characterized by infrared spectroscopy and the effect of the number of methylene units on thermal transitions determined by differential scanning calorimetry (DSC). The oligomers were pyrolyzed in argon and ammonia‐nitrogen atmospheres and the residues analyzed for boron, nitrogen atmospheres and the residues analyzed for boron, nitrogen and carbon.
The origin of arsenobetaine in marine animals
Authors: Edmonds J S , Francesconi K A 
Published: January 2005

AbstractTrimethyl(carboxymethyl)arsonium zwitterion (arsenobetaine) is virtually ubiquitous in marine animals consumed by man. Experimental work on the transformation of arsenate to arsenobetaine in the marine environment is reviewed. Current evidence favors the conversion of arsenate to dimethyl(ribosyl)arsine oxides by algae, and the microbially mediated transformation of dimethyl(ribosyl)arsine oxides to arsenobetaine or to its immediate precursors in the sediments. Information about the transfer of arsenobetaine from the sediments to marine animals is lacking.
Interaction of arsenic and selenium on the metabolism of these elements in hamsters
Authors: Ishizaki Mutsuo , Ueno Seiichi , Okazaki Tadashi , Suzuki Tomoko , Oyamada Noritaka 
Published: January 2005

AbstractThe interaction of arsenic and selenium compounds on the metabolism of these elements in golden hamsters was studied. Golden hamsters were divided into three groups and administered sodium selenite (Na2SeO3), sodium arsenite (NaAsO2) and Na2SeO3 with NaAsO2, respectively, by a single Subcutaneous injection of 25 m̈mol kg−1 body weight as As or Se (arsenic and selenium were calculated as weight of elemental arsenic and selenium). Selenium and arsenic metabolites were determined by high‐performance liquid chromatography–graphite furnace atomic absorption spectrometry (HPLC–GFA AA) and gas chromatography (GC). The results show (1): About 10% by weight of the given dose of selenium was excreted in expiration air as dimethylselenide (Me2Se) during 12 h after administration of Na2SeO3. Excretion of dimethylselenide with the respiratory air was inhibited by administration of Na2SeO3 simultaneously with NaAsO2. (2) Giving Na2SeO3 plus NaAsO2 had no appreciable effect on the excretion of the trimethylselenonium ion (Me3Se+) into the urine and the feces. (3) Giving Na2SeO3 plus NaAsO2 increaed the excretion into the feces of an insoluble unknown‐structure selenium compound, the proportion of which was 10.9% by weight of the given dose of selenium. (4) Giving NaAsO2 plus Na2SeO3 decreased the excretion of dimethylarsinic acid (Me2AsOOH) and inorganic arsenic into the urine during 120 h after the administration of the reagents, the decreased amount being 5.3% (dimethylarsinic acid) and 7.7% (inorganic arsenic) of the given dose of arsenic, respectively. (5) Giving NaAsO2 plus Na2SeO3 increased the excretion into feces of insoluble unknown‐structure arsenic compound and inorganic arsenic, the increased amounts being 10.6% and 7.0% of the given dose of arsenic, respectively. (6) Giving NaAsO2 plus Na2SeO3 decreased the excretion into feces of extractable unknown‐structure arsenic compound, and the decreased amount was 4.9% of the given dose of arsenic. (7) It made little difference to the excretion of monomethylarsonic acid [MeAsO(OH)2] into urine and feces and of dimethylarsinic acid (Me2AsOOH) into feces whether NaAsO2 was administered alone or with Na2SeO3.
The acute toxicity of tri‐n‐butyltin glycocholate
Authors: Sherman Larry R , Koch Joyce R , Thoman Charles J , Zimmerman Michael R 
Published: January 2005

AbstractThe oral acute toxicity for tri‐n‐butyltin glycocholate (TBT‐GA), a newly synthesized organotin steroid, was determined using Long Evans rats. The compound was suspended in corn oil and adminstered by gavage using standard techniques. Unlike tri‐n‐butyltin taurocholate, which exhibited two different toxicities, one for the tri‐n‐butyltin moiety and one for the taurocholic acid moiety, the TBT‐GA exhibited a single toxicity, that of the whole molecule. The LD50 value was 213 mg kg−1 (0.274 mmol kg), which on a millimolar basis is similar to that observed for other tri‐n‐butyltin compounds. The dead rats exhibited distended stomachs, enlarged ceca, and lesions in the intestinal tract.The actual cause of death could not be positively identified. Animals that survived more than three days also exhibited time‐ and dose‐related atrophy of the thymus gland. With 36% more male than female rats succumbing to TBT‐GA, the chemical appears to be more toxic towards male than female rats.
Perfluorinated membranes as catalyst supports
Authors: Hodges A M , Linton M , Mau A W‐H , Cavell K J , Hey J A , Seen A J 
Published: January 2005

AbstractThe perfluorinated polymer Nafion and porous PTFE/Nafion composite membranes have been employed as supports for nickel complexes or for platinum and palladium metal particles. The resultant materials have been employed as catalysts in various olefin conversion processes. Supported platinum and palladium metal systems were evaluated as catalysts for the hydrogenation of cyclohexene. Rates of reaction are better than those of commercially available catalysts; turnover numbers in excess of 6000 have been obtained with no poisoning apparent. Catalysts may be regenerated many times. The reduction rate approaches a limit at high pressures of hydrogen and has an activation energy of 13 kJ mol−1 in neat cyclohexene. Nafion was employed as a strong acid cocatalyst to activate and then support a nickel complex catalyst. The resultant catalyst was active for double‐bond‐shift isomerization.
Carbon monoxide poisoning as a probe for the active site(s) of a nickel‐based olefin oligomerization catalyst
Authors: Clutterbuck Linda M , Field Leslie D , Humphries Geoffrey B , Masters Anthony F , Williams Mark A 
Published: January 2005

AbstractThe interaction of the olefin oligomerization catalyst system derived from [Ni(sacsac)(PBu3)Cl] (sacsac = pentane‐2,4‐dithionate = dithioacetylacetonate) with carbon monoxide (CO) has been examined by a combination of 31P NMR and FTIR spectroscopy. The catalyst is rapidly and completely inhibited by CO; however, removal of the CO restores catalytic activity. A CO‐adduct of the active catalyst has a characteristic CO stretching frequency of 2042 cm−1, and δ31P 9.9 ppm. Carbon monoxide does not react with [Ni(sacsac)(PBu3)Cl], but [Ni(sacsac)(PBu3)(Cl)] reacts with any of Et2AlCl, BuLi, Li[Et3BH] or K[(s‐Bu)3BH] under an atmosphere of carbon monoxide in the presence or absence of olefin to produce [Ni(PBu3)(CO)3], which has been identified by FTIR and 31P NMR. [Ni(sacsac)(PBu3)Cl] reacts completely with BuLi or K[(s‐Bu)3BH] to form catalytically inactive species which yield active catalysts on addition of Et2AlCl.
The electrochemical synthesis of metallocenes, polymethylmetallocenes, ‘open metallocenes’ and metal phenylacetylides
Authors: Casey Allan T , Vecchio Angelica M 
Published: January 2005

AbstractMetallocenes, polymethylmetallocenes, metal dimethylpentadienyls and metal phenylacetylides were synthesized by the oxidation of the metal in a solution (acetonitrile, acetonitrile/tetrahydrofuran or acetonitrile/1,2‐dimethoxyethane) of the carbon acid C*H (where C*PhCC, C5H5, CH3C5H4, (CH3)5C5, indenyl, fluorenyl and 2,4‐dimethylpentadienyl). Metallocenes were extracted with hexane and sublimed in vacuo. Metal phenylacetylides precipitated during electrolysis. Current efficiencies indicate Faradaic behaviour. The method provides a significant improvement over the conventional route via alkali metal salts of the carbon acid.
Characteristics of selenium in australian marine biota
Authors: Maher W , Baldwin S , Deaker M , Lrving M 
Published: January 2005

AbstractThe occurrence, distribution and speciation of selenium in Australian marine biota is discussed. Biochemical pathways for the accumulation of selenium by marine organisms are also postulated. Comparison of the levels of selenium in macroalgae, fish, crustaceans and molluscs indicates that preferential accumulation of selenium by particular taxa does not occur. Phaeophyta have significantly lower selenium concentrations than Rhodophyta and Chlorophyta. Fish have lower selenium contents in muscle tissues than molluscs and crustaceans. Marine animals with different dietary intake (planktonic vs herbivorous vs carnivorous) are not observed to have significantly different levels of selenium (P>0.05). Selenium in all the organisms studied was predominantly associated with free amino‐acids or protein residues and was not present as characterizable inorganic selenium species (SeO32−, SeO42−). These results indicate that selenium is probably only incorporated into biota for specific biochemical purposes with any exces selenium being excreted or eliminated.
The fate of organoarsenic compounds in marine ecosystems
Authors: Hanaoka Ken′Ichi , Tagawa Shoji , Kaise Toshikazu 
Published: January 2005

AbstractMicrobial degradation experiments were performed with each standard arsenical [arsenobetaine, trimethylarsine oxide, dimethylarsinic acid, methanearsonic acid, inorganic arsenic(V) and inorganic arsenic(III)]. As typical origins for marine micro‐organisms, sediments, macro‐algae, mollusc intestine and suspended substances were used. The results were from these experiments led us to the following conclusions: (1) there is an arsenic cycle which begins with the methylation of inorganic arsenic on the route to arsenobetaine and terminates with the complete degradation of arsenobetaine to inorganic arsenic; (2) all the organoarsenic compounds which are derived from inorganic arsenic in seawater, through the food chains, have the fate that they, at least in part, finally return to the original inorganic arsenic.
Liquid–solid extraction of butyltin compounds from marine samples
Authors: Chiavarini S , Cremisini C , Ferri T , Morabito R , Ubaldi C 
Published: January 2005

AbstractEnvironmental damage due to organotins (TBT, DBT, MBT) released from antifouling paints is well documented. The concentrations of these compounds in seawater are usually at ppt (parts per 1012) levels. Many analytical techniques, including chromatographic and spectrophotometric ones, have been presented in the literature to detect organotins at these low levels. Liquid‐liquid extraction is commonly employed as a concentration method. However, it presents some disadvantages during sampling campaigns and requires large volumes of toxic and expensive solvents. In this paper we propose an analytical method based on a liquid‐solid extraction procedure that can be easily performed in the field and is characterized by good recoveries and high enrichment factors. Three different solid phases (Carbopack, LC 8 and LC 18) and five different eluting agents (methanol/tropolone, methanol, dichloromethane, hexane and diethyl ether) were evaluated. Carbopack and LC 18 were the most suitable solid phases. Inorganic tin was not retained on these solid phases and a separation of TBT from DBT and MBT was achieved, performing the elution in two steps with methanol and methanol/tropolone. In this way GF AA was suitably employed to obtain butyltin speciation data.
New organotin catalysts in urethane and polyurethane technology
Authors: Ratier M , Khatmi D , Duboudin J G 
Published: January 2005

AbstractThe use of organotin α‐substituted alcohols and carbamates as catalysts has been investigated in urethane and polyurethane preparations. These compounds have been shown to be new and very active catalysts. The mechanism of the reaction has been studied.
Historical cohort studies in three arsenic poisoning areas in japan
Authors: Tsuda Toshihide , Ogawa Takanori , Babazono Akira , Hamada Hirohisa , Kanazawa Susumu , Mino Yoshio , Aoyaam Hideyasu , Yamamoto Eiji , Kurumatani Norio 
Published: January 2005

AbstractThe results of historical cohort studies of three arsenic poisoning incidents in Japan are presented. The first episode was in a small mountainous community near an arsenic mine and refinery, at Toroku, where patients with chronic arsenism were certified by application of the Pollution Health Damage Compensation Law. The second area was in a small town, Namiki‐cho, near Nakajo‐machi, where wells were poisoned by arsenic produced in an arsenic(III) sulfide factory. As to the third cohort, eight residents of Nishikawa‐machi who ingested well‐water suffered arsenic poisoning about 35 years ago. The standardized mortality ratios were used in analyzing these data. Excesses of cancer mortality, especially lung cancer, were observed among the subjects in these areas. In Japan, there are many arsenic poisoning episodes, involving for example soy‐sauce poisoning, powdered‐milk poisoning and other incidents associated with arsenic mines. Thus it is necessary to clarify the chronic effects of arsenic in these areas.
Intake of different chemical species of dietary arsenic by the japanese, and their blood and urinary arsenic levels
Authors: Yamauchi Hiroshi , Takahashi Keiko , Mashiko Mari , Saitoh Juichiro , Yamamura Yukio 
Published: January 2005

AbstractWe calculated the intake of each chemical species of dietary arsenic by typical Japanese, and determined urinary and blood levels of each chemical species of arsenic. The mean total arsenic intake by 35 volunteers was 195±235 (15.8‐1039) μg As day−1, composed of 76% trimethylated arsenic (TMA), 17.3% inorganic arsenic (Asi), 5.8% dimethylated arsenic (DMA), and 0.8% monomethylated arsenic (MA): the intake of TMA was the largest of all the measured species. Intake of Asi characteristically and invariably occurred in each meal. Of the intake of Asi, 45‐75% was methylated in vivo to form MA and DMA, and excreted in these forms into urine. The mean measured urinary total arsenic level in 56 healthy volunteers was 129±92.0 μg As dm−3, composed of 64.6% TMA, 26.7% DMA, 6.7% Asi and 2.2% MA. The mean blood total arsenic level in the 56 volunteers was 0.73±0.57 μg dl−1, composed of 73% TMA, 14% DMA and 9.6% Asi. The urinary TMA levels proved to be significantly correlated with the whole‐blood TMA levels (r = 0.376; P<0.01).