摘要:

AbstractSpecies‐specific measurements of the five tetraalkyllead compounds used in gasoline and their intermediate decomposition products, the tri‐ and di‐alkyllead species, have been made in vehicle exhaust fumes. Under normal engine running conditions 0.3–3% of the lead emitted in exhaust is as an organic compound, but cold, choked engines emit proportionally much larger amounts of alkyllead. Alkyllead is emitted in both the gas and the aerosol

ISSN:0268-2605    

DOI:10.1002/aoc.590020202

出版商:Longman Group UK Ltd.    

年代:1988

数据来源: WILEY

摘要:

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 f

ISSN:0268-2605    

DOI:10.1002/aoc.590020203

出版商:Longman Group UK Ltd.    

年代:1988

数据来源: WILEY

摘要:

AbstractThe direct synthesis of the two industrially important organotin intermediates, di(n‐butyl)tin and di(n‐octyl)tin dihalides, has been investigated by reacting the appropriate alkyl halide with metallic tin undervarying conditions. Observations were made on the influences of temperature, pressure, reaction time, nature of the tin metal, organic halide/tin reactant ratios and the presence of catalysts on the extent of tin conversion and yields of the organotin products. The efficacy of the onium halides, notably n‐Bu4NI, Me3SI and Ph3MeAsI, either singly or in binary combinations with iodine or inorganic iodine compounds, in catalysing the synthesis of the above dialkyltins as well as higher di(n‐alkyl)tin analogues is de

ISSN:0268-2605    

DOI:10.1002/aoc.590020204

出版商:Longman Group UK Ltd.    

年代:1988

数据来源: WILEY

摘要:

AbstractTrihalogermyl‐furans and ‐thiopheneswere prepared by inserting germanium dibromide (GeBr2) generated from the dibromogermane(II) dioxanate complex into the carbon‐halogen bond of halo‐furans and ‐thiophenes. Their ethanolysis and transesterification by triethanolamine yielded the germatraneswhich were subjected to psychotropic activity assays. The psychotropic properties of germatranes were found to depend on the type of the heterocycle and on the position of the germatra

ISSN:0268-2605    

DOI:10.1002/aoc.590020205

出版商:Longman Group UK Ltd.    

年代:1988

数据来源: WILEY

摘要:

AbstractSeven new triorganotin(IV) complexes of the type R3SnL (L=N‐phthaloyl derivatives of glycine, DL‐alanine or N‐acetyl‐ and N‐benzoyl‐glycine and ‐cysteine; R‐n‐C4H9or C6H5) have been prepared by reacting the sodium salt of the ligand and the triorganotin(IV) chloride in 1:1 molar ratio in methanol. The complexes have been characterized by elemental analysis, molecular mass determination, IR and1H NMR spectroscopy. The complexes are monomeric in molten camphor and are moderateely soluble in the common organic solvents. The spectral data support cis five‐coordinate complexes with an unsymmetrical bidentate coordination of the carboxylate group to tin.The complexes exhibit some insecticidal effect on Bean Weevils (Sitophilus granaria) even at low concentration and they also show fungicidal activity onAspergillus nigerandHelminthosporium taulosum.Some of the complexes are found to be more effective than tri‐n‐butyltin and

ISSN:0268-2605    

DOI:10.1002/aoc.590020206

出版商:Longman Group UK Ltd.    

年代:1988

数据来源: WILEY

摘要:

AbstractAs part of a project to provide hydrophilic ferricenium compounds for biomedical investigations, several ferrocenyl‐alkanoic and ‐alkanedioic acids, including ferrocenylacetic, β‐ferrocenylpropionic and γ‐ferrocenylbutyric acids, ferrocylmalonic acid, and the two thioether derivatives, S‐ferrocyl‐ β‐mercaptopropionic acid and S‐ferrocylthiomalic acid, are chemically oxidized to the respective ferricenium salts. While oxidation with the nitromethane/tetrafluoroboroboric acid system affords poorly crystallizing tetrafluoroborate salts, for the most part possessing unsatisfactory solubility characteristics, more hydrophilic salts containing the tetrachloroferrate(III) (FeCl 4−) counterion, albeit contaminated with FeCl2, are obtained by treatment of the substrate acids with excess iron(III) chloride. The most promising method of ferricenium generation investigated in this study involves oxidation by means of the p‐benzoquinone‐HCL‐FeCl3system, which directly provides the respective ferricenium tetrachloroferrate salts. The IR and Mössbauer spectra confirm the expected ferricenium structures. The method appears attractive enough to be utilized in future investigations involving more complex notably polymeric, derivatives of

ISSN:0268-2605    

DOI:10.1002/aoc.590020207

出版商:Longman Group UK Ltd.    

年代:1988

数据来源: WILEY

摘要:

AbstractConventional (whole animal) toxicity tests were made withScrobicularia plana(Da Costa), an infaunal estuarine bivalve, and compared with the responses recorded from siphonal preparations. Exposure ofScrobiculariato low concentrations of triethyllead chloride and trimethyllead chloride, for 35 and 60 days respectively, produced typical response curves. However, mortality had not become asymptotic with time at lower concentrations, suggesting further mortality with increased exposure time. An approximate incipient lethal concentration was predicted.A siphonal preparation technique with isolated andin‐situinhalent siphons ofScrobiculariawas used to estimate the lowest effect concentrations of alkyllead compounds. Response to alkyllead was indicated by contraction of the siphon, recorded via an isotonic transducer. Trialkyllead compounds were more toxic than the respective dialkylleads and inorganic lead. Toxicity of trialklleads and inorganic lead. Toxicity of trialkylleads increased with alkyl chain length. Pure tetraethyllead did not cause any siphonal contraction even when applied directly to the preparation. It was concluded that tetraethyllead has a low toxicity or is non‐toxic in pure f

ISSN:0268-2605    

DOI:10.1002/aoc.590020208

出版商:Longman Group UK Ltd.    

年代:1988

数据来源: WILEY

摘要:

AbstractExperimental instrumentation for the speciation of butyltin compounds by hydride generation and gas chromatography‐quartz furnace atomic absorption spectrometry is described. Evaluation of a number of extraction methods revealed that simple acid leaching of oyster samples gave adequate recoveries. The levels of each butyltin species in oyster flesh and gill are reported together with the tentative identification of a mixed methylbutyltin compoun

ISSN:0268-2605    

DOI:10.1002/aoc.590020209

出版商:Longman Group UK Ltd.    

年代:1988

数据来源: WILEY

摘要:

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 progr

ISSN:0268-2605    

DOI:10.1002/aoc.590020210

出版商:Longman Group UK Ltd.    

年代:1988

数据来源: WILEY

摘要:

AbstractThere exists a high correlation between molecular total surface area (TSA) values and diorganotin toxicity towards several distinct types of organisms. This correlation was found for N2a neuroblastoma cells, 3T3 fibroblasts,Daphnia magna Rhithropanopeus harrisii and Ankistrodesmus falcatus. In the case ofRhithropanopeus harrisii, a high correlation was also found between TSA and toxicity for triorganotins as well. This study suggests that the relationship between TSA and toxicity is a function of the hydrophobicity of the organotin compounds rather than electronic or steric effects.

ISSN:0268-2605    

DOI:10.1002/aoc.590020211

出版商:Longman Group UK Ltd.    

年代:1988

数据来源: WILEY