ISSN:0268-2605    

DOI:10.1002/aoc.590020302

出版商:Longman Group UK Ltd.    

年代:1988

数据来源: WILEY

摘要:

AbstractSonochemical reactions involving organosilicon compounds are reviewed. Possible applications of ultrasonic irradiation for acceleration and initiation of various types of reactions are demonstrated along with examples from organic synthesis using organosilicon compounds. Also described are the sonochemical reactions of organic compounds containing the Group IVB elements germanium and tin, chemically related to silicon.

ISSN:0268-2605    

DOI:10.1002/aoc.590020303

出版商:Longman Group UK Ltd.    

年代:1988

数据来源: WILEY

摘要:

AbstractThe title compound, a new chiral alkyl 2,2′‐ bipyridine containing a rigid alkyl framework, can be prepared through a six‐step reaction sequence from (+)‐camphor. Coordination of the new ligand to rhodium(I) procatalysts occurs with difficulty and the resulting species display a very low stereoselectivity in the catalytic transfer hydrogenation of aceto

ISSN:0268-2605    

DOI:10.1002/aoc.590020304

出版商:Longman Group UK Ltd.    

年代:1988

数据来源: WILEY

摘要:

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.

ISSN:0268-2605    

DOI:10.1002/aoc.590020305

出版商:Longman Group UK Ltd.    

年代:1988

数据来源: WILEY

摘要:

AbstractIn the presence of iodine, a mixture of dichloromethane, iodoalkanes (alkyl = Me, Et, Pr, iso‐Pr, Bu, iso‐Bu, pentyl) and aluminum powder was irradiated at room temperature with ultrasound to give readily chloroiodomethane ICH2Cl. The preferred reactant to give the best yield of ICH2Cl was PrI. Alkylaluminum sesqui‐iodides were postulated as intermed

ISSN:0268-2605    

DOI:10.1002/aoc.590020306

出版商:Longman Group UK Ltd.    

年代:1988

数据来源: WILEY

摘要:

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 c

ISSN:0268-2605    

DOI:10.1002/aoc.590020307

出版商:Longman Group UK Ltd.    

年代:1988

数据来源: WILEY

摘要:

AbstractTributyltin compounds have been used for many years as wood preservatives. This study has provided, for the first time, an explanation for the previously reported dealkylation and/or volatilization of the tributyltin species in, and from, timber. Thus119Sn NMR studies have shown that, on impregnation into timber, bis(tributyltin) oxide, (Bu3Sn)2O, is rapidly converted to other tributyltin species, Bu3SnOX, and that these subsequently undergo disproportionation to Bu4Sn and Bu2Sn(OX)2compounds. We have additionally demonstrated that Bu4Sn, so produced, is not persistent in timber and is lost by volatilization. Since the rate of disproportionation of the Bu3SnOX species should be dependent upon the nature of the X group, it should be possible to affect significantly, if not to stop, this process by the use of alternative tributyltin fungicides, e.g. tributyltin methanesulphonate. However, tributyltin fungicides have been used successfully in wood preservation for at least 25 years. Therefore, it must be concluded that, even after disproportionation in timber, in service, sufficient preservative action is retained to prevent decay of wood under the conditions of natural exposure.

ISSN:0268-2605    

DOI:10.1002/aoc.590020308

出版商:Longman Group UK Ltd.    

年代:1988

数据来源: WILEY

摘要:

AbstractAn iron‐phthalocyanine polymer has been characterized by infrared spectroscopy, X‐ray diffraction and Mössbauer spectroscopy. The electrical properties of resistivity, dielectric constant and the thermally stimulated depolarization effect have been investigated in the temperature range 30–240°C. The depolarization of thermoelectret shows two current peaks at about 176°C and 200°C. The unpolarized sample also displays a pyroelectric current on heating, indicating the possibility of ferroelectric polarization. A temperature‐dependent measurement of the dielectric constant exhibits a dielectric maximum around 180°C which is likely due to electret current peaks. The results have been compared with a monomer of iron‐phthalocyanine and interpretations are made in terms of the highly delocalized π‐electron system of the phthalocyanine macrocycle being further extended

ISSN:0268-2605    

DOI:10.1002/aoc.590020309

出版商:Longman Group UK Ltd.    

年代:1988

数据来源: WILEY

摘要:

AbstractPolystyrene derivatives react with the lithioferrocenes Fe(η5‐C5H4Li)(η5C5H5),Fe(η5‐C5H5),Fe(η5‐C5H4Li)2,Fe[η5‐C5H3(CHMeNMe2)Li‐1,2] [η5‐C5H5], and with lithium ferrocenylphosphines, to yield ironcontaining materials. The Mössbauer spectra confirm the loading of unstrained ferrocene fragments, some oxidized, in all cases. The13C CP MAS NMR spectra also show the loading but the resolution (structural information) is not as good as can be obtained on model solid samples. Palladium(II) derivatives of the amine‐ and phosphine‐containg materials are active hydrogenation catalysts for olefins. Double‐bond migration also occurs

ISSN:0268-2605    

DOI:10.1002/aoc.590020310

出版商:Longman Group UK Ltd.    

年代:1988

数据来源: WILEY

摘要:

AbstractReaction of ferrocene with chlorendic anhydride (1,4,5,6,7,7‐hexachloro‐5‐norbornene‐2,3‐dicarboxylic acid anhydride) under Friedel–Crafts reaction conditions affords a new monosubstituted dervative of ferrocene which has significant flameretardant and smoke‐suppressant properties when incorporated into poly(vinyl chloride) (PVC). The monocarboxylic acid from the above reaction undergoes smooth methylation with diazomethane to give the corresponding methyl ester.1H and13C NMR spectra of these compounds have been compared with those obtained from similar compounds, namely β‐ferrocenoylpropanoic acid and its methyl ester. Distant asymmetric centres in the chlorendic anhydride substituent markedly affect the proton spectra of the ferr

ISSN:0268-2605    

DOI:10.1002/aoc.590020311

出版商:Longman Group UK Ltd.    

年代:1988

数据来源: WILEY