摘要:

AbstractThe separation of arylarsonic acids by HPLC on a reverse‐phase C18column is described. Solutions containing these arsenicals and others such as arsenobetaine are photo‐oxidized to arsenate by ultraviolet (UV) radiation (1200 W, 1 h exposure). This allows the analysis of the solution for arsenic by hydride generation techniques. The method, UV HGAA, is developed and applied to the determination of arsenic in the methanol extracts of the Manila clam (Verupis japonica) and the Horse clam (Schizothoerus nutal

ISSN:0268-2605    

DOI:10.1002/aoc.590020102

出版商:Longman Group UK Ltd.    

年代:1988

数据来源: WILEY

摘要:

AbstractThe infrared spectra of [CpFe(CO)2]2, [CpMo(CO)3]2and Mn2(CO)10(Cp=η‐C5H5) embedded in films of polystyrene (PS), poly(methyl methacrylate) (PMMA), and polystyrene‐polyacrylonitrile (PSAN), are comparable with those of the dimers in toluene, ethyl acetate and acetonitrile, respectively. Irradiation of the embedded dimers with UV light led to decomposition in PS and PMMA, while in PSAN the complexes Cp2Fe2(CO)3PSAN and Mn2(CO)9PSAN were formed, wherein a pendant nitrile group is coordinated to one of the metal atoms. Exposure of the embedded dimers to iodine vapour gave CpFe(CO)2I, CpMo(CO)3I and Mn(CO)5I with the reaction being much slower in PMM

ISSN:0268-2605    

DOI:10.1002/aoc.590020103

出版商:Longman Group UK Ltd.    

年代:1988

数据来源: WILEY

摘要:

AbstractThe problems of technique and equipment used in the crosslinking of polyethylene polymer are discussed. The practice of organosilicon chemistry for crosslinking of polyethylene chains is also considered. The use of a Cavity Transfer Mixer (CTM) for control of silane‐based crosslinking is described and the properties of the resultant polymers are tested. Use of this crosslinking method via the CTM produces polyethylene with improved hot‐water characterist

ISSN:0268-2605    

DOI:10.1002/aoc.590020104

出版商:Longman Group UK Ltd.    

年代:1988

数据来源: WILEY

摘要:

AbstractA novel method of analysis of inorganic and organometallic compounds is reported. Essentially this utilizes the well‐documented hydride generation technique, but in the present method the hydrides are generated from their involatile precursors (e.g. chlorides) on a GC column and separated from each other and from extraneous materials on the same GC column in a single process. Using the method, a solution of butyltin chlorides can be directly injected into a GC AA system to yield the volatile hydrides for separation, detection and quantification.To date, species analysed by this method include inorganic As(III), Me2AsOOH, inorganic Sb(III) and Sb(V), MeSnCl3, Me2SnCl2, Me3SnCl, Et2SnCl2, Et3SnCl, BuSnCl3, Bu2SnCl2, Bu3SnCl and Pr3SnCl.With the use of the internal standard Pr3SnCl and with the almost complete hydridization afforded by the technique, the procedure is shown to eliminate errors and to reduce the time involved in the analysis. The use of on‐column derivatization also allows for the possibility that, in some cases, organotin hydrides reported to be found in the natural environment may, in fact, be organotin chlorides being reported as hydrides owing to inadvertent hydride production on the column. Some reports of successful gas chromatography for organotin halides could also conceivably be due to on‐column hydride gener

ISSN:0268-2605    

DOI:10.1002/aoc.590020105

出版商:Longman Group UK Ltd.    

年代:1988

数据来源: WILEY

摘要:

AbstractA number of antitumor‐active octahedral organotin complexes of the type R2SnX2L2, where R=ethyl or phenyl, X = chloride or bromide, and L2= o‐ phenanthroline or 2‐(2‐pyridyl)benzimidazole, have been shown to exhibit in vitro antiherpes activity towards both herpes simplex virus types 1 and 2 (HSV‐1 and HSV‐2). In addition, a series of mono‐, di‐, and tri‐organotin halides (alkyl and phenyl) demonstrated weak antiherpes activity in the same viral assay system. Selectivity indexes for the tin compounds were calculated and compared with those available in the literature for a number of well‐characterized and commercially important antivirals, e.g. adenine‐9‐β‐D‐arabinofuranoside (ara‐A), cytosine‐β‐D‐arabinofuranoside (ara‐C), 5‐iodo‐2′‐deoxyuridine (IDU) and 9‐(2‐hydroxyethoxymethyl)guanine (acyclovir, ACY). Although the organotin complexes are less effective in vitro than either ACY or IDU, as determined by their selectivity indexes, they are comparable in activity with both ara‐A and ara‐C in this particular assay. With few exceptions, most notably (C2H5)2SnBr2(o‐phen), the organotin compounds examined in this study are more active against HSV‐1 (F strain) than HSV‐2 (MS strain). The results presented here represent the first study

ISSN:0268-2605    

DOI:10.1002/aoc.590020106

出版商:Longman Group UK Ltd.    

年代:1988

数据来源: WILEY

摘要:

AbstractThe incorporation of a poly[ferrocene‐1, 2 (1, 3: 1, 1′)diylmethylene] fraction with M̄n=2100 as a smoke suppressant additive into both unplasticized and di(2‐ethylhexyl)phthalate‐plasticized, calcium carbonate‐filled poly(vinyl chloride) (PVC) compositions entails appreciable reductions in smoke evolution during combustion tests relative to unmodified formulations. Best results, with smoke density reductions in the range 25‐80%, are obtained at the 3% loading level, with higher additive concentrations causing no further improvements. The findings of this study may have implications on the design of other polymeric engineering materials exposed to potential

ISSN:0268-2605    

DOI:10.1002/aoc.590020107

出版商:Longman Group UK Ltd.    

年代:1988

数据来源: WILEY

摘要:

AbstractThe stability of three synthetic pyrethroids (cypermethrin, deltamethrin and permethrin) to selected tributyltin compounds, Bu3SnX [where X = OSnBu3, Cl, O2CC6H5, O2C(naphthenyl), OSO2C2H5], (Bu3SnO)3PO and (Bu4N) (Bu3SnCl2), in toluene solution was investigated by infrared spectroscopy over a 24‐week period. It was found that only (Bu3Sn)2O reacted with the pyrethroids and that their order of reactivity was cypermethrin>deltamethrin>permethrin. An attempt was made to elucidate the reaction mechanism(s) occurring between (Bu3Sn)2O and the pyrethroids by studying mixtures of this tributyltin fungicide with simple model compounds, R1CO2R2where R1=CH3; R2=CH2C6H5and R1=cyclo‐C3H5and R2=CH2C

ISSN:0268-2605    

DOI:10.1002/aoc.590020108

出版商:Longman Group UK Ltd.    

年代:1988

数据来源: WILEY

摘要:

AbstractCytotoxicity of organotin compounds is assessed and their effectiveness against leukemia is discussed. The functional groups attached to the tin atom in organotin compounds control the cytotoxicity of the compound towards the thymus gland. The four organotin moieties which have the greatest toxic effect upon the thymus gland are the tri‐n‐butyltin, di‐n‐butyltin, tri‐n‐propyltin and di‐n‐octyltin groups. Compounds containing these groups also exhibit the poorest test‐control ratio (T/C) values when tested as anti‐cancer agents against leukemic mice

ISSN:0268-2605    

DOI:10.1002/aoc.590020109

出版商:Longman Group UK Ltd.    

年代:1988

数据来源: WILEY

摘要:

AbstractA method is described for the analysis of solutions containing inorganic tin and butyltin compounds. It can be used to determine total tin at a concentration of 20 ng dm−3using a 5 dm3sample. The method is based on solvent extraction with dichloromethane containing tropolone and determination of the tin as inorganic tin by atomic absorption spectroscopy using electrothermal atomization. The extracted butyltin compounds can be separated by paper chromatography and the tin content of the individual spot determined as above. Observations on the stability of butyltin compounds in water at the ∼2 mg dm−3(Sn) are inc

ISSN:0268-2605    

DOI:10.1002/aoc.590020110

出版商:Longman Group UK Ltd.    

年代:1988

数据来源: WILEY

摘要:

AbstractSamarium(II)‐induced coupling of acid chlorides with allylic halides gave diallylated tertiary alcohols. Monoallylated allylic ketones could not be obtaine

ISSN:0268-2605    

DOI:10.1002/aoc.590020111

出版商:Longman Group UK Ltd.    

年代:1988

数据来源: WILEY