摘要:

AbstractThe polarography of lead ion in dimethyl sulfoxide (DMSO) was investigated in the DMSO concentration range 0–80 vol.%. The complex species identified were Pb2(DMSO)4+3, Pb(DMSO)2+3and Pb(DMSO)2+6in [DMSO]<10 vol.%, 10<[DMSO]6.0. The rate constants of electro‐reduction and electro‐oxidation, activation energies were determined. The hydrolysis constants of lead ion in dimethyl sulfoxide concentration 40–70 vol.% atpH 4.5–6.0 were found to be of the order of 10−6. The stability constants of the Pb(DMSO)2+3and Pb(DMSO)2+0were also determined to be of the orders of 101an

ISSN:0009-4536    

DOI:10.1002/jccs.198300023

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractThe interaction between diethylenetriaminepentaacetic acid (DTPA or HsZ) and Ce(III) and Th(IV) ions has been investigated spectrophotometrically in aqueous solution at an ionic strength of 0.1 and for various temperatures. It has been found that the Ce(III)‐DTPA chelate (1:1) exhibited a characteristic absorption maximum at 297nm, and the optimumpH range is between 3.4 to 4.4. The absorption of Ce(III)‐DTPA chelate is considerably diminished by adding small amounts of Th(IV) ions. This phenomenon was used to evaluate the formation constant of Th(IV)‐DTPA chelate (1:1). The formation constants and the thermodynamic properties characterizing the formation of the chelates have been calculated at 25°. The results are as f

ISSN:0009-4536    

DOI:10.1002/jccs.198300024

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractThe mixture of metal ions [Bi(III), Fe(III), Fe(II), Cu(II), Zn(II), Ni(II), Co(II), Pb(II), Cd(II), Mn(II)] were separated in the bonded‐phase strong cation exchange column (Vydac‐401 SA) and monitored at 540nmafter a postcolumn reaction with 4‐(2‐pyridylazo)‐resorcinol (PAR). Citrate, tartrate, lactate and α‐hydroxyisobutyrate buffer were used as eluent and it has been found that the elution order of some metal ions were changed with different eluents. The detection limits and the calibration curves of metal ions were

ISSN:0009-4536    

DOI:10.1002/jccs.198300025

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractA method for the determination of trace molybdenum in uranium is described based on its specific catalytic reduction wave in the presence of nitric acid. Molybdenum is separated from uranium by α‐benzoin oxime extraction and determined by differential pulse polarography. As lower as 1 ng/ml of Mo(VI) is determinable and 98% of recovery can be obtained at present wo

ISSN:0009-4536    

DOI:10.1002/jccs.198300026

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractMethane pyrolysis has been performed in a recycled flow system in the temperature range of 1103 to 1220Kto investigate the time profile of product distribution. Hydrogen, ethylene, and benzene are found to be the major products before the soot formation. Similar to the literature reports of studies in conventional flow systems, the rate of methane conversion is slow at the beginning of the decomposition and becomes fast after an incubation period. This increase in the decomposition rate after the incubation period is generally called autocatalysis. The proposed reason for this autocatalysis has been the catalytic effect of the secondary products,i.e., soots and carbon deposits. The present study showed that autocatalysis started before the accumulation of these products, and that decomposition of propylene and other minor but reactive products might be attributed to this autocatalysis effect.

ISSN:0009-4536    

DOI:10.1002/jccs.198300027

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractPhytochemical examination on the leaves ofIlex cornutaLindl. (Aquifoliaceae) resulted in the isolation and identification of lupeol (I), 3β‐hydroxylup‐20(29)‐en‐30‐al (II), oleanolic acid (III), and β‐sitosterol‐β

ISSN:0009-4536    

DOI:10.1002/jccs.198300028

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY

摘要:

Abstractβ‐Sitosterol, β‐sitosteryl palmitate, β‐sitosteryl‐β‐D‐glucoside and cyclolaudenol were isolated from the rhizomes, long chain aliphatic esters and an UV stabilizer, octabenzone, were isolated from the leaves ofConio

ISSN:0009-4536    

DOI:10.1002/jccs.198300029

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractThree crystalline compounds, rhamnetin(1), rhamnocitrin(4), and kaempferol(6) were isolated from the hot methanol extract of leaves ofRhamnus formosanaMatsum.

ISSN:0009-4536    

DOI:10.1002/jccs.198300030

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractThe preparation, for the first time, of the deprotonated complexes of oxamic acid with La(III), Gd(III), Tb(III), Er(III), Tm(III) and Lu(III) is reported. Analytical results, conductometric measurements, magnetic moments and spectral data (IR and diffuse reflectance spectra) are discussed in terms of possible structural types. The oxamate anion acts as a N, O bidentate non‐bridging ligan

ISSN:0009-4536    

DOI:10.1002/jccs.198300031

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractComplexation reactions of 5,6,7,8,9,10,16,17‐octahydrodibenzo[e, m][1, 4]dioxa‐[8, 11]diazacyclotetradecine‐copper(II) complex with halide and pseudohalide ions have been studied at 25.0° in three water‐methanol mixed solvents by spectro‐photometric method. It is found that the equilibrium constants increases in the order of 50 vol.% CH3OH<75 vol.% CH3OH<95 vol.% CH3OH for solvents and I‐

ISSN:0009-4536    

DOI:10.1002/jccs.198300032

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY