摘要:

AbstractThe reaction rate for the reduction of cyanocobalamin (B12) with Ti(III) in HCl and KCl solutions at constant ionic strength was followed by spectrophotometric measurements at 15°, 20°, 25° and 30°C. The reaction rats was found to be of pseudo‐first‐order with respect to B12and of second‐order with respect to B12and Ti(III) in HCl solutions. The second‐order rate constant was given by for the processes, The values ofK0obtained were 0.80∼1.29 liter mole−1sec−1in the range of ionic strength 0.2∼0.5Mat 30°. The average activation energy

ISSN:0009-4536    

DOI:10.1002/jccs.197200022

出版商:WILEY‐VCH Verlag    

年代:1972

数据来源: WILEY

摘要:

AbstractUranyl chelate of 7‐iodo‐8‐hydroxyquinoline‐5‐sulphonic acid (ferron) has been studied spectrophotometrically in aqueous solution at 25° and at an ionic strength of 0.1M. The formation of this chelate waspHdependent, and the optimumpHrange was between 5.4 to 5.9, Its mole ratio of ligand to uranyl ion was found to be 2 to 1 stoichiometry and the stability constant, logK, was determined as 13.32±0.08. By using the wave‐length of 365mu, determination of trace amount of uranyl ion with the sensitivity of 0.54 γ/c

ISSN:0009-4536    

DOI:10.1002/jccs.197200023

出版商:WILEY‐VCH Verlag    

年代:1972

数据来源: WILEY

摘要:

AbstractMeta‐nitrobenzoylacetanilide (NBAA) forms violet coloured chelate Fe(NBAA)2with Fe (III) in 60% ethanol medium with λmaxat 530nm. The molar absorptivity, sensitivity, effect of diverse ions in spectrophotometric determination of iron, and effect of ionic strength on the stability constant have been investigated. The free energy of formation of the chelate, enthalpy change and the entropy change have also been calculated and are found to be −9.44kcal/mole, −4.97kcal/moleand 15.23e.u. respec

ISSN:0009-4536    

DOI:10.1002/jccs.197200024

出版商:WILEY‐VCH Verlag    

年代:1972

数据来源: WILEY

摘要:

AbstractElectrometric behavior of tetraphenylboron (TPB) on mercury electrode was investigated, Potentiometric titration of Hg2++with TPB−showed that TPB−reacted with Hg2++with stoichiometric ratios (equivalent) of 1:3 and 1:8 (TPB: Hg2++) to form diphenylmercury, Hg(C6H5)2, and phenylmercuric ion, C6H5—Hg+. Only 1:3 stoichiometry was found in the reverse titration. Potential response of TPB−on mercury assumed the same result, and furthermore, if the concentration of TPB−was around 10−3Mor higher, another stoichiometry of 1:1 with formation of Hg(I)‐tetraphenylborate might be possible. Controlled potential oxidation of TPB−on mercury gave Hg(C6H5)2and C6H5Hg+which were identified by m. p. measurements and elem

ISSN:0009-4536    

DOI:10.1002/jccs.197200025

出版商:WILEY‐VCH Verlag    

年代:1972

数据来源: WILEY

摘要:

AbstractIn the photolysis of diazomethane in the presence of ammonia, the ratio of the products, [CH3NH2/[C2H4], has been studied as a function of pressure, temperature and composition of diazomethane‐ammonia mixture, respectively. This ratio increases with increase in total pressure at low pressures and approaches a constant at high pressures.In the diazomethane‐methylamine system, the ratio of products, [CH3CH2NH2]/[(CH3)2NH], is independent of the pressure in the range from 23 to 500 torr. The rates of insertion of singlet methylene into C–H bond and N–H bond of CH3NH2are found to be about t

ISSN:0009-4536    

DOI:10.1002/jccs.197200026

出版商:WILEY‐VCH Verlag    

年代:1972

数据来源: WILEY

摘要:

AbstractReactions of tricyclopentadienyl cerium (IV) chloride (I) and bisindenyl cerium (TV) dichloride (II) with mono‐, di‐, and trihydroxy phenols have been studied and some phenoxide derivatives of (I) and (II) have been isolated. Infrared spectra and some physical characteristics of all these compounds are Repor

ISSN:0009-4536    

DOI:10.1002/jccs.197200027

出版商:WILEY‐VCH Verlag    

年代:1972

数据来源: WILEY

摘要:

AbstractNickel (II) and Cobalt (II) form in 50% ethanolic medium, a bluish violet complex with Bromopyrogallol Red (BPR) in the mole ratio of 1:1 (Ni(II)) and 1:2 (Co(II)), both having at 620nm, stable in thepH ranges 6.0‐7.5 and 5.5‐7.0, respectively. The thermodynamic stability constants and overall changes in the free energy of formation, enthalpy and entropy have been determined in both the cases.Beer's law is obeyed over the concentration range 0.5‐5.0ppmof Nickel and 0.2‐3.0ppmof Cobalt at 620nm. The net molar absorptivities are 1.6 × 104and 2.9 × 104and the sensitivities are 0.00367 and 0.00219 μgof Nickel and Cobalt percm,/2. The effect of diverse ions on the metal ions determination is als

ISSN:0009-4536    

DOI:10.1002/jccs.197200028

出版商:WILEY‐VCH Verlag    

年代:1972

数据来源: WILEY