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Chlorotriammineplatinum(II) Ion : Acid Hydrolysis and Isotopic Exchange of Chloride Ligand

Description: Abstract: The acid hydrolysis of [Pt(NH3)3Cl] has been shown to occur to a measurable extent. for this reaction: [APt(NH3)cCl]+ + H2O [chemical equilibrium symbol with rate constant k-1 above and k1 below] [Pt(NH3)c(H2O)]++ + Cl-, the equilibrium quotient was measured at 25 degree C and 35 degree C. At 25 degree C this quotient was 8.4 x 10-5 at [Mu] (ionic strength) = 0 and 25 x 10-5 at [mu] = .318 M. This variation is consistent with the expected changes in activity coefficients. [Delta]H for the reaction was found to be approximately 0. The rate constant, k1 was 2.3 x 10-5 sec.-1 at 25 degree C and it was nearly independent of ionic strength. The acid hydrolysis provides a mechanism for the exchange of the chloride ligand and Cl-. Exchange experiments with Cl36 showed that in addition to the acid hydrolysis, a process, first order in both, [Pt(NH3)3Cl] and Cl- with a rate constant of 6. 10-5 sec.-1M.-1 contributes to the exchange. The behavior of the entire series of chloro-ammines of platinum(II) toward acid hydrolysis and chloride exchange has been summarized, and a likely mechanism for the process has been discussed.
Date: May 15, 1961
Creator: Aprile, Ferruccio. & Martin, Don S., Jr.

Kinetics of the Alkylation and Acylation of Nickel Dipivaloyimethide

Description: Abstract: A study was made of the reactions of nickel dipivaloyimethide with the following reagents: tirphenylmethyl chloride, benzoyl chloride, [rho]-chloro and [rho]-methyl benzoyl chloride. Infrared spectra of the easily hydrolyzed product of tritylation seem to indicate that enol ether, the product of O-alkylation, is formed. the acyl halides reactor to give the triketones. the latter have been characterized by spectra and C, H, analysis. the kinetics of all the reactions studied were found to settle down to a second order rate law after a fast initial reaction. These reactions are catalyzed by an impurity in the acyl chloride. Then benzoyl chloride with a different purity was used, the second order rate constant for the benzoylation of nickel DPM ranged from 0.02-0.20. The air oxidation of nickel dipivaloymethide was found to compete with the acylations under the conditions of these studies. An investigation of the phenomenon showed that nickel pivalate is the major product. Pivalic acid was also detected in the product mixture. This oxidation takes place in chlorobenzene and in aromatic hydrocarbons. It occurs in 1201 when small amount on benzoyl chlorides are present.
Date: July 1959
Creator: Johnson, Kenneth Eugene & Hammond, George Simms, 1921-2005
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