Inorg. Chem. 1980, 19, 3284-3291
3284
Contribution from the Department of Chemistry and Chemical Engineering and the Saskatchewan Accelerator Laboratory, University of Saskatchewan, Saskatoon, Canada S7N OWO, and from the Hahn-Meitner-Institut fur Kernforschung GmBH, Bereich Strahlenchemie, D- 1000 Berlin 39, West Germany
Formation and Characterization of Platinum(111)-Ethylenediamine Complex Ions Using Pulse Radiolysis WILLIAM L. WALTZ,*Ia JOCHEN LILIE,*Ib R. TOM WALTERS,Ia and ROBERT J. WOODSIa
Received January 22, 1980
Pulse radiolysis experiments using conductivity, polarographic and UV-visible absorption detection techniques have been carried out on the reaction of hydroxyl radical with bis(ethylenediamine)platinum(II) perchlorate in aqueous media. This reaction is shown to proceed by OH addition to the platinum center to yield a nascent product where the metal is in a formal oxidation state of 111. The subsequent behavior of this Pt(II1) transient generates three additional transients, whose formations are dependent upon the pH and presence of free chloride ion. A mechanism is proposed whereby these transients are interrelated through acid-base, chloride substitution, and water elimination processes. Evidence is presented to support the classification of the Pt(II1) species into two groups having the compositions of Pt(en)2(X)"+ (X = OH, HzO, C1; n = 2, 3) and Pt(en)(en-H)2t (en-H = -NHCHzCH2NHz). For the former group, the respective wavelength maxima and molar absorption coefficients are 270 nm, ca. 4500 M-' cm-' (X = OH),
