Inner and outer-sphere reductive elimination during decomposition of the platinum(IV) β-ammonioethyl complex in aqueous solutions.

Autor: Zamashchikov, V., Mitchenko, S., Slinkin, S.
Zdroj: Russian Chemical Bulletin; 1994, Vol. 43 Issue 3, p478-484, 7p
Abstrakt: The β-ammonioethyl complex of platinum (IV), KPt(CHCHNH)Cl, undergoes two types of transformations in aqueous chloride solutions, i.e., inner- and outer-sphere reductive elimination, depending on the pH of the medium. In acidic solutions outer-sphere decomposition, which consists of an S2 attack by the chloride ion of the α-carbon atom of the complex anion [ trans-Pt(CHCHNH)Cl(HO)] (or at the complex with a vacant coordination site in the trans-position relative to the -CHCHNH group; these two variants are kinetically indistinguishable) occurs to yield β-chloroaminoethane and PtCl. In alkaline solutions decomposition occurs after deprotonation of the ammonium group of the starting complex as an intramolecular nucleophilic attack of the amino group at the α-carbon atom in [ trans-Pt(CHCHNH)Cl(HO)] (or in the complex with a vacant coordination site in the trans-position relative to the β-aminoethyl group). In this case aziridine (Az) and PtCl are the primary products. Aziridine is coordinated with the unreacted starting complex to give a compound that is stable with respect to reductive elimination. Cyclometallation of the latter species gives the uncharged complex insoluble in water. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
Externí odkaz: