Mechanisms of the Bridge Cleavage Reactions of Di-µ-hydroxo-, µ-Hydroxo-µ-oxo-, and Di-µ-oxo-bis { bis( o-phenanthroline )chromium(III)} Complex Ions in Acid and Base Media

Department of Chemistry, University of Kalyani, Kalyani-741 235
Manuscript received 26 November 1996, revjsed 2 June 1997, accepted 9 July 1997

Mechanistic studies on the bridge cleavage reactions of three double-bridged complexes, di-µ-hydroxo-, µ-hydroxo-µ-oxo-, and diµ- oxo-bis{bis(o-phenanthrolinc)chromium(III)} complex ions have been made in acidic (57-75°) and in basic (47-60°) media. In acid medium, bridge cleavage reaction of all the complexes takes place after transformation to the dihydroxo form, both by acid-catalyzed and acid-free paths. In basic medium, all the complexes transform to the di-oxo form which undergoes bridge cleavage by base independent path only. Bond cleavage processes are similar in both acidic and basic media.