Synthesis of [Cr(N-3)(bpy)(H2O)(3)](2+) complex and kinetics of its Cr-(aq(2+))-catalyzed aquation in acidic media

The [Cr(N-3)(bpy)(H2O)(3)](2+) complex (bpy =2,2'-bipyridine) was obtained in reaction between [Cr(bpy)H2O)(4)](3+) and HN3/N-3(-) buffer. The complex is very inert even in acidic media. An addition of Cr-(aq)(2+) leads to fast liberation of bipyridine and formation of [Cr(N-3)(H2O)(5)](2+) ion as the main product. It is the result of electron transfer from Cr(II) to Cr(III) center via azide bridge. The rate law and the apparent activation parameters have been determined.