Determining the site of reduction of 4-NO2-2,2 '-bipyridine and [Pt(4-NO2-2,2 '-bipyridine)Cl-2]

摘要

In situ UV/Vis and EPR spectroelectrochemistry experiments show that the unpaired electron in [4-NO2-bpy](1-) sits in an orbital which is based on the 4-NO2-py moiety and not spread over both py rings. The unpaired electron in [Pt(4-NO2-bpy)Cl-2](1-) is based on the 4-NO2-bpy ligand with some [bpy](1-) character. Labelling the NO2 group of 4-NO2-bpy with N-15 revealed that the larger coupling constant in the EPR spectrum of [4-NO2-bpy](1-) can be assigned to the N atom of the NO2 group. This coupling constant is significantly smaller in the EPR spectrum of [Pt(4-NO2-bpy)Cl-2](1-).