Mass Spectrometric Studies of Reductive Elimination from Pd(IV) Complexes

Reductive elimination of ethane from the palladium­(IV) complex [PdMe3(bpy)­I] (bpy = 2,2′-bipyridine) is studied by electrospray ionization mass spectrometry. Palladium­(IV) complexes can be detected as binuclear clusters [Pd2Me6I­(bpy)2]+ or as complexes [PdMe3(bpy)­(L)]+ stabilized by an electron-donating ligand L. Fragmentation of all palladium­(IV) complexes is dominated by elimination of ethane which corresponds to the reductive elimination coupling of the methyl groups. The associated energy demands for different complexes reveal that the mononuclear complexes with poorly electron-donating ligands provide the fastest reaction.