Tracking of the formation of binuclear nickel complexes of [Ni2(µ-O2PR1R2)2(bpy)4]Br2 type by ESI and MALDI mass spectrometry

Abstract The formation of binuclear nickel complexes of type [Ni 2 ( µ -O 2 PR 1 R 2 ) 2 (bpy) 4 ]Br 2 , where R 1  = H, R 2  = phenyl (Ph), 2,4,6-trimethylphenyl (Mes), 2,4,6-triisopropylphenyl (Tipp) or R 1 R 2  =  OCH 2 CH(Et)NHCH(Ph) ; bpy = 2,2′-bipyridine, in solution and their fragmentation behavior have been investigated by ESI and MALDI mass spectrometry. It was found that binuclear cationic fragments [Ni 2 ( µ -O 2 PR 1 R 2 ) 2 (bpy) 2 Br] + are characteristic ions displaying the formation of binuclear nickel(II) complexes in solution.