Tuning the Electrochemiluminescence Color by Potential: Design of a Series of Heterodinuclear Ir/Ru Labels

A series of heterodinuclear complexes RbPY)(2)Ru(bpy)(CH2)(n)(bpy)Ir(df-ppy)(2)](3+) (1, where bpy is 2,2'-bipyridyl, df-ppy is 2(2,4-difluorophenyl)pyridine, and n = 10, 12, 14) have been designed and synthesized. Both red (from the Ru moiety) and green (from the It moiety) electrochemiluminescence (ECL) can be acquired simultaneously thorough alternation of the scanning potentials; especially, a good linear calibration curve between the ECL intensity ratio (I-Ru/I-Ir) and the scanning potential can be reached over a potential range from 0.55 to 1.6 V. All of this provides a general methodology for developing electrochemistry induced light-emitting devices and a ratiometric ECL detection method.