The excited state properties of a series of ruthenium(II) amine-substituted bipyridyl complexes, [Ru(bpy)(n)(NNbpy)(3) (n)](2+), were investigated by steady-state and transient absorption spectroscopy, as well as quantum chemical calculations. The steady-state absorption spectra of these complexes in CH3CN show a distinct red-shift of the (MLCT)-M-1 absorption with increasing numbers of amine substituent, whereas the emission spectra indicate an energy gap order of [Ru(bpy)(3)](2+) > [Ru(bpy)(2)(NNbpy)](2+) > [Ru(NNbpy)(3)](2+) > [Ru(bpy)(NNbpy)(2)](2+). Nanosecond, femtosecond transient absorption and electrochemical measurements suggest that NNbpy ligand has a strong influence on the electronic and emission properties of these complexes, due to electron-rich amine substituent. We illustrate how the numbers of amine substituent modulate the spectroscopic properties of transition metal complexes, which is related to the design of new electro-active systems with novel photoelectrochemical properties. (C) 2017 Published by Elsevier B.V.