Highly stable eta(2)-porphyrin Ru(II) pi complexes have been synthesized. The formation of the eta(2) pi it bond has been facilitated through pi-pi stacking interactions between the porphyrin and the planar ligand on Ru. pi coordination of ruthenium to porphyrin results in dramatic changes in the aromaticity and electronic properties. These properties are controllable via fine-tuning of the ligand on ruthenium.