The title molecule, 2,2';9',2"-ter[1,10]phenanthroline can be prepared from 2,9-dichloro-1,10-phenanthroline in three steps through the corresponding diacetyl intermediate. The ligand acts as a hexadentate with K+, while two molecules form a trinuclear, helical complex with Cu(I), which evidences pi-stacking interactions and Cu-Cu distances of 3.01-3.04 angstrom. Electrochemical analysis shows a strong interaction between the Cu(I) centers.