The electronic structures, redox chemistry, and excited-state properties of tungsten-containing oligo-phenylene-ethynylenes (OPEs) of the form W[C(p-C6H4CC)(n-1)Ph](dppe)(2)Cl (n = 1-5; dppe =1,2-bis-(diphenylphosphino)ethane) are reported and compared with those of organic analogues in order to elucidate the effects of metal-for-carbon substitution on OPE bonding and electronic properties. Key similarities between the metallo- and organic OPEs that bear on materials-related functions include their nearly identical effective conjugation lengths, reduction potentials, and;14 orbital energies and delocalization. In addition to these conserved properties, the tungsten centers endow OPEs with reversible one-electron oxidation chemistry and long-lived emissive triplet excited states that are not accessible to organic OPEs. The electronic similarities and differences between metallo- and organic OPEs can be understood largely on the basis of pi/pi* orbital energy matching between tungsten and organic PE fragments and the introduction of an orthogonal mid-pi/pi*-gap d orbital in metallo-OPEs. These orbital energies can be tuned by varying the supporting ligands; this provides a means to rationally implement and control the emergent properties of metallo-OPE materials.