A comparative examination of the electronic interactions across a series of trimetallic actinide and mixed lanthanide-actinide and lanthanum-actinide complexes is presented. Using reduced, radical terpyridyl ligands as conduits in a bridging framework to promote intramolecular metal-metal communication, studies containing structural, electrochemical, and X-ray absorption spectroscopy are reported for (C5Me5)(2)An[-N=C(Bn)(tpy-M{C5Me4R}(2))](2) (where An = Th-IV, U-IV; Bn = CH2C6H5; M = La-III, Sm-III, Yb-III, U-III; R = H, Me, Et} to reveal effects dependent on the identities of the metal ions and R-groups. The electrochemical results show differences in redox energetics at the peripheral "M" site between complexes and significant wave splitting of the metal- and ligand-based processes indicating substantial electronic interactions between multiple redox sites across the actinide-containing bridge. Most striking is the appearance of strong electronic coupling for the trimetaillic Yb-III-U-IV-Yb-III, Sm-III-U-IV-Sm-III, and La-III-U-IV-La-III complexes, [8](-), [9b](-), and (10b](-), respectively, whose calculated comproportionation constant K-c is slightly larger than that reported for the benchmark Creutz-Taube ion. X-ray absorption studies for monometallic metallocene complexes of U-III U-IV, and U-V reveal small but detectable energy differences in the "white-line" feature of the uranium L-III-edges consistent with these variations in nominal oxidation state. The sum of these data provides evidence of 5f/6d-orbital participation in bonding and electronic delocalization in these multimetallic f-element complexes. An improved, high-yielding synthesis of 4'-cyano-2,2:6',2 ''-terpyridine is also reported.