Two novel ruthenium polypyridine complexes, [Ru(bpy)(2)Cl(BPEB)](PF6) and {[Ru(bpy)(2)Cl](2)(BPEB)}(PF6)(2) (BPEB = trans-1,4-bis[2-(4-pyridyl)ethenyl]benzene), were synthesized and their characterization carried out by means of elemental analysis, UV-visible spectroscopy, positive ion electrospray (ESI-MS), and tandem mass (ESI-MS/MS) spectrometry, as well as by NMR spectroscopy and cyclic voltammetry. Cyclic and differential pulse voltammetry for the mononuclear complex showed three set of waves around 1.2 V (Ru2+/3+), -1.0 V (BPEB0/-), and -1.15 (BPEB-/2-). This complex exhibited aggregation phenomena in aqueous solution, involving pi-pi stacking of the planar, hydrophobic BPEB ligands. According to NMR measurements and variable-temperature experiments, the addition of beta-cyclodextrin (betaCD) to [Ru(bpy)(2)Cl(BPEB)](+) leads to an inclusion complex, breaking down the aggregated array.