The one-electron reduction of [Pd-3(C7H7)(2)(CH3CN)(3)][BF4](2) in acetonitrile resulted in the formation of the dimer dication [Pd-6(C7H7)(4)(CH3CN)(4)][BF4] 2, whose structure containing a novel bitriangle hexapalladium skeleton was determined by X-ray crystallographic analysis. The dimer is stable in CD3CN at ambient temperature for several days but is highly air-sensitive. Similarly, the cycloheptatriene tripalladium complex [Pd-3(C7H7R)(2)(CH3CN)(3)][BF4](2) (R = H, t-Bu) dimerized upon one-electron reduction. Both monomer and dimer of cycloheptatriene complexes were structurally determined by Xray crystallographic analyses.