Pi-sextet resonance between Kekulé valence structures of benzenoid hydrocarbons are depicted by benzenoid resonance graphs. We outline the construction of the resonance graphs for families of benzenoid compounds. For the compounds considered the resonance graphs are built from fused n-dimensional cubes. We report the leading eigenvalue of the resonance graphs (λ) and two different bounds to the leading eigenvalue. Correlation between λ and RE is examined.