Figure shows the two general bicyclic structures to which the three compounds of Wu, Kim and co-workers belong; the difference between the two structures being the total number of π-electrons in the three arms, i.e., 4n (Type A) and 4n + 2 (Type B). Here it should be pointed out that the single -electrons at the two bridgehead C atoms displayed in the generalized structures do not represent radical centers but instead indicate that these -electrons are involved in -bonds to either of the three linkers. Indeed, the three-dimensional bicyclic structures can all be viewed as expanded naphthalenes (Figure ). Starting at naphthalene we increase the -electron count by expanding the six-membered rings through linkers while keeping the topology of Figure to ensure that each circuit allows for 2D Hückel-aromaticity. How do the -electron counts vary in these bicyclic compounds? Especially, when do they equal 6n + 2? For Type A expanded naphthalenes the -electron counts generally equal 4k + 4l + 4m + 2, which when k = l = m becomes 3×4k + 2 = 6×2k + 2. With n = 2k we get the -electron count 6n + 2. Thus, with three linkers of equal length the -electron counts of expanded naphthalenes happen to coincide with the -electron counts of truly 3D-aromatic molecules. This also applies for the Type B expanded naphthalenes with six extra electrons, still resulting in a 6n' + 2 count (n' = n + 1). Among 1 -3 and 1 6+ it is therefore only 1 and 1 6+