In contrast, efficient catalysis requires large windows, through which the substrates and products can access and In a pioneering report on Pd-N coordination cages, Fujita et al. reported that tris(4-pyridyl)triazine (4-TPyT) and 1.5 equiv of Pd 2+ cis-blocked with ethylenediamine (Figure ) co-assemble into a cage with the Td symmetry and four identical windows, each comprising a 36-membered macrocyclic ring (Figure ). When the same reaction was repeated with tris(3-pyridyl)triazine (3-TPyT in Figure ), a D2h-symmetric cage was obtained instead. This cage features two much larger, 52-atom windows (in addition to two small windows, composed of 20 atoms each; Figure ). The differing symmetries of the two cages can be related to the ligand structures, specifically, the angle between the C-C bond connecting the central and peripheral rings (blue in Figure ) and the N-Pd bond formed upon cage assembly, which we denote θ. In 4-TPyT, θ = 180º, leading to a Td cage (Figure ).