Recently, the spontaneous resolution of a racemic M6L8 octahedral cage (MOC-17) with three types of chirality has been reported in the absence of any external resolving agents (Figure ). As a prochiral moiety, once the free flip of the truxene core is locked after metal coordination, planar chirality of the consequent cage is determined based on the different orientation of the truxene core, i.e., anticlockwise (A) or clockwise (C). This is in addition to the axial chirality resulting from the R-or S-configuration achieved by twisting pyridyl groups and propeller chirality derived from the L and D arrangement of Py around the Cu II ions. For the purpose of investigating the intricate guest binding behavior, rational design of low-symmetry host systems that possess inherent conformational adaptability is utterly important. Subcomponent self-assembly of tritopic aniline subcomponent (A) with 3-nitropiconaldehyde (B) and Fe(NTf2)2 generated a Fe II 4L4 cage of S4 symmetry (MOC-18), in which all the Fe centers exhibit a mer stereochemical configuration, with equal distribution of D and L handedness (Figure ). In contrast, using 6-methyl-2formypiconaldehyde (C), a high-spin Fe II 3L2 sandwich species (MOC-22) has been generated, with the HS character resulting from the steric conflict between methyl groups and the neighbouring pyridyl rings around the Fe centers. Interestingly, treatment of the S4-symmetric MOC-18 with MM-CRY resulted in the formation of a T-symmetric cage (MOC-20), with all the metal centers adopting fac-D, whereas PP-CRY resulted in the isomers with fac-L metal vertices. On the other hand, optically active D-TRISPHAT housed inside the cavity resulted in the cage (MOC-21) with two C3symmetric diastereomers, with the major having a 3:1 fac:mer metal centre configuration. This unique example elucidates a case where the enantiopure guest molecule can lead to different stereoisomers of the host.