Pillar[n]arenes are new macrocyclic host and their organic guest-based supramolecular chemistry has been extensively studied.¹ However, their coordination compounds are very rare due to large cavity and lack of metallation site. Recently, we have proposed bicyclic,² tricyclic,³ and armed⁴ pillararenes as new build blocks for constructing metallosupramolecules. First, we synthesized a bicyclic pillar[5]thiacrown (rac-L) and resolved its enantiomers (in-pS-L and in-pR-L) (Fig. a).² The in-pS-L recognizes Hg²⁺ to trigger the chiral inversion to out-pR-L, and it takes place in the presence of ClO₄^- or NO₃^-. The crystallographic approach reveals that the anions act as coordination mode-directing species which play a decisive role on the chiral inversion. Second, the tricyclic pillar[5]‐bis‐dithiacrown shows the dimetalation via two crown subunits and then uptakes CN(CH₂)₂CN selectively over analogous dinitrile guests with different lengths (Fig. b).³ This is a chemical example of the adaptive guest binding of biological receptors which are rigidified by metalation to recognise substrates precisely. Third, one-pot reaction of a thiopyridyl pillar[5]arene (L) with silver(I) trifluoroacetate in the presence of a linear dinitrile guest C8, [CN(CH₂)_nCN, n=8], afforded the first example of a 2-D polypseudorotaxane {[Ag(L)(C8)_1.5]CF₃CO₂}_n whose guest C8 not only threads into the pillararene unit but also crosslinks the parallel coordinative polymeric arrays (Fig. c).⁴ The formation of the 2-D polypseudorotaxane is driven by adaptive rearragement of the 1-D backbone to minimize the repulsion between threading C8 and steric complementarity on crosslinking. A formation pathway of the 2-D polypseudorotaxane is proposed. The above works demonstrate a new perspective on metallosupramolecules of pillararenes. References 1. Ogoshi, T.; Kanai, S.; Fujinami, S.; Yamagishi, T.-a.; Nakamoto, Y. J. Am. Chem. Soc. 2008, 130, 5022. 2. Lee, E.; Ju, H.; Kuwahara, S.; Ikeda, M.; Habata, Y.; Lee, S. S. J. Am. Chem. Soc. 2018, 140, 9669. 3. Lee, E.; Ryu, H.; Ju, H.; Kim, S.; Lee, J.-E.; Jung, J. H.; Kuwahara, S.; Ikeda, M.; Habata, Y.; Lee, S. S. Chem. Eur. J. 2019, 25, 949. 4. Lee, E.; Ju, J.; Kim, S.; Jung, J. H.; Habata, Y.; Lee, S. S. In preparation.