Metallosupramolecules of Pillar[5]arene with Two Flexible Thiopyridyl Arms: A Heterochiral Cyclic Dimer and Organic Guest-Assisted Homochiral Poly-Pseudo-Rotaxanes

Seulgi Kim; In-Hyeok Park; Eunji Lee; Jong Hwa Jung; Shim Sung Lee

doi:10.1021/acs.inorgchem.2c00514

Metallosupramolecules of Pillar[5]arene with Two Flexible Thiopyridyl Arms: A Heterochiral Cyclic Dimer and Organic Guest-Assisted Homochiral Poly-Pseudo-Rotaxanes

Inorg Chem. 2022 May 9;61(18):7069-7074. doi: 10.1021/acs.inorgchem.2c00514. Epub 2022 Apr 28.

Authors

Seulgi Kim¹, In-Hyeok Park², Eunji Lee³, Jong Hwa Jung¹, Shim Sung Lee¹

Affiliations

¹ Department of Chemistry and Research Institute of Natural Science, Gyeongsang National University, Jinju 52828, South Korea.
² Graduate School of Analytical Science and Technology (GRAST), Chungnam National University, Daejeon 34134, South Korea.
³ Department of Chemistry, Gangneung-Wonju National University, Gangneung 25457, South Korea.

PMID: 35482519
DOI: 10.1021/acs.inorgchem.2c00514

Abstract

The formation of a cyclic dimer complex (1) and a poly-pseudo-rotaxane (2) of a racemic A1/A2-thiopyridyl pillar[5]arene (rac-L) with different chirality is reported. A one-pot reaction of rac-L with HgCl₂ afforded a heterochiral cyclic dimer complex, [Hg₂(pR-L)(pS-L)Cl₄]·8CH₂Cl₂ (1), in which two Hg²⁺ atoms and one (pR-L)/(pS-L) enantiomeric pair form a [2:2] metallacycle via a metal coordination-based cyclization. Interestingly, the same reaction in the presence of the linear dinitrile guest, CN(CH₂)₈CN (G), yielded a one-dimensional poly-pseudo-rotaxane, {[Hg(G@pR-L)Cl₂][Hg(G@pS-L)Cl₂]}_n (2), probably due to the rigidified ligand structure resulting from the dinitrile guest (G) threading. In 2, pR-L and pS-L generate two separated homochiral poly-pseudo-rotaxanes in a crystal. Both products are new members of the pillararene-derivative family. This study improves our understanding of self-assembly in nature and leads to this approach being an engineering tool for the construction of mechanically interlocked supramolecules.