Constructing π-Stacked Supramolecular Cage Based Hierarchical Self-Assemblies via π···π Stacking and Hydrogen Bonding

Guo-Ling Li; Zhu Zhuo; Bin Wang; Xue-Li Cao; Hai-Feng Su; Wei Wang; You-Gui Huang; Maochun Hong

doi:10.1021/jacs.1c01161

Constructing π-Stacked Supramolecular Cage Based Hierarchical Self-Assemblies via π···π Stacking and Hydrogen Bonding

J Am Chem Soc. 2021 Jul 28;143(29):10920-10929. doi: 10.1021/jacs.1c01161. Epub 2021 Jul 16.

Authors

Guo-Ling Li^{1

2}, Zhu Zhuo^{1

2}, Bin Wang^{1

2}, Xue-Li Cao^{1

2}, Hai-Feng Su³, Wei Wang^{1

2}, You-Gui Huang^{1

2}, Maochun Hong⁴

Affiliations

¹ CAS Key Laboratory of Design and Assembly of Functional Nanostructures and Fujian Provincial Key Laboratory of Nanomaterials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, China.
² Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials, Xiamen Institute of Rare Earth Materials, Haixi Institutes, Chinese Academy of Sciences, Xiamen, Fujian 361021, China.
³ College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, China.
⁴ State Key Laboratory of Structure Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, China.

PMID: 34270238
DOI: 10.1021/jacs.1c01161

Abstract

Constructing supramolecular cages with multiple subunits via weak intermolecular interactions is a long-standing challenge in chemistry. So far, π-stacked supramolecular cages still remain unexplored. Here, we report a series of π-stacked cage based hierarchical self-assemblies. The π-stacked cage (π-MX-cage) is assembled from 16 [MXL]⁺ ions (M = Mn²⁺, Co²⁺; X = Br^-, SCN^-, Cl^-; and L = tris(2-benzimidazolylmethyl)amine) via 18 intermolecular π-stacking interactions. The tetrahedral cage, consisting of four [MXL]⁺ ions as the vertexes and six pairs of [MXL]⁺ ions as the edges, features 48 exterior N-H hydrogen bond donors for hydrogen bond formation with guest molecules. By variation of the M²⁺/X^- pair, the π-MX-cage demonstrates unique versatility for incorporating a wide variety of species via different hydrogen-bonding modes during the assembly of hierarchical superstructures. In specific, the π-MnBr-cages encapsulate acetonitrile (CH₃CN) or cis-1,3,5-cyclohexanetricarbonitrile (cis-HTN) molecules in the central voids, while a core-shell tetrahedral inorganic cluster [Mn(H₂O)₆]@([Mn(H₂O)₄]₄[Br₄^2-]₆) (Mn@Mn₄-cage) is captured within the interstitial regions between cages. The π-CoSCN-cages are capable of stabilizing reactive sulfur-containing species, such as S₂O₄^2-, S₂O₆^2-, and HSO₃^- ions, in the hierarchical superstructure. Finally, H₂PO₄^- ions are incorporated between π-CoCl-cages, resulting in an inorganic mesoporous framework. These results provide insights into further exploring the chemistry and hierarchical assembly of supramolecular cages based on π-π stacking intermolecular interactions.