One-dimensional tubular architectures are of broad interest in many research fields owing to their unique physical and chemical properties. Great efforts have been paid to the efficient synthesis of different tubular materials for application purposes.  

Coordination-driven self-assembly has been proven to be a powerful approach in the bottom-up construction of designable supramolecular architectures. However, the directional self-assembly of infinite 1D mesoporous tubular structures within solution has rarely been explored. 

Prof. SUN Qingfu and his colleagues from Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, has recently made a great breakthrough in construction of mesoporous nanotubes from multiple tiny organic and inorganic components as building blocks with the aid of bottom-up hierarchical self-assembly process. 

Prof. SUN’s group found that the pyrazole ligand (2) can spontaneously react with dimetallic Pd^II clip (1) to form the saddle-like secondary building units (SBUs) (3) , then the pyridine units coordinated to bare PdII ions to afford larger discrete nanobarrel Pd₃₀L1₂₄L2₂₄ (4). As they have pointed out in the paper, with 78 components, this discrete unique structure contains the largest total number of components reported so far as for organopalladium complexes.

Interestingly, an unprecedented crystallization-driven cross-linking between discrete nanobarrel building units by spontaneous loss of the capping ligands to form infinite nanotubes 5 was also observed.  

Moreover, nanotube 5 has been shown to be an highly efficient catalyst for the Suzuki–Miyaura cross-coupling reactions, with as low as a 0.45 mol% loading based on Pd, demonstrating that these materials could be used for the precious metal catalyzed C-C formation reactions.  

This study opens up new possibilities for the fabrication of MMONTs materials using the solution bottom-up approach. Related result has been published recently in Angew. Chem. Int. Ed. a top journal in the chemistry field. (DOI: 10.1002/anie.201503295) 

This research was financially supported by the  National Natural Science Foundation of China, etc.

 Hierarchical self-assembly of mesoporous metal-organic natotubes (MMONTs) for catalysis(Image by Prof. SUN’s group)

Contact:

Prof. SUN Qingfu

Fujian Institute of Research on the Structure of Matter

Chinese Academy of Sciences

Email:qfsun@fjirsm.ac.cn