Stepwise construction of extra-large heterometallic calixarene-based cages

Abstract

Utilizing presynthesized large Na 2 Ni 12 Ln 2 clusters (Ln = Dy and Tb) supported by calixarene as molecular building blocks (MBBs), we have obtained a series of cationic trigonal prismatic heterometallic organic nanocages (HMONCs) with tunable sizes through a stepwise method. Specially, in each structure of the HMONCs, three linear dicarboxylate linkers substitute the peripheral coordinated acetate ligands of two Na 2 Ni 12 Ln 2 clusters to form an unprecedented Na 4 Ni 24 Ln 4 HMONC through a M 2 L 3 condensation. Moreover, magnetic study reveals that the Na 2 Ni 12 Dy 2 core retains its slow magnetic relaxation behavior. Gas sorption behaviors of these HMONCs were also studied. To the best of our knowledge, these HMONCs built from large heterotrimetallic Na 2 Ni 12 Ln 2 MBBs, which are based on smaller Ni 4 -calix ones, have not been reported in any other cages to date. In addition, this research also provides a new strategy for the design and construction of HMONCs with predictable structures and functional properties.