Assembly of unique interpenetrated metal-organic frameworks based on flexible tetra-carboxylate ligands

Entangled metal-organic frameworks (MOFs) are attracting more and more attentions attributed to their special performances, such as adsorption, fluorescence and catalysis. It is still of significant to synthesize new MOF with unique interpenetrating motif. In this work, two new MOFs, namely [(Me2)NH2]center dot[In(TCM)]center dot 4DMF (JOU-32), and [Cd2(TCM)(DMF)2]center dot 5DMF (JOU-33), have been successfully synthesized using flexible tetra-carboxylate ligand tetrakis(4-carboxyphenoxymethyl)methane (H4TCM). The structures of JOU-32 and JOU-33 were well characterized by single-crystal X-ray diffraction. It is shown that JOU-32 reveals a rare example of interpenetrating MOF with two different networks disorderedly distributed within the same crystal. JOU-33 is a (4,8)-connected flu topological structure based on [Cd4(COO)8(DMF)2] cluster. The fluorescent properties for both JOU-32 and JOU-33 have also been tested. The average life times for JOU-32 and JOU-33 were detected to be 2.39 and 2.42 ns, respectively. In addition, both JOU-32 and JOU-33 can be utilized as fluorescent probes for detection of NB. This work provides valuable clues for preparing new fluorescent MOFs with attractive structures.