A Novel Coordination Polymer Based on 4,4'-(Hexauoroisopropylidene)diphthalic Acid: Synthesis, Structure and Physical Properties

The design and synthesis of coordination polymers is an attractive area of research, not only owing to their diverse topology and intriguing structures but also due to their potential applications in many fields, such as ion-exchange, catalysis, luminescence, magnets, and gas storage. The mainstream method of constructing such coordination polymers is to utilize organic ligands with aromatic polycarboxylate groups, because of their excellent coordination capability and flexible coordination patterns. Among them, aromatic polycarboxylic derivatives, such as 1,2,4,5-benzenetetracarboxylic acid, 4,4'-oxydiphthalic acid, 4,4'-(hexauoroisopropylidene) diphthalic acid (H4FA), and so on, have been extensively used to prepare coordination polymers. Meanwhile, the flexible 1,4-bis(1,2,4-triazol-1-ylmethyl)-benzene (BTX) as an excellent derivative of triazole not only possesses the merits of triazole, but also can adopt different conformations compared with the corresponding 1,2,4-triazole ligand on the basis of the relative orientations of its CH2 groups.10 Taking these into consideration, we explored the self-assembly of Cd(II) ion, H4FA, and BTX under hydrothermal conditions, and obtained a novel 3D coordination polymer: [Cd3(BTX)2(HFA)2·2H2O]n. Herein, we report the synthesis, crystal structure, and physical properties