Cd(II)-coordination framework: Synthesis, anion-induced structural transformation, anion-responsive luminescence, and anion separation

摘要

A series of Cd(II) coordination frameworks that are constructed from a new oxadiazole-bridged ligand 3,5-bis(3-pyridyl-3-(3′-methylphenyl)-1,3,4- oxadiazole (L) and CdX_2 (X = NO_3 ~-, Cl ~-, Br~-, I~-, N_3 ~-, and SCN~-) were synthesized. The NO_3 ~- anion of the solid CdL_2(NO_3)_2·2THF (1) is able to be quantitatively exchanged with Cl~-, Br~-, I~-, SCN~-, and N3 ~- in the solid state. For Cl ~- and Br~-, the anion exchange resulted in a anion-induced structural transformation to form the structures of 2 and 3, respectively. In addition, the Cd(II) structure herein exhibits the anion-responsive photoluminescence, which could be a useful method to monitor the anion-exchange process. Notably, compound 1 can recognize and completely separate SCN ~-/N3 ~- with similar geometry.