Abstract:

To develop new long afterglow luminescent materials based on organics or coordination compounds, and improve the long afterglow performance through studying the relationship between the molecular structures and properties becomes one of the hot research topics currently. This experiment is mainly related to the Cu(I)-iodide cluster-based coordination polymer (CuIU). There are two phases for CuIU, C-CuIU and T-CuIU crystallized in the cubic and trigonal space groups, respectively. Though the molecular formulas of C- and T-CuIU are same, T-CuIU displays much better long afterglow property than C-CuIU. The synthesis of CuIU is performed in NaI aqueous solution at room temperature under gentle environment. The whole experiment is carried out through easy stirring, centrifugation and drying operations, which is appropriate for undergraduate laboratory teaching. The product obtained by short stirring time is verified as C-CuIU, while that with long stirring time is verified as T-CuIU. The transformation between C and T is easily controlled and they display notably different lifetimes. The plastic models of these two structures, preparation of luminescent ink and silk-screen printing are also introduced in teaching to further improve the vividness and interest of the course. This experiment is helpful for students to understand the synthesis method of metal cluster compounds and the deep relation between structures and properties in coordination compounds. Meanwhile, the experiment involves the operations of X-ray powder diffractometer, spectrofluorometer and thermal gravimetric analyzer, which promote the science and education integration in the teaching process.

Key words: Coordination polymers, Long afterglow, Structures and properties, Science research and education integration, Anti-counterfeit printing ink