π-Type halogen bonding enhanced long-last room temperature phosphorescence of Zn(II) coordination polymers for photoelectron response applications

The development of non-noble metal ions with potential organic phosphor ligands through strong coordination bonds can afford an effective platform for achieving persistent and tunable phosphorescence at room temperature. However, successful examples of coordination polymers (CPs) or metal-organic frameworks (MOFs) based long-last phosphorescent emission are still rarely explored. In this work, a new strategy is firstly used to achieve long-last phosphorescence via π-type halogen bonding in coordination polymer. By the selection of two isomers 5-BIPA and 4-BIPA with different Br atom substituted positions in isophthalic acid (IPA), two new Zn(II) based coordination polymers exhibiting long-last phosphorescent emission up to millisecond (ms) orders of magnitude were presented, which were further revealed by theory calculations. Optoelectronic measurements indicate that 1 shows high photoelectron response performance due to the delocalized π-type halogen bonding and long range order of π-conjugated chains affording large electrons channel for efficient charge transport.