Anion-induced chiral assembly: construction of Ag(i) coordination polymers for photocatalytic degradation of organic dyes

A racemic bis(pyridyl) ligand (L) was synthesized and characterized following our previous work. Subsequently, a series of Ag(i) coordination polymers (CPs) were synthesized from this ligand with silver(i) salts containing nine different anions and further characterized by single-crystal X-ray diffraction analysis. The crystal structures of CPs 1-9 show that the anions play a vital role in the chiral assembly process of L with different silver(i) salts, resulting in homochiral or heterochiral complexes. CPs 1-3 exist as 2D homochiral conglomerates formed by spontaneous chiral resolution. CPs 4-8 exist as 1D heterochiral tube-like chains, and CP 9 adopts a 1D heterochiral zig-zag chain structure. Furthermore, CPs 2, 4, and 9 were chosen as representatives to investigate their photocatalytic performances for the degradation of organic dyes. The results showed that CP 4 is much more active than CPs 2 and 9 for the degradation of both rhodamine B (RhB) and methylene blue (MB) under UV light irradiation, and it is thus inferred that CPs 4-8 are suitable as potential photocatalysts for the degradation of RhB and MB in water. This work has revealed that the chiral assembly structures induced by anions lead to differences in their photocatalytic performances.