Anion-induced 3d–4f luminescent coordination clusters: structural characteristics and chemical fixation of CO2 under mild conditions†
Two series of anion-induced 3d–4f luminescent clusters ZnII2LnIII2L4 (LnIII = Eu3+, Tb3+, Er3+, Yb3+, Nd3+) and ZnII4LnIII2L4 (LnIII = Tb3+, Nd3+) based on μ3-OH group were synthesized and characterized. The difference in anions not only leads to significant structural changes, but also changes the luminescent properties of the 3d–4f coordination clusters. These complexes show excellent catalytic performance for CO2 conversion to obtain cyclic carbonates with wide substrate scopes and high selectivity under mild conditions. Turnover numbers were up to 9000, and turnover frequencies obtained were 660 h−1. The ligand is simple and the complexes are easily obtained even on a large scale. Moreover, these complexes also feature lanthanide-characterized luminescence both in visible and near infrared regions with relatively long luminescence lifetimes and high quantum yields, suggesting promising multifunctional applications.