Achieving colour tuneable and white-light luminescence in a large family of dual-emission lanthanide coordination polymers

Abstract

Expanding the family of lanthanide terpyridine coordination polymers has yielded eighteen new complexes with two different phases, Ln(TPC)₂(HCOO)(H₂O) (Ln-1) and Ln(TPC)(HCOO)₂ (Ln-2) (Ln = Sm–Lu, except Tm). Both structures are composed of lanthanide cations interconnected by 2,2′:6′,2′′-terpyridine-4′-carboxylate ligands to yield one-dimensional chain topologies. However, the incorporation of an additional crystallographically unique decorative TPC ligand into Ln-1 gives rises to a distinct phase. The encapsulation of both metal- and ligand-based phosphors within single coordination polymers leads to dual-emission of the afforded materials. Furthermore, judicious lanthanide doping in heterometallic Ln-1 and Ln-2 allows for fine-tuning the photoluminescent colours over a wide range of gamut. Such a combination showcases the capability to fine-tune the emission colours from deep green, to red, and to blue. In addition, direct white-light emission upon UV excitation can be achieved in the Sm_xGd_1−x-1 system.