Dual emissive Ln(iii)–Ag(i) heterometallic chains based on tris(2-pyridyl)phosphine oxide

Abstract

Self-assembly reaction of Ln³⁺ and Ag⁺ ions with a multidentate N,O-donor ligand has been successfully applied to isolate the first examples of 4f–4d heterometallic coordination compounds based on a phosphine oxide linker. In particular, a series of one-dimension coordination polymers [LnAg(Py₃PO)₂(NO₃)₄]_n (Ln = Sm, Eu, Tb, Dy) have been synthesized employing tris(2-pyridyl)phosphine oxide (Py₃PO) as a bridging ligand. Coordination polymers exhibit good photostability and high thermal stability above 300 °C. Their solid-state photoluminescence spectra represent a combination of emissions originating from the lanthanide f–f transitions and Ag⁺-involved charge transfer, resulting in the color-tunable luminescence depending on excitation light.