Dual Emission in the Near-Infrared and Visible Regions from a Mixed Cyanido-Bridged Eu(III)/Nd(III)(4-OHpy)-Co(III) Layered Material

[Image: see text] Coordination polymers (CPs) with a dual emission spanning from the visible (vis) to near-infrared (NIR) regions of the electromagnetic spectrum are used for optical sensors, medical diagnostics, and telecommunication technologies. We herein report the synthesis, structural characterization, and optical response of heterometallic cyanido-bridged layered {[Eu(x)Nd(y)(4-OHpy)(2)(H(2)O)(3)][Co(CN)(6)]} CPs, where 4-OHpy = 4-hydroxypyridine, with a multicolor emission profile across the vis and NIR regions. The crystals show an efficient energy transfer (ET) from the 4-OHpy ligand and the [Co(CN)(6)] ions to the Eu(3+) and Nd(3+) ions, resulting in an enhanced photoluminescence (PL) efficiency. We study the ET with steady-state and time-resolved PL, reporting an ET between the Ln(3+) centers. The excitation-dependent emission of the mixed Ln(3+) CPs and the control over the PL lifetime yield new insights into the optoelectronic properties of these materials.