Color-Tunable and White-Light Luminescence in Lanthanide-Dicyanoaurate Coordination Polymers.

The new lanthanide-dicyanoaurate coordination polymers [nBu4N]2[Ln(NO3)4Au(CN)2] (Ln = Sm, Dy) and Sm[Au(CN)2]3·3H2O were prepared and structurally characterized and their luminescence spectra described. The emissions of solid-solutions of [nBu4N]2[Ln(NO3)4Au(CN)2] (Ln = Ce, Sm, Eu, Tb, and Dy) were explored with an emphasis on their capacity for luminescent color tuning and white-light emission via the selection of composition, excitation wavelength, and temperature. Specifically, the binary solid-solutions [nBu4N]2[Ce0.4Dy0.6(NO3)4Au(CN)2] and [nBu4N]2[Sm0.75Tb0.25(NO3)4Au(CN)2], and the ternary solid-solutions [nBu4N]2[Ce0.2Sm0.6Tb0.2(NO3)4Au(CN)2] and [nBu4N]2[Ce0.33Eu0.17Tb0.5(NO3)4Au(CN)2], were prepared and examined in terms of suitability for color-tuning capacity. These results showcase that the emission from the [nBu4N]2[Ln(NO3)4Au(CN)2] framework has the capacity to be tuned to extremes corresponding to deep reds (CIE coordinates 0.65, 0.35), greens (0.28, 0.63), and deep blue/violet (0.16, 0.06) as well as white (0.31, 0.33). Conversely, the emission of the Sm[Au(CN)2]3·3H2O framework, when doped with the green phosphor Tb(III), changes only slightly because of the predominantly Au(I)-based emission and Sm(III) → Au(I) energy transfer.