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

The new lanthanide–dicyanoaurate coordination polymers [ n Bu 4 N] 2 [Ln(NO 3 ) 4 Au(CN) 2 ] (Ln = Sm, Dy) and Sm[Au(CN) 2 ] 3 ·3H 2 O were prepared and structurally characterized and their luminescence spectra described. The emissions of solid-solutions of [ n Bu 4 N] 2 [Ln(NO 3 ) 4 Au(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 [ n Bu 4 N] 2 [Ce 0.4 Dy 0.6 (NO 3 ) 4 Au(CN) 2 ] and [ n Bu 4 N] 2 [Sm 0.75 Tb 0.25 (NO 3 ) 4 Au(CN) 2 ], and the ternary solid-solutions [ n Bu 4 N] 2 [Ce 0.2 Sm 0.6 Tb 0.2 (NO 3 ) 4 Au(CN) 2 ] and [ n Bu 4 N] 2 [Ce 0.33 Eu 0.17 Tb 0.5 (NO 3 ) 4 Au(CN) 2 ], were prepared and examined in terms of suitability for color-tuning capacity. These results showcase that the emission from the [ n Bu 4 N] 2 [Ln(NO 3 ) 4 Au(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 ·3H 2 O 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.