A class of
metal halide-based
metal-organic frameworks (MOFs) materials with multicolor tunable long-lasting emission and
white light properties were synthesized by self-
assembly of 15-
crown ether-5 (CE) ligands and
metal halide salts (CdX2), resulting in three complexes (15-5-CdCl2, 15-5-CdBr2, and 15-5-CdI2). In the
solid state, the complexes (15-5-CdCl2, 15-5-CdBr2, and 15-5-CdI2) all exhibited near-standard
white light emission under 340 nm
ultraviolet radiation at
room temperature, with CIE coordinates of (0.28, 0.32), (0.31, 0.39), and (0.30, 0.34), respectively. Simultaneously, they exhibit excitation-dependent room-temperature
phosphorescence (RTP)
ranging from blue / cyan to green / yellow, with 15-5-CdCl2 and 15-5-CdBr2 exhibiting multicolor tunable and visible light
luminescence (LPL) with time-resolved
luminescence lifetimes as high as 1-2 seconds. Single-
crystal X-
ray diffraction analysis and theoretical calculations indicate that the bright LPL of 15-5-CdCl2 and 15-5-CdBr2 originates from the aggregation state induced by the 15-
crown ether-5 ligand and
halogen bonds. The LPL obtained in this way can be widely used in lighting and display devices,
optical recording devices,
biological imaging, security systems, and other fields.