文摘
Light and heat dually sensitive luminescent materials have promising applications such as light emitting diodes, bioimaging, and memories but are rather scarce due to simultaneous requirements of stimuli induced structural flexibility and the existence of multiple emissions. In continuation of our research interest in tunable photoluminescent materials with templated organic ligands, we report herein two isostructural organic templated CdSO4-topological halogeno(cyano)cuprates with disorder of halogenide and cyanide, formulated as [Me2DABCO]2Cu4Br5(CN)3 (1) and [Me2DABCO]2Cu4I4.5(CN)3.5 (2) (Me2DABCO = N,N′-dimethyl-1,4-diazabicyclo[2.2.2]octane). Both 1 and 2 show a very strong emission band upon photoexitation with microsecond lifetime and high quantum yield. With the increase of excitation wavelength, the strong main emission band in 1 is gradually red-shifted from 495 to 535 nm, seemingly breaking Kasha’s rule, and the strong main emission in 2 also significantly red-shifted. With the decrease of temperature, the low energy emission in 1 also is red-shifted, while this phenomenon is not found in 2. The photochromic luminescence for 1 and 2 might be caused by multiple emission centers associated with disorder of halogenide and cyanide.