Highly tunable emission properties of solid-state supramolecular compounds based on Eu mixed-lanthanide complexes and cucurbit[6]uril

We obtained crystals of novel supramolecular compounds with cucurbit[6]uril which contain aquanitrato complexes of mixed lanthanides. The supramolecular approach was used to produce compounds exhibiting multicolor emission. An X-ray diffraction study demonstrated that the compounds have the following compositions: [{Ln 1 0.5 Ln 2 0.5 (H 2 O) 5 (NO 3 )} 2 CB[6]](NO 3 ) 4 ·HNO 3 · n H 2 O (Ln 1 = Eu, Ln 2 = Pr ( 1 ), Nd ( 2 ), Sm ( 3 ), Gd ( 4 ), Tb ( 5 ) Dy ( 6 ), Er ( 8 )), [{Ln 1 0.7 Ln 2 0.3 (H 2 O) 5 (NO 3 )} 2 CB[6]](NO 3 ) 4 ·HNO 3 · n H 2 O (Ln 1 = Eu, Ln 2 = Ho ( 7 )) and 2[Ln 1 0.5 Ln 2 0.5 (H 2 O) 8 ](NO 3 ) 3 ·CB[6]·2HNO 3 · m H 2 O (Ln 1 = Eu, Ln 2 = Yb ( 9 )). The luminescence properties of compounds 1-9 were investigated in the solid state. The color purity of compound 6 is very close to zero, so it is well suited for white-light generation and can be used for WLED applications. A cool white LED device was fabricated by combining the supramolecular compound 6 and a UV LED chip (365 nm) at a voltage of 3.0 V; the CIE, CCT and CP were (0.328; 0.313), 5736 K and 2%, respectively. Compounds 5 and 6 have different glow colors when irradiated with different wavelengths; modulation of light emission in such compounds can be used to protect against counterfeiting. A supramolecular approach for emission control.