Chromophore-immobilized luminescent metal-organic frameworks as potential lighting phosphors and chemical sensors

An organic chromophore H(4)tcbpe-F was synthesized and immobilized into metal-organic frameworks along with two bipyridine derivatives as co-ligands to generate two strongly luminescent materials [Zn-2(tcbpe-F)(4,4'-bpy)center dot xDMA] (1) and [Zn-2(tcbpe-F)(bpee)center dot xDMA] (2) [4,4'-bpy = 4,4'-bipyridine, bpee = 4,4'-bipyridyl-ethylene, tcbpe-F = 4',4''',4''''',4'''''''-(ethene-1,1,2,2-tetrayl) tetrakis(3-fluoro- [1,1'-biphenyl]-4-carboxylic acid), DMA = N,N-dimethylacetamide]. Compounds 1 and 2 are isoreticular and feature a 2-fold interpenetrated three-dimensional porous structure. Both compounds give green-yellow emission under blue light excitation. Compound 1 has a high internal quantum yield of similar to 51% when excited at 455 nm and shows selective luminescence signal change (e.g. emission energy and/ or intensity) towards different solvents, including both aromatic and nonaromatic volatile organic species. These properties make it potentially useful as a lighting phosphor and a chemical sensor.