A Water-Stable Metal-Organic Framework with a Double-Helical Structure for Fluorescent Sensing

Water instability is a crucial limiting factor in the practical application of most fluorescent metal organic frameworks (MOFs). Here, by introducing a fascinating double-helical structure generated through dense stacking of organic ligands, a water-stable fluorescence MOF has been synthesized, namely, [Cd-2(tib)(2)(bda)(2)]-(solvent)(n) (1) [tib = 1,3,5-tris(1-imidazolyl) benzene; H(2)bda = 2,2'-biphenyl dicarboxylic acid]. This helical structure helps to enhance the stability of 1 against common organic solvents and water, even acid/base aqueous solutions with a pH value ranging from 3 to 11. Furthermore, this material can be a potential fluorescent sensor for ketones.