Two-Dimensional Metal–Organic Framework with Wide Channels and Responsive Turn-On Fluorescence for the Chemical Sensing of Volatile Organic Compounds

We report a 2D layered metal–organic
framework (MOF) with
wide channels named NUS-1 and its activated analogue NUS-1a composed
of Zn4O-like secondary building units and tetra­phenyl­ethene
(TPE)-based ligand 4,4′-(2,2-di­phenyl­ethene-1,1-diyl)­di­benzoic
acid. Due to its special structure, NUS-1a exhibits unprecedented
gas sorption behavior, glass-transition-like phase transition under
cryogenic conditions, and responsive turn-on fluorescence to various
volatile organic compounds. Our approach using angular ligand containing
partially fixed TPE units paves a way toward highly porous MOFs with
fluorescence turn-on response that will find wide applications in
chemical sensing.