Rare Fluorescence Red-Shifted Metal–Organic Framework Sensor for Methylamine Derived from an N‑Donor Ligand

A three-dimensional (3D) metal–organic framework (MOF) [Cd­(bbip)­(NDC)] n (JXUST-8, bbip = 2,6-bis­(benzimidazol-1-yl)­pyridine, and H2NDC = 2,6-naphthalenedicarboxylic acid) with 8-connected bcg topology has been solvothermally synthesized and fully characterized. The fluorescence experiments demonstrate that JXUST-8 could selectively distinguish methylamine (MA) by fluorescence red shift, and the detection limit is 0.341 ppm. It is noteworthy that red-shift emission could enlarge the fluorescence signal, which is beneficial to realize sensing. In addition, JXUST-8 performs relatively good thermal stability, chemical stability, and reusability. Importantly, JXUST-8 could be considered as the first example of a bbip-based MOF as well as the second case of a fluorescence red-shifted MOF sensor toward MA.