A thiocyanate-based hybrid molecular salt as a new fluorescent chemosensor for fluoride

An organic–inorganic hybrid solid [(dpaH)+(NCS)−] (1) (dpa = 2,2′-dipyridylamine) based on an anionic template NCS− has been synthesized. Single crystal X-ray structural analysis reveals that NCS− templates assemble dpaH+ units into a 3-D layer structure along the b axis through strong hydrogen bonding. Molecular salt 1 works as an anion-binder efficiently and selectively for recognition and sensing purposes in aprotic solvents. This receptor shows changes both in its UV-Vis absorption and fluorescence emission spectra upon the addition of F−, resulting in high selectivity for fluoride detection in CH3CN. It is promising to use these systems in various sensing applications.