Formation of an ionic PTCA-PBA-NH2 complex and its fluorescent changes triggered by cyclic boronate ester establishing and cleavage reaction

A water-soluble and highly fluorescent ionic complex of 3,4,9,10-perylene tetracarboxylic acid (PTCA) with (2-(6-aminohexanamido)phenyl)boronic acid (PBA- NH2) was prepared via acid-base reaction. Fluorescent studies revealed the quenching effect of PVA or glucose to the emission of the ionic complex of PTCA/PBA-NH2. Interestingly, introduction of F− turned the quenched fluorescence on, and addition of Ca2+ made the emission off again. The reasons behind were ascribed to the formation and disruption of dynamic cyclic boronate esters owing to establishment and cleavage of another dynamic covalent bond of B-F. Accordingly, selective and reversible sensing of glucose (PVA), F− and Ca2+ was realized. Moreover, the ionic complex can be also used for qualitative but sensitive detection of trace water in methanol. Considering the convenience of construction of the PTCA-based molecular system, and the fact that it avoids complicated synthetic burden commonly encountered in developing perylene-based sensing fluorophores, we believe that the work as reported stands for a powerful strategy for developing functionality-led molecular systems.