Exceptional blueshifted and enhanced aggregation-induced emission of conjugated asymmetric triazines and their applications in superamplified detection of explosives

A novel conjugated asymmetric donor-acceptor (CADA) strategy for preventing the redshift in photoluminescence, as well as preserving the merits of donor-acceptor architectures, was proposed and demonstrated for two triazine derivatives, which showed highly efficient, narrow, and blueshifted ultraviolet light emission in solid films along with special aggregation-induced emission behavior. A mechanism of aggregation-induced locally excited-state emission by suppressing the twisted intramolecular charge-transfer emission for the spectacular optoelectronic phenomena of these CADA molecules was suggested on the basis of both experimental measurements and theoretical calculations. By taking advantage of this special CADA architecture, fluorescent probes based on aggregates of conjugated asymmetric triazines in THF/water for the detection of explosives show superamplified detection of picric acid with high quenching constants (>1.0×10⁷ M^-1) and a low detection limit of 15 ppb. Out with a bang! Highly efficient, narrow, and blueshifted ultraviolet light emission was observed in solid films of donor-acceptor (D-A) asymmetrically conjugated triazine-based molecules. The special aggregation-induced emission of the molecular system allowed the triazine aggregates to show superamplified detection of picric acid with high quenching constants (>1.0×10⁷ M^-1) and a low detection limit of 15 ppb (see figure).