Fluorescence modulation of naphthalene containing salicyl hydrazide-based receptor through aggregation-induced emission enhancement approach: Dual detection of lanthanum and cyanide ions in semi-aqueous medium

A photochromic salicylaldehyde hydrazone derivative based on CN isomerization and ESIPT mechanisms and its detection of Al3+ in aqueous solution

A simple photochromic Schiff base was successfully prepared by the condensation of salicylaldehyde and benzoyl hydrazine. This compound has reversible photochromic properties based on isomerization and ESIPT mechanisms. In organic solvents, after irradiation with 365 nm UV light for 2 min, the absorption peak at 367 nm of the compound showed a significant decrease, while a double absorption peak appeared at 418 nm and 438 nm, accompanied by a significant change of the solution color from colorless to yellow. The compound can also complex with Al³⁺ at the molar ratio of 2:1 in the water solution (acetonitrile/water, v/v, 1:99), resulting in significantly enhanced fluorescence of the compound, so as to achieve fluorescence detection of Al³⁺ in living cells and water samples.