β-Hydroxy-α-naphthaldehyde [2-(quinolin-8'-yloxy) acetyl] hydrazone as an efficient fluorescent chemosensor for Mg2+.

An efficient fluorescent sensor based on β-hydroxy-α-naphthaldehyde [2-(quinolin-8'-yloxy) acetyl] hydrazone (HL) for Mg2+ has been designed and synthesized. The receptor showed "off-on" fluorescent responses toward Mg2+ in acetonitrile. The reasons for this phenomenon is that the addition of Mg2+ to the solution of HL induce the formation of a 1:1 ligand-metal complex which inhibit excited-state intramolecular proton transfer (ESIPT).