Theoretical Design of Near-Infrared Al3+ Fluorescent Probes Based on Salicylaldehyde Acylhydrazone Schiff Base Derivatives.

The aim of this paper is to design near-infrared (NIR) Al3+ fluorescent probes based on a Schiff base to extend their applications in biological systems. By combining benzo[h]quinoline unit and salicylaldehyde acylhydrazone, we designed two new Schiff base derivatives. According to theoretical simulations on previous experimental Al3+ probes, we obtained the appropriate theoretical approaches to describe the properties of these fluorescent probes. By employing such approaches on our newly designed molecules, it is found that the new molecules have high selectivity toward Al3+ and that their corresponding Al3+ complexes can emit NIR fluorescence. As a result, they are expected to be potential NIR Al3+ fluorescent probes.