Hydrogen Bond‐Directed Molecular Packing and Dual Mechano chromic Luminescence of an Acylhydrazone‐Based Derivative in the Solid State and Its Application in Detection of Al3+ Ion

Abstract

AbstractN‐(4‐Diethylamino‐2‐hydroxylbenzylidene)‐3‐hydroxy‐2‐naphthohyd‐ razide (H3L) was synthesized at 80 °C and 110 °C, and H3L80 and H3L110 crystals were obtained. They have the same composition. The structural analysis showed that H3L80 and H3L110 are composed of one dimensional supramolecular chains via intermolecular O‐H…O and C‐H…O hydrogen bonds, which are further assembled to supra‐molecular networks through intermolecular C‐H…O bonds between 1D chains, resulting in their unique molecular packing modes. H3L80 crystals emitted at 530 nm and H3L110 crystals emitted at 610 nm under 465 nm light. The largely red‐shifted emission for H3L110 is attributed to the enhancement of molecular planarization and π‐conjugation of H3L110 compared to H3L80. The dual mechanochromic luminescence of H3L80 and H3L110 fluorophor could be reversibly carried out by grinding of H3L80 and H3L110 crystals and subsequent recrystallization of H3L80 and H3L110 samples. The microstructural stability of H3L110 was concentration‐dependent in solutions, such as DMSO, DMF and THF, resulting in change of fluorescence property. But, H3L80 microstructure was stable in solutions. H3L80 could be used to detect Al (III) ion with high selectivity and sensitivity in aqueous medium. Also, H3L80 could detect intracellular Al3+ ions.