Solid-State Emissive Metallo-Supramolecular Assemblies of Quinoline-Based Acyl Hydrazone

Abstract

Development of fluorescence-based sensory materials for metal elements is currently in the mainstream of research due to the simplicity and usability of fluorescence as a method of detection. Herein, we report a novel “bis”-quinoline-based acyl hydrazone—named bQH that could be synthesized by a facile, low-cost method through simple condensation of hydrazide with an aldehyde. This acyl hydrazone showed emissive properties through Zn selective binding, especially in its solid-state, as shown by experiments such as UV–Vis, photoluminescence (PL), nuclear magnetic resonance (NMR), and inductively-coupled plasma-optical emission spectroscopies (ICP-OES), and energy-dispersive X-ray spectroscopy (EDS) mapping. The binding modes in which bQH coordinates to Zn2+ was proved to consist of two modes, 1:1 and 1:2 (bQH:Zn2+), where the binding mode was controlled by the Zn2+ ion content. Under the 1:1 binding mode, bQH-Zn2+ complexes formed a polymeric array through the metallo-supramolecular assembly. The resulting bQH-Zn2+ complex maintained its fluorescence in solid-state and exhibited excellent fluorescence intensity as compared to the previously reported quinoline-based acyl hydrazone derivative (mQH).

Microcrystal Electron Diffraction Elucidates Water-Specific Polymorphism-Induced Emission Enhancement of Bis-arylacylhydrazone

“…In our previous work, it was found that the emission of quinoline-based acylhydrazone was enhanced upon binding to Zn 2+ by the planarization of the molecular structure. It was interesting that the Zn 2+ complex of the bis-acylhydrazone and similar compounds showed the enhanced emission in the solid state, which led us to investigate their origin of solid-state emission.…”

Inhibitory Potential of New Phenolic Hydrazide-Hydrazones with a Decoy Substrate Fragment towards Laccase from a Phytopathogenic Fungus: SAR and Molecular Docking Studies

“…They undergo easy dehydration to 1,3,4-oxadiazoles that present a variety of biological activities [33,34]. Hydrazide-hydrazones provide interesting properties in the field of supramolecular architecture [35][36][37][38][39], organic synthesis [33,40], chemo-and physical imaging [41][42][43][44], coordination [45][46][47][48][49], and in inorganic chemistry [50][51][52][53]. The numerous biologically active hydrazide-hydrazones are particularly worth paying attention to [54].…”

Modulation of an Alpha‐Beta Unsaturated N‐Acylhydrazone as Phase Selective Dual Efficient Chemosensor for Zn(II) and Al(III)

“…But among them fluorimetric measurement is of abiding interest due to its high selectivity and sensitivity . A good number of hydrazone compounds have been reported very recently as a sensor for the detection of aluminum ion and zinc ion or dual sensing for both the metal ions utilizing fluorescence spectroscopy in solution as well as in solid state . In connection with this, the spectroscopic identification and detection of zinc and aluminium using a hydrazone based ligand is in great demand now to find an easier, cheap, less time consuming synthetic route and corresponding uncomplicated precise detection of target metal ions.…”