Spectroscopic studies, TD/DFT calculations, electrochemical, antibacterial, and Hirshfeld surface analysis of Ni(II) and Co(III) complexes based on 3-ethoxy salicylaldehyde

Experimental and Theoretical Studies of Novel Cadmium(II) N2O-Schiff Base Complexes: Synthesis, Spectroscopic Characterization, X-ray Crystal Structure, and Fluorescent Properties

Three 2,6-dimethoxyaniline Schiff base cadmium(II) complexes were synthesized via a one-pot reaction and characterized by spectroscopic methods (NMR, FT-IR, EA), X-ray crystallography, SEM/EDX and fluorescent spectroscopy. The molecular structures of complexes 1-3 were elucidated by X-ray crystallography, revealing penta-coordinated cadmium(II) centers with distorted square-pyramidal geometries. Mononuclear molecules form supramolecular structures through intermolecular C-H···Cl interactions and π···π stacking interactions, which further stabilize the structures of the complexes. DFT calculations were performed to analyze the electronic structures and frontier molecular orbitals. The fluorescence properties of complexes 1-3 were investigated in both solid-state and solution, exhibiting characteristic emission bands. The study provides insights into the structural and luminescent properties of these cadmium(II) complexes, demonstrating their potential applications as luminescent materials.

A rare extra-long flexible salamo-based bisoxime as highly efficient and selective probe for fluorescent identification of CO32- ion and mechanism exploration

A novel extra-long carbon-chain salamo-like fluorescent chemical probe DNS (named as 2,2'-[1,10-(decanedioxy)bis(nitromethyldyne)]dinaphthol) containing ten methylene groups was synthesized based on the 2-hydroxy-1-naphthylaldehyde unit. Research has shown that the fluorescent probe DNS can achieve efficient and selective recognition of CO32- anions, with a detection limit LOD=1.59 × 10-8 M. The binding constant Ka = 3.7 × 104 M-1 and quantification limit is as low as LOQ=4.31 × 10-8 M, respectively. The possible identification mechanism of the fluorescent chemosensor DNS was analyzed and studied through fluorescence titration and nuclear magnetic titration. The results showed that the fluorescence chemical sensor DNS is deprotonated by CO32- anions, enhancing its fluorescence and producing a ICT effect.