Coumarin-derived Schiff base as a colorimetric and fluorescent dual-channel chemosensor for detecting HSO4− and bioimaging &amp; biosensing in Zebrafish

Salamo‐type ligand H2L was designed and synthesized and reacted with Cu (II) and Zn (II) acetate, respectively, to obtain two binuclear Cu (II) and Zn (II) complexes: [Cu2(L)2]·2CH3OH (1) and [Zn2(L)2] (2) having the same coordination number but distinct geometries. Complex 1 is a Cu (II) complex containing two crystalline ethanol molecules, where two Cu (II) atoms are surrounded by two utterly deprotonated (L)2− parts, forming slightly twisted tetragonal pyramidal configurations of pentacoordinate. In complex 2, two utterly deprotonated (L)2− parts surround two Zn (II) atoms, forming pentadentate twisted triangular bipyramidal configurations. The complexes were elucidated via IR analyses and ultraviolet spectroscopy. Using DFT theoretical calculation, MEPs, IRI, and Hirshfeld surface analysis to investigate further the molecular interactions and reaction sites. Ultimately, the fluorescence characteristics of H2L and its complexes 1 and 2 were discussed.

Structural, spectroscopic, fluorescent, and computational studies of binuclear copper (II) and zinc (II) complexes with an asymmetric salamo‐type ligand

Chai,

Li‐Tong,

Zhang

et al. 2024

Anion‐Modulated Construction of Two Novel Tetra‐ and Hepta‐Nuclear Ni(II) Salamo‐Type Clusters: Comparison of the DFT Calculations and Weak Interaction Analyses

Zhang,

Zheng

et al. 2024

Two novel tetra‐ and hepta‐nuclear Ni(II) salamo‐type clusters, [Ni4(L)2(μ2‐Cl)2(μ3‐OH)2(EtOH)2]⋅4CH2Cl2 (1) and [Ni7(L)3(μ3‐OEt)2(μ3‐OH)6(EtOH)2] (2), were constructed by modulating different anions (Cl− and NO3−). X‐ray crystallographic researches revealed that cluster 1 is a tetranuclear cluster consisting of a symmetric binuclear structure in which chloride ions are involved in coordination. Although cluster 2 consists of seven Ni(II) ions, three deprotonated (L)2− parts, two μ3‐ethoxy groups, six μ3‐OH− anions, and two coordinated ethanol molecules, in which it is quite rare for a large number of water molecules to be deprotonated to participate in the bridging of the cluster due to the alkaline environment. TEM electron scanning displayed the distinct shapes. Comparison of DFT calculations revealed that cluster 2 is less chemically reactive and more kinetically stable, which is in accordance with the analytical results of weak interactions, where the stronger weak interaction forces were presented, the more stable the molecule is. Finally, a comparative analysis of UV–Vis, IR, and fluorescence spectra were carried out.

A Turn‐On Fluorescence Probe Based on a New Salamo‐Co (II) Coordination Polymer for Tyrosine Detection and Its Application in Water Samples

Yuan,

Chai,

Zhang

et al. 2024

A novel salamo‐Co (II) coordination polymer probe CP was synthesized firstly, and its crystal structure, [Co3(L)2(PTA)(H2O)2]n·4nDMF, was determined by X‐ray diffraction analysis. The probe has a rare aggregation‐induced luminescence enhancement (AIEE) effect. When applied to amino acid detection, it was found to have a high selective recognition of tyrosine. With the increase of tyrosine, the fluorescent strength of the probe was enhanced in a short period of time. In addition, the binding ratio of probe to Tyr was determined by fluorescence titration experiment, and the detection limit LOD of probe CP for Tyr was calculated to be 2.57 × 10−9 M, and the binding constant Ka was 2.96 × 105 M−1. According to UV absorption spectrum, FT‐IR spectra, ESI mass spectrometry, and DFT calculation, it was speculated that Tyr can bind to the probe after adding Tyr into the probe solution, triggering FRET and ICT effects, resulting in increased fluorescence intensity and blue shift, and finally achieving the specific recognition of tyrosine by probe CP. Finally, the practical application of probe CP was studied. Through strip test and real water sample test, it was found that the probe can be used for qualitative and quantitative analysis of tyrosine.