The investigation on first Co(III) pyridine-including half-salamo-like complexes

Colorimetric/fluorescent dual-channel recognition of L-tryptophan with rapid and visual sensing of HNQB-Cu(II) in zebrafish and nuts

In this paper, a fluorescent probe HNQB-Cu(II) was designed and synthesized for the rapid and intuitive detection of L-tryptophan. HNQB-Cu(II) was prepared from 2-hydroxy-N'-(quinolin-2-ylmethylene)benzohydrazide and copper(II) nitrate. The weak interaction forces of the HNQB-Cu(II) probe were studied by DFT calculation, electrostatic filament analysis, interaction region indicator (IRI) research and molecular freedom analysis. Then the fluorescence full scan and anti-interference experiments were carried out for 20 amino acids, and the test results manifested that the HNQB-Cu(II) probe has good selective identification performance and anti-interference ability for L-tryptophan. The sensor displayed good advantages in terms of recognition L-tryptophan with high specificity and selectivity, good time stability and low limit of detection (LOD = 3.9466 μM, R2 = 0.97802) in DMF. Combined HNQB-Cu(II) and paper a strip to detect L-tryptophan through a color change. Interestingly, HNQB-Cu(II) exhibits a superior fluorescence effect caudal fin of zebrafish a fluorescence microscope. In order to further research the application of check and measure L-tryptophan, the content of L-tryptophan in three kinds of nuts (pumpkin seeds, walnuts and peanuts) was quantitatively analyzed. The results show that HNQB-Cu(II) can reveal the L-tryptophan content more conveniently and quickly.

A molecular sensor for selective recognition of Fe3+ by a functional seven-nuclear Zn(II) cluster compound formed from a quinoline-modified half-salamo-type Precursor

In this paper, we designed and synthesized a novel based on quinoline modification half-salamo-type Zn(II) complex([Zn7(L)6(μ3-OCH3)6]·(ClO4)2), namely ZP. The structure of ZP was determined by X-ray single-crystal diffraction, in which the Zn(II) ions displayed in two different coordination modes, ultimately forming a highly symmetric heptanuclear structure. The Zn(II) complex probe modified by quinoline luminescent group has excellent luminescence properties and selectively recognizes Fe3+ in aqueous solution. When Fe3+ is added to the aqueous solution of ZP, ZP exhibits an obvious fluorescence quenching effect in a relatively short period of time, with a high sensitivity. The lowest detection limit of ZP for Fe3+ was further determined by fluorescence titration to be 5.8 × 10-8 M-1. In order to further explore the mechanism of Fe3+ quenching on ZP fluorescence, we performed fluorescence titration experiments, XPS as well as ESI-MS characterization, which proved that the recognition of Fe3+ by ZP is the substitution of metal ions leading to fluorescence quenching. At the same time, we also examined the practical application of ZP in life, and found that ZP can quantitatively detect the content of Fe3+ in drugs and actual water samples, and the experimental results were highly consistent with test result of ICP-MS, which further demonstrated that the detection of ZP was highly accurate. In addition, the detection of Fe3+ by ZP can be applied over a wide pH range without interference from other metal ions.

An unusual highly sensitive dual-channel bis(salamo)-like chemical probe for recognizing B4O72-, sensing mechanism, theoretical calculations and practical applications

A bis(salamo)-like chemical sensor H3L ((1E,3E)-2-hydroxy-5-methylisophthalaldehyde O,O -di(3-((((E)-(2-hydroxynaphthalen-1-yl)methylene)amino)oxy)propyl) dioxime) was constructed. H3L is capable of recognizing B4O72- in H2O/DMF (1:9, v/v) solution by both fluorescent and colorimetric channels, bright green fluorescence was turned on when B4O72- was added to H3L and changed from colorless to yellow in natural light. The detection limit was 3.21 × 10-8 M. The identification has good anti-interfering ability, quickly responsive time (5 S) and broad pH detecting range (pH = 5-12). The mechanism of action was determined by 1H NMR titration, infrared spectrometry, HRMS spectra and further elucidated by theory calculations. The fluorescence imaging of bean sprouts and spiked recovery assays of actual water samples demonstrated the practical use of sensor H3L for the detection of B4O72-, which is expected to have applications for the detection of B4O72- in plants and the environment.

A fluorescent Salamo-Salen-Salamo-Zn(II) sensor for bioimaging and biosensing H2PO4- in Zebrafish and plants

A newly designed and synthesized Salamo-Salen-Salamo-Zn(II) complex sensor (sensor ZT) was extensively explored for anion sensing studies. The selectivity and sensitivity of the sensor ZT towards H2PO4- ions were based on ICT and CHEF effects, and via displacement pathways in DMSO/H2O (9:1, v/v) medium in the presence of other anions like, PO43-, HPO42- and P2O74- in a short time, separately. The prepared ZT sensor has excellent association constant and low detection lines. The sensing mechanism and binding mode of the sensor were studied by UV-Vis spectroscopy, HR-MS, 1H NMR titration and theory calculations (DFT & TD-DFT) for analytes. The time response and stability of the sensor are also given. Meanwhile, the sensor ZT can be widely used as a simple and effective solid-state optical sensor to detect H2PO4- by intuitive fluorescence changes. In addition, besides the environment can be used as a powerful instrument for detecting H2PO4-, based on the good biocompatibility and tissue permeability of ZT, effectively monitoring H2PO4- in cellular distribution by confocal microscopy using Zebrafish and bean sprout.

Coordination-Driven Salamo-Salen-Salamo-Type Multinuclear Transition Metal(II) Complexes: Synthesis, Structure, Luminescence, Transformation of Configuration, and Nuclearity Induced by the Acetylacetone Anion

A flexible polydentate Salamo-Salen-Salamo hybrid ligand H₄L was designed and synthesized, which has rich pockets (salamo and salen pockets) so that it may have fascinating coordination patterns with transition metal(II) ions. Four multinuclear transition metal(II) complexes, novel butterfly-shaped homotetranuclear [Ni₄(L)(μ₁-OAc)₂(μ_1,3-OAc)₂(H₂O)_0.5(CH₃CH₂OH)_3.5]·4CH₃CH₂OH (1), helical homotrinuclear [Zn₃(L)(μ₁-OAc)₂]·2CH₃CH₂OH (2), double-helical homotrinuclear [Cu₂(H₂L)₂]·2CH₃CN (3), and mononuclear [Ni(H₂L)]·1.5CH₃COCH₃ (4), have been synthesized and characterized by single-crystal X-ray diffraction. The effects of different anions [OAc^- and (O₂C₅H₇)^2-] on the complexation behavior of H₄L with transition metal(II) ions were studied by UV-vis spectrophotometry. The fluorescent properties of the four complexes were studied with zebrafish, which are expected to be a potential light-emitting material. Ultimately, interaction region indicator (IRI) valuations, Hirshfeld surface analyses, density functional theory (DFT & TD-DFT), electrostatic potential analyses (ESP), and simulations were carried out to further demonstrate the weak interactions and electronic properties of the free ligand and its four complexes.