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Metal−organic frameworks (MOFs) are attractive materials to be used as ionophores because of the array of nurturing features for instance a significant surface area, a porous structure, and also electrocatalytic activity. Aluminum is an important metal regarding its many applications such as in industry, biology, medicine, and so forth, so its estimation in very low levels is a challenging mission. Herein, a carbon paste electrode has been developed based on a novel prepared Cu-MOF with a nano-Schiff base linker. The prepared ionophore was characterized using many analytical and spectroscopic methods. The X-ray diffraction data suggested that the newly synthesized Cu-MOF has a mesoporous structure. For Al(III) determination in different real water and pharmaceutical samples, the established electrode has been successfully used with high precision (RSD% = 0.82−1.98) and accuracy (recovery % = 98.0−101.2) and showed good agreement with the atomic absorption spectroscopy results. The sensor under study exhibited Nernstian behavior toward the Al(III) ion (19.89 ± 0.63 mV decade −1 ) wrapping a large linear range of 1.0 × 10 −7 to 1.0 × 10 −1 mol L −1 with a low detection limit of 3.31 × 10 −8 mol L −1 . The working pH was 2.3−6.5 and the response time was 6 s. The fabricated sensor was highly selective for Al(III) ions. The response mechanism and surface reaction have been studied via scanning electron microscopy combined with energy-dispersive X-ray analysis and Fourier-transform infrared analysis.

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Three new binary and ternary metal complexes of Pt(II) with guaifenesin (GFS) drug have been prepared by chelation to guaifenesin ligand (as primary ligand) and glycine amino acid (HGly) and 1,10‐phenanthroline (1,10‐Phen) (as secondary ligands). Characterization was conducted based on elemental analysis, molar conductance, infrared (IR) spectroscopy, thermogravimetric analysis and X‐ray diffraction. The complexes were found to have the formulae [Pt(GFS)2]⋅3H2O (1), [Pt(GFS)2(Gly)]Cl⋅H2O (2) and [Pt(GFS)2(Phen)]Cl2 (3). Magnetic and spectroscopic data revealed complexes 1–3 to have octahedral geometry. IR spectra suggested that GFS ligand coordinated in mononegative tridentate mode (OOO) for 1 but in neutral bidentate mode (OO) for 2 and 3. In addition, HGly behaves as mononegative bidentate coordinated to Pt(II) metal via deprotonated carboxylate O and amino group. IR data also evidenced the bidentate nature of 1,10‐Phen ligand. The molecular and electronic structure of Pt(II) complex 1 was optimized theoretically and the quantum chemical parameters were calculated. Complexes 1–3 were screened for their antibacterial activity on Gram‐positive bacteria (Bacillus subtilis and Staphylococcus aureus) and Gram‐negative bacteria (Escherichia coli and Neisseria gonorrhoeae) and for their in vitro antifungal activity against Candida albicans. The three Pt(II) complexes showed remarkable biological and cytotoxic activity. The chelates were also screened for their in vitro anticancer activity against the MFC7 breast cell line. Complex 3 showed the highest activity with a low IC50 value of 3.38 μg ml−1.

Physicochemical studies were performed to study new ferrocene based Schiff base ligand (HL), (Z)-(4-(1-((2-carboxycyclohexa-2,4-dien-1-yl)imino)ethyl) [bis(η 5 cyclopenta-1,3-dien-1 yl)]iron with some transition metal ions to form a series of ferrocenyl derivatives bearing transition metal complexes of the type [M(L)Cl(H 2 O) 3 ] (M = Ni(II), Cu(II)), [M(L)Cl(H 2 O) 3 ]nH 2 O (M = Mn(II) (n = 1), Co(II) (n = 1), Zn(II) (n = 2) and Cd(II) (n = 3)) and [M(L)Cl(H 2 O) 3 ]Cl.nH 2 O(M = Cr(III) (n = 2) and Fe(III) (n = 1)). The new ligand and metal ion complexes have been prepared and characterized by IR, UV-Vis, 1 H-NMR, TG/DTA, elemental analysis and mass spectrometry. The TGA/DTG analysis revealed that the ferrocene precursors decompose spontaneously to form iron(II) oxide. The molecular and electronic structure of the ligand (HL) was optimized theoretically and the quantum chemical parameters were calculated. The molecular structure with a variety of functionalities can be used to investigate the coordination sites and the total charge density around each atom. DFT-based molecular orbital energy calculations of the new ligand have been also studied. All of the complexes were screened against a panel of Gram (+) bacteria: Streptococcus pneumoniae and Bacillis subtilis, Gram (−) bacteria: Pseudomonas aeruginosa and Escherichia coli and panel of fungi: Aspergillus fumigatu, Syncephalastrum racemosum, Geotricum candidum and Candida albicans. Anticancer activity screening for the tested compounds using 4 different concentrations of HL ligand against human tumor cells of breast cancer cell line MCF-7 were obtained. Molecular docking was used to predict the binding between HL ligand and human-DNA-Topo I complex (PDB ID: 1SC7), the receptors of breast cancer mutant oxidoreductase (PDB ID: 3HB5), crystal structure of Escherichia coli (PDB ID: 3T88), to identify the binding mode and the crucial functional groups interacting with the three proteins.

Three new metal complexes of 4-(benzylideneamino)-5-phenyl-4H-1,-2,4-triazole-3-thiol ligand (L) and three transition metal ions: Fe (III), Cu (II), and Zn (II) were synthesized and characterized. The ligand derived from 4-amino-5-phenyl-1,2,4-triazole-3-thiol and benzaldehyde was synthesized in a 1:1 molar ratio. All the chelates were characterized by elemental analysis, conductivity measurements, thermal analysis, FT-IR, and 1 H-NMR spectroscopy.The IR spectrum revealed that the Schiff base ligand coordinated in a neutral bidentate manner with the metal ions through the azomethine N and thiol S. The thiol group coordinated to the metal ions without proton displacement as confirmed from the 1 H NMR spectra. The conductivity data showed the electrolytic nature of the Fe (III) and Cu (II) complexes while the Zn (II) complex was nonelectrolyte. All metal complexes had octahedral structure as depicted by spectral and elemental analyses. The complexes start decomposition at 35 C, and they decomposed in four to five steps. The scanning electron microscope (SEM) analysis confirmed the presence of metal complexes in nanostructure. The 1,2,4-triazole Schiff base ligand (L) and its transition metal complexes have been screened for their antibacterial (Gram [+] bacteria): Bacillis subtilis and Staphylococcus aureus, (Gram [−] bacteria): Escherichia coli and Pseudomonas aeruginosa and two fungi: Candida albicans and Aspergillus flavus by agar diffusion method. The two metal complexes were subjected to molecular docking study against crystal structure of Aspergillus fumigatus (PDB ID: 6NE0) and crystal structure of Mycobacterium tuberculosis (PDB ID: 5UHF). The mode of binding between the A. fumigatus (PDB ID: 6NE0) and Mycobacterium tuberculosis strains and the complexes was discussed. K E Y W O R D S 1,2,4-triazole, Candida albicans, diffusion method, MOE, thermal analysis Three metal chelates of new Schiff base were prepared and characterized.