Cobalt, nickel, copper and zinc complexes with 1,3-diphenyl-1H-pyrazole-4-carboxaldehyde Schiff bases: antimicrobial, spectroscopic, thermal and fluorescence studies.

There are several researches on the preparation and application of hydrazone-linked covalent organic frameworks (COFs), and all of them generally necessitate rigid aromatic amines. Herein, we report a strategy for design and synthesis of COF with flexible alkyl amine as a building block and intramolecular hydrogen bonding as a knot in the network. The proof-of-concept design was demonstrated by exploring 1,3,5-triformylphloroglucinol and oxalyldihydrazide (ODH) as precursors to synthesize a novel COF material (TpODH), in which different organic building units are combined through hydrazone bonds to form two-dimensional porous frameworks. It should be pointed that irreversible enol-to-keto tautomerism and intramolecular N-H···O═C hydrogen bonding of TpODH would enhance the crystallinity and chemical stability, leading to large specific surface area of 835 m2 g-1. However, another COF synthesized with 1,3,5-triformylbenzene and ODH exhibited less crystallinity and low special surface area (94 m2 g-1). Representatively, the resulting TpODH afforded Cu(II) and Hg(II) capacities of 324 and 1692 mg g-1, respectively, which exceeded that of most COFs previously reported. Moreover, the Fourier-transform infrared and X-ray photoelectron spectroscopy spectra analyses were taken to demonstrate the adsorption mechanism. These results suggested that the materials could be applied to the removal of metallic ions in the future.

Fabrication of Hydrazone-Linked Covalent Organic Frameworks Using Alkyl Amine as Building Block for High Adsorption Capacity of Metal Ions

Transition metal complexes of thiosemicarbazone: Synthesis, structures and invitro antimicrobial studies

Herein, we report the synthesis of eight new mononuclear and binuclear Co2+, Ni2+, Cu2+, and Zn2+ methoxy thiosemicarbazone (MTSC) complexes aiming at obtaining thiosemicarbazone complex with potent biological activity. The structure of the MTSC ligand and its metal complexes was fully characterized by elemental analysis, spectroscopic techniques (NMR, FTIR, UV-Vis), molar conductivity, thermogravimetric analysis (TG), and thermal differential analysis (DrTGA). The spectral and analytical data revealed that the obtained thiosemicarbazone-metal complexes have octahedral geometry around the metal center, except for the Zn2+-thiosemicarbazone complexes, which showed a tetrahedral geometry. The antibacterial and antifungal activities of the MTSC ligand and its (Co2+, Ni2+, Cu2+, and Zn2+) metal complexes were also investigated. Interestingly, the antibacterial activity of MTSC- metal complexes against examined bacteria was higher than that of the MTSC alone, which indicates that metal complexation improved the antibacterial activity of the parent ligand. Among different metal complexes, the MTSC- mono- and binuclear Cu2+ complexes showed significant antibacterial activity against Bacillus subtilis and Proteus vulgaris, better than that of the standard gentamycin drug. The in silico molecular docking study has revealed that the MTSC ligand could be a potential inhibitor for the oxidoreductase protein.

https://www.mdpi.com/1420-3049/26/8/2288/pdf

New Mononuclear and Binuclear Cu(II), Co(II), Ni(II), and Zn(II) Thiosemicarbazone Complexes with Potential Biological Activity: Antimicrobial and Molecular Docking Study

Novel Nano‐sized bis‐indoline Derivatives as Antitumor Agents

The synthetic, spectroscopic, and biological studies of Cu(II), Ni(II), Zn(II), Co(II), Mn(II), Fe(III) and Cr(III) complexes of N4-(7′-chloroquinoline-4′-ylamino)-N1-(2-hydroxy-benzylidene)thiosemicarbazone (HL) obtained by the reaction of N4-(7′-chloroquinolin-4′-ylamino)thiosemicarbazide with 2-hydroxybenzaldehyde. The structures of the complexes were determined on the basis of the elemental analyses, spectroscopic data (IR, electronic, 1H and 13C NMR and Mass spectra) along with magnetic susceptibility measurements, molar conductivity and thermogravimetric analyses. Electrical conductance measurement revealed the non-electrolytic nature of the complexes. The resulting colored products are mononuclear in nature. On the basis of the above studies, only one ligand was suggested to be coordinated to each metal atom by thione sulfur, azomethine nitrogen and phenolic oxygen to form mononuclear complexes in which the thiosemicarbazone behaves as a monobasic tridendate ligand. The ligand and its metal complex...

https://www.tandfonline.com/doi/pdf/10.1080/14756360701631850

In-vitro antibacterial, antifungal activity of some transition metal complexes of thiosemicarbazone Schiff base (HL) derived from N4-(7'-chloroquinolin-4'-ylamino) thiosemicarbazide.

The Schiff base ligand, oxalyl [( 2 - hydroxybenzylidene) hydrazone] [corrected].H(2)L, and its Cu(II), Ni(II), Co(II), UO(2)(VI) and Fe(III) complexes were prepared and tested as antibacterial agents. The Schiff base acts as a dibasic tetra- or hexadentate ligand with metal cations in molar ratio 1:1 or 2:1 (M:L) to yield either mono- or binuclear complexes, respectively. The ligand and its metal complexes were characterized by elemental analyses, IR, (1)H NMR, Mass, and UV-Visible spectra and the magnetic moments and electrical conductance of the complexes were also determined. For binuclear complexes, the magnetic moments are quite low compared to the calculated value for two metal ions complexes and this shows antiferromagnetic interactions between the two adjacent metal ions. The ligand and its metal complexes were tested against a Gram + ve bacteria (Staphylococcus aureus), a Gram -ve bacteria (Escherichia coli), and a fungi (Candida albicans). The tested compounds exhibited high antibacterial activities.

https://www.tandfonline.com/doi/pdf/10.1080/14756360701448073

Antimicrobial, spectral, magnetic and thermal studies of Cu(II), Ni(II), Co(II), UO(2)(VI) and Fe(III) complexes of the Schiff base derived from oxalylhydrazide.

Khlood S. Abou Melha

Papers

In-vitro antibacterial, antifungal activity of some transition metal complexes of thiosemicarbazone Schiff base (HL) derived from N4-(7'-chloroquinolin-4'-ylamino) thiosemicarbazide.

Antimicrobial, spectral, magnetic and thermal studies of Cu(II), Ni(II), Co(II), UO(2)(VI) and Fe(III) complexes of the Schiff base derived from oxalylhydrazide.