Synthesis, structures and fluorescence of nickel, zinc and cadmium complexes with the N,N,O-tridentate Schiff base N-2-pyridylmethylidene-2-hydroxy-phenylamine

The review reports a short biography of the Italian naturalized chemist Hugo Schiff and an outline on the synthesis and use of his most popular discovery: the imines, very well known and popular as Schiff Bases. Recent developments on their "metallo-imines" variants have been described. The applications of Schiff bases in organic synthesis as partner in Staudinger and hetero Diels-Alder reactions, as "privileged" ligands in the organometallic complexes and as biological active Schiff intermediates/targets have been reported as well.

https://www.mdpi.com/1420-3049/18/10/12264/pdf

Schiff Bases: A Short Survey on an Evergreen Chemistry Tool

Schiff bases and their metal complexes have become well-known for catalytic (e.g., in various synthetic processes) and biological properties (e.g., antifungal, antibacterial, anti-malarial, and antiviral characteristics) since their discovery by Hugo Schiff in 1864. As synthetic compounds, they are employed as versatile tools in numerous applications such as fluorescent turn-on/turn-off sensors for the determination of diverse analytes (e.g., metallic components). As such, they can offer a way to identify toxic ions and/or to provide their speciation in environmental media. This review covers a broad range of Schiff bases that are used in sensing applications for metallic cations and anions in various kinds of environmental and biological media.

A review of the applications of Schiff bases as optical chemical sensors

Catechol oxidase and phenoxazinone synthase: Biomimetic functional models and mechanistic studies

https://arrow.tudublin.ie/cgi/viewcontent.cgi?article=1030&context=ittsciart

Anticancer and antifungal activity of copper(II) complexes of quinolin-2(1H)-one-derived Schiff bases

Cd(II) and Cu(II) complexes of polydentate Schiff base ligands: synthesis, characterization, properties and biological activity

Schiff base ligands HL1–HL6 have been prepared from the reaction of 2,6-diformyl-4-t-butylphenol and 2,6-di-formyl-4-methylphenol with various aromatic amines in ethanolic solution. The Schiff base ligands 2,2′-dipyridine (dp) mixed-ligand CuII complexes have been obtained. Mixed-ligand CuII complexes containing the dp ligand have ionic nature and they conduct the electricity in solution media. The complexes have been obtained in two different forms: one of them is [Cu2(Ln)Cl3] (n: 1, 2, 3, 4, 5 and 6) and other complexes have the general formula [Cu2(Ln)(dp)2]3Cl. Ligands and their complexes have been characterized by elemental analyses, FT-IR, electronic spectra, molar conductance, 1H(13C)-n.m.r. and mass spectral data. Their stoichiometric protonation constants have been determined potentiometrically in dioxan using a combined pH electrode at 25 °C, under a nitrogen atmosphere. For the calculation of the protonation constants, PKAS computer programme has been used. The effects of the substituents on the protonation constants and the additivities of these effects are discussed. The antimicrobial activity studies of the ligands and their complexes have been studied against the Bacillus megaterium, Micrococcus luteus, Corynebavterium xenosis, Enterococcuc faecalis, bacteria and Saccoramyces cerevisia, yeast. The catalytic properties of the complexes have been studied on the ascorbic acid, catechol and 2,6-di-t-butylphenol substrates. Thermal behaviour of the complexes has been studied by thermal techniques.

Mixed-ligand copper(II) complexes: Investigation of their spectroscopic, catalysis, antimicrobial and potentiometric properties

The complexation processes between CuII and the antiviral drug, valacyclovir hydrochloride (H2L), were studied under different reaction conditions, using UV-Vis, IR and mass spectra, magnetochemical, thermogravimetric, atomic absorption, conductivity, and elemental analysis data. Using the Job method, the compositions of these complexes were determined. Under the ligand (H2L) excess (M:L = 1:1–1:10). In aqueous solutions, a binuclear violet complex Cu2(HL)2L(H2O)4 is formed, with an octahedral structure. Under comparable amounts of the reagents, in MeOH solutions, a green mononuclear complex Cu(H2L)Cl2 is formed. Protonation constants of the H2L, and stability constants of its Cu2+ complexes, were determined by potentiometric titration in H2O media at 25 ± 0.02 °C under a N2 atmosphere and ionic strength of 0.1 m NaCl. It has been observed that H2L has three protonation constants. The divalent metal ion Cu2+ forms stable 2:1 and 2:2 complexes with H2L. The antimicrobial activity studies of the valacyclovir and it’s complexes have been studied against some gram positive species: (Corynebacterium xerosis, Bacillus brevis, Bacillus megaterium, Bacillus cereus, Mycobacterium smegmatis, Staphylococcus aureus, Micrococcus luteus, Enterococcus faecalis) and gram negative (Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, Yersinia enterocolitica, Kluyveromyces fragilis, Saccharomyces cerevisiae, Candida albicans) bacteriaz.

Spectroscopic and Analytic Properties of New Copper(II) Complex of Antiviral Drug Valacyclovir

In this study, we synthesized the amine compounds 2-{(E)-[(2-aminoethyl)imino]methyl}phenol (H3A) and 2-{(E)-[(3-aminopropyl)imino]methyl}-6-methoxyphenol (H3B) as the starting materials. From reac...

Havva Demirelli

Papers

Cd(II) and Cu(II) complexes of polydentate Schiff base ligands: synthesis, characterization, properties and biological activity

Mixed-ligand copper(II) complexes: Investigation of their spectroscopic, catalysis, antimicrobial and potentiometric properties

Spectroscopic and Analytic Properties of New Copper(II) Complex of Antiviral Drug Valacyclovir

Synthesis and Characterization of Polydentate Schiff-Base Ligands and Their Complexes

Investigations into the Inhibition of Luminol Chemiluminescence by some Novel Metal Complexes