12 research outputs found
The ligational behavior of an isatinic quinolyl hydrazone towards copper(II)- ions
<p>Abstract</p> <p>Background</p> <p>The importance of the isatinic quinolyl hydrazones arises from incorporating the quinoline ring with the indole ring. Quinoline ring has therapeutic and biological activities whereas, the indole ring occurs in Jasmine flowers and Orange blossoms. As a ligand, the isatin moiety is potentially ambidentate and can coordinate the metal ions either through its lactam or lactim forms. In a previous study, the ligational behavior of a phenolic quinolyl hydrazone towards copper(II)- ions has been studied. As continuation of our interest, the present study is planned to check the ligational behavior of an isatinic quinolyl hydrazone.</p> <p>Results</p> <p>New homo- and heteroleptic copper(II)- complexes were obtained from the reaction of an isatinic quinolyl hydrazone (HL) with several copper(II)- salts <it>viz. </it>Clˉ, Brˉ, NO<sub>3</sub>ˉ, ClO<sub>4</sub><sup>-</sup>, SO<sub>4</sub><sup>2- </sup>and AcO<sup>-</sup>. The obtained complexes have O<sub>h</sub>, T<sub>d </sub>and D<sub>4h</sub>- symmetry and fulfill the strong coordinating ability of Clˉ, Brˉ, NO<sub>3</sub>ˉ and SO<sub>4</sub><sup>2- </sup>anions. Depending on the type of the anion, the ligand coordinates the copper(II)- ions either through its lactam (NO<sub>3</sub>ˉ and ClO<sub>4</sub><sup>-</sup>) or lactim (the others) forms.</p> <p>Conclusion</p> <p>The effect of anion for the same metal ion is obvious from either the geometry of the isolated complexes (O<sub>h</sub>, T<sub>d </sub>and D<sub>4h</sub>) or the various modes of bonding. Also, the obtained complexes fulfill the strong coordinating ability of Clˉ, Brˉ, NO<sub>3</sub>ˉ and SO<sub>4</sub><sup>2- </sup>anions in consistency with the donor ability of the anions. In case of copper(II)- acetate, a unique homoleptic complex (<b>5</b>) was obtained in which the AcO<sup>- </sup>anion acts as a base enough to quantitatively deprotonate the hydrazone. The isatinic hydrazone uses its lactim form in most complexes.</p
Ligand substitution reactions of a phenolic quinolyl hydrazone; oxidovanadium (IV) complexes
<p>Abstract</p> <p>Background</p> <p>Quinoline ring has therapeutic and biological activities. Quinolyl hydrazones constitute a class of excellent chelating agents. Recently, the physiological and biological activities of quinolyl hydrazones arise from their tendency to form metal chelates with transition metal ions. In this context, we have aimed to study the competency effect of a phenolic quinolyl hydrazone (H<sub>2</sub>L; primary ligand) with some auxiliary ligands (Tmen, Phen or Oxine; secondary ligands) towards oxidovanadium (IV) ions.</p> <p>Results</p> <p>Mono- and binuclear oxidovanadium (IV) - complexes were obtained from the reaction of a phenolic quinolyl hydrazone with oxidovanadium (IV)- ion in absence and presence of N,N,N',N'- tetramethylethylenediamine (Tmen), 1,10-phenanthroline (Phen) or 8-hydroxyquinoline (Oxine). The phenolic quinolyl hydrazone ligand behaves as monobasic bidentate (NO- donor with O- bridging). All the obtained complexes have the preferable octahedral geometry except the oxinato complex (<b>2</b>) which has a square pyramid geometry with no axial interaction; the only homoleptic complex in this study.</p> <p>Conclusion</p> <p>The ligand exchange (substitution/replacement) reactions reflect the strong competency power of the auxiliary aromatic ligands (Phen/Oxine) compared to the phenolic quinolyl hydrazone (H<sub>2</sub>L) towards oxidovanadium (IV) ion; (complexes <b>2 </b>and <b>3</b>). By contrast, in case of the more flexible aliphatic competitor (Tmen), an adduct was obtained (<b>4</b>). The obtained complexes reflect the strength of the ligand field towards the oxidovanadium (IV)- ion; Oxine or Phen >> phenolic hydrazone (H<sub>2</sub>L) > Tmen.</p
Synthesis, Spectral and Structural Studies of a Novel Semicarbazone Synthesized from Quinoline-2-Carboxaldehyde and N4-Phenyl-3-Semicarbazide
Study of attention measured by event-related potential as a predictive factor of violence among patients with schizophrenia and substance use disorder
Synthesis, spectroscopy, electrochemistry and thermal study of vanadyl tridentate Schiff base complexes: theoretical study of the structures of compounds by ab initio calculations
Hydrogen bonding in thiobenzamide synthon and its Cadmium complex: Crystal structure and Hirshfeld analysis
Synthesis, Spectral Characterization and Crystal Structures of Dioxidomolybdenum(VI) Complexes Derived from Nicotinoylhydrazones
Synthesis and spectral analysis of N-substituted pyrrole salicylaldehyde derivatives-electropolymerization of a new nickel(II)-Schiff base complex derived from 6-[3′-N-pyrrolpropoxy]-2-hydroxyacetophenone and 1,2-diaminoethane
Mortality, Rehospitalisation and Violent Crime in Forensic Psychiatric Patients Discharged from Hospital: Rates and Risk Factors
Hidden diversity among aquatic heterotrophic flagellates: ecological potentials of zoosporic fungi
International audienceSince the emergence of the ‘microbial loop' concept, heterotrophic flagellates have received particular attention as grazers in aquatic ecosystems. These microbes have historically been regarded incorrectly as a homogeneous group of bacterivorous protists in aquatic systems. More recently, environmental rDNA surveys of small heterotrophic flagellates in the pelagic zone of freshwater ecosystems have provided new insights. (i) The dominant phyla found by molecular studies differed significantly from those known from morphological studies with the light microscope, (ii) the retrieved phylotypes generally belong to well-established eukaryotic clades, but there is a very large diversity within these clades and (iii) a substantial part of the retrieved sequences cannot be assigned to bacterivorous but can be assigned instead to parasitic and saprophytic organisms, such as zoosporic true fungi (chytrids), fungus-like organisms (stramenopiles), or virulent alveolate parasites (Perkinsozoa and Amoebophrya sp.). All these microorganisms are able to produce small zoospores to assure dispersal in water during their life-cycles. Based on the existing literature on true fungi and fungus-like organisms, and on the more recently published eukaryotic rDNA environmental studies and morphological observations, we conclude that previously overlooked microbial diversity and related ecological potentials require intensive investigation (i) for an improved understanding of the roles of heterotrophic flagellates in pelagic ecosystems and (ii) to properly integrate the concept of ‘the microbial loop' into modern pelagic microbial ecology