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Wyświetlanie 1-5 z 5
Tytuł:
Thermal and long period stability of series of V(V), V(IV) and V(III) complex with Schiff base ligands in solid state
Autorzy:
Szklarzewicz, Janusz
Jurowska, Anna
Hodorowicz, Maciej
Gryboś, Ryszard
Powiązania:
https://bibliotekanauki.pl/articles/93074.pdf
Data publikacji:
2019
Wydawca:
Państwowa Wyższa Szkoła Zawodowa w Tarnowie
Tematy:
vanadium
complex
Schiff base
salicylaldehyde
hydrazide
thermogravimetry
wanad
kompleks
baza Schiffa
aldehyd salicylowy
hydrazyd
termograwimetria
Opis:
The synthesis and physicochemical properties of three new complexes of vanadium at +5, +4 and +3 oxidation state are described and discussed. The octahedral surrounding of vanadium for V(III) complexes of [V(L1)(HL1)] general formula is filled with two ONO tridentate ligand L, for V(IV) one ONO ligand L, oxido ligand and 1,10-phenanthroline (phen) as a co-ligand are presented in complexes of [VO(L2)(phen)]. For V(V) the complexes of [VO2(L1)(solv)] type were formed. As ligands, the H2L Schiff bases were formed in reaction between 5-hydroxysalcylaldehyde and phenylacetic hydrazide (H2L1) and 3,5- dichlorosalicyaldehyde and 4-hydroxybenzhydrazide (L2). The magnetic moment measurements, in 8 year period, show, that V(III) complexes slowly oxidise to V(IV) with preservation of the nonoxido character of the complexes, while V(IV) complexes were found to be stable. The TG and SDTA measurements indicate, that thermal stability depends mainly on the oxidation state of vanadium. The less thermally stable are the V(V) complexes, while V(IV) and V(III) are stable up to ca. 200oC. In solution, at pH 2 (similar to that in human digestion system), again the V(IV) are the most stable, only at pH 7.0 V(III) complexes had higher stability. The most stable, thus best for pharmaceutical use, are V(IV) complexes.
Źródło:
Science, Technology and Innovation; 2019, 4, 1; 30-36
2544-9125
Pojawia się w:
Science, Technology and Innovation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Tridentate hydrazido-hydrazones vanadium complexes. Synthesis, properties and biological activity
Autorzy:
Szklarzewicz, Janusz
Jurowska, Anna
Hodorowicz, Maciej
Matoga, Dariusz
Gryboś, Ryszard
Filipek, Barbara
Sapa, Jacek
Głuch-Lutwin, Monika
Mordyl, Barbara
Kazek, Grzegorz
Powiązania:
https://bibliotekanauki.pl/articles/93144.pdf
Data publikacji:
2019
Wydawca:
Państwowa Wyższa Szkoła Zawodowa w Tarnowie
Tematy:
vanadium
complex
Schiff base
structure
hydrazide
biological activity
wanad
kompleks
baza Schiffa
Struktura
hydrazyd
aktywność biologiczna
Opis:
Nine new vanadium complexes, with tridentate Schiff base ligand based on 3,5-di-tertbutyl-2-hydroxybenzaldehyde and different hydrazides, are described and characterized. The X-ray crystal structure of complex 8 shows distorted octahedral geometry of vanadium, with ONO ligand in equatorial position. The tridentate Schiff base ligand forms six membered and five-membered chelate rings at the V(V) acceptor center, with the corresponding bite angles being 82.97(9)˚ and 74.48(9)˚. The molecules are gathered by means of intermolecular OH...N hydrogen bond and layered by π...π interactions involving the pyridine and phenolate rings. Such interactions expand the structure along the crystallographic a axis. The complexes were characterized by the elemental analyses, IR, UV-Vis, EPR spectroscopy, cyclic voltammetry, thermogravimetry and magnetic susceptibility measurements. The stabilization role of co-ligands is discussed. The cytotoxicity versus HepG2 hepatocytes and inhibition of human recombinant PTP1B was studied.
Źródło:
Science, Technology and Innovation; 2019, 4, 1; 9-20
2544-9125
Pojawia się w:
Science, Technology and Innovation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis, structure and properties of V(III, IV and V) complexes with ONO Schiff bases
Autorzy:
Szklarzewicz, Janusz
Jurowska, Anna
Olszewska, Agata
Hodorowicz, Maciej
Gryboś, Ryszard
Kruczała, Krzysztof
Powiązania:
https://bibliotekanauki.pl/articles/93196.pdf
Data publikacji:
2019
Wydawca:
Państwowa Wyższa Szkoła Zawodowa w Tarnowie
Tematy:
vanadium
complex
Schiff base
oxidation state
structure
IR
UV-Vis
EPR
wanad
kompleks
baza Schiffa
stan utlenienia
struktura
Opis:
The synthesis and physicochemical properties of vanadium(III,IV,V) complexes with Schiff base ligands based on 3,5-dibromo-4-methoxy-salicylaldehyde and phenylacetic hydrazide (H2L1), 5-chlorosalicylaldehyde and 4-hydroxybenzhydrazide (H2L2) and 5- chlorosalicylaldehyde and 2-hydroxybenzhydrazide (H2L3) were presented. The formulas of the complexes {[V(L1)(HL2)]·EtOH (1), [VO(L2)(phen)]·2H2O (2) and [VO(L3)(EtO)] (3)} were proposed based on the elemental analysis, IR and UV-Vis spectra. Additionally, the IR and UV-Vis spectra (in solvents as well as in a solid state) have been discussed from the vanadium oxidation state point of view. The single crystal structure of 3 shows triclinic, P-1 space group, structure is stabilized by hydrogen bonds and strong π-π stacking interactions. The oxidation state of the metal centre was also confirmed by the magnetic susceptibility measurements. The stability of the complexes was measured in pH = 7.00 and in pH = 2.00 which allows to evaluate the use of these compounds as insulin mimetic compounds.
Źródło:
Science, Technology and Innovation; 2019, 4, 1; 37-46
2544-9125
Pojawia się w:
Science, Technology and Innovation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis, structure and properties of V(V) monooxido complex with ONO tridentate Schiff base
Autorzy:
Jurowska, Anna
Szklarzewicz, Janusz
Hodorowicz, Maciej
Gryboś, Ryszard
Powiązania:
https://bibliotekanauki.pl/articles/93142.pdf
Data publikacji:
2019
Wydawca:
Państwowa Wyższa Szkoła Zawodowa w Tarnowie
Tematy:
vanadium
complex
Schiff base
structure
5methoxysalicylaldehyde
phenylacetic hydrazide
wanad
kompleks
baza Schiffa
struktura
5 aldehyd metoksysalicylowy
hydrazyd fenylooctowy
Opis:
The oxidovanadium(V) Schiff base complex of formula [VO(L)(EtO)(EtOH)] (where H2L = Schiff base ligand derived from 5-methoxysalicylaldehyde and phenylacetic hydrazide) was synthesized and described. Complex crystalizes in triclinic P-1 space group. Octahedral geometry of the vanadium(V) centre is filed with oxido, ONO L2- ligand and two solvent molecules both in ethoxo and as neutral ethanol form. The complex is neutral, with 5- and 6-memebered ring formed by ONO ligand coordinated in octahedral plane with oxido and EtOH ligands in vertical positions. Two isomers are present in the unit cell, with different position of 5-membered ring versus vertical plane. The elemental analysis, magnetic susceptibility, thermogravimetry and spectroscopy (IR, UV-Vis) measurements were measured and are discussed. The cyclic voltammetry measurements show irreversible processes for vanadium(IV/V) redox system. Thermal stability both in a solid state (TG and SDTA measurements) as well as in solutions (at pH 7.0 and 2.0, studied by UV-Vis spectroscopy) is discussed.
Źródło:
Science, Technology and Innovation; 2019, 4, 1; 21-29
2544-9125
Pojawia się w:
Science, Technology and Innovation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis, structure and properties of V(IV) complex with N’-[(E)-(2,3-dihydroxyphenyl)metylidene]-2- phenylacetohydrazide
Autorzy:
Szklarzewicz, Janusz
Jurowska, Anna
Hodorowicz, Maciej
Gryboś, Ryszard
Powiązania:
https://bibliotekanauki.pl/articles/93158.pdf
Data publikacji:
2019
Wydawca:
Państwowa Wyższa Szkoła Zawodowa w Tarnowie
Tematy:
vanadium
complex
Schiff base
structure
2,3-dihydroxybenzaldehyde
phenylacetic hydrazide
wanad
kompleks
baza Schiffa
Struktura
2,3-dihydroksybenzaldehyd
hydrazyd fenylooctowy
Opis:
The synthesis and physicochemical properties of new vanadium(IV) complex of formula [VO(L)(phen)] is described. The L denotes ONO tridentate Schiff base derived from 2,3-dihydroxybenzaldehyde and phenylacetic hydrazide, while phen = 1,10-phenanthroline used as a co-ligand to stabilize the V(IV) oxidation state. The single crystal X-Ray crystal structure indicates on octahedral geometry of vanadium centre, with 1,10-phenanthroline nitrogen trans to the V=O bond. The complex crystalizes in a monoclinic P21/c space group, very unusual is that only one isomer is present in the crystal structure. The structure is stabilized by very weak hydrogen bonds and H··π and π···π interactions. The phenyl ring of hydrazide is strongly curved from ONO ligand plane by 70.95˚. The spectroscopic characterization (IR, UV-Vis) as well as the cyclic voltammetry measurements are presented and discussed
Źródło:
Science, Technology and Innovation; 2019, 4, 1; 1-8
2544-9125
Pojawia się w:
Science, Technology and Innovation
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-5 z 5

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