Synthesis, Photoluminescence and Electrical Study of Pyrazolone-Based Azomethine Ligand Zn(II) Complexes

Гусев, А. Н.; Braga, Elena; Tyutyunik, A. S.; Gurchenko, Vladimir S.; Berezovskaya, Maria; Kryukova, Mariya A.; Кискин, М. А.; Linert, Wolfgang

doi:10.3390/ma13245698

Cited by 18 publications

(5 citation statements)

References 41 publications

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“…Резистивный механизм проводимости, характеризующийся коэффициентом m, соответствует диапазону напряжений от 0 до 0.125 В (коэффициент m1, Таблица 1). Токовый режим с ограниченным пространственным зарядом (space charge limited conduction (SCLC)) [30] работает в диапазоне напряжений от 0.125 до 0.7 В (коэффициент m2, Таблица 1). Третий диапазон, соответствующий переносу заряда за счет механизма trap charge limited conduction (TCLC) работает при напряжениях более 0.7 В (коэффициент m3, Таблица 1) [30].…”

Section: результаты и обсуждениеunclassified

Electrophysical and temperature characteristics of Ag2S quantum dots thin layers

Мазинов,

Тютюник,

Гурченко

2024

RENSIT

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В работе представлено исследование электрофизических свойств тонких плёнок коллоидных квантовых точек сульфида серебра (КТ Ag2S/SiO2) и квантовых точек сульфида серебра, декорированных плазмонными наночастицами золота (КТ Ag2S/SiO2/Au). Проведено исследование температурных зависимостей проводимости в диапазоне температур от 300 до 360 К. Были получены значения энергии активации из линейных аппроксимаций вольт-амперных характеристик в координатах Аррениуса. Показано, что декорирование КТ Ag2S/SiO2 плазмонными наночастицами золота приводит к увеличению ширины запрещенной зоны с 0.29 до 0.89 эВ. В работе рассчитан фактор идеальности и определены основные механизмы проводимости представленных тонкоплёночных структур. Показано, что декорирование КТ Ag2S/SiO2 наночастицами Au приводит к изменению типа проводимости. Согласно модели Мотта-Герни рассчитана подвижности носителей заряда.

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Section: результаты и обсуждениеunclassified

Electrophysical and temperature characteristics of Ag2S quantum dots thin layers

Мазинов,

Тютюник,

Гурченко

2024

RENSIT

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“…The bands at 337 nm (29673 cm -1 ) and 364 nm (27472 cm -1 ) are attributed to the chromophore of the ligand in the complex. The Zn(II) complex shows a broad absorption band at 404 nm (24752 cm -1 ) that can be assigned to L-M charge transfer [39] .…”

Section: Electronic Spectra Of the Schiff Base And Its Corresponding ...mentioning

confidence: 99%

Synthesis, characterization, and biological activity of Cu(II), Ni(II), and Zn(II) complexes of a tridentate heterocyclic Schiff base ligand derived from thiosemicarbazide and 2-benzoylpyridine

et al. 2022

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Ni(II), Cu(II), and Zn(II) complexes of the tridentate heterocyclic ligand, 2-(phenyl(pyridin-2-yl)methylene)hydrazine-1-carbothioamide (HL) have been synthesized and characterized by various spectroscopic techniques and elemental analyses. Infrared spectroscopy shows that the ligand coordinates to the metal ions through the azomethine and pyridine nitrogen atoms as well as the sulfur atom of the thioamide group to form a tridentate chelate system. In vitro screening of metal complexes against four bacterial strains (Staphylococcus aureus (ATCC 43300), Klebsiella pneumoniae (ATCC 700603), Methicillin resistant staphylococcus aureus (ATCC 33591), Shigella flexneri (NR 518)) and four fungal strains (Candida albicans (NR 29444), Candida albicans (NR 29445), Candida albicans (NR 29451), Candida krusei (HM 1122)) indicate that the Cu(II) complex showed good antibacterial activity on Methicillin resistant staphylococcus aureus (ATCC 33591) while the Zn(II) complex showed moderate activity against some of the bacterial and fungi strains. Antioxidant studies reveal that the complexes are more potent than the ligand to eliminate free radicals, with the Ni(II) complex showing the best free radical scavenger.

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“…Azole and benzazole ESIPT-capable derivatives are workhorses in the area of ESIPT studies. − The most common molecular pattern of these compounds which is widely relied upon in the design of ESIPT dyes includes the proton-accepting azole/benzazole moiety combined with the proton-donating 2-hydroxyphenyl group or its analogues introduced in the α position to the azolic N atom. In contrast, pyrimidine derivatives are relatively rarely used for the design of ESIPT-fluorophores in comparison with azole and benzazole ones. ,− However, being combined with suitable proton-donating groups, they can serve as proton-accepting moieties. ,, Moreover, introducing additional donor groups in the pyrimidine core can lead to more complex molecular architectures of pyrimidine-based compounds suitable for binding metal ions and providing numerous sites for protonation, including isomeric ones. ,, In turn, the synthesis of isomeric ESIPT-capable compounds allows researchers to shed more light on the impact of structural factors on ESIPT and on relationships between ESIPT and luminescence. − The coordination of conventional dyes and ESIPT emitters to metal ions with d electronic configuration such as Zn 2+ is known to enhance the quantum efficiency of emission. − Earlier we demonstrated that emissions of 4-(1 H -pyrazol-1-yl)-6-(2-hydroxyphenyl)pyrimidines and 2-(2-hydroxyphenyl)-4-(1 H -pyrazol-1-yl)pyrimidines, which belong to two different isomeric families (Chart ), share such a common feature as dual emission associated with singlet-to-singlet and triplet-to-singlet transitions, which is contributed by anti-Kasha fluorescence of the tautomeric form. ,, However, their coordination behavior toward Zn 2+ ions appeared to be quite different, whereas the 4-(1 H -pyrazol-1-yl)-6-(2-hydroxyphenyl)pyrimidine derivative can bind Zn 2+ ions through the N,N-site of the molecule, which produces multicolor emission of the complex, 2-(2-hydroxyphenyl)-4-(3,5-dimethyl-1 H -pyrazol-1-yl)pyrimidine derivatives cannot do this. We associated this with steric effects imposed by methyl and phenyl substituents introduced in positions 3 and 5 of the pyrazolyl group.…”

Section: Introductionmentioning

confidence: 99%

Complexes on the Base of a Proton Transfer Capable Pyrimidine Derivative: How Protonation and Deprotonation Switch Emission Mechanisms

Shekhovtsov,

Vorob’eva,

Nikolaenkova

et al. 2023

Inorg. Chem.

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A rare example of pyrimidine-based ESIPT-capable compounds, 2-(2-hydroxyphenyl)-4-(1H-pyrazol-1-yl)-6-methylpyrimidine (HL H ), was synthesized (ESIPT�excited state intramolecular proton transfer). Its reactions with zinc(II) salts under basic or acidic conditions afforded a dinuclear [Zn 2 L H 2 Cl 2 ] complex and an ionic (H 2 L H ) 4 [ZnCl 4 ] 2 • 3H 2 O solid. Another ionic solid, (H 2 L H )Br, was obtained from the solution of HL H acidified with HBr. In both ionic solids, the H + ion protonates the same pyrimidinic N atom that accepts the O−H•••N intramolecular hydrogen bond in the structure of free HL H , which breaks this hydrogen bond and switches off ESIPT in these compounds. This series of compounds which includes neutral HL H molecules and ionic (L H ) − and (H 2 L H ) + species allowed us to elucidate the impact of protonation and coordination coupled deprotonation of HL H on the photoluminescence response and on altering the emission mechanism. The neutral HL H compound exhibits yellow emission as a result of the coexistence of two radiative decay channels: (i) T 1 → S 0 phosphorescence of the enol form and (ii) anti-Kasha S 2 → S 0 fluorescence of the keto form, which if feasible due to the large S 2 −S 1 energy gap. However, owing to the efficient nonradiative decay through an energetically favorable conical intersection, the photoluminescence quantum yield of HL H is low. Protonation or deprotonation of the HL H ligand results in the significant blue-shift of the emission bands by more than 100 nm and boosts the quantum efficiency up to ca. 20% in the case ofand (H 2 L H )Br have the same (H 2 L H ) + cation in the structures, their emission properties differ significantly, whereas (H 2 L H )Br shows dual emission associated with two radiative decay channels: (i) S 1 → S 0 fluorescence and (ii) T 1 → S 0 phosphorescence, (H 2 L H ) 4 [ZnCl 4 ] 2 •3H 2 O exhibits only fluorescence. This difference in the emission properties can be associated with the external heavy atom effect in (H 2 L H )Br, which leads to faster intersystem crossing in this compound. Finally, a huge increase in the intensity of the phosphorescence of (H 2 L H )Br on cooling leads to pronounced luminescence thermochromism (violet emission at 300 K, sky-blue emission at 77 K).

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Synthesis, Photoluminescence and Electrical Study of Pyrazolone-Based Azomethine Ligand Zn(II) Complexes

Cited by 18 publications

References 41 publications

Electrophysical and temperature characteristics of Ag2S quantum dots thin layers

Electrophysical and temperature characteristics of Ag2S quantum dots thin layers

Synthesis, characterization, and biological activity of Cu(II), Ni(II), and Zn(II) complexes of a tridentate heterocyclic Schiff base ligand derived from thiosemicarbazide and 2-benzoylpyridine

Complexes on the Base of a Proton Transfer Capable Pyrimidine Derivative: How Protonation and Deprotonation Switch Emission Mechanisms

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