Artem V. Dmitriev

Synthesis, structure, photo- and electroluminescence studies of bis[2-(N-tosylamino)benzylidene-4′-dimethylaminophenylaminato]zinc

A new bis[2-(N-tosylamino)benzylidene-4′-dimethylaminophenylaminato]zinc complex was synthesized, its structure was studied by methods of elemental analysis, IR spectroscopy, 1H NMR spectroscopy, X-ray absorption spectroscopy, and quantum chemical calculations. Electron absorption and photoluminescence spectra of the zinc complex were investigated. An OLED device based on it was made and found to emit “soft” yellow light with CIE coordinates (x = 0.431, y = 0.537) and radiation luminance 1300 cd m−2 at a working voltage of 14 V.

Synthesis and photo- and electroluminescent properties of copolyfluorenes with nile red fragments in side chains

New copolyfluorenes containing units of 4,7-dibromo-2,1,3-benzothiadiazole (green luminophore) and 3,6- or 2,7-dibromocarbazole derivatives with side-chain fragments of green (4-pyrrolidinyl-1,8-naphthalimide) and red (Nile red) luminophores and additional carbazole or diphenyloxadiazole groups are synthesized via the Suzuki copolycondensation reaction. The structure of the polymers is modified via insertion of triphenylamine, aryloxadiazole, and quinoxaline units in the backbone of copolyfluorenes and via introduction of triphenylamine, fluorene, and benzene terminal groups. The molecular-weight characteristics of the polycondensation products and the specific features of the transfer of polyfluorene emission energy to the indicated luminophores in solutions and films are studied. Coating the emissive copolyfluorene layer with electron-conducting and hole-blocking layers of poly[9,9-bis(6′-diethoxyphosphorylhexyl)fluorene] makes it possible to increase the brightness of light-emitting diodes (to 2380–3900 cd/m2) and their current and luminance efficiencies.

Synthesis, Crystal Structure, and Electroluminescent Properties of Zinc and Cadmium Tetradentate Azomethine Complexes

Chemical and electrochemical syntheses of zinc(II) and cadmium(II) complexes based on tetradentate Schiff bases (H2L1 and H2L2) resulting from condensation of 2-tosylaminobenzaldehyde with 3,6-dioxa-1,8-octanediamine or 4,9-dioxa-1,12-dodecanediamine were performed. The structure, composition, and properties of the complexes were studied by elemental analysis, IR, 1H NMR, and UV spectroscopy, X-ray absorption spectroscopy, and X-ray diffraction. The zinc(II) and cadmium(II) complexes luminesce in a DMF solution in the blue spectral region (λPL = 425–433 nm), the photoluminescence quantum yield φ being 0.25–0.30. Multilayer zinc(II)- and cadmium(II)-based electroluminescent structures with green-blue emission of the exciplex nature were fabricated.

Synthesis, structure, and spectral studies of zinc and cadmium complexes with 2-tosylaminobenzaldehyde and aminoquinoline azomethine derivatives

New zinc and cadmium complexes with 3-[2-(N-tosylaminobenzylidene)]aminoquinoline (HL1) and 6-[2-(N-tosylaminobenzylidene)]aminoquinoline (HL2) were synthesized. The structures of HL1, HL2 and complexes ML2 (M = Zn, Cd) were established based on the elemental analysis data, IR spectroscopy, 1H NMR spectroscopy, and quantum chemical calculations. Electron absorption and photoluminescence spectra of the complexes were studied. OLED devices were developed, where ZnL22 complexes were used as an emission layer. This device emitted yellow light with CIE x = 0.436, y = 0.492 and x = 0.463, y = 0.484, maximum luminance at 10 V was 126 and 150 cd m−2, respectively.

Bis[2-(4′-Bromopyrazolyl-1′)-3-Tosylaminopyridinato]zinc(II): Synthesis, structure, and luminescence properties

Abstract2-(4′-Bromopyrazolyl-1′)-3-tosylaminopyridine (HL3) and its complex ZnL2 (I) are synthesized, and their structures are studied by IR, UV, and 1H NMR spectroscopy. The molecular structure of complex ZnL2 is determined by X-ray diffraction analysis. The atomic structure of ZnL2 is confirmed by the optimization of the molecular geometry using quantum-chemical calculations in the density functional theory approximation. The experimental bands in the absorption spectrum of complex I are interpreted on the basis of the calculations, and its photoluminescence properties are studied.