Anatolii S. Burlov

Luminescent complexes with ligands containing C=N bond

Data on luminescent complexes with azomethine ligands are generalized and systematized. The synthesis and luminescent properties of complexes with acyclic and cyclic azomethines are considered.

The novel azomethine ligands for binuclear copper(II) complexes with ferro- and antiferromagnetic properties

A series of novel binuclear ferro- and antiferromagnetic Cu(2+) chelates of structurally broadly varied Schiff bases (derived from o-tosylamino(hydroxyl)benzaldehydes and monoalkylated o-phenylenediamine, o-aminophenol, o-aminothiophenol, 1,2-diaminobenzimidazole, 1-aminobenzimidazoline-2-thione) and β-diketimines (derived from 2,6-di-i-Pr-aniline) has been prepared. The tautomerism of the ligands and structureof their copper complexes have been studied with the use of IR, 1H NMR EPR and EXAFS spectroscopy. Molecular and crystal structure of a β-diketimine copper dimer has been determined by X-ray crystallography. The magnetic measurements (2–300 K) performed for all the complexes showed that the ferro- and antiferromagnetic character of the exchange interaction depends both on the structure of the coordination site (origin of the ligating centers) and the structure of the ligands (in particular, on the type of the cycle annelated to the bridging fragment). Whereas S-binding metal chelates 13 (X = NTs, Y = S, R = H) are diamagnetic, the complexes 15 with annelated azole moieties are ferromagnetic.

Electrochemical synthesis of metal (II) complexes of Schiff base 2-tosylamino (2′-pyridyl)aniline: the crystal structure of bis-[2-tosylamino(2′-pyridyl)anilinato]cobalt(II)

Abstract Complexes of cobalt(II), nickel(II), copper(II), zinc(II) and cadmium(II) with the anion of the Schiff base 2-tosylamino(2′-pyridyl)aniline (HL) have been prepared by using an electrochemical procedure. These compounds were characterized by elemental analysis, IR, UV and NMR spectroscopy, and in the case of [CoL2] by X-ray diffraction methods. In this compound the cobalt(II) atom is in a distorted tetrahedral environment, each Schiff base anion acting as a bidentate ligand with the pyridine nitrogen atom uncoordinated.

Metal complexes with azomethines containing the isomeric E-Z azo fragments

Cobalt and zinc complexes with phenylazosalicylaldehyde azomethines were obtained by chemical and electrochemical syntheses. The B3LYP/6-311G(d, p) calculations showed that the azo group in both the ligands and the complexes are mainly in the E-form.

Electrochemical and Chemical Synthesis of New Luminescent Schiff Base Complexes

Bis-chelate complexes of zinc, cadmium, lead, and mercury with o-N-tosylbenzylidene imines containing the C7H15 and C18H37 substituents at the C=N group nitrogen atom were prepared by the methods of electrochemical and chemical syntheses. The structure of the azomethines and their complexes was established by the methods of heteronuclear 1H, 13C NMR spectroscopy (multidimensional and multinuclear COSY, HETCOR and HETCOR_LONG techniques). The complexes, as demonstrated by the X-ray analysis for the zinc chelate, have strongly distorted octahedral structure formed by the four azomethine nitrogen atoms and two oxygen atoms of the tosyl fragments. The coordination compounds show fluorescence in the blue part of the spectrum in high quantum yields for the zinc chelates.

Complexing properties of ambidentate benzo-15-crown-5-substituted azomethine ligands

Crown-containing azomethines and their zinc complexes were prepared. Examination of their structure by 1H and 7Li NMR and electronic spectroscopy showed that, in accordance with the concept of hard and soft acids and bases, the hard lithium cation coordinates to the crown ether fragment with the formation of mono-(Li) and binuclear (Li, Zn) complexes.

Self-assembling tetranuclear complexes of a tridentate Schiff base

A tetranuclear KZn3 complex consisting of three tridentate dibasic N2O donor ligands (derived from mono-N-phenyl-substituted 5-nitro-o-phenylenediamine) and one methylato group has been synthesized. Single-crystal multi-temperature (100–350K) X-ray diffraction studies of the complex reveal that {[ZnL]3OMe}− units are assembled by K…ON2 contacts into layers. Mutual position of the KO6 and {[ZnL]3OMe}− fragments of neighboring layers is temperature dependent.

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.

Zinc complexes of 1-Propyl-2-(2-tosylaminophenyl)-5-aminobenzimidazole: Synthesis, structure, and luminescence properties

Abstract1-Alkyl-2-(2-tosylaminophenyl)-5-aminobenzimidazole and related zinc complexes are synthesized. The structure of the complex with zinc pivalate is determined by X-ray diffraction analysis. The fluorescence with the anomalous Stokes shift of the benzimidazole ligand system in solution is transformed into the fluorescence with the normal Stokes shift upon complex formation due to blocking the mechanism of intramolecular proton transfer in the excited state or upon the transition to the crystalline state formed by zwitterionic forms that are generated due to the proton transfer from the sulfonamide group to the amino group.

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.