S. Z. Vatsadze

Stereoelectronic Chameleons: The Donor–Acceptor Dichotomy of Functional Groups

Stereoelectronic factors account for the apparent reversal of donor-acceptor properties of a variety of functional groups by a simple change of their orientation in space. The new reactivity patterns that arise from spatial anisotropy are associated with chameleonic behavior of common organic functionalities.

Reaction of cross-conjugated dienones with phenyl- and 2-pyridylhydrazines

New pyrazoline derivatives were synthesized by condensation of dienones based on cyclohexanone and N-substituted piperidin-4-ones with phenylhydrazine and 2-pyridylhydrazine. The reaction with phenylhydrazine produces trans isomers.

Effect of supercritical drying parameters on the phase composition and morphology of aerogels based on vanadium oxide

Aerogels based on vanadium oxide were obtained by supercritical drying in carbon dioxide (scCO2) and organic solvents (acetone, n-hexane, n-heptane, and n-octane). The performed study allowed us to reveal the effect of experimental parameters (precursor type, type of primary and secondary solvents) on the phase composition and morphology of obtained aerogels. The obtained samples were studied by X-ray diffractometry, scanning electron microscopy, and capillary nitrogen adsorption-desorption (BET) method.

Synthesis, Characterization and Properties of Some Main-Chain Ferrocene-Based Polymers Containing Aromatic Units

Four main-chain ferrocene-based polymers containing aromatic units, including poly(o-Cresolphthalein 1,1′-ferrocene dicarboxylate) (PCPFD), poly(cresol red 1,1′-ferrocene dicarboxylate) (PCRFD), poly(2,4-quinolinediol 1,1′-ferrocene dicarboxylate) (PQDFD), and poly(sudan orange G 1,1′-ferrocene dicarboxylate) (PSOFD), were successfully synthesized. The solution polycondensation reaction was employed for the synthesis of PCPFD and PCRFD while PQDFD and PSOFD were synthesized via an interfacial polycondensation reaction. The synthesized polymers were characterized by 1H and 13C NMR, UV–VIS absorption and FTIR spectra and X-ray diffraction. The synthesized main-chain ferrocene-based polymers are generally amorphous. The effect of organic solvent, scan rate, electrolyte concentration and [Fe] concentration on the cyclic voltammetric behavior of the synthesized polymers were examined. The thermal properties were investigated employing thermogravimetric analysis. The results revealed the relative thermal stability of the polymers. The liquid crystalline properties were studied. The results indicated that the synthesized polymers exhibited nematic phases during the scan cycles of heating and cooling with high phase duration.

Synthesis of new derivatives of 5,6,7,8-tetrahydro-1,6-naphthyridines and their pharmacological properties

Abstract1,5-Dicarbonyl derivatives of piperidine and tropane were studied in the heterocyclization with hydroxylamine hydrochloride. All the 5,6,7,8-tetrahydro-1,6-naphthyridines obtained exhibit a pronounced analgesic effect.

Copper–Bispidine Complexes: Synthesis and Complex Stability Study

A new series of dicarboxylic derivatives of bispidines have been synthesized to develop novel copper(II) complexes suitable as imaging agents for positron emission tomography. For characterization purposes, copper complexes of bispidines were synthesized in the pure form and in quantitative yields by neutralization of ligands with malachite. The formation of complexes and their stoichiometries were studied by potentiometric titration, cyclic voltammetry, and spectroscopic methods. The stability constants were found to be fairly suitable for copper cation fixation inside dianionic chelate molecules.

Synthesis of novel linear exo-bidentate bispyridine ligands and their complexes with silver(I) tetrafluoroborate

Novel exo-bidentate ligands containing two γ-pyridyl fragments and their complexes with silver(i) tetrafluoroborate were synthesized.

New supramolecular synthons based on 3d transition metal complexes with bidentate bispidines: synthesis and structural, spectroscopic, and electrochemical studies

A new supramolecular synthon, a 2L: 1M complex of bidentate bispidine with transition metal, was suggested. A number of complex compounds of 1,5-dimethylbispidin-9-one with Cuii, Niii, and Coii salts (perchlorates, chlorides, bromides, nitrates, trifluoroacetates) were synthesized. The structure and composition of complexes obtained were estimated based on the combination of physicochemical methods of analysis (elemental analysis, X-ray diffraction analysis, NMR, IR, and Raman spectroscopy, electron absorption spectroscopy, ESI mass spectrometry, CVA). The composition of most complexes in the solid state corresponds to the formula ML2X2, and in a number of cases the fragment [ML2]2+ is retained in solution, which was shown by NMR spectroscopy for nickel complexes and by mass spectrometry for copper complexes. In the case of copper chloride, the composition of the acetonitrile solutions in the presence of the ligand depends on the ratio of starting compounds and their concentration: an increase in proportion of CuCl2 and concentration shifts the equilibrium to the side of complexes with higher nuclearity. A 2L: 1M complex of bispidine with metal was for the first time structurally characterized using copper(ii) nitrate derivative as an example. The CVA method showed existence of reversible electrochemical reduction of the metal for a number of complexes (the products of the reaction of 1,5-dimethylbispidin-9-one with nickel(ii) and cobalt(ii) chlorides, as well as with nickel(ii) bromide). According to the IR and Raman spectra, chelation of metals with 1,5-dimethylbispidin-9-one leads to the shift of the absorption band of the ligand carbonyl group from 1700 to 1721–1744 cm−1. Nickel(ii) and copper(ii) perchlorates and nitrates were concluded to be the most promising complexation agents for the binding of two NH,NH-bispidine ligands in a coordination polymer.

New aspects of the aldol condensation of acetylpyridines with aromatic aldehydes

Aldol condensation of acetylpyridines with aromatic aldehydes was studied. A series of new products of cascade reactions were isolated and characterized.

Novel dienone-based ligands for the synthesis of coordination polymers

New angular exo-dentate 3,3′-bipyridyl-type ligand [L = 2,6-di(3-pyridylmethylidene)cyclohexanone, 1] with conjugated dienone system was used for the synthesis of {[AgL]NO3}n, 2. An X-ray structural determination showed that 2 is composed of polymeric chains (–Ag–L–)n, twinned via metallophilic and stacking interaction.