55 research outputs found

    Neutral and cationic half-sandwich arene ruthenium, Cp*Rh and Cp*Ir oximato and oxime complexes: Synthesis, structural, DFT and biological studies

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    The reaction of [(p-cymene)RuCl2]2 and [Cp*MCl2]2 (M = Rh/Ir) with chelating ligand 2-pyridylcyanoxime {pyC(CN)NOH} leads to the formation of neutral oximato complexes having the general formula [(arene)M{pyC(CN)NO}Cl] {arene = p-cymene, M = Ru, (1); Cp*, M = Rh (2);Cp*, M = Ir (3)}. Whereas the reaction of 2-pyridyl phenyloxime {pyC(Ph)NOH} and 2-thiazolyl methyloxime {tzC(Me)NOH} with precursor compounds afforded the cationic oxide complexes bearing formula [(arene)M{pyC(ph)NOH}Cl]+ and [(arene)M{tzC(Me)NOH}Cl]+{arene = p-cymene M = Ru, (4), (7); Cp*, M = Rh (5), (8); Cp*, M = Ir (6), (9)}. The cationic complexes were isolated as their hexafluorophosphate salts. All these complexes were fully characterized by analytical, spectroscopic and X-ray diffraction studies. The molecular structures of the complexes revealed typical piano stool geometry around the metal center within which the ligand acts as a NNʹ donor chelating ligand. The Chemo-sensitivity activities of the complexes evaluated against HT-29 (human colorectal cancer), and MIAPaCa-2 (human pancreatic cancer) cell line showed that the iridium-based complexes are much more potent than the ruthenium and rhodium analogues. Theoretical studies were carried out to have a deeper understanding about the charge distribution pattern and the various electronic transitions occurring in the complexes

    JINR-IAP FEM oscillator with Bragg resonator

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    A FEM-oscillator with a reversed guide magnetic field and a Bragg resonator as a RF radiation source for collider applications was studied. The configuration with a step of the corrugation phase is proved to be advantageous. It possesses such features as a high efficiency, precise tunability of the operating frequency and a narrow spectral band. It is demonstrated experimentally that such an oscillator is capable of operating at frequencies of ~30 GHz in single-mode regime with the frequency tuning in interval up to 6%. Frequency and spectrum measurements have been performed with precision of ~0.1%

    Effects of Pore Walls and Randomness on Phase Transitions in Porous Media

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    We study spin models within the mean field approximation to elucidate the topology of the phase diagrams of systems modeling the liquid-vapor transition and the separation of He3^3--He4^4 mixtures in periodic porous media. These topologies are found to be identical to those of the corresponding random field and random anisotropy spin systems with a bimodal distribution of the randomness. Our results suggest that the presence of walls (periodic or otherwise) are a key factor determining the nature of the phase diagram in porous media.Comment: REVTeX, 11 eps figures, to appear in Phys. Rev.

    JINR activity in microwave sources for TeV range linear colliders

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    Results of theoretical and experimental studies of the microwave radiation sources on the base of the induction linac LIU-3000 (JINR, Dubna) are presented. In particular, a FEM-oscillator with the reversed guide magnetic field and Bragg resonator as well as an electron beam buncher in the two-beam accelerator (TBA) driver was studied
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