Browsing by Author "Paraschivescu, Andrei"

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    Crystal structure of 4,4-bipyridine-containing complexes of copper(II) nitrate with 1-[(2-Hydroxyethylimino)methyl]naphthalen-2-ol and 2-[(2-hydroxyethylimino)methyl]phenol [Articol]
    (2009) Ciumacov, Iurie; Țapcov, Victor; Petrenko, Peter A.; Popovschi, Liliana; Simonov, Iurie; Bocelli, Gabrielle; Antoșciac, Boris; Paraschivescu, Andrei; Gulea, Aurelian
    The crystal structures of (μ-4,4-bipyridine)-di(nitrato-1-[(2- hydroxyethylimino)methyl]naphthalen-2-olocopper (I) and catena-di(μ-4,4'- bipyridine)di(μ-4,4'-bipyridine)-di(nitrato-2-[2-(hydroxyethylimino) methyl]phenolocopper)diaquacopper(II) nitrate (II) were determined. In the crystal of I, each of the two copper atoms coordinates a singly deprotonated tridentate azomethine molecule, a nitrate ion, and bipyridine, which functions as a bridge between the central atoms. The copper coordination polyhedron is a slightly distorted tetragonal pyramid with the base formed by the imine and bipyridine nitrogen atoms and the phenol and alcohol oxygen atoms. The axial site in the pyramid is occupied by the oxygen atom of the monodentate nitrate groups. In the trinuclear structure II with C2 crystal chemical symmetry, the terminal coordination unit is composed through copper coordination of monodeprotonated 2-[2-(hydroxyethylimino)methyl]phenol, bipyridine, and the nitrate anion. In the crystal, the trinuclear molecules form infinite ribbons along the z axis in which the pyridine molecules perform the bridging function. The central copper atom has an octahedral configuration formed by the nitrogen atoms of four 4,4'-bipyridine molecules and oxygen of two water molecules
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    Use of some catalysts in radiolytical split of water [Articol]
    (2002) Cecal, Alexandru; Paraschivescu, Andrei; Gulea, Aurelian; Palamaru, Mircea; Iordan, Alexandra; Popa, Karin; Craus, Mihai
    The present paper deals with the study of catalyzed water radiolysis under the influence of γ-rays emitted by a 60Co source (Λ = 3 × 104 Ci) with a dose rate of 8.3 kGy/h, for hydrogen production. Thirty-one solid inorganic compounds, insoluble in water, were tested as catalysts. They belong to: coordination compounds of some metallic ions with organic ligands based on salycilaldehyde or naphthalenaldehyde derivatives, mixed oxides, RhCl3 supported on a Al2O 3 layer and bimetallic compounds with EDTA ligand. The released hydrogen quantity, determined by mass spectrometry, was approximately 7-35 times greater than the one produced by simple radiolysis of water, in the absence of catalysts.