Waldemar Nowicki

Dioxovanadium(V) Schiff base complexes of N-methyl-1,2-diaminoethane and 2-methyl-1,2-diaminopropane with aromatic o-hydroxyaldehydes and o-hydroxyketones: synthesis, characterisation, catalytic properties and structure

Abstract Nineteen new dioxovanadium(V) complexes with unsymmetrical tridentate Schiff base ligands, obtained by a single condensation of 2-methyl-1,2-diaminopropane or N-methyl-1,2-diaminoethane with salicylaldehyde and its derivatives, 2-hydroxy-1-naphthaldehyde, 2-hydroxyacetophenone, 1-hydroxy-2-acetonaphthone and 2-hydroxybenzophenone, were prepared. The complexes were characterized by their 1H and 51V NMR, IR, and UV–Vis spectra. Crystal structure of the 2-(4-amino-4-methyl-2-aza-1-penten-1-yl-κ2N)-3,5-dimethoxyphenolato-κO-dioxovanadium(V), VO2(C13H19N2O3), has been obtained by X-ray diffraction studies. The structure revealed a rarely encountered in VO2(tridentate Schiff base) complexes a distorted trigonal-bipyramidal coordination geometry. The complexes comprising ligands derived either from N-methyl-1,2-diaminoethane or 2-methyl-1,2-diaminopropane and 5-methoxysalicylaldehyde catalyse the oxidation of thioanisole to the corresponding sulfoxide by cumene hydroperoxide.

Isotopes of polonium (210Po) and uranium (234U and 238U) in the industrialised area of Wiślinka (North Poland)

Phosphogypsum is very much enriched in natural polonium 210Po, while the uranium radionuclides (234U and 238U) tend to be in waters around waste dumps. The migration and distribution of uranium and polonium radionuclides in analysed water samples are not uniform. The amounts of uranium isotopes in a retention reservoir around the waste dump are 100 times higher than in typical natural river waters. The concentration of uranium in surface water samples collected near Wiślinka (North Poland) ranged widely between 0.05 ± 0.02 and 430 ± 5 µg L–1. In phosphogypsum samples, uranium concentrations varied in the range of 4.03 ± 0.08 and 0.65 ± 0.05 mg kg–1 in samples collected in 1997 and 2007, respectively. We observed that the activity ratio 234U/238U is approximately about one in the phosphogypsum (0.90 ± 0.06 and 0.97 ± 0.03) and in the water of the immediate surroundings of waste heap (1.00 ± 0.06 and 1.07 ± 0.05), while in surface river water from Martwa Wisła River is higher than one (1.10 ± 0.07 and 1.16 ± 0.13). The phosphogypsum samples contain much higher 210Po activity in comparison with uranium radionuclides. The concentration of 210Po in phosphogypsum samples is similar or slightly higher in 1997 and 2007 (600 ± 10 and 700 ± 10 Bq kg–1, respectively). Finally, the principal sources of 210Po, 234U, 238U radionuclides in the Wiślinka area waste dump are phosphorites and phosphogypsum, produced by Phosphoric Fertilisers Industry of Gdańsk.

Synthesis and Spectral Properties of the Europiumciiid Chelates with Schiff Bases

Abstract The complexes of Eu(III) and the Schiff bases were obtained and the structure, nature of chemical bonds, and symmetry of the compounds were eluciaded on the basis of spectroscopic and elemental analysis data. Two of the compounds were the monomers with 8-coordinated europium and one of them was a dimer with 6-coordinated europium.

Polonium (210Po), uranium (234U, 238U) isotopes and trace metals in mosses from Sobieszewo Island, northern Poland

The activity of polonium 210Po and uranium 234U, 238U radionuclides, as well as trace metals in mosses, collected from Sobieszewo Island area (northern Poland), were determined using the alpha spectrometry, AAS (atomic absorption spectrometry) and OES-ICP (atomic emission spectrometry with inductively coupled plasma). The concentrations of mercury (directly from the solid sample) were determined by the cold vapor technique of CV AAS. The obtained results revealed that the concentrations of 210Po, 234U, and 238U in the two analyzed kinds of mosses: schrebers big red stem moss (Pleurozium schreberi) and broom moss (Dicranum scoparium) were similar. The higher polonium concentrations were found in broom moss (Dicranum scoparium), but uranium concentrations were relatively low for both species of analyzed mosses. Among the analyzed trace metals the highest concentration in mosses was recorded for iron, while the lowest for nickel, cadmium and mercury. The obtained studies showed that the sources of polonium and uranium isotopes, as well as trace metals in analyzed mosses are air city contaminations transported from Gdańsk and from existing in the vicinity the phosphogypsum waste heap in Wiślinka (near Gdańsk).

Crystal structure and magnetic properties of catena-μ-(pyrazine-N,N′)bis[(p-nitrobenzoyl)trifluoroacetonato-O,O′]copper(II)

Abstract The X-ray crystal structure, variable-temperature magnetic susceptibilities and e.s.r. spectra are reported for the title complex. The complex crystallises as infinite chains in which the copper(II)-β-diketonate units are bridged axially by ambidentate pyrazine ligands with a Cu⋯Cu separation of 7.6700(2) A. The magnetic susceptibility measurements in the range 5–325 K are consistent with the ferromagnetic intrachain exchange. The S =1/2 Heisenberg ferromagnetic linear chain analysis results in magnetic parameters of g =2.12 and J/k =0.6 K.

Metal benzoylpivaloylmethanates. Part III. Manganese(III) and iron(III) chelates

SummaryThe synthesis and principle properties of several novel tris[1-(4′-X-phenyl)-4,4-dimethylpenta-1, 3-dionato]-iron(III) and manganese(III) complexes, where X=MeO, Me, H, F, Cl and NO2, are described. Magnetic susceptibility measurements in the 4.2–295 K range show a near Curie behaviour and a constant magnetic moment for manganese(III) complexes and for iron complexes, with X=F, Cl or NO2. Iron complexes with ligands having substituents: X=MeO, Me and H, show weak antiferromagnetic interaction (J=ca.−8 cm−1 for the two former compounds) and a decrease in magnetic moment with decreasing temperature. In both manganese(III) and iron(III) complexes the diketonate ligand can be easily replaced by chlorine. Equilibrium constants could be evaluated only for substitution of the third diketonate ligand by chloride in the iron complexes on the basis of spectrophotometric measurements. For manganese chelates, the replacement of the second diketonate by chloride is accompanied by reduction of manganese(III) →manganese(II) and free organic radical formation is observed.

Infrared Transmision and Photoacoustic Spectra (PAS) of Europium(III) Chelates with Schiff Bases. Part 1. Complex with H2salen

Abstract The results of application of infrared transmission and photoacoustics spectroscopic methods for characterization of europium(III) complex with Schiff base are presented in the spectral range of 400 - 3500 cm−1. The analysis of the spectra enables the idetification of the frequencies corresponding to the vibrations of Eu-ligand bonds and the frequencies of the intraligand vibrations.