A combined experimental and theoretical approach for structural study on a new cinnamoyl derivative of 2-acetyl-1,3-indandione and its metal(II) complexes

The synthesis, structure and spectral properties of a new cinnamoyl derivative of 2-acetyl-1,3-indandione (2AID), p-fluoro-cinnamoyl-1,3-indandione, LH and its metal(II) complexes with Cu(II), Zn(II) and Cd(II), are described. In order to verify the molecular structure of the free ligand and its metal complexes, model geometries based on the spectroscopic data were optimized using quantum chemical methods. The experimental spectroscopic data (IR and NMR) of the ligand, LH, complemented by the calculated ones, show that it exists in the exocyclic enolic form in the gas phase, solution and solid state. Good quality single crystals of Cd(II) complex were obtained from a DMSO solution and were studied by means of single-crystal X-ray diffraction. The data show bidentate coordination of the ligand and two DMSO molecules coordinated to the metal centre, thus forming a complex with octahedral geometry. On the contrary, the spectroscopic data on the amorphous samples indicate a square planar geometry of the Cu(II) complex and distorted octahedral geometry for Zn(II) and Cd(II) complexes with two water molecules coordinated to the metal centre. The used quantum chemical method for structure optimization of the transition metal complexes, B3LYP/LANL2DZ, shows very good agreement with the crystallographic data and, therefore, was also employed for structural determination for the non-crystalline complexes. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Incorporation of group III,IV and V elements in 3C–SiC(1 1 1) layers grown by the vapour–liquid–solid mechanism

We report on a comparative investigation of the incorporation of group III, IV and V impurities in 3C–SiC heteroepitaxial layers grown by the vapour–liquid–solid (VLS) mechanism on on-axis α-SiC substrates. To this end, various Si-based melts have been used with addition of Al, Ga, Ge and Sn species. Homoepitaxial α-SiC layers grown using Al-based melts were used for comparison purposed for Al incorporation. Nitrogen incorporation depth profile systematically displays an overshoot at the substrate/epilayer interface for all the layers. Ga and Al incorporations follow the same distribution shape as N whereas this is not the case for the isoelectronic impurities Ge and Sn. This suggests some interaction between Ga/Al and N coming from the high bonding energy between the group III and V elements, which does not exist with Ge and Sn. This is why both incorporate as a cluster. A model of incorporation is proposed taking into account metal-N and metal-C bonding energies together with the solid solubility of the corresponding nitrides.     

XPS studies of short pulse laser interaction with copper

The effect of laser ablation on copper foil irradiated by a short 30 ns laser pulse was investigated by X-ray photoelectron spectroscopy. The laser fluence was varied from 8 to 16.5 J/cm² and the velocity of the laser beam from 10 to 100 mm/s. This range of laser fluence is characterized by a different intensity of laser ablation. The experiments were done in two kinds of ambient atmosphere: air and argon jet gas.The chemical state and composition of the irradiated copper surface were determined using the modified Auger parameter (α′) and O/Cu intensity ratio. The ablation atmosphere was found to influence the size and chemical state of the copper particles deposited from the vapor plume. During irradiation in air atmosphere the copper nanoparticles react with oxygen and water vapor from the air and are deposited in the form of a CuO and Cu(OH)₂ thin film. In argon atmosphere the processed copper surface is oxidized after exposure to air.     

Synthesis, characterization and spectroscopic properties of some 2-substituted 1,3-indandiones and their metal complexes

New 2-acyl-1,3-indandione derivatives, compounds 1–4, were obtained by condensation of 2-acetyl-1,3-indandione with benzaldehyde, thiophene-2-aldehyde, thiophene-3-aldehyde and furane-2-aldehyde, respectively. The structures of the newly synthesized 2-substituted 1,3-indandiones were characterized by means of spectroscopic methods (FT-IR, ¹H and ¹³C NMR, UV-Vis and MS). Based on the obtained results it is suggested that the compounds exist in the exocyclic enolic form. Mass spectral fragmentation paths are also proposed. In order to verify the possibility for tautomerization processes of the newly synthesized compounds their absorption spectra were recorded in various solvents. Furthermore, the complexation properties of the compounds with metal(II) ions were also studied. A series of non-charged complexes with Cu(II), Cd(II), Zn(II), Co(II) and Ni(II) was isolated and analyzed by elemental analyses and IR. The paramagnetic Cu(II) complexes were studied by EPR and distorted, flattened tetrahedral structures are predicted. The other metal complexes show the presence of water molecules, most probably coordinated to the metal ion, thus forming octahedral geometry. Ultimately, the studied properties of the newly synthesized compounds, 1–4, suggest that they may find application as extracting agents for metal ions, rather than as optical sensors.      

The investigation of the reaction22Na(n,p)22Ne for a neutron energy to 1,000 eV

TheK-internal conversion coefficient of the 205 keV (7/2⁺→5/2⁺) transition in¹⁰⁷Cd was determined. From the measured value α _K =0.0552±0.0009 and the known value of theE2/M1 mixing ratio δ² a value of 6.3±1.5 was deduced for the penetration parameterλ. Information derived on effective gyromagnetic ratios in the frame of an extreme single particle model is briefly discussed.     

Hyperfine splitting and isotope shift in the optical transition of Eu isotopes and electromagnetic moments of Eu

The laser-induced resonance fluorescence in an atomic beam was used in order to measure the hyperfine splitting of the 4f ⁷ 6s ² and 4f^{7 6s6p} levels in ^151,153,155Eu isotopes. The hfs constants A and B of the unstable ¹⁵⁵Eu were determined for the first time: MHz, MHz and MHz. With these data and after corrections for second-order hyperfine structure perturbations the nuclear moments of ¹⁵⁵Eu were deduced: n.m. and b. In addition new and more precise values of the hfs constants of the excited state for the stable ^151,153Eu were obtained. They are as follows: MHz, MHz and MHz, MHz. The hyperfine anomalies % and % were extracted from the corrected hfs constants. Received 28 July 1999 and Received in final form 14 January 2000     

Atomic Absorption Assessment of Mineral Iron Quantity in Ferritin

ABSTRACT

The goal of this work is to study the possibilities for quantitative determination of the number of iron atoms in the mineral core of ferritin by atomic absorption spectroscopy (AAS). Distinctive AAS measurements show iron content between 1000 and 4500 atoms per molecule ferritin.^[ 1-6 McKnight , J. ; White , N. ; Moore , G. R. Effect of copper(II) on the aerobic oxidative uptake of iron(II) by horse spleen ferritin . J. Chem. Soc. 1997 , 21 , 4043 – 4045 . Kyung , S. K. ; Mun , H. R. ; Lee , J. H. Iron cores of tadpole ferritin: Native, reconstituted and recombinant H-chain ferritins . Inorg. Chim. Acta 2000 , 298 , 107 – 111 . Beard , J. L. ; Burton , J. W. ; Theil , E. C. Purified ferritin and soybean meal can be sources of iron for treating iron deficiency in rats . J. Nutr. 1996 , 126 , 154 – 160 . Chasteen , N. D. ; Theil , E. C. Iron binding by horse spleen apoferritin. A vanadyl(IV) EPR spin probe study . J. Biochem. 1982 , 257 , 7672 – 7677 . Treffry , A. ; Harrison , P. M. Incorporation and release of inorganic phosphate in horse spleen ferritin . Biochem. J. 1978 , 171 , 313 – 320 . Harrison , P. M. Ferritin: An iron-storage molecule . Semin. Hematol. 1977 , 14 , 55 – 70 .  ^] This motivated us to investigate the amount of iron in the horse spleen ferritin with atomic absorption spectroscopy under application of the Bulgarian standard BDS EN 14082/2003 Foodstuffs—Determination of Trace Elements—Determination of Lead, Cadmium, Zinc, Copper, Iron and Chromium by Atomic Absorption Spectrometry (AAS) after Dry Ashing.^{[ 7} BDS EN 14082/2003 Foodstuffs—Determination of Trace Elements—Determination of Lead, Cadmium, Zinc, Copper, Iron and Chromium by Atomic Absorption Spectrometry (AAS) after Dry Ashing. www.bds–bds.org . [Google Scholar] ^]

We have obtained as a result 1792 atoms in one ferritin molecule. This result is in accordance with previous results, published by leading researchers.^{[ 4} Chasteen , N. D. ; Theil , E. C. Iron binding by horse spleen apoferritin. A vanadyl(IV) EPR spin probe study . J. Biochem. 1982 , 257 , 7672 – 7677 . [Google Scholar] ^{, 5} Treffry , A. ; Harrison , P. M. Incorporation and release of inorganic phosphate in horse spleen ferritin . Biochem. J. 1978 , 171 , 313 – 320 . [Google Scholar] ^] The investigation of the iron content with AAS under the use of the Bulgarian standard can be a good opportunity to study many other objects of biological interest.