Rapid separation of212Pb−212Bi−208Tl by high-performance liquid ion chromatography

Fast radiochemical separation of carrier-free²¹²Pb–²¹²Bi–²⁰⁸Tl in radioactive equilibrium was performed using the HPLC technique with an ion-exchange column /ION-210 for cation exchange, ION-110 for anion exchange and C18 loaded with cation-exchange sites/. Optimal results are obtained with the ION-110 column.²⁰⁸Tl and²¹²Pb are eluted by 0.5M HCl in 2.5 and 5 min, respectively.²¹²Bi is recovered by elution with 1M HNO₃.     

Synthesis,characterization and cytotoxic activity of organoruthenium(II)-halido complexes with 5-chloro-1H-benzimidazole-2-carboxylic acid

Three new ruthenium(II)-arene halido complexes, [(η⁶-p-cymene) RuX(L)] (1–3), were synthesized in a reaction of [(η⁶-p-cymene)RuX₂]₂ with 5-chloro-1H-benzimidazole-2-carboxylic acid (HL) in ethanol (X^– = Cl^– (1), Br^– (2), I^– (3)). The complexes were characterized by elemental analysis, mass spectrometry, IR, ¹H and ¹³C NMR spectroscopy. The cytotoxic activity of the ligand precursor and its ruthenium complexes was tested by MTT assay in human cancer cell lines: lung adenocarcinoma (A549), myelogenous leukemia (K562) as well as in one normal human fetal lung fibroblast cell line (MRC-5). The results show that ruthenium(II)-arene complexes possess enhanced cytotoxicity when compared to HL in the range of concentrations up to 300 µM. In terms of halido ligand substitution, cytotoxic activity toward A549 and K562 cell lines in 1–3 serie significantly increased (e.g., IC₅₀ values for K562: 1: 205.76 µM; 2: 174.77 µM; 3: 83.97 µM). All studied compounds were found to be ineffective toward MRC-5. Hydrolysis of 1–3 was followed by UV-vis spectroscopy at 25?°C, revealing ligand-substitution reactions at the Ru(II) center. Compounds 2 and 3 underwent rapid hydrolysis ranging from a few minutes for the aquation to ca. 20?min, confirming typical Ru-arene behavior in aqueous solutions.     

Density Functional Theory Calculations of Structural,Electronic, and Magnetic Properties of the 3d Metal Trifluorides MF3 (M = Ti-Ni) in the Solid State

We employ density functional theory with Hubbard U correction or hybrid functionals to study the series of magnetic 3d metal trifluorides MF₃ (M = Ti-Ni). Experimental lattice parameters are reproduced with an error margin of 0.5%–4.3%. Cooperative Jahn–Teller distortions are reproduced for MnF₃, but also found in TiF₃ and CoF₃ at smaller levels compared to MnF₃. Trends in electronic structure with respect to positions of the d bands are linked to the magnetic properties where M = Ti-Cr are weak magnetic Mott–Hubbard insulators, M = Fe-Ni are strong magnetic charge-transfer insulators and MnF₃ falls in between. Our work contributes to the characterization of the relatively unknown NiF₃, since FeF₃ and CoF₃ have similar electronic and magnetic properties. However, NiF₃ does not show a Jahn–Teller distortion as present in CoF₃. © 2019 Wiley Periodicals, Inc.     

Embedding procedure for ab initio correlation calculations in group II metals

In order to apply ab initio wave-function-based correlation methods to metals, it is desirable to split the calculation into a mean-field part and a correlation part. Whereas the mean-field part (here Hartree-Fock) is performed in the extended periodic system, it is necessary to use for the correlation part local wave-function-based correlation methods in finite fragments of the solid. For these finite entities it is necessary to construct an embedding. The authors suggest an embedding scheme which has itself no metallic character but can mimic the metal in the internal region, where the atoms are correlated. With this embedding it is also possible to localize the metallic orbitals in the central part. The long-range nonadditive contributions of metallicity and correlation are treated with the method of increments. In this paper they present different ways to construct such an embedding and discuss the influence of the embedding on the correlation energy of the solid.     

Brownmillerites CaFeO2.5 and SrFeO2.5 as Catalyst Support for CO Oxidation

The support material can play an important role in oxidation catalysis, notably for CO oxidation. Here, we study two materials of the Brownmillerite family, CaFeO_2.5 and SrFeO_2.5, as one example of a stoichiometric phase (CaFeO_2.5, CFO) and one existing in different modifications (SrFeO_2.75, SrFeO_2.875 and SrFeO₃, SFO). The two materials are synthesized using two synthesis methods, one bottom-up approach via a complexation route and one top-down method (electric arc fusion), allowing to study the impact of the specific surface area on the oxygen mobility and catalytic performance. CO oxidation on ¹⁸O-exchanged materials shows that oxygen from SFO participates in the reaction as soon as the reaction starts, while for CFO, this onset takes place 185 °C after reaction onset. This indicates that the structure of the support material has an impact on the catalytic performance. We report here on significant differences in the catalytic activity linked to long-term stability of CFO and SFO, which is an important parameter not only for possible applications, but equally to better understand the mechanism of the catalytic activity itself.     

Wavelet-modified binary phase-only morphological correlation for color pattern recognition

This paper reports a morphological phase-only correlation technique based on bit-map representation for recognition of color as well as grey images in a hybrid digital-optical correlation architecture. The color image is decomposed into its R, G and B components, and each component is further decomposed into eight disjoint elementary images depending upon the bit-map representation of the color value at each pixel. Bit-map representation of the pixel values of an image reduces the required computational time. A set of twenty-four disjoint wavelet-modified binary phase-only filters (WBPOFs) are generated from these bit-map decomposed images. The target image is similarly decomposed into eight disjoint images each of R, G and B and their digital Fourier transforms multiplied with the corresponding WBPOFs. The product functions thus obtained are added up to form a single resultant product function, whose optical Fourier transformation gives the correlation peaks for the presence of R, G and B components in the image. The single product function overcomes the necessity of obtaining the final optical Fourier transformation of the R, G and B components separately. The novelty of this approach lies in the fact that the WBPOFs synthesized by this procedure are thus able to identify both colored as well as gray images and can tolerate salt-and-pepper noise to a considerable extent.     

Electron correlation contribution to the /ceria(1 1 1) interaction

We have investigated the electron correlation contribution to the interaction energy of the N₂O/ceria(1 1 1) system at the CCSD(T) level. N₂O binds either with the N-end towards the surface with an interaction energy or with the O-end with . In the former case almost the entire binding energy is due to electron correlation effects, in the latter these effects contribute with about 60%. Analyses of the interaction energy contributions show that most of the electron correlation part originates from the interaction of N₂O with the O ions in the topmost surface layer.     

Symmetric spaces approach to some fixed point results

In this paper we present a simple and unified approach to the fixed point results on cone symmetric spaces and metric type spaces based on symmetric spaces fixed point theory. We also give a new characterization of semi-metric spaces with open balls.     

Thermoresponsive Poly(2‐oxazine)s

The monomers 2‐methyl‐2‐oxazine (MeOZI), 2‐ethyl‐2‐oxazine (EtOZI), and 2‐n‐propyl‐2‐oxazine (nPropOZI) were synthesized and polymerized via the living cationic ring‐opening polymerization (CROP) under microwave‐assisted conditions. pEtOZI and pnPropOZI were found to be thermoresponsive, exhibiting LCST behavior in water and their cloud point temperatures (T_CP) are lower than for poly(2‐oxazoline)s with similar side chains. However, comparison of poly(2‐oxazine) and poly(2‐oxazoline)s isomers reveals that poly(2‐oxazine)s are more water soluble, indicating that the side chain has a stronger impact on polymer solubility than the main chain. In conclusion, variations of both the side chains and the main chains of the poly(cyclic imino ether)s resulted in a series of distinct homopolymers with tunable T_CP.