Solvent effects on oxygen atom transfer reaction between manganese(V)-oxo corrole and alkene

Pseudo-first order reaction rate constants of 5,10,15-tris（pentafluorophenyl）corrole Mn（V）-oxo (F₁₅CMn（V）-oxo),5,15-bis（pentafluorophenyl）-10-（phenyl）corrole Mn（V）-oxo(F₁₀CMn（V）-oxo),5,15- bis（phenyl）-10-（pentafluorophenyl）corrole Mn（V）-oxo（F₅CMn（V）-oxo） and 5,10,15-tris（phenyl）corrole Mn（V）-oxo（F₀CMn（V）-oxo） with a series of alkene substrates in different solvents were determined by UV-vis spectroscopy.The results indicated that the oxygen atom transfer pathway between Mn（V）-oxo corrole and alkene is solvent-dependent.     

Preparation, nano purification, quality control and labeling optimization of [64Cu]-5,10,15,20-tetrakis (penta fluoro phenyl) porphyrin complex as a possible imaging agent

Cu-64 was produced via the ⁶⁸Zn (p,αn)⁶⁴Cu nuclear reaction (≈200 mCi, >95 % chemical yield at 180 μA for 1.1 h irradiation, (radionuclidic purity >96 %, copper-67 as impurity) followed by purification with amino functionalized nano magnetic oxide, Fe₃O₄ aiming to remove trace amount of heavy metal ions from aqueous media due to achieve ultra pure [⁶⁴Cu] CuCl₂ for labeling step. [⁶⁴Cu] labeled 5,10,15,20-tetrakis(penta fluoro phenyl) porphyrin ([⁶⁴Cu]-TFPP) was prepared using freshly prepared [⁶⁴Cu] CuCl₂ (Cu-64; T _1/2 = 12.7 h) and 5,10,15,20-tetrakis(penta fluoro phenyl)porphyrin (H₂TFPP) for 60 min at 100 °C under reflux condition (radiochemical purity: >97 % ITLC, >98 % HPLC, specific activity: 14–16 GBq/mmol). Stability of the complex was checked in final formulation and human serum for 24 h. The partition coefficient was calculated for the compound (log P = 0.73). The biodistribution of the labeled compound in vital organs of wild-type rats was studied using scarification studies and PET imaging up in 2 and 4 h after injection. A detailed comparative pharmacokinetic study performed for ⁶⁴Cu cation and [⁶⁴Cu]-TFPP. The complex is mostly washed out from the circulation through kidneys and liver and can be an interesting tumor imaging/targeting agent due to high specific uptake and rapid excretion through the urinary tract.     

Preparation and evaluation of an ion imprinted sol–gel material for selective solid-phase extraction of Ni(II)

An ion imprinted silica sorbent was prepared using a sol–gel process for selective extraction of Ni(II) ions from water samples. Bis(dibenzoylmethanto)nickel(II) complex was used as template; phenyltrimethoxysilane and 3-aminopropyltriethoxysilane as functional monomers and tetraethylorthosilicate as reticulating agent. The material was packed in solid-phase extraction (SPE) column. The effect of sampling volume, elution conditions, sample pH and sample flow rate on the extraction of Ni ions from water samples were studied. The relative selectivity coefficients of imprinted sorbent for Ni(II)/Co(II), Ni(II)/Cu(II) and Ni(II)/Cd(II) were 23.7, 30.3 and 24.4, times greater than non-imprinted sorbent, respectively. The relative standard deviation of the eight replicate determinations of Ni(II) was 4.2%. The detection limit was 0.9 µg L^?1 using flame atomic absorption spectrometry. The developed method was successfully applied to the determination of trace nickel in water samples.     

Polypyrrole–montmorillonite nanocomposite as sorbent for solid‐phase microextraction of phenolic compounds in water

A fiber‐coated polypyrrole–montmorillonite nanocomposite was prepared for solid‐phase microextraction. The fiber coating can be prepared easily; it is mechanically stable and exhibits relatively high thermal stability. The prepared fiber was evaluated for the extraction of some phenolic compounds from aqueous sample solutions by gas chromatography–mass spectrometry. The effects of the extraction and desorption parameters including extraction time, extraction temperature, stirring rate, ionic strength, pH and desorption temperature and time have been studied. At optimum conditions, the repeatability for one fiber (n = 5), expressed as % relative standard deviation was between 6.5 and 7.8% for the phenolic compounds. The detection limits for the studied phenolic compounds were between 0.05–1.3 ng/mL. The developed method offers the advantage of being simple to use, with shorter analysis time, lower cost, thermal stability of the fibers, and high relative recovery in comparison to conventional methods of analysis.     

Preparation of CoFe2O4/sawdust and NiFe2O4/sawdust magnetic nanocomposites for removal of oil from the water surface

In this study, CoFe₂O₄/Sawdust and NiFe₂O₄/Sawdust magnetic nanocomposites were synthesized using a hydrothermal method, and then characterized using X-ray powder diffraction, Infrared, scanning electron microscopy, Brunauer–Emmett–Teller/Barrett–Joyner–Halenda, and vibrating-sample magnetometer techniques. In this study, unmodified sawdust (US), modified sawdust (MS), unmodified CoFe₂O₄/sawdust (UCS), modified CoFe₂O₄/sawdust (MCS), unmodified NiFe₂O₄/sawdust (UNS), and modified NiFe₂O₄/Sawdust (MNS) magnetic nanocomposites, which are inexpensive, economical, environmentally friendly absorbents, and have a high selective hydrophobic, were used for the removal of oil from the water surface. The results show that the UCS, MCS, UNS, and MNS magnetic nanocomposites can selectively absorb the oil spreading on the water surface, due to its superhydrophobicity and superoleophilicity, and can be easily collected from water under the influence of a magnetic field. In addition, the results showed that the absorbents reach their equilibrium at the 30-min mark. Among all the absorbents, the MNS magnetic nanocomposite showed the maximum absorption capacity (18.172 g/g) at the 40-min mark. The results of the kinetic studies showed that the second-order kinetic equation with the highest correlation coefficient had the best fit with the experimental results.     

Synthesis,characterization and crystal structures of new Zinc(II) and Nickel(II) complexes containing morpholine moiety and their antibacterial studies

The ligand 1,2-dimorpholinoethane (DME) was used to prepare Zn(II) and Ni(II) complexes of the general formulation MLX₂ (L = DME, X = Cl or NO₃). Zinc(II) complex exhibits spectral properties indicative of a distorted tetrahedral geometry, with DME coordinating through two nitrogen atoms and two chlorides completing the tetrahedron. This is in contrast to the six-coordinated, distorted octahedral geometry exhibited by nickel(II) complex of DME when NO₃ was used as counter ions. The X-ray diffraction confirms the structures of two complexes and shows that the ligand coordinates through two nitrogen atoms while the two ether linkages are not involved in complexation, which would have been the case if the morpholine rings were in the boat form. The ligand and related complexes have antibacterial activity against the five Gram-positive bacteria: Bacillus subtilis ATCC 6633, Staphylococcus aureus ATCC 6538, Bacillus cereus NRRL-B-3711, Enterococcus faecalis ATCC 29212 and Streptococcus pyogenes and also against the three Gram-negative bacteria: Escherichia coli ATCC 11230, Pseudomonas aeruginosa ATCC 15442 and Klebsiella pneumonia ATCC 70063. The results showed that in some cases the antibacterial activity of the complexes exceeded the one of sulfisoxazole used as a standard.     

Propagation characteristics of tilted partially coherent rectangular flat-topped beam in turbulent atmosphere

In this paper, the effects of atmospheric turbulence on the intensity distribution of a tilted Rectangular Partially Coherent Flat-Topped (RPCFT) beam were studied. An analytical formula for the intensity distribution was derived. POWER In Bucket (PIB) value is calculated numerically. The effects of source parameters – such as correlation length, order of flatness and tilt coefficient – on the intensity were analyzed. Detailed analysis demonstrates that these parameters have an influence on beam propagation properties. The analyses are illustrated by numerical examples and graphs.     

The effects of annealing temperature on structural and optical properties of S-doped ZnO nanobelts

In this study, the effects of thermal annealing temperature on the structural and optical properties of S-doped ZnO nanobelts were investigated. The XRD pattern shows that the crystallinity of S-doped ZnO nanobelts improves with increased annealing temperature. Room temperature photoluminescence spectroscopy of the as-grown S-doped ZnO nanobelts shows no detectable ultraviolet peak with the broad peaks in the visible emission region at 480, 505, and 518 nm. A weak peak in the ultraviolet region at 383 nm appears after annealing at 400 and 600 °C. Raman spectroscopy of the sample also shows a significant change with an increase in the annealing temperature.     

Multiplication operators on Hilbert spaces of analytic functions

Let be a Hilbert space of functions analytic on a plane domain such that for every in the functional of evaluation at is bounded. Assume further that contains the constants and admits multiplication by the independent variable z, M_z, as a bounded operator. We give sufficient conditions for M_z to be reflexive.Received: 17 February 2004     

Filtered optical feedback induced frequency dynamics in semiconductor lasers

We demonstrate experimentally and numerically that, by spectrally filtering the delayed optical feedback into a semiconductor laser, one can elicit novel dynamics in the frequency of the laser output light on a time scale that is set by the delay time of the feedback. In particular, we show that through a judicious choice of the filter bandwidth, and its frequency relative to that of the laser, one can produce controlled oscillations in the frequency of light from the laser.