Mono- and bi-iron chalcogenocarboxylate complexes

A series of thiocarboxylato and selenocarboxylato monomeric CpFe(CO)₂ECORCOCl and dimeric [CpFe(CO)₂ECO]₂R iron complexes have been synthesized and characterized. The interaction of (μ-E_x)[CpFe(CO)₂]₂ (E = S; x = 2–4. E = Se; x = 1) with di-acid chlorides (ClCORCOCl) in a 1:1 molar ratio gave the monomeric complexes CpFe(CO)₂ECORCOCl for R = 1,3-C₆H₄, 2,6-C₅H₃N, 1,2-C₆H₄. However, the dimeric complexes [CpFe(CO)₂ECO]₂R were obtained from the same reactants in a 2:1 metal-to-ligand molar ratio in which R is 1,3-C₆H₄, 2,6-C₅H₃N or C₂H₄. The monomer versus dimer production mainly depends on the electronic and steric factors of the R-moiety. The new monomeric and dimeric thio- and selenocarboxylato iron complexes have been characterized by spectroscopic techniques (¹H- and ¹³C-NMR, IR) and by elemental analysis. The structures of [CpFe(CO)₂SCO]₂(1,3-C₆H₄) and its seleno analogue [CpFe(CO)₂SeCO]₂(1,3-C₆H₄) were determined by X-ray structure determination.     

Copper (II)-Surfactant Complex and Its Nano Analog as Potential Antitumor Agents

The in vitro anticancer activity of copper cetyl trimethyl ammonium bromide (Cu-CTAB)-loaded cyclodextrin nanoparticles on Ehrlich ascites carcinoma (EAC), colon cancer cells (HCT 116), liver cancer cells (HepG-2), breast cancer cells (MCF-7), and cervix cancer cells (Hela) was investigated using MTT due assay. Cyclodextrin nanoparticles loaded with Cu-CTAB exerted in vitro anticancer activity against the previous human cancer cell lines comparable to the activity of free non-entrapped in nanoparticles macro-particle Cu-CTAB. The nano analog was synthesized by physical loading using grinding with ball mill. The ratio between Cu-CTAB and cyclodextrin oligosaccharide was 1 Cu-CTAB: 3 cyclodextrin. The particle size of the nano derivative was determined using the transmitted electron microscope (TEM).     

SYNTHESIS AND REACTIONS OF TRIPHENYLPHOSPHONIMINOGLYOXALIC ACID ANILIDE ARYLHYDRAZONES

Abstract

A series of α-azidoglyoxatic acid anilide arylhydrazones 2 were prepared and converted to the corresponding phosphonimines 6 by reaction with triphenylphosphine. Treatment of the latter with acyl chlorides yielded the phosphonium salts 9 which afforded, upon treatment with triethylamine, 1, 5-disubstituted 1H-1, 2, 4-triazole-3-carboxylic acid anilides 11. Acid hydrolysis of 6 yielded the amidrazones 8.     

Ruthenium(II) complexes with tetradentate pyridylthioazoimine [N,S,N,N] ligands: Synthesis, crystal structure and spectroscopy

The Ru(II) complexes cis-[Ru(L)Cl₂] (C1-C3) of novel tetradentate NSNN ligands (L) {where L is C₅H₄N-CH₂-S-C₆H₄NC(COCH₃)-NN-C₆H₄X, and X is H (L1), CH₃ (L2) and Br (L3)}, were synthesized and characterized by spectroscopy (IR, UV/vis and NMR), cyclic voltammetry and crystallography. The tetradentate ligands were isolated as the amidrazones H₂L {where H₂L is C₅H₄N-CH₂-S-C₆H₄NH-C(COCH₃)N-NH-C₆H₄X and X is H (H₂L1), CH₃ (H₂L2) and Br (H₂L3)} as shown by crystallography of H₂L1, but oxidize to azoimines during the formation of the Ru(II) complexes. A crystallographic analysis of C1 showed that the Ru(II) centre is in a distorted octahedral coordination sphere in which the tetradentate ligand occupies three equatorial sites and one axial site (two azoimine nitrogens and a thio sulfur in the equatorial plane and an axial pyridine nitrogen) and two chlorides occupying axial and equatorial coordination sites. The Ru(II) oxidation state is greatly stabilized by the novel tetradentate ligand, showing Ru(III/II) couples ranging from 1.43 to 1.51 V. The absorption spectrum of C1 in acetonitrile was modelled by time-dependent density functional theory.     

EDXRF,FTIR, and XRD characterization of low calcium oxalate urinary stones collected from arid area

Low calcium oxalate urinary stones from the kidney, bladder, and ureter have been collected from the arid area (Taif, Saudi Arabia). After careful washing and drying of the collected stones, the samples were converted into a contamination-free homogenous fine powder with a particles' size smaller than 50 μm. The processed urinary stone powders were studied using attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), laboratory setup and synchrotron radiation X-ray diffraction (XRD), and energy-dispersive X-ray fluorescence (EDXRF). The activated function groups, quantitative phase analysis, and the semi-quantitative elemental analysis of the present urinary stones were identified. Seventeen elements were measured in most of the urinary stone samples. The significant elements are Ca, P, S, Cl, Zn, K, Fe, and Cu, whereas other elements were found alternatively in a few number of urinary stone samples. It was recognized that Ca exists with low concentration, which indicates the presence of different calcium phases even with low percentages. In 33% of the urinary stones, the phosphorus (P) was not measured, but there were high concentrations of sulfur (S) and low concentrations of Ca up to 2.15 ± 0.05%. The ATR-FTIR results indicate that the most compounds of the present urinary stones were urea and cystine combined with low ratios of calcium oxalate and calcium phosphate compounds. The quantitative phase analysis of the XRD of selected samples proves the presence of the cystine, urea, and calcium oxalate phases with different weight percent.     

An inverse problem of identifying the time-dependent potential in a fourth-order pseudo-parabolic equation from additional condition

The aim of this work is to identify numerically, for the first time, the time-dependent potential coefficient in a fourth-order pseudo-parabolic equation with nonlocal initial data, nonlocal boundary conditions, and the boundary data as overdetermination condition. This problem emerges significantly in the modeling of various phenomena in physics and engineering. From literature we already know that this inverse problem has a unique solution. However, the problem is still ill-posed by being unstable to noise in the input data. For the numerical realization, we apply the quintic B-spline (QB-spline) collocation method for discretizing the pseudo-parabolic problem and the Tikhonov regularization for finding a stable and accurate solution. The resulting nonlinear minimization problem is solved using the MATLAB subroutine lsqnonlin. Moreover, the von Neumann stability analysis is also discussed.