Nano-sized Cu(II) and Zn(II) complexes and their use as a precursor for synthesis of CuO and ZnO nanoparticles: A study on their sonochemical synthesis,characterization, and DNA-binding/cleavage,anticancer, and antimicrobial activities

Two new divalent copper (C1) and zinc (C2) chelates having the formulae [M(PIMC)₂] (where M = Cu(II), Zn(II) and PIMC = Ligand [(E)-3-(((3-hydroxypyridin-2-yl)imino)methyl)-4H-chromen-4-one] were obtained and characterized by several techniques. Structures and geometries of the synthesized complexes were judged based on the results of alternative analytical and spectral tools supporting the proposed formulae. IR spectral data confirmed the coordination of the ligands to the copper and zinc centers as monobasic tridentate in the enol form. Thermal analysis, UV-Vis spectra and magnetic moment confirmed the geometry around the copper center to be tetrahedral, square pyramidal and octahedral. Study of the binding ability of the synthesized compounds with Circulating tumor DNA (CT-DNA) bas been evaluated applying UV-Vis spectral titration and viscosity measurements. The copper and zinc oxides were achieved from the copper and zinc nano-particles structures Schiff base complexes as the raw material after calcination for 5 hr at 600°C. On the other hand, synthesized of C1 and C2 NPs were used as suitable precursors to the preparation of CuO and ZnO NPs. Finally, the synthesized of the two complexes exhibited enhanced activity against the tested bacterial (Staphylococcus aureus and Escherichia Coli) and fungal strains (Candida albicans and Aspergillus fumigatus) as compared to HPIMC. Among all these synthesized compounds, C1 exhibits good cleaving ability compared to other newly synthesized C2.     

Controlled synthesis of ZnO nanoparticles from a Zn(II) coordination polymer: Structural characterization,optical properties and photocatalytic activity

A zinc coordination polymer derived from pyridine-2,6-dicarboxylate (PDC), {[Zn₂(PDC)₂]}_n, was successfully prepared via conventional, sonication and microwave-irradiation methods. The composition and characteristics of the obtained coordination polymers (CPs) were investigated by elemental analysis, TGA/DTA, X-ray diffraction and spectroscopic techniques. The so obtained CPs were heat-treated in the air at 600 °C for 2 h to produce ZnO of nanosized particles (NPs). It is of interest to note that the synthesis approach of the precursor greatly affects both the nanoparticle size and the structure of the resulting ZnO NPs. Moreover, the smallest particle size was associated with the sample derived from the ultrasonically prepared precursor. TEM analysis revealed that all samples have sphere-like morphologies. Structural analysis of the prepared ZnO samples was conducted and compared using Rietveld analysis of their PXRD patterns. Optical band gap calculations based on analysis of the UV–vis spectra of ZnO samples using Tauc's power law were achieved. The highest band gap of 3.63 eV was observed for ZnO sample obtained from the ultrasonically prepared precursor. Furthermore, the photocatalytic activity of ZnO NPs for the removal of Eosin Y color was monitored. The highest removal efficiency was recorded for ZnO originated from the ultrasonically synthesized precursor. Enhancement of removal efficiency that reached 98% was attained in only a period of 8 min. Its recycling test showed that it can be reused without structural changes over four cycling experiments.     

Simulation model for shapiro time delay and light deflection experiments

The time delay experiment proposed by I.I. Shapiro in 1964 and conducted in the seventies was the most precise experiment of general relativity until that time. Further experimentation has improved the accuracy level of both the time delay and the light deflection experiments. A simulation model is proposed that involves only a simple mass and time transformation factor involving velocity of light. The light deflection and the time delay experiments are numerically simulated using this model that does not use the general relativistic equations. The computed values presented in this paper compare well with recent levels of accuracy of their respective experimental results.     

A novel method for the preparation of T3 free plasma/serum for routine RIA

A novel method to eliminate T₃ from gross sera/plasma based on prior treatment with 8-anilino-1-naphthalene sulphonic acid has been standardized. This method is rapid with a minimum loss of protein and uses only small quantities of charcoal. The treated sera have been tested for acceptance in the RIA system for routine assays.     

Working group report: Neutrino and astroparticle physics

This is the report of neutrino and astroparticle physics working group at WHEPP-7. Discussions and work on CP violation in long baseline neutrino experiments, ultra high energy neutrinos, supernova neutrinos and water Cerenkov detectors are discussed.     

Effect of Mn substitution on the delicate balance between structure and properties of Gd1.4Ce0.6Sr2RuCu2O10

Some new members of a ruthenocuprate(2212) series have been synthesized by Mn substitution for Ru in Gd_1.4Ce_0.6Sr₂RuCu₂O₁₀. Characterization by x-ray diffraction (XRD) phase analysis has been carried out. Changes in structural features on substitution, including a significant change in lattice parameter for a very low substitution level, have been observed. Four-probe resistivity studies indicate the coexistence of superconductivity and magnetism for the pristine compound and a semiconductor-like upturn in resistivity and the absence of superconductivity even for very low levels of Mn substitution. AC susceptibility measurements show a progressive suppression of the magnetic transition temperature as well as a smearing of the magnetic transition as a function of Mn substitution. Possible reasons for the absence of superconductivity have been discussed.     

Electronic and molecular properties of an adsorbed protein monolayer probed by two-color sum-frequency generation spectroscopy

Two-color sum-frequency generation spectroscopy (2C-SFG) is used to probe the molecular and electronic properties of an adsorbed layer of the green fluorescent protein mutant 2 (GFPmut2) on a platinum (111) substrate. First, the spectroscopic measurements, performed under different polarization combinations, and atomic force microscopy (AFM) show that the GFPmut2 proteins form a fairly ordered monolayer on the platinum surface. Next, the nonlinear spectroscopic data provide evidence of particular coupling phenomena between the GFPmut2 vibrational and electronic properties. This is revealed by the occurrence of two doubly resonant sum-frequency generation processes for molecules having both their Raman and infrared transition moments in a direction perpendicular to the sample plane. Finally, our 2C-SFG analysis reveals two electronic transitions corresponding to the absorption and fluorescence energy levels which are related to two different GFPmut2 conformations: the B (anionic) and I forms, respectively. Their observation and wavelength positions attest the keeping of the GFPmut2 electronic properties upon adsorption on the metallic surface.     

Cobalt(II), nickel(II), copper(II) and zinc(II) complexes of conjugated 3-(benzylidene/salicylidene)-β-diketones (having no enolisable γ-carbon proton) and their reactions

Transition Metal Chemistry - The synthesis and structural characterization of new metal(II) chelates (M = CoII, NiII, CuII and ZnII) of neutral conjugated bidentate β-diketone ligands, having...     

Synthesis of 2,3-dimethyltetra-cyclo(5.5.1.04,13.010,13)trideca-2,5-dien-9-one,a new derivative of all-cis-(5.5.5.5)fenestrane

Intramolecular arene-olefin photoreaction of methyl-6-methyl-2-phenylhept-5-enoate (9a) leads to the tetracyclic product 10a, from which the fenestra-dienone, 2, has been obtained. Mechanistic aspects of the photoreaction are discussed.