Bis­(O,O′‐di‐p‐tolyldithiophosphato‐S,S′)(1,10‐phenanthroline‐N,N′)nickel(II)

The title coordination complex, [Ni(C₁₄H₁₄O₂PS₂)₂(C₁₂H₈N₂)] or [Ni(pMePh‐dtp)₂(phen)] (phen is 1,10‐phenanthroline; dtp is di­aryl­di­thio­phosphate), has a non‐crystallographic twofold axis of symmetry through the Ni atom and the phen moiety. Two O,O‐di‐p‐tolyl­di­thio­phosphate (dtp) ions act as bidentate ligands. The central metal atom is coordinated by four S atoms from two dtp groups and two N atoms from the phen ligand. The title compound displays distorted octahedral geometry around the central Ni atom.     

A silica-supported palladium-bis(oxazoline) complex efficiently catalyzes the synthesis of cinnamic acid derivatives via Mizoroki–Heck coupling reactions

A palladium(II)-bis(oxazoline) complex supported on silica (Pd-BOX-Si) was prepared, characterized and applied as a catalyst in Mizoroki–Heck cross-coupling reactions. The bis(oxazoline) (BOX) ligand has a hydroxyl group that can be anchored to 4-benzyl chloride-functionalized silica gel, followed by the coordination of palladium(II) chloride. The catalytic activity and the recyclability of Pd-BOX-Si have been investigated in the production of cinnamic acid derivatives via Mizoroki–Heck coupling reactions of acrylates with aryl halides; The Pd-BOX-Si catalyst demonstrated excellent catalytic activity. Characterization of the recycled Pd-BOX-Si catalyst revealed its good stability under the reaction conditions employed.     

Peculiar reaction behavior of 1,3-oxathiolan-5-one toward various reagents: Molecular modeling studies and in vitro antioxidant and cytotoxicity evaluation

Chemical reactivity of 2-methyl-2-phenyl-1,3-oxathiolan-5-one (1) toward various reagents such as hydroxyaldehyde, ketone, α,β unsaturated carbonyl compounds, heterocyclic amine, hydrazine, and hydrazide to give unpredicative opened and fused heterocyclic systems was investigated. Moreover, treatment of compound 1 with bromoester to afford the respective fused system, 2-methyl-2-phenylfuro[3,2-d][1,3]oxathiol-5(6H)-one (6) was implemented. Besides, ¹H–¹H nuclear overhauser effect spectroscopy was used for full confirmation of the compound 19. In addition, the density functional theory modeling study outcomes were discussed and all of the new synthesized compounds were evaluated as antioxidants and cytotoxicity assay against hepatocellular carcinoma cell line.     

Electron transfer at tetrahedral cobalt(II). Part II‡. Kinetics of silver(I) ion catalysed reduction of peroxodisulphate

Transition Metal Chemistry - The kinetics of the silver(I) ion catalysed reduction of peroxodisulphate by 12-tungstocobaltate(II) anion in aqueous HC1O4 has been studied. Although the reaction in...     

Aero-thermo-mechanical characteristics of imperfect shape memory alloy hybrid composite panels

A nonlinear finite element model is provided to predict the static aero-thermal deflection and the vibration behavior of geometrically imperfect shape memory alloy hybrid composite panels under the combined effect of thermal and aerodynamic loads. The nonlinear governing equations are obtained using Marguerre curved plate theory and the principle of virtual work taking into account the temperature-dependence of material properties. The effect of large deflection is included in the formulation through the von Karman nonlinear strain-displacement relations. The thermal load is assumed to be a steady-state constant-temperature distribution, whereas the aerodynamic pressure is modeled using the quasi-steady first-order piston theory. The Newton-Raphson iteration method is employed to obtain the nonlinear aero-thermal deflections, while an eigenvalue problem is solved at each temperature step and static aerodynamic load to predict the free vibration frequencies about the deflected equilibrium position. Finally, the nonlinear deflection and free vibration characteristics of a composite panel are presented, illustrating the effects of geometric imperfection, temperature rise, aerodynamic pressure, boundary conditions and shape memory alloy fiber embeddings on the panel response.     

All-optical time-division demultiplexing and spatial pulse routing with a GaAs/AlGaAs microring resonator

We report what is to our knowledge the first demonstration of all-optical time-division demultiplexing and spatial pulse routing in a compact nonlinear GaAs/AlGaAs microring resonator operating at 1.55 microm . Switching is through the refractive-index change induced by two-photon absorption. The switching time of the device, limited by the ring-charging time and the recombination time of the induced carriers, is measured to be 30 ps. The switching on-off contrast, limited by the slight mismatch between the input and output coupling coefficients, exceeds 8 dB. The device can be used for time-division multiplexing as well.     

Multiobjective strategies in power systems planning

The rapidly changing decision environment in electrical systems planning calls for a new approach in planning procedures and mathematical tools. The method proposed in this study decomposes the decision making into two strata, one at the strategy setting, the other at the project selection level. For the strategy setting level, a multiobjective dynamic linear programming model is used in generating system expansion decision alternatives. The suitability of the modelling approach is considered from the various aspects such as congruence, flexibility, transparency, and accuracy.An application of the model to the Turkish electrical system is also presented, where expansion alternatives to the year 2000 are generated. Three criteria were observed: cost, environmental impact and risk.     

Electrical and chemical characteristics of nano-meter gold encapsulated in mesoporous and microporous channels and cages of FSM-16 and Y zeolites

The dc and ac conductivities as well as the dielectric constant () were measured for different zeolites encapsulated gold (AuCl₃) samples at different temperatures (300-500 K) and various frequencies (5 kHz-1 MHz). The conductivity was found to change in the order Au/FSM-27>Au/NaY>Au/FSM-47. Sorbed water contained inside zeolites assists greatly the proton mobility (zeolite protons) and the ion mobility (Na⁺ and Au⁺) and hence enhance the electric conduction in the temperature range 300-373 K. Raising the temperature over 373 K induces dehydration effect that assists the metallic gold formation and thus a dramatic loss in conductivity was revealed. The conduction mechanism was expected to be partially ionic and partially electronic. The IR study showed that the exposure of Au zeolites to CO gas produced a characteristic band of Au⁺-CO at 2180 cm⁻¹ that tends to decrease with temperatures and even vanishes at 376 K in favor of Au⁰-CO at 2128 cm⁻¹. Similarly, a phase transition at 338 K, that occurs in the range 300-376 K, was confirmed by DTA to further emphasize the temperature regions of either Au⁺ cations (338 K) or Au⁰ (376 K) formation.     

In-beam γ spectroscopy using DIC with a radioactive Ne beam

A study of deep-inelastic and multi-nucleon transfer reactions to populate neutron-rich O, Ne and F nuclei is here presented. The reaction under analysis employed a beam of radioactive ²⁴Ne at 7.9 AMeV, provided by the SPIRAL facility at Ganil, impingin on a ²⁰⁸Pb target. The reaction products have been detected in the VAMOS spectrometer in coincidence with gamma rays measured by the EXOGAM array. Preliminary results here presented show a selectivity in the population of states of different nature.