Structural Elucidation of {[(CH3)2SnCl2·H2O]2·18-crown-6} n and its Hydrogen Bonding in Solution by HMBC Spectroscopy

Behavior of {[(CH₃)₂SnCl₂·H₂O]₂·18-crown-6}_n in solution have been investigated by HMBC NMR. The results show that coordination of water to tin containing species and its hydrogen bonding to crown ether remains intact in non-coordinating solvent in contrast to coordinating solvent. H-NMR reveals that the chemical shift of water in complex varies by solvent of crystallization.     

Synthesis and structural characterization of diorganotin(IV) complexes with 2,6‐pyridinedicarboxylic acid

Two new diorganotin(IV) derivatives of 2,6‐pyridinedicarboxylic acid, {[Ph₂Sn(2,6‐C₅H₃N)(COO)₂][Na(2,6‐C₅H₃N)(COOH) (COO)(CH₃OH)₂]} ( 1 ) and [Me₂Sn(2,6‐C₅H₃N)(COO)₂(H₂O)]^•H₂O ( 2 ) were synthesized by the reaction of Ph₃SnCl and PhMe₂SnI with 2,6‐pyridinedicarboxylic acid, respectively in the presence of sodium methoxide or potassium iso‐propoxide. The prepared compounds were characterized by mass spectrometry, IR, ¹H, ¹³C and ¹¹⁹Sn NMR spectroscopies. The molecular structures of both complexes were determined by a single‐crystal X‐ray analysis. The X‐ray structure revealed pentagonal bipyramidal geometry around the tin atom for compound 1, which is incorporated with a hexacoordinated monosodium derivative of 2,6‐pyridinedicarboxylic acid. Complex 2 adopts a monomeric structure with two carboxylate oxygen atoms coordinated to tin in monodenate form from equatorial positions, and the coordination number is raised to six as the oxygen of water and pyridine nitrogen occupies the other equatorial positions of octahedron. Copyright © 2007 John Wiley & Sons, Ltd.     

Direct Solar Charging of an Organic–Inorganic,Stable, and Aqueous Alkaline Redox Flow Battery with a Hematite Photoanode

The intermittent nature of the sunlight and its increasing contribution to electricity generation is fostering the energy storage research. Direct solar charging of an auspicious type of redox flow battery could make solar energy directly and efficiently dispatchable. The first solar aqueous alkaline redox flow battery using low cost and environmentally safe materials is demonstrated. The electrolytes consist of the redox couples ferrocyanide and anthraquinone‐2,7‐disulphonate in sodium hydroxide solution, yielding a standard cell potential of 0.74 V. Photovoltage enhancement strategies are demonstrated for the ferrocyanide‐hematite junction by employing an annealing treatment and growing a layer of a conductive polyaniline polymer on the electrode surface, which decreases electron–hole recombination.     

Synthesis and Characterization of 8-hydroxyquinoline Complexes of Tin(IV) and Their Application in Organic Light Emitting Diode

A series of 8-hydroxyquinoline complexes of tin, Q(2)SnCl(2) (Q?=?2-methyl-8-hydroxyquinoline, 8-hydroxyquinoline, 5,7-dibromo-8-hydroxyquinoline, 5-chloro-8-hydroxyquinoline, 5,7-dichloro-8-hydroxyquinoline and 5-nitro-8-hydroxyquinoline) were prepared by reacting stannous dichloride with 8-hydroxyquinoline and its derivatives. All complexes were characterized by elemental analysis, mass spectrometry and infrared, UV-vis and (1)H NMR spectroscopes. Furthermore, the molecular structure of a representative complex, dichlorido-bis(5-nitro-quinolin-8-olato-2N,O)tin(IV), was determined by single-crystal X-ray diffraction. The photoluminescence (PL) properties of all prepared compounds and electroluminescence (EL) property of a selected complex (Q?=?5-chloro-8-hydroxyquinoline) were investigated. The results showed that the emission wavelength can be tuned by electron donating or withdrawing group substituent on 8-hydroxyquinoline. Application of prepared complexes in fabrication of an OLED has been demonstrated.     

Investigation of porous media effects on lithium-ion battery thermal management

Journal of Thermal Analysis and Calorimetry - The utilization of porous media and its effects on thermal management of internally cooled lithium-ion battery with the aid of porous media has been...     

Insulator-based dielectrophoretic focusing and trapping of particles in non-Newtonian fluids

Insulator-based dielectrophoretic (iDEP) microdevices have been limited to work with Newtonian fluids. We report an experimental study of the fluid rheological effects on iDEP focusing and trapping of polystyrene particles in polyethylene oxide, xanthan gum, and polyacrylamide solutions through a constricted microchannel. Particle focusing and trapping in the mildly viscoelastic polyethylene oxide solution are slightly weaker than in the Newtonian buffer. They are, however, significantly improved in the strongly viscoelastic and shear thinning polyacrylamide solution. These observed particle focusing behaviors exhibit a similar trend with respect to electric field, consistent with a revised theoretical analysis for iDEP focusing in non-Newtonian fluids. No apparent focusing of particles is achieved in the xanthan gum solution, though the iDEP trapping can take place under a much larger electric field than the other fluids. This is attributed to the strong shear thinning-induced influences on both the electroosmotic flow and electrokinetic/dielectrophoretic motions.     

Assessing the Efficiency of Sodium Ferrate Production by Solution Plasma Process

Plasma Chemistry and Plasma Processing - Application of sodium ferrate (Na2FeO4) is considered as the environmental friendly and cost-effective method for oxidation, coagulation and disinfection...     

Electroosmotic flow of non‐Newtonian fluids in a constriction microchannel

Insulator‐based dielectrophoresis has to date been almost entirely restricted to Newtonian fluids despite the fact that many of the chemical and biological fluids exhibit non‐Newtonian characteristics. We present herein an experimental study of the fluid rheological effects on the electroosmotic flow of four types of polymer solutions, i.e., 2000 ppm xanthan gum (XG), 5% polyvinylpyrrolidone (PVP), 3000 ppm polyethylene oxide (PEO), and 200 ppm polyacrylamide (PAA) solutions, through a constriction microchannel under DC electric fields of up to 400 V/cm. We find using particle streakline imaging that the fluid elasticity does not change significantly the electroosmotic flow pattern of weakly shear‐thinning PVP and PEO solutions from that of a Newtonian solution. In contrast, the fluid shear‐thinning causes multiple pairs of flow circulations in the weakly elastic XG solution, leading to a central jet with a significantly enhanced speed from before to after the channel constriction. These flow vortices are, however, suppressed in the strongly viscoelastic and shear‐thinning PAA solution.     

Direct numerical simulation of transitional flow in a finite length curved pipe

Transition to turbulent flow in a curved pipe has been well studied through experiments and numerical simulations. Numerical simulations often use a helical pipe with an infinite length such that the inlet and outlet boundary conditions can be modelled as periodic which greatly reduces computational time. In this study, we examined a finite length curved pipe with Poiseuille flow imposed at the inlet and a stress-free boundary condition at the outlet. Direct numerical simulation of the Navier-Stokes equations for rigid walls and a Newtonian fluid was performed using nek5000. Straight extensions were added to the inlet and outlet such to diminish the impact of boundary conditions on the flow field in the region with curvature. The examined model has a pipe radius of curvature that is three times the pipe radius. The model has ～355 million nodes and required an order of magnitude greater computational time when compared with an infinite length curved pipe. Results show that the critical Reynolds number, the lowest value with instabilities present in the flow, is much greater than that of a straight pipe and occurs near Re=5000–5200. This is larger than the critical Reynolds number typically reported for an infinite length curved pipe (Re=4200–4300).