Synthesis,characterization, and electroanalytical studies of Pb2+-selective polypyrrole-Zr(IV) phosphate ion exchange membrane

Journal of Solid State Electrochemistry - Polypyrrole-Zr(IV) phosphate (PPyZP) composite cation exchange material was synthesized by chemical oxidative polymerization of pyrrole with the help of...     

A new flavone from Malaysia Borneo Marsdenia tinctoria

Marsdenia tinctoria is an indigo producing plant commonly found in Borneo, Malaysia. In this present study, one new flavone kapitone (1) and three known compounds, that is 3,2’-dihydroxyflavone (2), 1-methylcyclobutene (3) and dimethyl isatoate (4) were isolated from the Malaysia Borneo M. tinctoria R. Br. (Apocynaceae). These compounds were isolated and characterised using extensive chromatographic and spectroscopic methods.     

Nickel(II) complexes bearing pyrazolylpyridines: synthesis,structures and ethylene oligomerization reactions

Reactions of 2‐bromo‐6‐(3,5‐dimethyl‐1H‐pyrazol‐1‐yl)pyridine ( L1 ) and 2,6‐bis(3,5‐dimethyl‐1H‐pyrazol‐1‐yl)pyridine ( L2 ) with NiCl₂ and NiBr₂ led to the formation of their respective metal complexes [NiCl₂(L1)] ( 1 ), [NiBr₂(L1)] ( 2 ) and [NiBr₂(L2)] ( 3 ) in moderate to high yields. The complexes were characterized using elemental analyses, mass spectrometry and single‐crystal X‐ray diffraction for 2 . The solid‐state structure of 2 confirmed the bidentate coordination mode of L1 and formation of a monometallic compound. Activation of the nickel(II) pre‐catalysts with methylaluminoxane afforded active catalysts in the ethylene oligomerization reaction to produce mainly butenes (84–86%). In contrast, activation of nickel(II) pre‐catalyst 2 with ethylaluminium dichloride resulted in partial Friedel–Crafts alkylation of the toluene solvent by the preformed oligomers. Complex structure, nature of co‐catalyst employed, type of solvent and reaction conditions influenced the catalytic behaviour of these pre‐catalysts. Copyright © 2015 John Wiley & Sons, Ltd.     

Mesoporous Rh Emerging from Nanophase‐separated Rh‐Y Alloy

Mesoporous precious metals with abundant active sites and high surface area have been widely recognized as high‐performance catalytic materials. However, the templated synthesis is complex and costly. Herein, we report a mesoporous rhodium (m‐Rh) that can be readily synthesized from entangled nanofibres of Rh and Y₂O₃ without templates. The entangled nanofibres, prepared from uniform Rh‐Y alloys under redox atmosphere, were the key precursor in the synthesis processes. Moreover, the m‐Rh efficiently catalyzed carbon dioxide reforming of methane (DRM) at a low reaction temperature of 683 K. Further, electrochemical methods of CO electro‐oxidation were innovatively used to demonstrate the stability of CO and oxygen species for the DRM reaction.     

Proximity effect in the finite and incommensurate ferromagnet/superconductor systems

The original theory of a proximity effect is proposed for the bi- and tri-layered system ferromagnetic metal/superconductor (F/S) in dirty limit. The F₁/S/F₂ trilayer is examined more closely. The distinctions in materials, in thicknesses of F layers (d_f1 and d_f2), in parameters interfaces, and in local environments of layers are considered among the causes of incommensurability of trilayer. The peculiar T_c(d_f1, d_f2) interference pattern is predicted for the F₁/S/F₂ systems. The reentrant superconductivity and possibility of the better observability of the spin-valve regime are discussed.