Organocalcium compounds have been reported as efficient catalysts for various alkene transformations. In contrast to transition metal catalysis, the alkenes are not activated by metal-alkene orbital interactions. Instead it is proposed that alkene activation proceeds through an electrostatic interaction with a Lewis acidic Ca(2+) . The role of the metal was evaluated by a study using the metal-...

Using density functional theory with a van der Waals-corrected functional, we elucidate how CO(2) binds to a novel "BTT-type" metal-organic framework (MOF) featuring open metal centers. We show that CO(2) binds most favorably to open metal cation sites, but with an adsorption energy that can be three times more sensitive to the choice of the bridging ligand than to metal cation choice. A strong...

Understanding the electrode/electrolyte interface is crucial for optimizing electrocatalytic performances. Here, we demonstrate that nature of alkali metal cations can profoundly impact oxygen evolution activity surface-mounted metal–organic framework (SURMOF) derived electrocatalysts, which are based on NiFe(OOH). In situ Raman spectroscopy results show shifts Ni−O bending vibration inversely ...

Alkali metal salts M′[(η5-C5H5)M(CO)n] (M′ = alkali metal, M(CO)n = e. g. Fe(CO)2, Ru(CO)2, Mo(CO)3, W(CO)3) [1 – 7] are important starting materials for a wide range of half-sandwich complexes with covalent metal-metal and metal-element bonds. However, since these highly reactive anionic species are commonly prepared and reacted in situ, little is known about their solid-state structures, and ...

To enable large-scale reactive dynamic simulations of copper oxide/water and copper ion/water interactions we have extended the ReaxFF reactive force field framework to Cu/O/H interactions. To this end, we employed a multistage force field development strategy, where the initial training set (containing metal/metal oxide/metal hydroxide condensed phase data and [Cu(H(2)O)(n)](2+) cluster struct...

The in vitro cytotoxicity of nine metal cations common in dental casting alloys was evaluated using Balb/c 3T3 fibroblasts and four toxicity parameters: total protein production, 3H-leucine incorporation, 3H-thymidine incorporation, and MTT-formazan production. Concentrations causing 50% toxicity compared to controls (TC50's) and reversibility of these effects were determined. The range of pote...

Varying the extraframework metal cation on alkali exchanged mordenite tunes ethanol dehydrogenation properties of ZnO supported mordenite, resulting in enhanced lifetime, low ethylene selectivity and increased acetaldehyde productivity per Zn.

and optical properties of rabbit muscle pyruvate kinase activated with Co(II), Ni(II), Mg(II), and Mn(I1) were studied. The stoichiometry of metal binding to enzyme was found to be 4 metal ions per tetrameric enzyme for Co(I1) and Ni(I1) by carrying out circular dichroic titrations. Cu(I1) and Fe(I1) were inactive. Ca(I1) and Zn(I1) were not activating, and were inhibitory with respect to all o...

In this study, we have analysed the influence of cation?? interactions on stability and properties superoxide dismutase (SOD) active centres. The number formed by arginine is higher than lysine in cationic group, while those histidine are comparatively ? group. energy contribution resulting from most frequent was lower range strong hydrogen bonds. involving transition metal ions as cation more ...

[reaction: see text] Effects of metal cation recognition on photosensitized E-Z isomerization of 1,2-dichloroethylene have been investigated with two types of m,p- and o,o'-podand (oligo-oxyethylene unit) benzophenones 2 and 3. With increasing cation size, the %Z ratio at the photostationary state was changed from 67 to 91% for 2 but remained almost unchanged (86-88%) for 3. These results were ...