Adsorption of Ethylene on Neutral, Anionic and Cationic Gold Clusters

The adsorption of ethylene molecule on neutral, anionic and cationic gold clusters consisting of up to 10 atoms has been investigated using density-functional theory. It is demonstrated that C2H4 can be adsorbed on small gold clusters in two different configurations, corresponding to the pi- and di-sigma-bonded species. Adsorption in the pi-bonded mode dominates over the di-sigma mode over all considered cluster sizes n, with the exception of the neutral C2H4-Au5 system. A striking difference is found in the size-dependence of the adsorption energy of C2H4 bonded to the neutral gold clusters in the pi and di-sigma configurations. The important role of the electronic shell effects in the di-sigma mode of ethylene adsorption on neutral gold clusters is demonstrated. It is shown that the interaction of C2H4 with small gold clusters strongly depends on their charge. The typical shift in the vibrational frequencies of C2H4 adsorbed in the pi- and the di-sigma configurations gives a guidance to experimentally distinguish between the two modes of adsorption.Comment: 30 pages, 10 figure

On a homogeneous electrochemical reaction of prussian blue/everitt's salt system

Voltammetric, chronopotentiometric, and spectroelectrochemical studies qn the homogeneous-phase (single phase) reaction of Prussian blue (PB)/Everitt's salt (ES) system in KC1 aqueous solution were carried out as a model for understanding the homogeneous electrochemical reaction of manganese dioxide. Analytical results of voltammetric and chronopotentiometric studies on PB/ES system indicated that the electrode potential was represented by the empirical formula.</p

A Note on the Global Challenges and Local Regional Responses in the Tohoku Dstrict before the Collapse of the Bubble Economy

This is a brief of ”A Note on the Global Challenges and Local Regional Responses in the Tohoku District before the Collapse of the Bubble Economy.” In this Note I would like to think about how the Tohoku District moved just before the collapse of Bubble Economy in the beginning of 1990\u27s, that is, during the 20 years from 1970\u27s to 1980\u27s.　This Note is composed of the following five chapters. Chapter Ⅰis on Major Economic Indexes on the Tohoku District before the Collapse of Bubble Economy, Chapter II on The Changes of Infrastructure in the Tohoku District, Chapter III on Present Situation and Prospect of the Industrial Structure in the Tohoku District, Chapter IV on The Internationalization in the Tohoku District and Chapter V The Transition of Japanese Development Policy and the Regional Responses in the Tohoku District. In this Note I would like to emphasize the followings problems:　①Since the latter of 1970\u27s the infrastructure network of the Tohoku District has considerably changed because of construction of the high-speed transportation system.　②Since 1980\u27s the industrial structure in Tohoku has obviously changed from the pure agricultural region to the more industrialized and urbanized region.　③Since 1976 the number of new factories constructed in Tohoku has increased year by year, especially in High-tech-related industries.　④The working styles of farmers have basically changed from pure farmer type into that of the parttime farmer type to get a money outside of paddy farming.　⑤In Japan the policy of local and regional development is basically prescribed by the National Development Policy (Zenkoku-Sogo-Kaihatu-Keikaku in Japanese)

Electrochemistry of Redox Reaction II. On the Kinetic Equations for Chronopotentiometry

Basic kinetic equations of chronopotentiometric potential-time curves, in which the equations for reversible, quasi-reversible and irreversible electron transfer process appeared in special cases, were given and a chronopotentiometric method for determining kinetic parameters was proposed therefrom. The method was demonstrated for Fe(3+)/Fe(2+) redox reaction in acidic aqueous media. The limitations of the method and the double-layer charging effects on the potential-time curve were discussed. The extension of the method to more general electrode processes was also considered

Measurement of High Temperature Thermodynamic Propertiesof Several Binary Alkali Silicate Glasses

The method for continuous measurement of the high temperature heat content, developed by W.Oelsen et al. and applied to the glasses by M.Tashiro, was examined and modified in some points. Relations between the temperature and heat contents referred to the standard temperature 25℃, were determined for the some glasses of R(2)O-SiO(2) system, and the specific heats as well as the entropies were calculated. Comparing the results, some views have been obtained relating to the effect of the species and content of alkali ions on the thermodynamic quantities of such glasses

Electrochemistry of Redox Reaction III. On the Kinetic Equations for Chronoamperometry

A basic kinetic equation of potential-step chronoamperometric current-time curve controlled by the rates of diffusion and electron transfer for a simple one-electron charge transfer reaction was given and various features of current-time curves were deduced from a theoretical treatment. The current-time equations for reversible and irreversible electron transfer processes appear as special cases with limited conditions of the equation reported in the present paper. And a potential-step chronoamperometric method to determine kinetic parameters from a current-time curve was proposed therefrom. The extension of a basic kinetic equation to more general multistep charge-transfer process was also considered

Potential Sweep Voltammetry of Na(2)O-SiO(2) Glass Melt by Stationary Platinum Electrodes

Potential sweep voltammetries of Na(2)O·SiO(2) and Na(2)O·2SiO(2) at 730-1200°C were performed with the stationary platinum wire electrode and with the sweep rates of 40 and 120mV/sec. Although current-potential relation of Na(2)O . SiO(2) at 1200°C gave stationary S-shape pattern, those of the rest were transient modes with hysteresis. From the voltammetric considerations, a reversible oxygen electrode process where diffuion of free oxygen anion or silicate anion may be a rate-determining stage was tentatively proposed. Approximate estimations of decomposition voltage supported that a sole reaction process such as the decomposition of Na(2)O or indirect decomposition of SiO(2) in the melt was most probable

Electrochemistry of Redox Reaction I. On the Kinetic Equations for Rotating Disk Technique

An equation on the current-polarization voltage characteristics of single charge transfer redox reaction on a rotating disk electrode (RDE) was given and a curvefitting method to determine kinetic parameters from an observed polarization curve was proposed therefrom. The method was demonstrated for Fe(2+)/Fe(3+)redox reaction in acidic aqueous electrolyte on Pt-RDE and the limitation of the method was discussed. The extension of the method to multistep charge transfer reaction was also considered

An Ab Initio Study of the Reaction Mechanism of Co++NH3

To investigate the mechanism for N–H bond activation by a transition metal, the reactions of Co+(3F,5F) with NH3 have been studied with complete active space self-consistent field (CASSCF), multireference configuration interaction (MR-SDCI), and multireference many body perturbation theory (MRMP) wave functions, using both effective core potential and all-electron methods. Upon their initial approach, the reactants yield an ion–molecule complex, CoNH+3(3E,5A2,5A1), with retention of C3ν symmetry. The Co+=NH3 binding energies are estimated to be 49 (triplet) and 45 (quintet) kcal/mol. Subsequently, the N–H bond is activated, leading to an intermediate complex H–Co–NH+2 (C2ν symmetry), through a three-center transition state with an energy barrier of 56–60 (triplet) and 70–73 (quintet) kcal/mol. The energy of H–Co–NH+2, relative to that of CoNH+3, is estimated to be 60 to 61 (triplet) and 44 (quintet) kcal/mol. However, the highest levels of theory employed here (including dynamic correlation corrections) suggest that the triplet intermediate HCoNH+2 may not exist as a minimum on the potential energy surface. Following Co–N or H–Co bond cleavage, the complexH–Co–NH+2 leads to HCo++NH2 or H+CoNH+2. Both channels (triplet and quintet) are found to be endothermic by 54–64 kcal/mol