A comparative study on the interaction between tin(II) porphyrin and selected group 8B metals for potential application as reduction catalysts

We study the interaction between tin(II) porphyrin (SnPor) with platinum and non-precious Group 8B metals (iron, cobalt and nickel) by density functional theory and discuss the electronic properties of the resulting products. We also model the interaction of the resulting compounds with water where applicable. Our studies indicate that, SnPor-Ni possesses electronic properties similar to SnPor-Pt, suggesting that it may possess similar photocatalytic properties for reduction reactions, such as converting water to hydrogen gas.     

Ion Chromatographic determination of trace anions and cations in high-purity water

An ion chromatographic measuring system for the off-line and on-line determination of some trace anions and cations in high-purity water is presented. The ng/L level of anions and cations in 20-130 mL high-purity water can be analyzed after preconcentration on ion exchange columns. The concentrated solutes are eluted by eluents from the trap column and separated using a Dionex analytical column. The quantification of each ion is achieved using the suppressor technique and conductivity detector. The influence of various parameters on the results is discussed. The detection limits of cations and anions are between 10 and 30 ng/L for chloride, bromide, nitrate, phosphate, sulphate, sodium, ammonium, potassium, magnesium and calcium ions.     

Stepwise elongation effect on the two-photon absorption of self-assembled butadiyne porphyrins

Butadiyne-porphyrin dimer arrays, which were generated by complementary coordination of the central zinc atom to imidazolyl followed by metathesis, were elongated stepwise and their 2PA properties were explored.     

Water-soluble self-assembled butadiyne-bridged bisporphyrin: a potential two-photon-absorbing photosensitizer for photodynamic therapy

We have synthesized a novel, two-photon-absorbing photosensitizer for two-photon-absorption photodynamic therapy (2PA-PDT). The molecule is a butadiyne-bridged porphyrin dimer terminated with two water-soluble porphyrin monomers connected through Zn-imidazolyl self-assembly and covalently linked through olefin metathesis. It has an effective two-photon-absorption (2PA) cross-section value, sigma((2)), of 33 000+/-4600 GM with 5-ns pulses at 890 nm measured by using the open-aperture Z-scan technique. The compound was found to generate singlet oxygen, cytotoxic for tumor cells in photodynamic therapy (PDT), under 2PA conditions by conducting photobleaching experiments with anthracene-9,10-dipropionic acid sodium salt (ADPA).     

Influence of interparticle interactions on the kinetics of self-assembly and mechanical strength of nanoparticulate aggregates

Computer simulations based on Discrete Element Method have been performed in order to investigate the influence of interparticle interactions on the kinetics of self-assembly and the mechanical strength of nanoparticle aggregates.Three different systems have been considered.In the first system the interaction between particles has been simulated using the JKR (Johnson,Kendall and Roberts) contact theory,while in the second and third systems the interaction between particles has been simulated using van der Waals and electrostatic forces respectively.In order to compare the mechanical behaviour of the three systems,the magnitude of the maximum attractive force between particles has been kept the same in all cases.However,the relationship between force and separation distance differs from case to case and thus,the range of the interparticle force.The results clearly indicate that as the range of the interparticle force increases,the self-assembly process is faster and the work required to produce the mechanical failure of the assemblies increases by more than one order of magnitude.     

JT-60U装置温度分布剖面不变性的实验研究

在一系列H模放电条件下，建立了一个旨在研究等离子体温度分布剖面不变性的数据库。介绍了数据库建立过程中要解决的关键问题和所用软件，对等离子体温度分布剖面不变性及芯部约束与边缘参数的关系进行了研究。     

A study on the stability of O2 on oxometalloporphyrins by the first principles calculations

The authors investigated the interaction of oxometalloporphyrins (MO(por))--specifically, MoO(por), WO(por), TiO(por), VO(por), and CrO(por)--with O(2) by using first principles calculations. MoO(por) and WO(por) undergo reactions with O(2); on the other hand, TiO(por), VO(por), and CrO(por) do not. Next, they compared the interaction of MoO(por) and WO(por) with O(2). Activation barriers for the reactions of MoO(por) and WO(por) with a side-on O(2) are small. For MoO(por)(O(2)), the activation barrier for the reverse reaction that liberates O(2) is also small; however, that for WO(por)(O(2)) is large. The experimental results that photoirradiation with visible light or heating of Mo (VI)O(tmp)(O(2)) regenerates Mo (VI)O(tmp) by liberating O(2) while W (VI)O(tmp)(O(2)) does not [J. Tachibana, T. Imamura, and Y. Sasaki, Bull. Chem. Soc. Jpn. 71, 363 (1998)] are explained by the difference in activation barriers of the reverse reactions. This means that bonds formed between the W atom and O(2) are stronger than those between the Mo atom and O(2). The bond strengths can be explained by differences in the energy levels between the highest occupied molecular orbital of MoO(por) and WO(por), which are mainly formed from the a orbitals of the central metal atom and pi(*) orbitals of O(2).     

N-fused carbazole-zinc porphyrin-free-base porphyrin triad for efficient near-IR dye-sensitized solar cells

N-fused carbazole-zinc porphyrin-free-base porphyrin triad featuring an ethynyl-linkage was synthesized; efficient sensitization as long as 900 nm was demonstrated and an overall light-to-electricity conversion efficiency of 5.21% was achieved under AM 1.5 G one sun illumination.     

Ion Chromatographic determination of trace anions and cations in high-purity water

An ion chromatographic measuring system for the off-line and on-line determination of some trace anions and cations in high-purity water is presented. The ng/L level of anions and cations in 20–130 mL high-purity water can be analyzed after preconcentration on ion exchange columns. The concentrated solutes are eluted by eluents from the trap column and separated using a Dionex analytical column. The quantification of each ion is achieved using the suppressor technique and conductivity detector. The influence of various parameters on the results is discussed. The detection limits of cations and anions are between 10 and 30 ng/L for chloride, bromide, nitrate, phosphate, sulphate, sodium, ammonium, potassium, magnesium and calcium ions.