Nitrosyl rhenium complexes: Syntheses,properties, and structures of acetylacetonato derivatives

Some new complexes of rhenium containing monocoordinating acetylacetone viz. [Re(NO)(acac)₂(Cl)H₂O], Re(NO)(acac)₃(acacH)(H₂O)₂ have been synthesized by reacting acetylacetone with either Re(NO)Cl₃ · H₂O or Re(NO)(OH)₃ · H₂O. The preparation of [Re(NO)(py)(acac)₂(Cl) · H₂O], [Re(NO)(acac)(OH)(Cl) · H₂O], [Re₂(NO)₂(acacH)₃(acac)₂ · Cl₄], [Re(NO)(acac)₂(OH) · H₂O] · 2 H₂O have also been described. These complexes were characterized through their elemental analyses, u.v., vis, i.r., ¹Hn.m.r., magnetic, and conductance data.     

NCO自由基与SO_2、CS_2反应的速率常数

利用波长为266nm的激光光解CHBr3产生CH自由基,其与NO反应作为NCO自由基的来源.在298K,总压2660Pa的条件下,采用激光诱导荧光的方法,研究了NCO自由基与SO2、CS2的反应.得到了NCO自由基与SO2、CS2双分子反应速率常数分别为(1.8±0.3)×10-11和(3.1±0.4)×10-12cm3·molecule-1·s-1.对这两个反应在B3LYP/6-31 G(d)的水平上进行理论研究的结果表明,NCO自由基与SO2、CS2的反应是加成反应,其机理是NCO自由基中的N原子攻击反应物的中心原子,得到加成产物.     

环戊二烯热聚产物及二聚环戊二烯加氢产物的质谱

本实验用色谱－质谱－计算机联用仪测定了环戊二烯热聚产物及双环戊二烯加氢产物的质谱，讨论了环状化合物的开裂规律，有开环断裂反应及骨架重排等问题。     

Average local electrostatic potential and the core-valency separation in atoms

The average local electrostatic potential function, V(r)/ ρ(r), is calculated for 87 atoms, Li-Ac, in the ground state using the nonrelativistic average-over-configuration numerical Hartree-Fock density. It is found empirically that in a given atom the shell boundaries are expressed as the successively increasing maxima in V(r)/ ρ(r) and the outermost maximum presents good approximate estimates of the core-valence separation in atoms. The likeness in behavior of V(r)/ ρ(r) at each shell boundary with the maximum hardness principle is discussed. The single-exponent-fit parameters for the electron density in the valency region are provided for all atoms. © 1995 John Wiley & Sons, Inc.     

萘降解菌LHJ38生物合成靛蓝的研究

萘降解菌LHJ38在金属盐培养基中加入水杨酸钠诱导培养后能提高其生物合成靛蓝的能力,在LB培养基中加入水杨酸钠反而抑制了其生物合成靛蓝的能力.与LHJ38最适生长pH值不同,LHJ38生物合成靛蓝的最佳pH值范围是8.45—9.45,在pH为8.95的情况下生物合成靛蓝能力是其在pH值为6.95的情况下的两倍.     

Diaryl ethers using Fischer chromium carbene mediated benzannulation

[formula: see text] The biological relevance and irresistible synthetic challenge of compounds containing the diaryl ether linkage encourages the development of new methodologies targeted toward this structural subunit. The syntheses of diaryl ethers 2 using a benzannulation strategy that formally involves a [3 + 2 + 1] cycloaddition between aryloxy-substituted Fischer carbenes 1 and alkynes are described. This methodology provides a neutral near ambient temperature formation of diaryl ethers.     

PBA@POM Hybrids as Efficient Electrocatalysts for the Oxygen Evolution Reaction

To realize the effective conversion of renewable energy through water decomposition, efficient electrocatalysts for the oxygen evolution reaction (OER) are essential. In this article, PBA@POM was successfully prepared with a Prussian blue analogue (PBA) as the initial structure. A facile hydrothermal process is reported for obtaining PBA@POM by etching the cubic PBA with a strong Brønsted acid, H₃PMo₁₂O₄₀ (HPMo). The hollow cube structure not only exposes more active sites but also promotes electron transport, which results in excellent electrocatalytic activity for the OER. Compared with the PBA, which initially simply adhered to POM, the optimum PBA@POM hybrids display remarkably enhanced OER catalytic activity, with an almost constant overpotential of 440 mV at a current density of 10 mA cm^?2 and a small Tafel slope (23.45 mV dec^?1). The facilely prepared PBA@POM with good electrochemical activity and stability promises great potential for the OER.