光学活性化合物的工业合成

本文介绍了光学活性化合物研究现状及发展趋势。并从技术和经济角度论述了工业合成光学活性化合物的可能性     

New ferrocene-containing structures: Poly(silyl ester)s

Two new polymeric structures containing ferrocene units along the chains, namely poly(silyl ester)s, have been synthesized and characterized: a geminal poly(silyl ester) (g-PSE) and one having a disiloxane spacer between the silyl ester groups (s-PSE). The condensation polymerization of AA/BB monomer systems in solution was used in both cases as preparation method involving a silicon-containing diol, (diphenylsilane diol or 1,3-bis(hydroxy)-tetramethyldisiloxane), and 1,1′-di(chlorocarbonyl)ferrocene. The polymers were investigated by differential pulse voltammetry in order to evaluate the redox behavior. Due to the presence of the silyl ester groups in the chain, these polymers are hydrolytically degradable.     

Nucleophilic reactivity of the peroxide anion in aqueous-alcoholic solutions in the presence of detergents

The reactivity of hydroxide and peroxide anions with 4-nitrophenyl N,N-dimethylcarbamate in aqueous-alcoholic detergent media and in “oil in water” microemulsions has been studied. Aqueous-alcoholic solutions of cationic (CTAB) and neutral (Triton X-100) surface active substances have promise for decomposition of substrates by a nucleophilic mechanism. __________ Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 43, No. 6, pp. 358–363, November–December, 2007.     

LiCoO_2 electrode/electrolyte interface of Li-ion batteries investigated by electrochemical impedance spectroscopy

The storage behavior and the first delithiation of LiCoO2 electrode in 1 mol/L LiPF6-EC:DMC:DEC elec- trolyte were investigated by electrochemical impedance spectroscopy (EIS). It has found that, along with the increase of storage time, the thickness of SEI film increases, and some organic carbonate lithium compounds are formed due to spontaneous reactions occurring between the LiCoO2 electrode and the electrolyte. When electrode potential is changed from 3.8 to 3.95 V, the reversible breakdown of the resistive SEI film occurs, which is attributed to the reversible dissolution of the SEI film component. With the increase of electrode potential, the thickness of SEI film increases rapidly above 4.2 V, due to overcharge reactions. The inductive loop observed in impedance spectra of the LiCoO2 electrode in Li/LiCoO2 cells is attributed to the formation of a Li1-xCoO2/LiCoO2 concentration cell. Moreover, it has been demonstrated that the lithium-ion insertion-deinsertion in LiCoO2 hosts can be well described by both Langmuir and Frumkin insertion isotherms, and the symmetry factor of charge transfer has been evaluated at 0.5.     

拟多维高效液相色谱法分离纯化双峰驼精清中的活性蛋白

利用一种新的高效液相色谱洗脱技术，建立了 ｐＨ缓冲液／离子对二元洗脱模式，对双峰驼精清的两种提取物的反相柱上进行了分离，得到了较纯的活性蛋白组分。该法操作简单、快速、比常规ＨＰＬＣ有更高的选择性及峰容量，并可减少活性蛋白的失活。     

CuO／活性炭和Fe2O3／活性炭催化还原NO

ＣｕＯ／活性炭和Ｆｅ_２Ｏ_３／活性炭催化还原ＮＯ高志明，赵震，杨向光，吴越（中国科学院长春应用化学研究所长春１３００２２）关键词活性炭，还原，ＮＯ，氧化铜，氧化铁目前，对固定源的ＮＯ处理是采用Ｖ２Ｏ５／ＴｉＯ２作催化剂，ＮＨ３作还原剂的选择催化还原方...     

新的手性配体促进的二芳基二酸和联萘酚的不对称合成

由手性配体α-D-葡萄糖衍生物5，6，7以及薄荷醇（8）和葑醇（9），经 Ulmann偶联反应得到光学活性的（R）－和（S）－6，6′－二硝基联苯－2，2′－ 二甲酸（4a),(R)-6,6′-二甲基联苯－2，2′-二甲酸（4b),(R)-1,1′－联萘－2 ，2′－二甲酸（13）。以三个手性膦酰胺16，17，18和CuCl组成的手性络合物为 催化剂，通过2－萘酚直接氧化偶联得到（S）－2，2′－联萘酚（15）。产物4， 13，15具有中等ee值的光学活性。     

Kinetics and mechanism of gold dissolution in thiourea solutions: Effect of sulfide ions

Chronoamperograms for gold in solutions containing 0.1 M thiourea, 0.5 M H₂SO₄, and catalytically active sulfide ions at the concentration c ₁ from 1 × 10^?5 to 4 × 10^?5 M are obtained at different potentials with the aid of an automated setup intended for renewing the electrode surface directly in the solution by cutting off a thin surface layer of the metal. It is shown that the results of measurements of the current practically coincide at a constant value of the product c ₁ t, where t is the time period elapsed after the renewal of the electrode surface. Such a coincidence testifies to a diffusion nature of processes that hamper accumulation of sulfide ions at the gold surface. This fact permitted the use of a procedure developed previously for the calculation of polarization curves at constant values of surface coverage θ by catalytically active ions. At θ = const, the voltammetric curves for gold in sulfide-containing thiourea solutions are shown to correspond to the Tafel equation. With the surface coverage increasing, the effective values of the exchange current i ₀, transfer coefficient α, and anodic reaction order with respect to thiourea P _a increase from the values i }~ 10^?5 A cm^?2, α }~ 0.12, and P _a = 0.2, which are characteristic of pure solutions, to 2 × 10^?4 A cm^?2, α }~ 0.5, and P _a = 1.1 (at θ }~ 0.5). An interpretation to the established regularities is given.