前驱体水解对纳米铂形状控制合成的影响

以聚丙烯酸钠(NaPA: M_w ≈ 2100)为保护剂，对比研究了H_2还原K_2PtCl_4 和K_2PtCl_6水溶液制备纳米铂晶粒的形状选择性，揭示了前驱体的水解对纳米铂 晶粒的形状控制合成具有显著影响。文献中通常采用的合成立方形状纳米铂的 K_2PtCl_4前驱体在水溶液中不稳定，避光静置一周会析出黑色沉淀。这种不稳定 性导致了以K_2PtCl_4为Pt前驱体的合成结果难以重复。相比而言，避光静墨的 K_2PtCl_6水溶液很稳定，以它为前驱体合成的纳米铂通常为削角八面体。 K_2PtCl_6水溶液暴露于室内光线中会出现[PtCl_6]~(-2)的光致水解。当[PtCl_6] ~(2-)的紫外特征吸收峰(260nm)由于光致水解完全消失后，以聚丙烯酸钠为保护剂 ，通过H_2还原可以有选择性地(约80%)合成由{100}晶面包裹的立方体形状的纳米 铂。     

MnOx在ZrO2上分散状态及对CO氧化的影响

近年，氧化铝载体以其独特性能引起多方面的关注［1］．当将Pt、Rh金属担载在ZrO2上时，在金属和氧化物之间存在着强的相互作用［2，3］，从而提高了CO氧化和NO的还原性能．目前，许多作者曾对ZrO2。负载氧化铜催化剂进行了较系统的研究[4，5]：氧化锰对许多重要的催化反应有广     

六氯合铂酸钾与金属硫蛋白的体外反应

本文报道了K₂PtCl₆与兔肝Zn₇MT-Ⅱ和apoMT-Ⅱ的反应包含一个氧化还原反应和一个取代反应。通过紫外可见光谱、园二向色谱、柱层析和X-光电子能谱研究了该反应的性质、铂在反应产物中的键合位置和氧化态。金属硫蛋白(MT)被氧化成单体、双聚和多聚产物，其中含有分子间和分子内CyS-SCy二硫键。Pt(Ⅳ)被还原成Pt(Ⅱ)然后键合于产物中。随着K₂PtCl₆与MT的反应摩尔比和反应时间的增加，键合于产物中的Pt(Ⅱ)的计量数增加而蛋白中所含Zn(Ⅱ)的量减少。当Zn₇MT与4和超过10摩尔的K₂PtCl₆反应时，分别得到了Pt₄Zn₄MT和Pt₈MT。当apoMT与7及超过25倍的K₂PtCl₆在pH 2条件下反应时，分别得到了Pt₇MT和Pt₁₅MT。动力学数据表明K₂PtCl₆与apoMT的反应比与Zn₇MT的反应快。     

Geometries,vibrational frequencies,and electron affinities of X2Cl (X=C,Si,Ge) clusters

Ab initio quantum chemical calculations have been performed on X₂Cl^? and X₂Cl (X = C, Si, Ge) clusters. The geometrical structures, vibrational frequencies, electronic properties and dissociation energies are investigated at the Hartree–Fock (HF), Møller–Plesset second‐ and fourth‐order (MP2, MP4), CCSD(T) level with the 6‐311+G(d) basis set. The X₂Cl (X = C, Si, Ge) and X₂Cl^? (X = Si, Ge) take a bent shape obtained at the ground state, while C₂Cl^? has a linear structure. The impact on internal electron transfer between the X₂Cl and the corresponding anional clusters is studied. The three different types of electron affinities (EAs) at the CCSD(T) are reported. The most reliable adiabatic electronic affinities, obtained at the CCSD(T)/cc‐pvqz level of theory, are predicted to be 3.30, 2.62, and 1.98 eV for C₂Cl, Si₂Cl, and Ge₂Cl, respectively. The calculated EAs of C₂Cl and Ge₂Cl are in good agreement with theoretical results reported. The correlation effects and basis sets effects on the geometrical structures and dissociation energies are discussed. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2007     

Room‐Temperature Solution‐Processed PbS Quantum Dot Solar Cells

Colloidal quantum dots (CQDs) are attractive absorber materials for high‐efficiency photovoltaics because of their facile solution processing, bandgap tunability due to quantum confinement effect, and multi‐exciton generation. To date, all published performance records for PbS CQDs solar cells have been based on the conventional hot‐injection synthesis method. This method usually requires relatively strict conditions such as high temperature and the utility of expensive source material (pyrophoric bis(trimethylsilyl) sulfide (TMS‐S)), limiting the potential for large‐scale and low‐cost synthesis of PbS CQDs. Here we report a facile room‐temperature synthetic method to produce high‐quality PbS CQDs through inexpensive ionic source materials including Pb(NO₃)₂ and Na₂S in the presence of triethanolamine (TEA) as the stabilizing ligand. The PbS CQDs were successfully prepared with an average particle size of about 5 nm. Solar cells based on the as‐synthesized PbS CQDs show a preliminary power conversion efficiency of 1.82%. This room‐temperature and low‐cost synthesis of PbS CQDs will further benefit the development of solution‐processed CQD solar cells.     

珊瑚中硼的分离及其同位素组成的测定

介绍了用硼特效树脂和阴、阳混合离子交换树脂相结合进行珊瑚中硼的分离和纯化方法，满足了正热电离质谱法测定硼同位素的要求，并且对几个珊瑚样品进行了硼的分离和硼同位素组成的测定，结果满意，为研究珊瑚中的硼同位素示踪古海洋环境变化提供了可能。     

2,3,7‐Triazabicyclo[3.3.0]octenes Prepared by Tandem Cascade Reaction of Allyl Azides and Olefinic Dipolarophiles

Tandem cascade reactions of allylazides and olefinic dipolarophiles to give cis‐fused 2,3,7‐triazabicyclo [3.3.0]octenes ( 5, 6 or 7 ) are reported. Therein, an intermolecular dipolar cycloaddition of azide and alkene gave a triazoline which was followed by isomerization of the triazoline to a diazoester ( 4 ) and then an intramolecular dipolar cycloaddition from the diazo functional group and the double bond in 4 to give 5 . Compound 5 may further more undergo a Michael addition to give 7‐substituted‐ 2,3,7‐ triazabicyclo [3.3.0]oct‐2‐ene ( 6 ) or a tautomerization to give 2,3,7‐triazabicyclo[3.3.0]oct‐3‐ene ( 7 ). The reaction may be manipulated to stop at a particular stage by adopting a suit able solvent or an appropriate temperature.     

二水草酸锌脱水的热分解动力学研究

提出一种多升温速率-等温法确定机理函数g(α)的新方法;并用迭代的等转化率法求出较为可靠的活化能Ea;在Ea和g(α)的基础上计算出指前因子A.用该法对二水草酸锌（ZnC2O4•2H2O）脱水反应的热分解动力学三因子进行了求算,得出Ea为87.22 kJ•mol－1, A为4.2120×108～7.2328×108 s－1;以及随机成核和随后生长型机理函数Am（Avrami-Erofeer）,其积分形式g(α)=[－ln(1－α)] 1/m和微分形式f(α)=m(1－α)•[－ln(1－α)](1－1/m),调节因子m=1.85～2.00.     

Cooperatively assembled liquid crystals enable temperature-controlled Förster resonance energy transfer

Balancing the rigidity of a π-conjugated structure for strong emission and the flexibility of liquid crystals for self-assembly is the key to realizing highly emissive liquid crystals (HELCs). Here we show that (1) integrating organization-induced emission into dual molecular cooperatively-assembled liquid crystals, (2) amplifying mesogens, and (3) elongating the spacer linking the emitter and the mesogen create advanced materials with desired thermal–optical properties. Impressively, assembling the fluorescent acceptor Nile red into its host donor designed according to the aforementioned strategies results in a temperature-controlled Förster resonance energy transfer (FRET) system. Indeed, FRET exhibits strong S-curve dependence as temperature sweeps through the liquid crystal phase transformation. Such thermochromic materials, suitable for dynamic thermo-optical sensing and modulation, are anticipated to unlock new and smart approaches for controlling and directing light in stimuli-responsive devices.

A temperature-sensitive Förster resonance energy transfer system was constructed using a highly emissive liquid crystal co-assembled with Nile red, enabling thermo-optical modulation for controlling and directing light in stimuli-responsive devices.     

The Aldol Reaction of Allenolates with Aldehydes in the Presence of Magnesium Diiodide (MgI2) as Catalyst

Stereoselective synthesis of (Z)‐α‐(hydroxyalkyl)‐β‐iodoacrylates (=(2Z)‐2‐(hydroxyalkyl)‐3‐iodoprop‐2‐enoates) was achieved in a one‐pot coupling reaction from methyl prop‐2‐ynoate, Me₃SiI, and an alkanal under mild conditions with MgI₂ as catalyst (→ 1 – 9 ; see Table and Scheme 1). Baylis‐Hillman β‐iodo adducts were generated in excellent yields with high (Z)‐selectivity. The conversion of methyl prop‐2‐ynoate to an active methyl 3‐iodo‐1‐[(trimethylsilyl)oxy]allenolate intermediate in situ followed by carbonyl addition is proposed as the reaction sequence (Schemes 1 and 2).