Recent Advances in Rare‐Earth Polypnictides

The polypnictide complexes of rare earth cations have drawn the attention of the scientific community for their uncommon bonding modes and potential applications. Herein, we present a systematic and comprehensive summary on recent advances in the field of rare earth polypnictides, focusing on their synthesis, structures, and reactivities. The structural stabilizing effects imposed by the electropositive rare earth cations as well as the reducing capability of rare earth precursors in the synthesis of these polypnictide complexes are described in this review. We also disscuss in detail the bonding interactions and coordination modes between rare earth cations and polypnictide clusters as well as the similarities and the peculiarity of some structures.     

Synthesis and Structure of Mixed Distannoxane Dimers [ClR_2SnOSnR''''_2Cl]_2

1,1,3,3-Tetraorganodistannoxanes [XR2SnOSnR2X]2 (R = alkyl, Ph; X = halogen, NCS, OAc, OR) are a kind of organotin oxo clusters. They have received considerable attention because they are useful catalysts for many reactions1-5. And recently S. W. Ng reported that [XR2SnOSnR2X]2 (R = Bu, X = OOCCH2SC(O)N(CH2CH2)2O) had more active antitumor activity than cis-platin in vitro6. A characteristic feature of symmetric tetraorganodistannoxanes in the solid state is their dimeriz…     

SnO2-Nb2O5/MgAl2O4/α-Al2O3催化环氧乙烷水合制乙二醇

采用水热稳定的MgAl2O4尖晶石对-αAl2O3载体表面进行修饰,采用具有较强亲水性能的SnO2对活性组分Nb2O5进行修饰,制备了SnO2-Nb2O5/MgAl2O4/-αAl2O3催化剂,并用于环氧乙烷水合制乙二醇反应.采用X射线衍射、红外光谱和程序升温脱附研究了Sn/Nb摩尔比对催化剂酸性、环氧乙烷在催化剂表面的吸附状态和吸附强度以及催化剂性能的影响.结果表明,Sn/Nb摩尔比明显影响催化剂的组成和结构;催化剂的结构不同,环氧乙烷在催化剂表面的吸附强度存在明显差别,催化剂的催化性能明显不同.     

双功能催化剂体系作用下乙烯二聚和共聚合的研究

用乙烯为原料在双功能催化剂体系的作用下通过二聚和共聚合反应，直接合成线性低密度聚乙烯（ＬＬＤＰＥ）．所用二聚反应催化剂为钛酸正丁酯（Ｔｉ（ＯＢｕ）_４），共聚催化剂为ＴｉＣｌ_４／ＭｇＣｌ_２（ＺＭ－１催化剂）．研究了二聚反应动力学行为及影响双功能催化剂体系动力学过程的一些因素．结果表明利用这两种催化剂组成双功能催化剂体系能够很方便地制得密度范围在０．９０－０．９３，Ｅｔ／１０００Ｃ在１０－４０的ＬＬＤＰＥ．     

胶束溶液中高氯酸二水(四胺)合钴(Ⅲ)配合物催化磷酸二酯水解的研究

本文合成了疏水性高氯酸二水（四胺）合钴（Ⅲ）配合物，研究了它与非离子表面活性剂Brij35形成的金属2胶束催化二（对硝基苯酚）磷酸二酯水解的动力学及其机理。结果表明此金属胶束对磷酸二酯水解的速率大约提高10^4倍，这主要是由于表面活性剂胶束的pH效应和浓聚效应所致，暗示着顺式二水类配合物形成的金属胶束是一个潜在的磷酸二酯水解剪切的催化剂。     

CuO/Al2O3催化剂高温固相反应的原位XRD和Raman研究

采用原位XRD和激光Raman光谱等技术对CuO/Al2O3系列催化剂高温下的表面组成和体相结构的变化进行研究.结果表明,随着焙烧温度升高,CuO首先与载体Al2O3发生固相反应生成CuAl2O4.CuAl2O4层能阻止外层CuO进一步向载体Al2O3扩散,从而使部分CuO稳定在CuO/Al2O3催化剂的表层.     

清除树脂在组合化学中的应用

清除树脂是一种特殊的固相试剂。近五年，它们被广泛的用于平行液相法合成组合化学库，简化液相组合化学库的纯化操作。本文综述了清除树脂在纯化操作中的使用策略。根据清除纯化原理，介绍了共价键型和离子键型两类清除树脂。给出了清除树脂在组合化学中的具体应用实例。最后对清除树脂的发展作了展望。     

Circularly Polarized Absorption Property of Tetra-4[4''''-(2-methylbutoxy)benzoyloxy]phenyl Porphyrin by Introducing Optical Pendant Groups

Circularly polarized luminescent(CPL) materials possess special dissymmetric optical property, i.e. luminescent light having different intensities for left (L) and right(R) circularly polarized components. Recently, these materials have been applied in colour-image projection, stereoscopic displays and light-emitting diodes(LEDS)1-7. We have synthesized a new porphyrin derivative, tetra-4[4'-(2-methylbutoxy)benzoyloxy] phenyl porphyrin [T(MBBP)P], by introducing a chiral group, which p…     

Study of urinary nucleosides as biological marker in cancer patients analyzed by micellar electrokinetic capillary chromatography

Thirteen normal and modified nucleosides, primarily degradation products of transfer ribonucleic acid (tRNA), were evaluated as potential tumor markers for cancer patients. Their urinary concentrations were determined by means of micellar electrokinetic capillary chromatography (MEKC) in the urine from 54 healthy adults and 70 cancer patients, then quantitatively expressed as a function of creatinine excretion. It was found that urinary nucleosides for cancer patients were on the average significantly higher than those for healthy controls, however, no significant differences were found between male and female or between different ages. Based on 13 urinary nucleoside concentrations, principal component analysis (PCA) could be used to classify 72% of cancer patients from the healthy controls. The present study shows that the precise measurement of urinary nucleosides by MEKC in combining with PCA technique may provide a clinically useful approach for diagnosis of cancer.     

环境和生物样品中铂族金属的分析研究进展

评述了近年来环境和生物样品中痕量铂族金属的分析研究进展，重点介绍了样品的预处理和分离富集技术以及检测手段等。