Synthesis, structure, and luminescent and magnetic properties of novel lanthanide metal-organic frameworks with zeolite-like topology

A series of microporous lanthanide metal-organic frameworks [Ln(BTC)(DMF)(2) x H(2)O, Ln = Tb (1), Dy (2), Ho (3), Er (4), Tm (5), Yb (6); DMF = N,N'-dimethylformamide] with 4 x 4 x 4 x 6 x 6 x 8 topology, which is very common in the zeolite topologies, have been synthesized under mild conditions. The single-crystal X-ray diffraction analysis reveals that they exhibit the same three-dimensional (3D) architecture and crystallize in monoclinic symmetry space group C2/c. Organic and inorganic four-connected nodes link each other to form a 3D open framework. The framework contains approximate 13 Angstrom x 7 Angstrom rectangle channels along the [1,1,0] and [1,-1,0] directions, respectively. The luminescent properties of these complexes have been studied, and complex 1 shows a Tb(3+) characteristic emission in the range of 450-650 nm at room temperature. Complexes 1-5 exhibit antiferromagnetic interaction between Ln(3+) ions. The water sorption isotherm shows that about 15 water molecules per unit cell can be adsorbed into the micropores of dehydrated complex 4.     

Emission enhancement of conjugated polymers through self-assembly of unimolecular micelles to multi-micelle aggregates

By using a cosolvent self-assembly approach, the emission of multi-micelle aggregates from star copolymer unimolecular micelles is enhanced greatly through restriction of concentration self-quenching and intermolecular aggregation of a conjugated polymer core, due to the existence of a PEG shell of HCP-star-PEG unimolecular micelles.     

Sesquiterpenoids from the Rhizome of Ligularia virgaurea

Two novel sesquiterpene dimers, compounds 1 and 2 , were isolated from the rhizome of Ligularia virgaurea, together with the six known sesquiterpenoids 3 – 8 . Their structures were established by physico‐chemical and spectroscopic methods, especially by means of 1D‐ and 2D‐NMR as well as HR‐MS analyses. A mechanism based on a classical Diels–Alder cyclization is proposed for the formation of the dimer 1 from the precursors 8 and the quinone form of 6 (Scheme).     

Determination of MK-0431 in human plasma using high turbulence liquid chromatography online extraction and tandem mass spectrometry

A robust and sensitive method using high turbulence liquid chromatography (HTLC) online extraction with tandem mass spectrometry (MS/MS) for the determination of MK-0431 in human plasma was developed and validated to support the clinical studies. This HTLC online extraction method eliminated the time-consuming offline sample extraction procedures and significantly increased productivity. A narrow bore large particle size reversed-phase column (Cyclone, 50 x 1.0 mm, 60 microm) and a BDS Hypersil C18 column (30 x 2.1 mm, 3 microm) were used as extraction and analytical columns, respectively. The linear dynamic range of the calibration curve was 0.5 to 1000 ng/mL. Intraday validation was conducted using five calibration curves prepared in five lots of human control plasma, and the intraday precision (RSD%) was from 2.4 to 9.0% and the accuracy was from 98.0 to 103% of the nominal value. The intraday precision (RSD%, n = 5) for plasma quality control (QC) samples varied from 2.0 to 5.3% and accuracy from 103 to 105% of the nominal value. The interday precision (RSD%) for 100 sets of plasma QC samples in 29 analytical runs varied from 6.3 to 9.0% and the accuracy from 98.8 to 104% of the nominal value. No significant difference was observed between the interday and intraday precision and accuracy of the QC samples.     

酚醛树脂固化过程的红外光谱分析

利用红外光谱(IR)及其变温样品池、定量分析程序对酚醛树脂固化过程中的结构变化进行了研究,它对于酚醛树脂固化过程的质量控制具有重要意义。     

2，2＇－偶氮二异丁酸二甲酯的合成及其热分解反应的研究

本文研究了２，２＇－偶氮二异丁酸二甲酯的合成及其在甲苯、二甲苯中的热分解反应动力学，得到了其热分解反应速度常数与反应温度的关系式：Ｋ＿ｄ＝１．６３×１００￣（－１４）ｅｘｐ（－１２３．３ＫＪ／ＲＴ）２，２＇－偶氮二异丁酸二甲酯作为苯乙烯自由基聚合的引发剂，其单体转化率随引发剂用量的增加而增高，产物分子量则随之下降；引发剂用量在５％以上时，可得到分子量低于１０￣３的含有酯基端基的聚合物。     

穿过液膜的自发电势振荡

本文研究的体系是在一个U 形玻璃管里,底部加入苦氨酸的硝基苯溶液(油相)作为人造液膜,右边支管中加入含乙醇的十八烷基三甲基氯化铵的水溶液,左边支管中加入蔗糖水溶液(或去离子水).电势振荡振幅在20—150mV 之间.根据文献报导,表面活性剂穿过油相产生界面振荡.本实验用的十八烷基三甲基氯化铵(简称C_(18)~+Cl~-)是一个阳离子型表面活性剂,与苦氨酸(简称HA)接触时显橙红色,