PREPARATION OF PARTICLE SIZE NARROWLY DISTRIBUTED LOW-DENSITY STYRENE DIVINYLBENZENE COPOLYMER MICROBEADS

In view of the importance of dispersion agent, the amount of the crosslinking monomer andthe diluent in suspension polymerization for the production of particle size narrowly distributedIow-density styrene divinylbenzene copolymer microbeads (LDPS), their actions are preliminarilyinvestigated in this paper. Experimental results indicate that when both the gelatine and polyvinylalcohol (PVA) are used as dispersion agents, the better effect is achieved. DVB is helpful to theformation of the lower density fine particles, the proportion of the DVB/St should be between1:1～1.5:1. Compared with toluene, gasoline is the more effective diluent for the above target.     

Novel preparation of organic polymer-based monolithic column by microwave irradation

Microwave irradiation was firstly attempted for the preparation of organic-based monoliths of poly（styrene-divinylbenzene- methacrylic acid）, which single step in situ polymerization was carried out during 15 min. The colunm permeability, electrophoretic and chromatographac behaviors were comparatively evaluated using pressure-assisted CEC, GEC and low pressure-driven separation modes. The largest theoretical plates for the preparing column could be close to 18,0000 plates/m for thiourea in the mode of p-CEC. It provided a viable alternative to traditional initiation means for the perparation of monolithic capillary columns.     

吖啶类衍生物的荧光性质

用比较法测得23种啶类衍生物的荧光量子效率（Φf)，以评估这些化合物的荧光性质，结果表明，N－烃基吖啶酮类化合物的荧光量子效率要比9－取代苯基吖啶类和9－取代苯亚甲基－10－甲基－9，10－二氢吖啶类化合物的荧光量子效率大，在非极性溶剂中，9－聚代苯亚甲基－9，10二氢吖啶分子内的强吸电子基NO2增强荧光量子效率，强推电子基OCH3降低荧光量子效率，这些测量结果与取代基的电子作用经验规律不相符，这种现象可以用分子内电荷转移理论进行解释。     

Transition metal 1,2-bidentate thiolates as building blocks and their construction into cluster complexes

Simple fragments of transition metal 1,2-bidentate thiolates, the so-called building blocks of the general compositions ML₃, ML₂, ML, M(O)L₂, ML₂L, MLL, etc. have been proposed to constitute the di-, tri- and tetranuclear complexes concerned in this review. Structureal regularities and characteristics have been discussed and summarized according to the thiolato ligands edt and pdt, bdt and tdt, mp, and mpo, and mpp, respectively.Abbreviations H₂mpo o-mercaptophenol - Hmpo 2-mercaptopyridine-N-oxide - R₂dtc N,N-dialkyldithiocarbamate - Haet 2-aminoethanethiol - H₂bdt o-benzenedithiol - H₂pdt 1,2-propanedithiol - H₂tdt toluene-3,4-dithiol - Hmpp-mppH bis-(3-hydroxy-2-pyridyl)disulfide - Hmp-mpH bis-(2-oxyphenyl)disulfide - H₂edt 1,2-ethanedithiol - dppe 1,2-bis(diphenylphosphino)ethane - H₂tedt 3,4,5,6-tetrachlorobenzene-1,2-dithiol - H₂tpdt 3-thiapentane-1,5-dithiol - H₂mnt maleonitriledithiol - Him imidazole - Bz benzyl - py pyridine     

一阶导数光谱K系数法同时测定硝基酚钠三组分

研究和建立了同时测定硝基酚钠混合三组份的新方法——一阶导数光谱K系数法。确定了最佳实验条件和测定波长,方法简便、快速、准确。通过对动植物细胞赋活增进剂中邻硝基酚钠、对硝基酚钠、5-硝基愈创木酚钠三组份的直接测定,其相对误差小于2%,相对标准偏差小于3%,回收率为99～103%。     

Highly efficient, one-step macrocyclizations assisted by the folding and preorganization of precursor oligomers

Highly efficient, one-step macrocyclizations leading to the formation of macrocyclic hexa(aramides) in high yields (69-82%) are described. The one-step macrocyclizations were facilitated by the preorganization or folding of the backbones of uncyclized precursors in the course of macrocyclization. The preorganization of backbones was achieved by the presence of localized three-centered hydrogen bonds that were adopted in the design of a class of closely related, backbone-rigidified foldamers. The macrocyclization involved reactions between diacid chloride 1 and diamine 2. The crude reaction mixtures and products were conveniently examined by mass spectrometric method (MALDI-TOF). Compared to most traditional one-step macrocyclizations that usually require high dilution conditions and often lead to very low overall yields of the desired products, cyclic hexamers 3 were obtained as the overwhelmingly major product under a variety of reaction conditions, suggesting the generality of this approach.     

煤的超临界醇萃取脱硫：Ⅲ.形态硫的变化

本文分别应用Ｍｏｓｓｂａｕｅｒ谱和ＸＰＳ（Ｘ射线光电子能谱）技术考察不同反应 条件下固体产物中的无机硫和有机硫的形态变化，结果表明；在超临界醇萃取脱硫过程中，黄铁矿硫的转化反应如下：ＦｅＳ２－ＦｅＳ＋Ｆｅ１－ｘＳ，，转化的数量和深度主要取决于反应温度。２７５℃时磁黄铁矿（Ｆｅ１－ｘＳ）形式为ＦｅＳ１．１０１，４５０℃时为ＦｅＳ１．０８５；有机硫基团中ＰｈＳＨ ，Ｐｈ２Ｓ和四氢噻吩较易脱除，Ｐｈ２Ｓ     

脱羧氯雷他定的合成

脱羧氯雷他定 (ＤＣＬ)是一种有效的非镇定性抗组织胺 ,对过敏性鼻炎 ,糖尿病、咳嗽、普通感冒、流行性感冒、关节痛及其它不适症状都有很好的疗效[1～2 ] 。它克服了氯雷他定、酮康唑、红霉素、伊曲康唑等易引发黑色素瘤、纤维肉瘤、胃刺激、肥胖症、心律失调、传导紊乱等症状的缺点。且它的使用剂量只有氯雷他定的十分之一 ,有很好的市场前景和实际应用价值。ＭａｒｋＷ .Ｈｏｌｌａｄａｙｅｔａｌ[3] 在水溶液中由酸、碱催化得到了脱羧氯雷他定 ,但无具体操作和反应结果报道。Ａ .Ｋ .ＧｕｎｎａｒＡｂｅｒｇ[1] 直接用ＫＯＨ在绝对无水…     

Structure and Two-photon Excited Blue Fluorescence of an Asymmetrical Substituted Stilbene

In common fluorescence process, molecular excitation is caused by the absorption of at least a single photon with shorter wavelength. When certain laser is used as the pump source, some compounds can be excited by simultaneous absorption of at least two photons and then the emission of up-converted fluorescence may occur. This process is called two-photon excited fluorescence (TPEF)1,2. Because of several advantages of TPEF, including intrinsic high three-dimensional resolution and the p…     

手性双氨基醇-Et2Zn催化的不对称直接羟醛缩合反应

以1,3-二溴丙酮和(2'S)-(二苯基羟甲基)-四氢吡咯为原料,合成了两种新型手性氨基醇1,3-双[(2'S)-(二苯基羟甲基)-1-四氢吡咯基]丙酮(3)和1,3-双[(2'S)-(二苯基羟甲基)-1-四氢吡咯基]-2-丙醇(4),总产率分别为39%和35%.手性双氨基醇3-/4-Et2Zn可催化未修饰醛、酮的不对称直接羟醛缩合反应,对映体过量最高9%.