牛血清白蛋白与十二烷基硫酸钠作用的机理

利用电动势法得到了牛血清白蛋白(BSA)与十二烷基硫酸钠(SDS)相互作用的结合等温线. 通过四阶导数紫外光谱法和荧光光谱法研究了相互作用过程中芳香族氨基酸残基微环境极性的变化. 通过研究发现, 随着SDS浓度的逐渐增大, SDS在BSA上的平均结合数(v)逐渐增大, 色氨酸(Trp)残基所处微环境的极性在减弱后保持基本不变, 酪氨酸残基所处微环境的极性在明显增强后稍有减弱, 苯丙氨酸残基所处微环境的极性略有增强. 结果表明, 当v由0增大到14时, SDS主要结合在BSA的Trp-213附近并逐渐形成聚集体, 从而诱导BSA由结构域ⅡA 开始逐渐展开. 此后, SDS呈正协同作用的特点与BSA 结合, v急剧增大. 当v约为302 时, SDS在BSA上的结合基本达到饱和, BSA的构象趋于稳定.     

硝基基团修饰的金属有机框架化合物的合成及晶体结构表征

分别以2种硝基羧酸配体EBNB(1,2-二(3-硝基苯甲酸)-乙烯)和NPA(3-硝基邻苯二甲酸)与BPY(4,4′-联吡啶)及金属锌反应,配位溶剂热法合成了2种具有硝基基团修饰的二核金属簇为基本构筑单元的金属有机框架化合物[Zn2(EBNB)2(BPY)2·2H2O]n(1)和[Zn2(NPA)2(BPY)2·H2O]n(2)。通过X-射线单晶衍射法测定了2种配合物的结构,其中配合物1属于三斜晶系,P1空间群,a=0.818 62(9)nm,b=1.142 20(14)nm,c=1.428 63(17)nm,α=96.803 0(10)°,β=93.045 0(10)°,γ=102.472(2)°,V=1.290 8(3)nm3,Z=2,Mr=595.81,Dc=1.533 g·cm-3,μ=1.01 mm-1,F(000)=608,T=293(2)K;配合物2属于三斜晶系,P1空间群,a=1.154 06(14)nm,b=1.190 86(16)nm,c=1.459 52(19)nm,α=98.029(1)°,β=98.749(1)°,γ=113.579(2)°,V=1.771 9(4)nm3,Z=2,Mr=879.35,Dc=1.648 g·cm-3,μ=1.43 mm-1,F(000)=892,T=293(2)K。同时也对2种配合物的发光性能进行了测试,测试结果表明2种配合物具有较好的荧光性能。     

N-Protection of amines using pyridinium 2, 2, 2-trifluoroacetate ionic liquid as an efficient and reusable catalyst

A simple, green, and efficient method for the N-tert-butoxycarbonylation of amines by pyridinium 2,2,2- trifluoroacetate （[Py][OTf]） as an efficient and reusable catalyst is reported. In general, electron donating groups on aryl group give rise to the higher yields than electron withdrawing groups. Clean reaction, short reaction times, high yields, reusability of catalyst, and easy preparation of it are some advantages of this work.     

Blue electroluminescence of a novel Zn~(2+)–β-diketone complex with a carbazole moiety

In this letter, a novel zinc complex of Zn(ECTFBD)2 was synthesized by an environment-friendly grinding technique in high yield. Its structure was confirmed by1H NMR, MS and EA. HECTFBD is 1-(9-ethyl-9Hcarbazol-3-yl)-4,4,4-trifluorobutane-1,3-dione. Zn(ECTFBD)2-based light-emitting devices were fabricated. The architecture of the devices was ITO/PEDOT(40 nm)/100 wt% PVK: 40 wt% OXD-7: x wt% Zn(ECTFBD)2(85 nm)/CsF(1.5 nm)/Al(100 nm), where x = 1, 5, and 10(relative to the mass of PVK and OXD-7). The three devices displayed blue emissions with peaks at 450, 458, and 460 nm, respectively. A maximum luminous efficiency of 0.86 cd/A and a luminance of 228 cd/m2were achieved by the 1 wt% doped device. So, we demonstrated further that Zn2+–b-diketone complexes can be effectively severed as a class of new electroluminescent materials. In addition, the thermal stability of Zn(ECTFBD)2 was tested and the UV–vis and photoluminescent behaviors of Zn(ECTFBD)2 in CH2 Cl2 were investigated.     

岩石抽提物中极性化合物超高分辨质谱识别

采用具有超高分辨率的负离子电喷雾-傅立叶变换离子回旋共振质谱（ESI FT-ICR MS）分析了储层岩石抽提物中的石油酸及中性氮化物的分子组成,得到了抽提物中杂原子化合物类型分布、等效双键数（Double bonds equivalent,DBE）及碳数分布特征。研究结果表明,储层抽提物中含有多达16种不同杂原子类型的化合物,包括N1、N1O1、N1O2、N1O3、N1S1、N1S2、N2、N2S1、O1、O1S1、O2、O2S1、O1S2、O2S2、O3和O4,其中N1、N1S1、O2及O2S1类具有较高的相对丰度。抽提物中的N1类化合物以咔唑和苯并咔唑类化合物为主;N1S1类化合物以C2~C8烷基取代的咔唑并苯并噻吩类化合物为主;O2类化合物主要为1~2环环烷酸,其次还在抽提物中鉴别出具有较高相对丰度的DBE为5和6的O2类化合物;而O2S1类化合物中以DBE为7和8的O2S1具有最高的相对丰度。     

可调苯氧基修饰的聚(苯乙烯-苯乙烯基膦酸)-磷酸氢锆固载手性Mn~III(Salen)高效催化烯烃环氧化（英文）

使用不同空间位阻的苯氧链接手臂修饰的聚(苯乙烯基-苯乙烯膦酸)-磷酸氢锆轴向固载手性MnIII(Salen)催化剂(Cat1–Cat3),随后在间氯过氧苯甲酸(m-CPBA)为氧化剂的体系中考察了固载催化剂的催化性能.同时,在相同氧化体系下测试了一系列均相催化剂类似物(Cat4–Cat6).结果表明,在非均相条件下,可调变苯氧链接手臂的邻位取代基对催化剂活性起着重要作用,环氧化产物的对映选择性随着取代基位阻的增加而增大,但产物转化率有一定程度下降.此外,非均相催化剂即使在没有轴向助剂的参与下(通常需要添加,为了增大催化活性)仍然表现出非常高的催化活性,尤其对α-甲基苯乙烯反应,其对映选择性从6.8%增加到76.8%,转化率从19.8%上升到90.7%.制备的非均相催化剂11次的循环使用实验表明,在前5次使用后催化剂活性与对映选择性没有明显变化.     

Synthesis,chiroptical properties of a helical polyacetylene derivative carrying urea moieties

A novel phenylacetylene derivative containing urea groups was synthesized and polymerized with a Rh catalyst to give the corresponding polymer, poly（1） with moderate number-average molecular weights. The poly（1） was soluble in toluene, CHCI3, CH2C12, THF, DMF, and DMSO, but insoluble in hexane, diethyl ether and MeOH. The specific rotation and circular dichroism （CD） spectroscopic studies revealed that poly（1） took predominantly one-handed helical structures. The presence of intramolecular hydrogen bonding was confirmed by liquid-state IR spectroscopy. The helicity of poly（1） could be tuned by temperature and anion. The helical conformation of the polymer was stable against Br but susceptible to F.     

单分子电导测量技术及其影响因素

Molecular electronics is an important field for the application of nanotechnologies with an ultimate goal of building functional devices using single molecules or molecular arrays to realize the same functionality as macroscopic devices. To attain this goal, reliable techniques for measuring and manipulating electron transfer processes through single molecules are essential. There are various techniques and many environmental factors influencing single-molecule electronic conductance measurements. In this review, we first provide a detailed introduction and classification of the current well-accepted techniques in this field for measuring single-molecule conductance. All available techniques are summarized into two categories: the fixed junction technique and break junction technique. The break junction technique involves repeatedly forming and breaking molecular junctions by mechanically controlling a pair of electrodes moving into and out of contact in the presence of target molecules. Single-molecule conductance can be determined from the conductance plateaus that appear in typical conductance decay traces when molecules bind two electrodes during their separation process. In contrast, the fixed junction technique is to fix the distance between a pair of electrodes and measure the conductance fluctuations when a single molecule binds the two electrodes stochastically. Both techniques comprise different application methods and have been employed preferentially by different groups. Specific features of both techniques and their intrinsic advantages are compared and summarized in Section 4.     

金属串配合物[MoMoCo(npo)4(NCS)2]的配位结构及其与电场的关系

应用密度泛函理论B3LYP方法研究了具有分子导线潜在应用的金属串配合物[MoMoCo(npo)4(NCS)2](npo=1,8-萘基-2-酮)的配位结构及其受电场作用的影响。配位方式记为(n,m),其中n、m分别表示4个赤道配体npo^-的O与Co和Mo配位的个数:n=0,1,2,3,4;m=4,3,2,1,0。结果表明:(1)零电场下,基态能量高低为(0,4)>(4,0)>(3,1)≈(1,3)>(2,2),5种配位方式均可稳定存在且互为竞争态。Z方向偶极矩μ(Z)值大小为(0,4)(+)>(1,3)(+)>(2,2)(-)>(3,1)(-)>(4,0)(-)(+、-表示μ(Z)值的正负,与Z方向相同即为正,相反即为负),4个npo^-趋向越一致能量越高极性越大。(2)Mo-Mo具有四重键,键长随μ(Z)值减小而减小,而Mo-Co键长则相反。随μ(Z)值减小前线轨道中πNCS(1)轨道能降低,π'NCS(2)轨道能升高。(3)Z方向电场作用下,除(0,4)外所有配位方式的Mo1-N8键显著增长,结构不稳定。(4)电场作用下前线轨道能级交错,μ(Z)为正值的(0,4)、(1,3)的能隙E_LUMO-HOMO在-Z方向电场中降低更显著,μ(Z)为负值的(2,2)、(3,1)和(4,0)的能隙在Z方向电场中降低更显著。分子极性越大,随电场强度增强能隙降低越显著,分子导电性可能越好。(0,4)、(3,1)和(4,0)可能具有整流效应,但(3,1)和(4,0)的稳定性较低。     

含硅功能化聚烯烃:合成及应用

聚烯烃功能化改性是获得高性价比新材料的有效途径。含硅功能化聚烯烃(SFPO)是聚烯烃分子结构中含有机硅功能基团或有机硅聚合物链段的一类功能化聚烯烃的统称。由于有机硅功能基团及有机硅聚合物特殊的理化性质,SFPO通常具有丰富反应性或优异性能,成为一类有代表性的功能化聚烯烃。SFPO可以作为反应性中间体,用于制备具有复杂拓扑结构的功能化聚烯烃(如星型聚合物、梳型聚合物、接枝共聚物)或聚烯烃共价键接枝改性纳米材料;SFPO还可作为功能性添加剂(如增容剂、加工助剂,表面改性剂),用于开发聚烯烃新材料。近年来,研究人员在含硅功能化聚烯烃研究领域取得了系列进展,本文旨在对相关工作进行系统总结,以期引起同行注意并促进相关研究深入发展。