液晶聚氨酯的合成与性质

采用熔融酯交换法合成端基为羟基的液晶复合二酸二丁二醇酯（ＴＯＢＢ）,再与２,４－ＴＤＩ或ＭＤＩ反应;或用聚己二酸丁二醇酯二醇（ＰＢＡ）替代部分ＴＯＢＢ制备液晶聚氨酯。用差热扫描量热仪和偏光显微镜检测其液晶性。结果表明：ＰＢＡ替代部分ＴＯＢＢ后,降低聚氨酯相转变温度,中介相温度范围变窄。     

两个苯并咪唑羧酸稀土配合物的合成、晶体结构及荧光性质

合成了1,3-二羧甲基苯并咪唑有机配体,并与氯化铕、氯化钐反应得到了两个新的稀土配合物,通过元素分析、X-射线单晶衍射及X-射线粉末衍射对其进行表征。晶体结构表明,两个配合物结构均为两个金属中心被4个配体桥联形成Ln_2O_8型双核次级结构基元,通过(κ~1-κ~1-μ_2)-(κ~1)-μ_3配位模式与配体形成(4,4)拓扑的二维网络结构。同时测定了这两个配合物的热稳定性及Eu配合物的荧光性质。     

二硝酰胺钾的合成、晶体结构及性能

以N-脒基脲二硝酰胺盐(GUDN)和氢氧化钾为原料合成了二硝酰胺钾(KDN),用元素分析、傅里叶红外光谱对其结构进行了表征。培养了KDN的单晶,并通过X射线单晶衍射仪测定了其晶体结构。采用差示扫描量热分析仪(DSC)研究了KDN的热分解行为,并测试了其感度。结果表明,KDN晶体属于单斜晶系,P2(1)/n空间群,晶胞参数为:a=0.661 0(11)nm,b=0.927 2(15)nm,c=0.719 4(12)nm,β=97.568(3)°,V=0.437 1(12)nm~3;Z=4;Dc=2.236g/cm~3;F(000)=288。KDN的熔点为128℃,撞击感度大于50cm,摩擦感度为0,静电感度为142.53mJ,感度低于RDX,是一种钝感的二硝酰胺类含能材料。     

间硝基苯胺水杨醛Schiff碱过渡金属配合物的合成及性质

合成了4种间硝基苯胺水杨醛Schiff碱过渡金属配合物,其结构经UV-Vis、IR、元素分析、摩尔电导率测定等表征。荧光光谱表明,4种配合物都能强烈猝灭牛血清白蛋白（BSA）的内源荧光。生物活性实验表明,配合物对金黄色葡萄球菌（S.aureus）、大肠杆菌（E.coli）、枯草芽孢杆菌（B.subtilis）、绿脓杆菌（P.aeruginosa）均有不同程度的抑菌作用,其中对绿脓杆菌的抑菌活性较强。4种配合物的抑菌活性均大于配体的抑菌活性。     

手性salen配合物合成及应用研究进展

简述了Salen配合物的合成以及在不对称催化中的应用。     

酰基吡唑啉酮希夫碱及配合物的合成、结构及生物活性

综述了酰基吡唑啉酮希夫碱及配合物的合成、结构和生物活性.介绍了非水溶剂法、固相合成法、水相合成法、溶剂热合成法等配合物合成方法.分析了酰基吡唑啉酮希夫碱参与过渡金属、稀土金属配位成键的方式,以及相应配合物空间构型为四面体、平面正方形、八面体、十二面体的结构关系.讨论了标题化合物对金黄葡萄球菌、枯草杆菌、大肠杆菌等的抑制...     

肉桂醛-2-呋喃甲酰腙钴配合物的合成、晶体结构及热稳定性

以肉桂醛-2-呋喃甲酰腙与Co Cl2·6H2O为原料,在不同的反应条件下合成得到两个钴配合物,并通过FTIR、热重分析、X-射线单晶衍射等手段对其进行了表征。X-射线单晶衍射结果表明:两个配合物均为四角双锥构型,属单斜晶系。配合物Co(L)2(H2O)2属P21/c空间群,晶胞参数为a=1.706 2(2)nm,b=1.059 17(13)nm,c=0.742 00(9)nm;β=101.738(2)°,V=1.312 9(3)nm3,Z=2。配合物Co(L)2(Imz)2属C2/c空间群,晶胞参数为a=2.481 4(2)nm,b=0.848 96(8)nm,c=1.936 96(18)nm;β=121.132 0(10)°,V=3.492 7(6)nm3,Z=4。热重分析表明,两个配合物均有较高的热稳定性。     

对-亚苯基双苯并咪唑过渡金属配合物的合成和荧光性质研究

合成了2,2’-对亚苯基双苯并咪唑的铜、钴、镍配合物,采用元素分析、红外光谱、紫外光谱和摩尔电导率等进行表征,研究了固体荧光性质,发现Ni（II）配合物的荧光发射峰红移了101nm,荧光寿命增加到配体的12倍。     

吡唑-3-甲酸钴的合成、晶体结构及其与牛血清白蛋白的相互作用

利用吡唑-3-甲酸为配体,通过溶液法与氯化钴反应合成出一种钴的配合物,用X射线单晶衍射仪对其进行表征。结果显示,该配合物为单斜晶系,空间群为P21/c,a=0.509 94(2)nm,b=1.139 55(5)nm,c=0.936 80(4)nm,β=95.925(5)°。钴与两个配体分子的N、O原子和水分子的氧原子配位,形成八面体结构。利用紫外-可见吸收光谱与荧光光谱研究它与牛血清白蛋白(BSA)的相互作用。结果表明,该配合物与BSA形成稳定的复合物,荧光猝灭属于静态猝灭,猝灭速率常数kq为3.54×1012L/(mol·s),结合常数K=7.06×105L/mol,结合位点n=1.259 5。     

2-巯基吡啶与Cu(I)配合物的合成、晶体结构及光物理性质

利用Cu(I)前体[Cu(CH3CN)4]BF4与配体2-巯基吡啶、邻菲罗啉进行反应,合成了一种新型铜(I)配合物:{[Cu3(py2tH)6](BF4)3.H2O}n。运用X-射线单晶衍射方法确定了其晶体结构。同时,利用现代波谱方法对配合物的光物理性质进行研究。发射光谱显示在632nm处的发射峰属于金属到配体的电荷跃迁,即MLCT。     

异核双金属化合物Cp(CO)2Fe-Sn(CH2 CMe2Ph)3的合成与晶体结构

以四氢呋喃为溶剂 ,合成了含Sn、Fe的环戊烯基二羰基铁的异核双金属化合物 ,并对配合物进行了元素分析、IR光谱分析 ,使用SimensP4单晶衍射仪测定了配合物的晶体结构。结构分析表明 ,该配合物属于三斜晶系 ,空间群P - 1。晶胞参数 :a =10 0 79(2 )A° ,b =10 975 0 (10 )A°,c =17 14 5 (3)A° ;a =82 0 30 (10 )° ,β =77 770 (10 )°,γ =6 3 70 0 (10 )° ,Z =2     

The Relationship between the Spatial Arrangement of Pigments and Exciton Transition Moments in Photosynthetic Light-Harvesting Complexes

Considering bacteriochlorophyll molecules embedded in the protein matrix of the light-harvesting complexes of purple bacteria (known as LH2 and LH1-RC) as examples of systems of interacting pigment molecules, we investigated the relationship between the spatial arrangement of the pigments and their exciton transition moments. Based on the recently reported crystal structures of LH2 and LH1-RC and the outcomes of previous theoretical studies, as well as adopting the Frenkel exciton Hamiltonian for two-level molecules, we performed visualizations of the LH2 and LH1 exciton transition moments. To make the electron transition moments in the exciton representation invariant with respect to the position of the system in space, a system of pigments must be translated to the center of mass before starting the calculations. As a result, the visualization of the transition moments for LH2 provided the following pattern: two strong transitions were outside of LH2 and the other two were perpendicular and at the center of LH2. The antenna of LH1-RC was characterized as having the same location of the strongest moments in the center of the complex, exactly as in the B850 ring, which actually coincides with the RC. Considering LH2 and LH1 as supermolecules, each of which has excitation energies and corresponding transition moments, we propose that the outer transitions of LH2 can be important for inter-complex energy exchange, while the inner transitions keep the energy in the complex; moreover, in the case of LH1, the inner transitions increased the rate of antenna-to-RC energy transfer.     

配位聚合物[Cu(bipy)(H_2O)_2]SO_4的合成及晶体结构表征

在水醇溶液中合成了标题配位聚合物[Cu(bipy)(H2O)2]SO4(bipy=2,2-′bipyridine),进行了元素分析、X射线衍射等表征。X射线衍射结果表明,此配合物属单斜晶系,空间群为Cc,晶胞参数为:a=1.5138(2)nm,b=1.2455(8)nm,c=0.7001(8)nm,β=106.013(3)°,V=1.2690(0)nm3,Z=4,Dc=1.841 g/cm3,μ=1.913 mm-1,F(000)=716。配合物中的金属铜离子与一个2,2′-联吡啶、2个水分子配位,形成一个变形的四边形结构。配合物通过O-H…O氢键构建为三维超分子。     

Electronic Communication in the Mixed-valence States of Cyclobutadienecobalt Complexes having Two Ferrocenes and Two Anthraquinones

Two geometric isomers, Z and E forms of (η⁴-cyclobutadiene)(η⁵-cyclopentadienyl) cobalt simultaneously containing two ferrocene moieties and two anthraquinone moieties, 1 and 2, respectively, were synthesized, and their crystal structures were determined. These molecules formed double mixed-valence states caused by ferrocene–ferrocenium and anthraquinone–anthrasemiquinone electronic communications. In both 1 and 2, the thermodynamic stability of the mixed-valence state for the ferrocene moieties was higher than that of the anthraquinone moieties because of the orbital coupling of the CB–Co bridging unit. The comproportionation constant, K _c, for the ferrocene moieties was similar between 1 and 2, whereas the mixing coefficient, α, and the off-diagonal matrix-coupling element in the Marcus-Hush two-state model, H _AB, evaluated from analysis of the intervalence charge transfer (IVCT) band were larger for 1 than for 2. These results suggest the existence of higher electrostatic repulsion between two ferrocenium cations in 1 than in 2 and the occurrence of through-bond electronic communication. K _c for the anthraquinone moieties in the E form is smaller than that of the Z form, probably due to the through-space electronic interaction.     

同位素水精馏非稳态过程制备低氘水的研究与应用

根据水精馏过程中氢、氧稳定同位素的分离特性,以及同位素精馏的稳态和非稳态级联过程的理论分析和研究,应用于水精馏法生产重氧(18O)水的分离过程,在连续生产重氧(18O)水的同时,间歇副产低氘水,使一套同位素分离装置能同时制备二种同位素产品,开发了同位素水的综合制备的技术,提高了分离装置的有效利用率.     

2-氨基嘧啶超分子配合物[Cu(2-AP)2(NO3)2]的合成与晶体结构

以2-氨皋嘧啶缩水杨醛席夫碱和硝酸铜为原料,在常温下,用甲醇和水为溶剂合成了配合物[Cu（2,Ap）2（NO3）2]（2-Ap=2,氨基嘧啶）。通过红外光潜、元素分析、X-射线单品衍射对它进行了结构解析和表征,并系统研究了配合物的结构特点。     

Synthesis of oligomer vinyl acetate with different topologies by RAFT/MADIX method and their phase behaviour in supercritical carbon dioxide

Poly(vinyl acetate) (PVAc) has been shown to exhibit anomalously high solubility in CO₂ as compared to other vinyl hydrocarbon polymers. Understanding the phase behaviour of PVAc with different topologies in CO₂ is very important for its potential applications as suitable surfactant, or phase transfer agent in a CO₂ solvent process. In this study, a series of PVAcs with different topologies (bi-arms, tri-arms, tetra-arms) were synthesized by RAFT/MADIX method. The structures and molecular weights of these polymers were characterized by ¹H NMR and GPC. The phase behaviours of PVAcs in dense carbon dioxide fluid were determined, and the results show that the PVAc with more arms has lower cloud point pressure.     

Synthesis and Evaluation of Polycarboxylate-Type Superplasticizers with Different Carboxylic Contents Used in a Cement System

A series of polycarboxylate-type superplasticizers (PCs), possessing almost the same degree of polymerization and different molar ratios of methacrylic acid (MAA) to methyl poly (ethylene oxide) methacrylate (MPEOM), were synthesized, and the effect of carboxylic content on the fluidity, water-reducing ratio, bleeding, setting time, mechanical strength, and rheological behavior in a cement system was systematically evaluated in this paper. When the molar ratio of MAA to MPEOM is 3.6:1, PC has better performance for improving the dispersing ability to cement particles, reducing the apparent viscosity of cement suspensions, increasing the water-reducing ratio, and improving the mechanical strength of hardened mortar over PC with other molar ratios. In addition, the more carboxylic content of PC, the greater retardation effect of cement paste, and the higher the bleeding water percentage (BWP) of fresh mortar.     

Depth-Profiling of Crystal Structure, Texture, and Microhardness in a Functionally Graded Tooth Enamel

The graded nature of crystal structure, texture, and microhardness of human enamel has been characterized by grazing-incidence synchrotron radiation diffraction and Vickers indentation. Results show that the composition of tooth enamel consists mainly of calcium apatite or hydroxyapatite (HAP). The HAP crystals formed near the occlusal surface are aligned approximately orthogonal to each other between the axial and occlusal sections. In addition, the tooth enamel has been shown to be a hierarchical graded biomaterial with a distinct gradation in crystallinity, texture, crystallite size, and hardness, which is somewhat akin to that of the fibrous microstructures found in natural plants. A "graded-interface" approach is proposed as a biomimetic model for designing new dental or restorative materials as well as for joining of dissimilar materials.