ZnO纳米片/微棒复合体的制备、结构及光学性能

以十六烷基三甲基溴化铵(CTAB)为表面活性剂,以氯化锌和氢氧化钠为原料,在低温水热条件下制备出具有纳米片状接枝结构的ZnO微棒。通过扫描电镜(SEM)、X射线衍射(XRD)、透射电镜(TEM)、光致发光(PL)和拉曼光谱(Raman)对产物的形貌、晶体结构和光学性能进行了表征。结果表明,表面活性剂CTAB对产物最终形貌的形成具有重要作用;微棒表面所接枝的薄片为多晶结构;产物光致发光峰是较少见的弱蓝光发射与强红光发射;同时对这种ZnO微棒的生长机理进行了探讨。     

Synthesis of linear and V-shaped oligo(phenylene ethynylene) derivatives: geometric effects on photophysical properties

<正>A series of linear and V-shaped oligo(phenylene ethynylene) derivatives 1-3 were synthesized through sequent Sonogashira coupling and propargyl alcohol deprotection reaction in high yields.The alkoxy chains(i.e.,n-hexyloxy groups) were introduced to assure good solubility of compounds 1-3 in common solvents.The photophysical properties of 1-3 in solution depend strongly on the geometries of these compounds.     

铈锆固溶体的合成及其在CH_4和CO催化燃烧反应中的应用

分别利用固态反应和共沉淀法制备了铈锆固溶体,并以其为载体制备了车用三效催化剂,考察其在CH4和CO催化燃烧反应中的作用.研究发现固态反应法所得固溶体孔分布较宽,热稳定性较差,但表面较多的缺陷位贡献于其较高的储氧性能.而共沉淀法所得样品拥有较高的热稳定性和催化活性.固溶体的还原性质可以通过铈锆比调控.关联催化剂对CH4和CO的催化氧化性能发现,具有较大比表面积、集中孔径分布和较高储氧能力的固溶体显示了较低的催化剂起燃温度和较高的催化活性.     

一维梯子型链状有机双膦酸铜Cu_3{(C_5NH_(11))C(OH)(PO_3)_2}_2(H_2O)_4·4H_2O的合成和表征(英文)

本文报道了一个新的有机双膦酸铜化合物Cu3{(C5NH11)C(OH)(PO3)2}2(H2O)4·4H2O(1)的合成及结构。该化合物呈梯子型双链结构,由Cu(1)O5四方锥体和Cu(2)O6八面体通过{PO3C}四面体以共顶点方式连接而成。相邻的双链以几乎相互垂直的方式堆积,通过氢键作用形成了具有孔道的三维超分子网络结构,晶格水分子填充其中。磁性研究表明在铜离子间存在反铁磁相互作用。     

稀土配位聚合物{(H_2prz)[Ln_2(pzdc)_4(H_2O)_2]·5H_2O}_n(Ln=Eu,Tb)的合成、结构和性质

以Ln(NO3)3、H2pzdc(2,3-吡嗪-二羧酸)和prz(哌嗪)为原料,在水热条件下得到了2个结构新颖的稀土配位聚合物{(H2prz)[Ln2(pzdc)4(H2O)2]·5H2O}n(Ln=Eu(1),Tb(2))。对它们进行了元素分析、红外光谱、粉末X-射线衍射、热重等分析,并用X-射线衍射测定了它们的单晶结构。2个配合物的晶系都属于三斜晶系,P1空间群。研究了它们的荧光性质,固体荧光实验测试结果表明,2个配合物在室温下均表现出相应稀土离子的特征荧光发射。     

对称排列的咔唑基树状分子的合成及其光物理性能和电化学性能(英文)

采用乌尔曼缩合反应合成了新型的咔唑基树状分子;利用核磁共振谱仪(1HNMR,13CNMR)和飞行时间质谱仪(MALDI-TOF-Mass)对其进行了表征;并评价了树状分子的荧光性能和电化学性能.结果表明,所合成的咔唑基树状化合物在394nm处发蓝光,同时具有低的HOMO能级.     

混价四核铜(I/II)配合物[Cu_2L_2][Cu(pht)_2]_2的合成、晶体结构及性质研究

报道四核铜配合物[Cu2L2][Cu(pht)2]2[Hpht:苯妥英,即5,5-二苯基-2,2咪唑烷酮;L:N-(3-氨基丙基)二乙醇胺]的溶剂热合成、晶体结构及其性质研究.该晶体属单斜晶系,P21/n空间群,晶胞参数:a=0.9240(1)nm,b=2.4559(2)nm,c=1.5572(2)nm,β=97.489(2)o,V=3.5035(7)nm3,Dc=1.499Mg/m3(g/cm3),Z=2,F(000)=1636,μ=1.270mm-1,R1=0.0503,wR2=0.1135[I2σ(I)],GOF=1.014.XPS结合X射线单晶结构分析,表明该配合物分子有混价铜组成,包括两个Cu(I)和两个Cu(II),其中每个Cu(I)分别与两个苯妥英配体提供的氮原子配位,N—Cu(I)—N的夹角为177.1°,每个Cu(II)与L配体的五个配位原子配位(N2O3),形成一个稍变形四方锥结构,两个Cu(II)通过N-(3-氨基丙基)二乙醇胺中的一个羟基氧桥连接形成双核阳离子,琼脂扩散法测试结果表明配合物、配体和铜盐对3种受试细菌均有一定的活性.配合物与DNA的相互作用测定研究表明,该配合物是以插入方式与小牛胸腺DNA结合.     

含不同共轭桥的TCNQ开闭壳层体系NLO性质的DFT研究

采用密度泛函理论(DFT)结合有限场(FF)方法,对不同共轭桥连接的四氰代二甲基苯醌(TCNQ)开壳层和闭壳层电子态的非线性光学(NLO)系数进行计算,并以乙烯桥为例讨论共轭链长度与NLO性质的关系.结果表明:开壳层体系的极化率和二阶超极化率值都大于闭壳层体系,且共轭桥的共轭性越强,体系的极化率和二阶超极化率越大;在自由基体系中,单重态的二阶超极化率随双自由基成分y和自旋多重度的增加而增大.体系的共轭链增长,BLA(BondLength Alternation,共轭分子中相邻单、双键键长差的平均值)逐渐减小,双自由基成分y逐渐增大,体系的二阶超极化率也逐渐增大.     

茶多酚的表面性能研究

通过分别测试二碘甲烷、水、甲酰胺等液体在茶多酚上的接触角,并根据van Oss-Chaudhury-Good的组合理论对茶多酚的表面性能进行研究。结果表明茶多酚的表面能随着茶多酚的含量增加而提高;且随着茶多酚的含量增加,儿茶素类物质即含酚羟基类物质的含量进一步增加,形成氢键的几率进一步增大,导致分子之间作用力和氢键力加大,因而使茶多酚的表面能提高。     

Thermal behaviour and mechanical properties of novel RTV silicone rubbers using divinyl-hexa[(trimethoxysilyl)ethyl]-POSS as cross-linker

Divinyl-hexa[(trimethoxysilyl)ethyl]-POSS (DVPS) as an octavinyl-POSS derivative was first prepared. A series of novel polydimethylsiloxane (PDMS)/DVPS hybrid materials as room temperature vulcanized (RTV) silicone rubber were prepared. The chemical incorporation of novel POSS into hydroxyl-terminated PDMS system by hydrolytic condensation reaction was verified by attenuated total reflection (ATR) infrared spectroscopy. Thermal degradation, thermo-oxidative stability and mechanical properties of these novel RTV silicone rubbers were studied by means of thermogravimetric analysis and tensile testing. The results exhibited significantly enhanced effects on the thermal stabilities and mechanical properties as compared to the PDMS polymer prepared with tetraethoxysilane (TEOS). The observed improvements in thermal properties could be attributed to the effective three-dimensional network structures resulting from the structure of DVPS. The thermal decomposition of the RTV silicone rubbers in nitrogen was also monitored by TGA coupled with real-time FTIR, and the degradation residues were also characterized by FTIR. It was found that the POSS cross-linker facilitated the formation of cross-links in the degradation residues. The striking improvement in mechanical properties could be attributed to the synergistic action of the structure of three-dimensional multi-arm cross-linker (vinyl-POSS derivative), the plasticization of self-cross-linking Vinyl-POSS derivative and perfect distribution of vinyl-POSS derivative.