无配体参与钯催化烯烃与芳基三烷氧基硅烷的交叉偶联反应

考察了钯催化下一系列烯烃化合物与不同芳基三烷氧基硅烷的反应,发展了一种新型无配体参与的Heck类型反应方法.研究表明:以Pd(OAc)2为催化剂,在K2CO3,n-Bu4NF 3H2O和AgOAc存在下,该Heck类型反应能够得到中等及优良的偶联产率,并且表现出较高的区域选择性和立体选择性.根据实验结果以及相关文献,对该Heck类型偶联反应的可能机理进行了探讨.     

水杨醛双缩二氨基硫脲二丁基锡配合物的合成及杀菌活性研究

利用1,5-水杨醛双缩二氨基硫脲席夫碱与二丁基氧化锡为原料,在苯-甲苯混合溶剂中回流反应合成了有机锡席夫碱配合物,用元素分析、红外光谱、核磁共振谱对目标化合物结构进行了结构表征,并用X-射线单晶衍射对其结构进行了确证.晶体结构分析表明,标题配合物的晶体属三斜晶系,P-1空间群,每个独立单元中含有两个分子结构单元,晶胞参数:a=1.29705(6)nm,b=1.36654(7)nm,c=1.68517(8)nm,α=72.059(1)o,β=87.339(1)o,γ=63.435(1)o,V=2.5270(2)nm3,Z=4,Dcalc =1.433 g/cm3,μ=1.119 mm-1,F(000)=1112,R1=0.0563,wR2=0.1530.分子间经典的N-H...N氢键使分子相互缔合形成二聚体,后者再通过范德华作用力结合堆积形成完全的晶体结构.杀菌活性测定结果表明,标题化合物及其类似物的杀菌活性具有较大的选择性,对苏云金杆菌(B.thuringiensis)和枯草杆菌(B.Subtilis)的杀菌能力较高,而对大肠杆菌(E.Coli)和金黄色葡萄球菌(S.Aureus)的杀菌能力较低.     

Crystal Structure and Fluorescent Study of a Terbium(Ⅲ) Coordination Polymer

A novel Tb(Ⅲ) coordination polymer [Tb(bpapO2)2(NO3)3]n [bpapO2 = N2,N6- bi(pyridin-2-yl)pyridine-2,6-diamine-N,N'-dioxide-dioxide] has been synthesized and it exhibits terbium's characteristic fluorescent emission under UV radiation of 326 nm at room temperature. X-ray structural determination indicates that each terbium(Ⅲ) ion, centered in TbO8 core, connects to three adjacent coordinate centers via a bi-dentate ligand bpapO2, forming a one-dimensional coordination polymer. The compound crystallizes in the triclinic system, space group P1, with a = 11.2271(5), b = 11.7997(5), c = 14.8016(6) Ⅲ, α = 72.7060(10), β = 89.9630(10), γ = 66.7680(10)o, Z = 2, Dc = 1.822 g/cm3, V = 1705.14(13) Ⅲ3, F(000) = 932, the final R = 0.0340 and wR = 0.0669 for 4812 observed reflections with I 2σ(I).     

基于滴定突跃的计算探讨多元弱酸分步滴定的准确条件

多元弱酸分步滴定的准确条件一直是酸碱滴定中的一个教学难点。基于分布分数的分析指出了当前分析化学教材中有关探讨磷酸分步滴定的某些错误结论,并在此基础上,通过滴定突跃大小的计算,对多元弱酸分步滴定的准确条件进行了探讨分析。结果表明：若人眼判断滴定终点时有±0.2pH的不确定性时,滴定误差控制在0.5%,强碱滴定多元弱酸时,分步滴定的准确条件是：Kai/Ka(i+1)≥105.0;cKai≥10-8.7。     

含电子给体乙炔二茂铁化合物的光谱及电化学性质

合成了三种含电子给体乙炔基桥连二茂铁化合物Fc—C≡C—Ph—(p-OMe)(3a),Fc—C≡C—Ph—(p-NMe2)(3b)与Fc—C≡C—Ph—(p-NPh2)(3c),并对其结构、光化学及电化学性质进行了表征.吸收光谱表明,所有化合物在可见光区400-550nm都可归属为Fe(II)→Cp—C≡C—Ph—(p-R)(Cp为环戊二烯基)的金属到配体的电荷跃迁(MLCT)光谱,同时检测到3a与3c氧化态在近红外区(分别位于946与1044nm)可归属为Cp—C≡C—Ph—(p-R)→Fe(III)的配体到金属的电荷跃迁(LMCT).电化学测试结果表明,三种化合物都有稳定的Fc+/Fc可逆氧化还原电位,且3b与3c还出现Ph—NR2的氧化电位.3b对质子表现出光及电化学敏感性,随着质子的加入,其MLCT光谱红移,Fc+/Fc电位正移,而Ph—NR2+/Ph—NR2峰消失.     

Synthesis, Structure and Photoluminescent Property of an Entangled Cd（Ⅱ） Complex Constructed from a Rigid Imidazolyl Ligand

The assembly of rigid 1, 4-di(1H-imidazol-4-yl)benzene (L) and Cd(OAc)2·2H2O affords an entangled complex [Cd(L)2(OAc)2]n (1) which was characterized by single-crystal X-ray diffraction, IR, elemental analysis and PXRD. The complex crystallizes in monoclinic, space group P21/c with a = 8.2603(9), b = 11.8162(13), c = 14.4138(16), β = 105.309(2)o, V = 1356.9(3)3, Z = 2, C28H26CdN8O4, Mr = 650.97, Dc = 1.593 g/cm3, μ = 0.856 mm?1, S = 1.015, F(000) = 660, the final R = 0.0456 and wR = 0.1366 for 2532 observed reflections (I > 2σ(I)). 1 possesses [Cd(L)2]n layer motifs, and parallel sets of layer motifs aggregate into a 2D + 2D → 3D mutually interpenetrated system. Photoluminescence study revealed that complex 1 exhibits strong fluorescent emission bands in the solid state at room temperature.