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希土化合物由于涉及f轨道,用分子轨道方法有一定困难,前人曾采用过多种处理方法。  相似文献
2.
RE[CH2(CH2)4CONC4H9]3(NO3)3(RE=La,Dy)的合成和晶体结构   总被引:1,自引:0,他引:1  
采用X-射线四园衍射仪测定了Dy「Ch2(CH2)4CONC4H9」3(NO3)3和La「CH2(CH2)4CONC4H3」3(NO3)3的晶体结构。两个配合物具有相似的结构,均属单斜晶系,空间群为P21/c。晶体参数:Dy「La」:a=1.8564(3)「1.8564(2)」nm,b=0.9769(2)「0.9834(1)」nm,c=2.1863(6)「2.20038(7)」nm,β=96.08  相似文献
3.
引 言 希土化合物由于涉及f轨道,用分子轨道方法有一定困难,前人曾采用过多种处理方法。文献[8]报导了希土-2,2’-联吡啶配位方法和性质研究。文献[8],[9]对镧与2,2—联吡啶,硝酸配合物的合成,性质和结构亦作过研究。本文采用适用于镧系元素化合物电子结构计算的自旋非限制的INDO方法来研究La(C_(10)H_8N_2)_2(NO_3)_3的电子结构和化学键。  相似文献
4.
La(III) complex with 1-phenyl-3-methyl-5-hydroxy-4-pyrazolyl phenyl ketone (PMBP)-isonicotinoyl hydrazone (La-complex) was synthesized in the work. The crystal of the La-complex was determined by X-ray diffraction analyses, the crystal of the complex is rhomb, space group R3 with Z = 6, the coordination polyhedron of the complex is a tricapped triprism configuration with the nine-coordinate atoms, and the La-complex molecule looks like a helix structure according to its spacefill picture. Besides, it has been discovered that the La-complex possesses cytotoxic activities, and inhibitory rate for Leukemia cells (L1210) is 87.1%. The interaction of the La-complex with DNA was investigated by absorption spectrum, fluorescence, CD spectrum and viscosity measurements. The DNA-binding constant for the La-complex is (4.30 ± 0.14) × 106 M−1.  相似文献
5.
A catalytic enantio- and diastereoselective Michael reaction was achieved to construct vicinal quaternary and tertiary carbon centers in one step. Using 5 mol % of La(O-i-Pr)3 and 10 mol % of a new N-linked-BINOL type ligand, the reaction of α-substituted β-keto esters to cyclic enones provided the corresponding Michael adducts in up to quantitative yield with a diastereomeric ratio up to 86/14 and enantiomeric excess up to 86% for the major isomer. An alternative catalyst preparation method using La(OTf)3 instead of La(O-i-Pr)3 was also examined.  相似文献
6.
稀土硝酸盐与双啮杂环胺配体α,α′联吡啶(bipy)的配合物研究不多.Hart 等合成了Ln(NO_3)_3(bipy)_2配合物;亦已解析了3个晶体结构:La(NO_3)_3(bipy)_2,Tb(NO_3)_3(bipy)_2,La(NO_3)3·bipy·2H_2O·(B-15-C-5)(B-15-C-5=苯并15-冠-5,).我们对La(NO_3)_3(bipy)_2的电子结构和化学键作过研究.本文利用自旋非限制适于稀土配合物计算的INDO方法研究了La(NO_3)_3·bipy·  相似文献
7.
标题化合物由La(NO3)3·nH2O,1,10-邻菲罗啉(phen)和乙酰丙酮等在无水乙醇和水的混合溶剂中合成并用IR谱和X射线结构分析进行表征。晶体学数据如下:C24 H21LaN8O14,Mr= 784.40, 三斜, P1, a= 7.124(1), b= 11.047(2), c= 19.393(4), α= 81.10(3), β= 87.79(3), γ= 74.36(3)°, V= 1452.0(5)3, Z= 2, Dc=1.794g/cm 3, F(000)= 780, μ(MoKα)= 1.557m m - 1。化合物由阳离子〔phenH〕+ 和配合阴离子〔La(NO3)4(H2O)(phen)〕- 及一个结晶水分子组成。配合阴离子中以La原子为中心,周围被2 个N原子(来自phen)和9 个O原子(来自NO3- 和H2O)所占据,构成较为罕见的11 配位。晶胞中两两阳离子〔phenH〕+ 及两两配体phen 平面之间均相互平行堆积,并有多种类型的氢键存在,这些都可以降低能量,有利于化合物在晶体中的堆积。  相似文献
8.
白花丹素(Plumbagin,简称PLN)是从传统中药白花丹中提取出来的具有抗肿瘤活性的萘醌类化合物(2-甲基-5-羟基-1,4萘醌),而白花丹素镧(Ⅲ)配合物[PLN—La(Ⅲ)]对MCF-7、BEL7404和NIC-460等肿瘤细胞株具有体外细胞毒活性.采用荧光光谱、同步荧光及紫外光谱法研究了PLN和PLN—La(Ⅲ)与牛血清白蛋白(BSA)的相互作用.结果表明,PLN和PLN—La(Ⅲ)均可通过静态荧光猝灭的方式减弱BSA的荧光强度;同PLN相比,PLN—La(Ⅲ)与BSA的结合常数较小.  相似文献
9.
A new La(Ⅲ) complex, {[La(L)(NO3)(H2O)3]·H2O}n (L = 1,10-phenanthroline- 2,9-dicarboxylate), has been synthesized and structurally determined by X-ray diffraction analysis. The complex crystallizes in the monoclinic system, space group P21/c with a = 7.7358(17), b = 8.1664(18), c = 28.271(6) , β = 95.184(4)°, V = 1778.6(7)3, Z = 4, C14H14LaN3O11, Mr = 539.19, Dc = 2.014 g/cm3, μ = 2.471 mm–1, F(000) = 1056, the final R = 0.0350 and wR = 0.0659. In this complex, each metal center adopts a ten-coordination geometry formed by two N atoms from a ligand L and eight O atoms from three H2O molecules, a nitrate ion and carboxylates of two ligands. Each ligand adopts a N2,O3-pentdentate coordination mode using two N and two O atoms chelating a La(III), and using another O atom of carboxylate to bridge another La(III) center resulting in a 1D helical chain molecule. Intermolecular strong O–H···O and weak C–H···O hydrogen bonds extend the 1D chain structure into a 3D supramolecular architecture.  相似文献
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