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11.
用希夫碱钴(Ⅱ)和铜(Ⅱ)配合物作为模型化合物,系统地研究了轴向配体的碱性对模型化合物ESR参数的影响。实验发现,钴(Ⅱ)配合物的│A│张量随轴向配体碱性的增加而减小,而铜(Ⅱ)配合物的│A│张量正好相反。用π反馈作用解释了这一现象。  相似文献   
12.
李宝龙  龚景海 《力学季刊》2013,34(2):246-255
确定细胞骨架的结构和力学特性,建立和完善细胞骨架力学模型,是研究细胞在外界机械刺激下的复杂力学响应的关键。本文基于柔性结构设计中的找形分析,提出了一种新型的细胞骨架力学模型——找形模型。找形模型依靠随机理论生成模型中的单元,利用找形分析确定细胞模型的最终形状,模型更加接近真实的细胞骨架结构。与经典的细胞骨架力学模型(如泡沫模型、张力整合模型、索网模型等)相比,找形模型反映了细胞骨架结构的多样性和复杂性,符合细胞处于预应力状态的试验观测;找形模型计算出的细胞弹性模量为103Pa数量级,与大多数的细胞试验结果相符;另外,找形模型还可以分析细胞骨架组成成分的含量、几何尺寸和力学属性对细胞刚度的影响。  相似文献   
13.
1 INTRODUCTION The extraction chemistry of uranium is a veryimportant research field, and the new high extrac-tants of uranium have being studied for several deca-des[1, . Our interest is studying the behaviors of new 2]extractants and their st…  相似文献   
14.
The novel complex {[Co(bipy)(azpy)2(NCS)2]·H2O}n (where bipy=4,4′-bipyridine, azpy=4,4′-azobisp- yridine) has been synthesized and characterized by elemental analyses, IR, UV, thermal analyses, and vari-able-temperature magnetic susceptibility. The crystal (C32H26CoN12OS2, Mr=717.70) belongs to the orthorhombic, space group Pnna, a=2.21312(16)nm, b=1.40403(10)nm, c=1.14237(8)nm, V=3.5497(4)nm3, Z=4, Dc=1.343g·cm-3, μ=0.645mm-1, F(000)=1476, and final R1=0.0691, wR2=0.1129 for 231 parameters and 1674 observed reflections [I >2.00σ(I)]. The Co(Ⅱ) atom is, in a distorted octahedral geometry, coordi-nated by six nitrogen atoms from two bridging bipy, two monodentate azpy, and two thiocyanate groups. The bridging ligand bipy links Co(Ⅱ) atoms to form the infinite “rod" with terminal coordination azpy ligand acting as sidearms. Unprecedented three parallel interpenetrating two-dimensional (4,4) networks and novel infinite triple helices are formed via hydrogen-bonding interactions. CCDC: 155588.  相似文献   
15.
The extraction behavior of N,N′-diethyl-N,N′-dibenzenyl-urea (DEDBU) to Uranium(Ⅵ) and Thorium(Ⅳ) from nitric acid solution was studied by using xylene as diluent. The effects of aqueous HNO3 concentration and ex-tractant concentration on the extraction distribution ratio of U(Ⅵ) and Th(Ⅳ) were studied, and the results show that the extraction behavior of the extractant to U(Ⅵ) is similar to tributyl phosphate (TBP), the solvation numbers for DEDBU and TBP are two, respectively. Under the experiment condition, the extractant does not show the extraction behavior to Th(Ⅳ), this result exhibits that the extractant has good application to separate U(Ⅵ) and Th(Ⅳ). The crystal structure of the complex UO2(NO3)2[CH2(CH2)2CONC8H17]2 was determined by single crystal X-ray diffraction. Crystal data: C24H46N4O10U, triclinic, space group , a = 8.662(2)?, b= 10.07(2)?, c= 10.895(3)?, α = 103.77(2)°, β = 92.01(2)°, γ = 96.23(2)°, V= 915.7(4)?3, Mr = 934.78, Z= 1, Dc= 1.695 g·cm-3, F(000) = 462, μ = 4.495mm-1, R= 0.0250, wR= 0.0591, observed reflec-tions 3566 (I>2σ(I)).The central uranyl ions is coordinated by six oxygen atoms, two of them are from the carbonyl groups of N,N′-diethyl-N,N′-dibenzenyl-urea molecules, and the other four are from two nitrate groups.  相似文献   
16.
In the presence of NH4PF6, reaction of [PPh4][(η5-C5Me5)WS3Cu3Br(dppm)] with excess pyridine afforded red prismatic crystals, [(η5-C5Me5)WS3Cu3Br(Py)3(dppm)](PF6) (1). It was characterized by elemental analy-sis, IR, UV-vis and 1H NMR spectroscopy and X-ray diffraction. 1 crystallizes in an orthorhombic system with space group Pna21 and unit cell parameters a=2.1124(4)nm, b=1.8944(4)nm, c=1.3338(2)nm, V=5.3375(19)nm3Z=4, Dc=1.807g·cm-3Mr=1452.42, F(000)=2864, μ=4.342mm-1R1=0.0487, wR2=0.1027. The structure of the cluster cation contains an incomplete cubane-like WS3Cu3 core where Cu(1) and Cu(2) atoms are bridged by a dppm ligand. Each of the three Cu atoms adopts a distorted tetrahedral coordi-nation geometry. The W-Cu(1), W-Cu(2) and W-Cu(3) distances are 0.27698(17)nm, 0.2772(17)nm, and 0.27065(9)nm, respectively. CCDC: 199845.  相似文献   
17.
The thermal behaviors of the complexes of Cu(DMTZB)4X2 (DMTZB=3,3‘-dimethyl-1-(1H-1,2,4-triazol-1-yl)-2-butanone, X=NO3 or ClO4) and Cu(DMTZB)2 X2 (X=Br or Cl) in a nitrogen atmosphere were studied under the non-isothermal conditions by simultaneous TG-DTG-DSC, EDS and elemental analysis techniques. The resuits showed that their decomposition proceeded in three different ways mainly depending on the anions in the molecules. The heat effect associated with the decomposition step of DMTZB molecules was also different. The decomposition mechanisms and the kinetic parameters of DMTZB were determined and calculated by jointly using four methods, which showed that its pyrolysis was controlled by D3 mechanism but with different activation energies and pre-exponential factors for different complexes.  相似文献   
18.
1INTRODUCTION The macrocyclic compounds play an important ro-le in life science and materials science[1].In recent years,teta has gained extensive attention as a raw material of crystal engineering,and its coordination behavior with metallic ion has been …  相似文献   
19.
用热重法(TG)研究了4种苯甲酰丙酮合铜和1,1,1-三氟-3-(2-噻吩基)丙酮合铜的偶氮二吡啶一维长链聚合配位化合物在动态氮气气氛下的热行为,结合元素分析和能谱技术,确定了各步分解的组分,并讨论了其晶体结构与热性质的关系。应用新的非线性等转化率法,并结合其他方法考察了各步分解反应的属性,进行了动力学分析,并试对传统动力学方法的适用性进行了讨论。  相似文献   
20.
1苯-基-3甲-基-4苯-甲酰基-吡唑啉酮-5(HPMBP)是一类含有氮杂环的β-二酮螯合剂,现在已经广泛应用于金属离子的分离和分析[1-4]。它与许多金属离子生成的配合物的生物活性明显增强,显示了广谱的抗菌、抗病毒和抗肿瘤等性质,引起了化学家对它与金属离子的配位作用以及配合物的晶  相似文献   
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