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971.
三氯化一缬氨酸六水合稀土固体配合物的合成及红外光谱   总被引:6,自引:0,他引:6  
在水溶液中合成了Ln(Val)·Cl_3·6H_2O(Ln=La,Nd,Sm,Gd,Er).利用元素分析和容量滴定法确定了其组成。测定了配合物的红外光谱,对其主要红外吸收带进行了归属。红外光谱结果表明,缬氨酸以内盐的形式存在于配合物中,并通过羟基与稀土离子配位,6个水分子亦参与了配泣,推测La和Nd配合物具有一维无限长锭结构,而Sm、Gd和Er配合物为双核配合物.  相似文献   
972.
A new 1,3,4-oxadiazole-contanining rhenium(I) complex,with the formula [Re(CO)_3(Bphen)(PTOP)],(Bphen=bathophe- nardine,PTOP=4-(5-p-tolyl-1,3,4-oxadiazd-2-yl)pyridine),is synthesized and characterized by elemental analysis,IR,~1H NMR, UV-vis and luminescence spectroscopy.The double-layer electroluminescence devices based on the Re(I) complex have been fabricated by spin-coating technique.The turn-on voltage,maximum efficiency,and brightness for green emission obtained from the devices are 9V,2.1cd/A and 165cd/m~2,respectively.  相似文献   
973.
In this article, we make a connection between the Rumer transformation, used in the study of the genetic code‐doublets, and the negation of classic logic. A unified classification is given, relying on two Klein's 4‐groups describing the symmetries of the 16 doublets of nitrogenous bases and those of the 16 binary connectives of classic logic, both groups being subgroups of a larger noncommutative group with eight elements we identify as the dihedral group D4. Also, some connections with other works are briefly considered. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2003  相似文献   
974.
席夫碱自组装单分子膜的电化学行为   总被引:6,自引:0,他引:6  
利用自组装技术将席夫碱硫醇衍生物在金表面形成自组装单分子膜,并初步研究了此自组装单分子膜的电化学行为,发现该席夫碱分子在0.1 mol•L-1的KCl溶液中具有电化学不可逆氧化还原行为,且随着自组装时间的增加表观电极反应速率常数值显著减小,最后减小为0,并对此进行了解释.  相似文献   
975.
Novel diiron complexes with an Fe2(mu-OMe)2 core were studied as models of the active site of nonheme iron-containing enzymes. X-ray crystal structures of the complexes showed the existence of two types of ligand folding-parallel and twisted-both of which have four virtually equivalent phenolato groups sticking out from the Fe2O2 rhombic plane. Cyclic voltammetry measurements revealed two or more distinct redox waves in a region of relatively high potential, in addition to known Fe(II)/Fe(III) redox waves in a region of lower potential. These new peaks were assigned to the high-valence state of iron atoms, that is, Fe(III)Fe(IV) and Fe(IV)Fe(IV), resonating with the phenoxyl radical(s). The split width of the redox waves ranged from 0.14 to 0.20 eV, which may be a measure of the electronic interaction of the phenolate groups through the Fe2(mu-OMe)2 core.  相似文献   
976.
双金属氰化物配合物的制备、表征及催化性能   总被引:7,自引:0,他引:7  
 制备了基于钴氰化锌的双金属氰化物配合物(DMC)催化剂,并\r\n用元素分析、X射线衍射和红外光谱等手段进行了表征,考察了催化剂\r\n的结构与组成对其催化活性的影响以及该催化体系催化环氧烷烃开环聚\r\n合的特点.结果表明,含ZnCl2和叔丁醇的非晶态DMC催化剂具有最高的\r\n催化活性.该催化体系使聚合物的分子量可控,不饱和度很低(<14μ\r\neq/g),逐步聚合所得到的聚合物的分子量分布较窄(Mn/Mw<1.4\r\n8).13CNMR分析结果表明,甲基氧丙环均聚物的链结构具有无规立构\r\n的特点,且链节分布几乎都为头-尾方式.IR分析结果表明,甲基氧丙\r\n环-环氧乙烷共聚物的链结构是无规分布的.  相似文献   
977.
The stoichiometry of thermal decomposition and enthalpy and structural changes were studied for the compounds formed by penetration of [Ni(4-Etpy)4(NCS)2] (I) into Ca-montmorillonite (II) or Cr-, Zr- and Al-pillared analogues (III, IV and V, respectively). The mass fractions of complex I in II, III, IV or V are different. It was found for all studied compounds that the release of L (L=4-Etpy) is a three-step process (-2L, -1L, -1L), and differences occurred in enthalpy changes (δH in kJ per mole of I) corresponding to the individual processes. These differences and the changes in diffraction and spectral properties of the species formed after intercalation are assumed to have their roots in different intramolecular guest-host interactions in the studied compounds. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   
978.
The equilibrium constants and molar absorptivities for the fast formation of a 1:3 complex between cadmium(II) (Cd(II)) and dithizonate anion, in the presence of cationic and non-ionic surfactants, allowed a simple and fast spectrophotometric determination of total cadmium. Indeed, the molar absorptivities of the Cd(II)-dithizone (Dz) complex formed in the presence of the neutral Triton X-100 and cationic cetyltrimethylammonium bromide (CTAB) surfactants are almost twice the value observed in the standard method and the maxima of absorption are shifted by about 40 nm when compared with the standard method. Clearly, the use of neutral and cationic surfactants promotes a higher value of the molar absorptivities of the complex, resulting in an increase in the sensitivity of the method. Application of the method to the desorption of Cd(II) ions from clays is illustrated.  相似文献   
979.
梅崇珍  陶偌偈  王庆伦 《化学学报》2007,65(12):1129-1134
合成了一种新的不对称双Schiff碱Cu(II)单核配合物Cu(HLt) (1) (H3Lt为N-3-羧基水杨醛-N'-水杨醛-缩1,3-丙二胺)及其两个异三核配合物[(CuLt)2Ni]•2.5H2O (2)和[(CuLt)2Mn]•5H2O (3), 并用元素分析、红外光谱、电子光谱对它们进行了结构表征. 用X射线单晶衍射法测定了配合物3的晶体结构, 其晶胞中每个不对称单元包含一个异三核中性分子, 在此三核分子中, 中心Mn2+离子位于[O6]的变形八面体配位环境中, 两个端基Cu2+离子位于[N2O2]的平面正方场中. 在5~300 K范围内测定了两个三核配合物的变温磁化率, 经拟合得化合物2的磁交换参数为-57.7 cm-1, 化合物3的磁交换参数为-28.5 cm-1, 表明在两个异三核配合物中, 中心M2+离子与外部Cu2+离子间存在弱的反铁磁自旋交换作用.  相似文献   
980.
Peaks in collision cross sections are often interpreted as resonances. The complex dilation method, as well as other methods relying on analytic continuation of the scattering formalism, can be used to clarify whether these structures are true resonances in the sense that they are poles of the S‐matrix and the associated Green function. The performance of the Mittag–Leffler expansion and T‐matrix Green function expansion methods are formally and computationally compared. The two methods are applied to two model potentials. Eigenenergies, s‐wave residues, and cross sections are computed with both methods. The resonance contributions to the cross sections are further analyzed by removing the residue contributions from the Mittag–Leffler and Green function expansion sums, respectively. It is suggested that the contribution of a resonance to a cross section should be defined through its S‐matrix residue. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2007  相似文献   
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