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1.
镧与甘氨酸和邻菲绕啉三元配合物的合成及光谱表征   总被引:6,自引:0,他引:6  
合成了三元固体配合物La(Gly)3(Phen).3H2O(Gly为甘氨酸,Phen为邻菲绕啉),测定了配体和配合物的红外光谱,拉曼光谱,研究配体与镧配位的主要特征峰的变化,并利用热重-红外光谱联用技术,研究了配合物的稳定性和热分解情况。  相似文献   

2.
铽-甲基吲哚乙酰丙酮三元配合物发光过程研究   总被引:1,自引:0,他引:1  
测定和分析了RE.L1.L2(RE=Tb(Ⅲ)、Gd(Ⅲ),L1=3M(3甲基吲哚-1-乙酰基丙酮),L2=TPPO、Phen、Dipy)三元配合物的荧光光谱、磷光光谱、磷光寿命及变温荧光光谱等.讨论了Tb(Ⅲ)与配体之间的能级匹配和L1与L2的三重态之间传能的问题,说明了影响这些三元配合物荧光效率的主要因素及其发光过程.  相似文献   

3.
用红外光谱研究阴离子对镧甘氨酸配合物结构的影响   总被引:3,自引:1,他引:2  
本文合成了阴离子为氯离子和高氯酸根的镧的甘氨酸配合物La(Gly)3(ClO4)3·H2O和La(Gly)3Cl3·3H2O,测定了配合物的红外光谱,并作了比较研究。结果表明:配合物因阴离子的不同而形成二种不同的结构,二者都为一维长链结构,但甘氨酸的配位方式不同;在La(Gly)3Cl3·3H2O中,有两分子水参与了配位,而La(Gly)3(ClO4)3H2O中则有一分子的高氯酸根参与了配位。  相似文献   

4.
在无水乙醇溶液中分别合成了Eu^2+离子、Tb^3+离子与2,2‘-联吡啶、1,10-邻菲罗啉押种配合物,研究了配合物的荧光性质,由于Phen含有较大范围的共轭π键和较好的刚性平面,含Phen配合物的荧光强度均要比配合物的强;配合物的高分辨荧光光谱表明,Eu^3+离子在Eu(Dipy)2Cl3’2H2O和Eu(Phen)2Cl3.2H2O配合物中处于C1或C2或C5的对称性位置。  相似文献   

5.
合成了双水杨醛缩乙二胺席夫碱(SALEN)与镍的配合物Ni3(SALEN)2(NO3)6·H2O及镧系镍的异核配合物Ln2Ni3(SALEN)6(NO3)12·H2O(Ln=La,Nd,Sm,Gd,Yb,Y).以紫外、红外光谱、磁化率,特别是1HNMR及EPR波谱等方法研究了它们在组成、结构和配位等方面的异同.GdNiSALEN配合物的EPR谱表明其在低温THF中呈“单峰效应”.文中讨论了配合物在不同溶剂中峰宽的相对关系、配合物晶体场强度及Gd3+周围局部对称性问题  相似文献   

6.
镧和铕与邻菲罗啉谷氨酸配合物的NMR和IR研究   总被引:1,自引:0,他引:1  
合成了稀土镧和铕与谷氨酸,邻菲罗啉形成的二元及三元配合物,经元素分析确定该配合物的组成为Ln(phen)(Glu)3.7H2O(Ln=La,Eu);Eu(Glu)3;12H2O。用核磁共振和红外光谱研究与配体与稀土离子的配位方式,讨论了稀土离子的顺磁性及屏蔽效应对配合物的NMR谱图的影响。  相似文献   

7.
Nd(Pro)3(Phen)Cl3·2H2O三元固体配合物的FTIR光谱和Raman光谱   总被引:2,自引:0,他引:2  
合成了Nd(Pro)3(Phen)Cl3.2H2O三元固体配合物,测定了配合物的 红外光谱和Raman光谱,对配合物分子的振动频率作了归属。光谱数据表明,钕(Nd )屯脯食氨酸(Pro)的羧酸基形成四员螯环,与邻啡罗啉(Phen)的C=N基形成五员螯环。  相似文献   

8.
在水溶液中制备出配合物[Ln(Gly)2.4H2O].Cl3.nH2O(Ln=G,Er,Yb),测定了配合物的红外光谱,并对其主要红外吸收带进行了归属。结果表明,甘氨酸以内盐的形式存在于配合物中,并通过羧基与稀土离子配位。四个水分子参与了配位,在Gd和Er的配合物还有一个不分子未参与配位。推测Yb配合物为对称的一维无限长链结构,其余两种配合物为不对称的一维无限长链。  相似文献   

9.
报道了稀上铕(Eu3+)与吡啶-2,6-二甲酸(H2DPC)及邻啡啉(Phen)形成的二元和三元固体配合物的制备.对它们进行了元素分析,确定该配合物的组成为二元Na3[Eu(DPC)3]2H2O和三元NaEu(DPC)2·4H2O,对上述配合物的结构作了核磁共振氢谱(1HNMR)、碳谱(13CNMR)和氮谱(14NNMR)及红外光谱(IR)的研究.吡啶-2,6-二甲酸中的羧基以单齿配位(整个分子为三齿配位).二、三元配合物中铕的配位数分别为9和8.  相似文献   

10.
硝酸稀土组氨酸配合物的拉曼光谱   总被引:1,自引:0,他引:1  
研究了组成为RE(His)(NO3)3·H2O(RE=La~Nd,Sm~Lu,Y;His=L~a-histidine)固态配合物的拉曼光谱。结果表明,配合物中RE^3+与羧基氧原子配位,氨基和味唑环均未参与配位,NO3^-为双齿配位。配合物羧基振动峰的ΔυCOO^as-s-与镧系离子的原子序数作图服从Oddo-Harkins规律。  相似文献   

11.
We solve several problems that involve imposing metrics on surfaces. The problem of a strip with a linear metric gradient is formulated in terms of a Lagrangian similar to those used for spin systems. We are able to show that the low energy state of long strips is a twisted helical state like a telephone cord. We then extend the techniques used in this solution to two–dimensional sheets with more general metrics. We find evolution equations and show that when they are not singular, a surface is determined by knowledge of its metric, and the shape of the surface along one line. Finally, we provide numerical evidence by minimizing a suitable energy functional that once these evolution equations become singular, either the surface is not differentiable, or else the metric deviates from the target metric.  相似文献   

12.
The relation for the dependence of the rate of radiationless energy conversion of the S 1 state k q on the polarity of the medium, obtained previously by the author, has been used to interpret the known literature data on the lifetime of the S 1 state of solutions of some caratenoids and phthalimides. It has been shown that in alcohols and water (normal and deuterated ones) the fluorescence quenching of 4-amino-, 4-methylamino-, and 4-dimethylamino-N-methylphthalimides (4AMP, 4MAMP, and 4DMAMP) as well as of peridinine in alcohols is due to H-bond formation. It has been established that a twofold increase in the number of amine atoms of hydrogen on passing from 4MAMP to 4AMP, as well as deuteration of solvents in the case of 4DMAMP, is followed by a decrease in k q by a factor of 1.6 and 1.75, respectively. The mechanism of quenching in complexes formed with solvent molecules by means of the H-bond is discussed. It has been concluded that the quenching of fluorescence of phthalimides in such complexes is mainly due to the intersystem crossing initiated by the oscillations of the protons or deuterons of the H-bonds.  相似文献   

13.
我们测定了两种单链核糖体失活蛋白(肥皂草素和天花粉蛋白)的FTIR和FTRaman光谱。利用FTIR光谱酰胺Ⅲ区域对蛋白质的二级结构进行定量分析,计算了各种二级结构的含量。从肥皂草素和天花粉蛋白的二级结构分析可见,二者在结构上具有某种相似性,为二者功能上的相似性提供了依据。  相似文献   

14.
Abstract

Infrared spectra of the products of one- and two -step reduction of both benzil and benzil-180 have been investigated in dimethylsulfoxide-d6 and tetrahydrofurane solutions. Anion-radicals have been obtained by electrochemical reduction of benzil and benzil-180; dinegative ions have been prepared by reduction of the same ketones with potassium mirror in vacuo. The band assignment has been performed using the group vibrational concept and isotopic shift data. The previous assignment of the C[dbnd]O stretching band of benzil anion-radical-has been discussed and corrected. Two bands in the infrared spectra of benzil dianion have been found to be sensitive upon 180 isotope labelling. This result certifies the presence of cis-configuration of benzil dianion in the investigated solutions. A decrease of ca. 290 cm-1 has been found for vC[dbnd]O after the transformation of the neutral benzil into an anion-radical. Conversion of benzil anion-radical into dianion has been accompanied by an additional vC[dbnd]O downward shift of 105 cm?1  相似文献   

15.
The high-pressure and high-temperature behaviors of LiF and NaF have been studied up to 37 GPa and 1000 K. No phase transformations have been observed for LiF up to the maximum pressure reached. The B1 to B2 transition of NaF at room temperature was observed at ~28 GPa, this transition pressure decreases with temperature. Unit-cell volumes of LiF and NaF B1 phase measured at various pressures and temperatures were fitted using a P–V–T Birch–Murnaghan equation of state. For LiF, the determined parameters are: α0 = 1.05 (3)×10?4 K?1, dK/dT = ?0.025 (2) GPa/K, V 0 = 65.7 (1) Å3, K 0 = 73 (2) GPa, and K′ = 3.9 (2). For NaF, α0 = 1.34 (4)×10?4 K?1, dK/dT = ?0.020 (1) GPa/K, V 0 = 100.2 (2) Å3, K 0 = 46 (1) GPa, and K′ = 4.5 (1).  相似文献   

16.
受控核聚变两大途径的对比与结合   总被引:6,自引:0,他引:6  
谭宝林 《物理》2002,31(3):159-161
目前人们探索受控核聚变主要是从两个方向着手:磁约束受控核聚变和惯性约束受控核聚变,但目前还无法判定到底哪一种途径更为可取,文章首先对这两种途径进行对比,指出各自的特点和困难,在此基础上提出了一种结构相对简单,成本相对较低的三轴六极磁镜系统设想,希望能将磁约束和惯性约束和惯性约束结合起来,以实现受控核聚变反应。  相似文献   

17.
潘峰  戴连荣 《物理学进展》2004,24(2):216-258
本文总结了计算黑克、布劳、及伯曼 温采尔代数在各种工数链下诱导及分导系数的线性方程方法(LEM)。特别强调了关于A,B,C,D型李代数及其量子情形与其中心代数之间的舒尔 魏尔 布劳双关性关系。这一关系使我们能够利用相应中心代数的诱导及分导系数计算出经典李代数及其量子情形的耦合与重新耦合系数。讨论了从该方法得到B,C,D型李代数不可约表示克罗内克积分解的应用。基于LEM还得到了处理对应于置换群CG系列问题的黑克代数张量积的方法。  相似文献   

18.
Motivated by interest in the geometry of high intensity events of turbulent flows, we examine the spatial correlation functions of sets where turbulent events are particularly intense. These sets are defined using indicator functions on excursion and iso-value sets. Their geometric scaling properties are analysed by examining possible power-law decay of their radial correlation function. We apply the analysis to enstrophy, dissipation and velocity gradient invariants Q and R and their joint spatial distributions, using data from a direct numerical simulation of isotropic turbulence at Reλ ≈ 430. While no fractal scaling is found in the inertial range using box-counting in the finite Reynolds number flow considered here, power-law scaling in the inertial range is found in the radial correlation functions. Thus, a geometric characterisation in terms of these sets’ correlation dimension is possible. Strong dependence on the enstrophy and dissipation threshold is found, consistent with multifractal behaviour. Nevertheless, the lack of scaling of the box-counting analysis precludes direct quantitative comparisons with earlier work based on multifractal formalism. Surprising trends, such as a lower correlation dimension for strong dissipation events compared to strong enstrophy events, are observed and interpreted in terms of spatial coherence of vortices in the flow.  相似文献   

19.
本文阐述了等色染料离子对形成的实验方法,等色染料离子对的缔全机理及其形式,用吸收光谱的能级图,从电子理论角度论述了等色染料离子对的缔合效应等色化,溶剂效应等以化机理。列表示出等色染料离子对的高灵敏度,从而证明了等色染料离子对的萃取光度,浮选光度及萃取荧光光度法是高灵敏度和超灵敏度的新体系,为金属痕量和超痕量分析开辟了更为宽广的前景。  相似文献   

20.
The kinetics and mechanism of the nucleophilic vinylic substitution of dialkyl (alkoxymethylidene)malonates (alkyl: methyl, ethyl) and (ethoxymethylidene)malononitrile with substituted hydrazines and anilines R1–NH2 (R1: (CH3)2N, CH3NH, NH2, C6H5NH, CH3CONH, 4‐CH3C6H4SO2NH, 3‐ and 4‐X‐C6H4; X: H, 4‐Br, 4‐CH3, 4‐CH3O, 3‐Cl) were studied at 25 °C in methanol. It was found that the reactions with all hydrazines (the only exception was the reaction of (ethoxymethylidene)malononitrile with N,N‐dimethylhydrazine) showed overall second‐order kinetics and kobs were linearly dependent on the hydrazine concentration which is consistent with the rate‐limiting attack of the hydrazine on the double bond of the substrate. Corresponding Brønsted plots are linear (without deviating N‐methyl and N,N‐dimethylhydrazine), and their slopes (βNuc) gradually increase from 0.59 to 0.71 which reflects gradually increasing order of the C–N bond formed in the transition state. The deviation of both methylated hydrazines is probably caused by the different site of nucleophilicity/basicity in these compounds (tertiary/secondary vs. primary nitrogen). A somewhat different situation was observed with the anilines (and once with N,N‐dimethylhydrazine) where parabolic dependences of the kinetics gradually changing to linear dependences as the concentration of nucleophile/base increases. The second‐order term in the nucleophile indicates the presence of a steady‐state intermediate ‐ most probably T±. Brønsted and Hammett plots gave βNuc = 1.08 and ρ = ?3.7 which is consistent with a late transition state whose structure resembles T±. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

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