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1.
UV-Vis spectrum and the third-order nonlinear optical properties of the chiral camphor-derived β-diketonate have been studied at the B3LYP/6-31G* level. The results showed that the introduction of electron-drawing group-CF3 and-C3F7 on β-diketonate made the strongest absorption peak red-shift and the lowest energy absorption blue-shied. Introduction of-OC2H5 on the benzene or pyridine ring made the lowest energy absorption blue-shift. When the-C2H3 was introduced on the benzene or pyridine ring, the lowest energy absorption was red-shifted. Introduction of electron-donating group on β-diketonate can enlarge their nonlinear optical properties. On the contrary, the introduction of electron-drawing group dropped it down.  相似文献   
2.
1 INTRODUCTION Hydrothermal synthesis of Mo(V) phosphates has allowed various structures, all characterized by the presence of identical clusters with the composition Mo12MP8X62 (X = O, OH) to be stabilized[1~6]. Many Mo(V) phosphates with such clusters have been iso- lated to date. The first compound was discovered by Haushalter and Lai[1] for M = Na with the formula (PPh4)2[(H3O)2NaMo6P4O24(OH)7]?5H2O. Recently, a second type of structure has been observed for M = Na (Na8(…  相似文献   
3.
The Poincaré-Bertrand formula takes an important position in the study of complex singular integral.The Poincaré-Bertrand formula on the complex sphere in the multidimensional complex Euclidian spaces was given by Sheng Gong.Using the method of solid angular coefficient,the authors extend the Poincaré-Bertrand formula on the complex sphere to the building domain of the complex biballs,and obtain a more general Poincaré-Bertrand formula with the solid angular coefficients.  相似文献   
4.
1 INTRODUCTIONChiralphosphinesareusefulligandsinenantioselectivecatalysiswithtransitionmetalcomplexes〔1〕,someofthemderivedfromsugarsarealsoofpotentialapplicationsinbiphasiccatalysis〔2〕andmedicine〔3〕.Bythenucleophilicreplacementreaction,itisdifficul…  相似文献   
5.
A novel compound of chiral spiro{1-bromo-4-hydroxy-5-N-cyclohexyl-butyro-lactam-6-oxo-dirings3.1.0hexane-2,3′-(4′-diphenylcarbinol-5′-menthyloxy-butyrolatone)} was synthesized via tandem nucleophilic substitution reaction under mild conditions=and its structure was determined by IR =1H NMR=elemental analysis and X-ray diffraction.The crystal structure of this compound is of monoclinic system=space group P21 with a=9.7356(9)=b=12.2760(12)=c=14.9577(14)=β=101.0300(10)°=Mr=680.66=Z=2=V=1754.6(3)3=Dc=1.288 g/cm3=μ(MoKα)=1.216 mm-1=F(000)=716=the final R=0.0434 and wR=0.0996.  相似文献   
6.
A dimeric chromium compound has been synthesized by hydrothermal method and characterized by IR, EPR spectra and TG-DTA technique. The title compound [Cr(aea)]2(OH)2 (aea = N-(2-aminoethyl)aspartate) crystallizes in monoclinic, space group P21/c with a = 8.9393(10), b = 6.7198(7), c = 14.6791(16) A, β = 91.0580(10)°, V= 881.63(17) A3, Z= 2, Mr = 486.34, De= 1.832 g/cm3, F(000) = 500,μ = 1.296 mm-1, R = 0.0271 and wR = 0.0756. Single-crystal X-ray structural analysis indicates that the title compound consists of two Cr(aea) units linked by two bridging hydroxyl groups. The geometry around each chromium center is approximately octahedral and completed by two hydroxyls and a quadridentate ligand which is formed when ethylenediamine reacts with maleic acid.  相似文献   
7.
提出一种新的降维方法, 加权方差估计(WVE), 它包含了切片平均方差估计(SAVE)作为特例. 并且利用Bootstrap方法从WVE中 选择出最优估计, 给出了维数的选择方法. 该最优估计通常远好于已有方法, 比如切片逆回归(SIR)等. 已有的许多方法, 如SIR, SAVE等, 通常对每个 观测给予相同的权来估计中心子空间(CS). 通过引入权函数, WVE根据观测样本距中心子空间的距离, 对不同观测给予不同权重. 权函数使得WVE在很 一般或复杂的情形下有很好的表现, 比如, 回归变量的分布严重偏离椭圆对称分布. 而椭圆对称分布假设是许多方法 的基本假定, 如SIR, SAVE等. 和已有方法相比, WVE对自变量的分布不敏感. 本文建立了WVE的相合 性. 与其他方法的模拟比较表明了WVE的优点.  相似文献   
8.
1 INTRODUCTION Molybdenum(I) compounds, in particular Mo(I)-SR compounds, are rare amongst numerous Mo compounds. So far, only the following compounds [Mo2(CO)8-n(SR)2(CH_3CN)n] (R = C6H5, CH_2CO2Et, n = 0, 2)[1~5] have been reported in the literature. Recently, we make an effort to develop investigations on Mo(I) compounds on the basis of preparing new Mo(I) compounds by introducing different functional ligands into Mo2(SR)2(CO)8, then determining their structures and measur…  相似文献   
9.
1 INTRODUCTION The design synthesis of metal oxide heterpoly compounds have been the subject due to their diverse structures and potential applications in catalysis, sorption, electrical conductivity, ion exchange and anti-virus[1]. Molybdenum phosphates with microporous framework serve as a new kind of inorganic microporous materials. In the course of our investigation on the synthesis of Molybdenum phosphates, we have hydrothermally synthesized an organically templated solid material[…  相似文献   
10.
1 INTRODUCTION A number of hydroxypyrones and hydroxypyridinones are being assessed or considered as orally effective chelators for treatment iron or aluminum overload[1,2]. Almost all present and potential applications involve the tris-ligand complexes of metal(III) cations, as for example in administration of iron(III) complexes for the treatment of anaemia[3], and the appropriate isotopes (e.g. 67Ga, 111In, 90Y) for radiotherapy or the isotopes of gadolinium for magnetic resonance …  相似文献   
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