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61.
合成了一种含吡唑啉酮的三脚架结构化合物 1,1,1 三 { 1′ [2′ 氧杂 5′ 氧代 5′ ( 1″ 苯基 3″ 甲基吡唑啉酮 4″ 基 )戊基 ] }丙烷 (H3 L)及其 7个稀土配合物。通过元素分析、摩尔电导、质谱、红外光谱、核磁共振谱、荧光光谱等对H3 L及其稀土配合物的组成及性质进行了表征。分析结果表明 :H3 L的分子式为C45H50 N6O9,配合物的组成比为REL·0 5H2 O (RE =La ,Sm ,Eu ,Gd ,Tb ,Dy ,Yb) ;该三脚架形配体分别以醚氧、烯醇氧及吡唑酮环上的羰基氧与稀土离子进行配位 ,形成内配型配合物。荧光光谱分析表明SmL·0 5H2 O ,EuL·0 5H2 O ,TbL·0 5H2 O ,DyL·0 5H2 O配合物具有三价稀土离子的特征线状荧光 ,其中TbL·0 5H2 O的荧光强度最强 ,表明T(配体 )→5D4(Tb)能级更为匹配 ,从而进行分子内能量有效传递 ;由EuL·0 5H2 O的荧光光谱图形推测 ,Eu3 +离子在该配合物中处于非对称中心 相似文献
62.
Changlun Chen Di Xu Xiaoli Tan Xiangke Wang 《Journal of Radioanalytical and Nuclear Chemistry》2007,273(1):227-233
The fate and transport of toxic metal ions and radionuclides in the environment is generally controlled by sorption reactions.
The extent of sorption of divalent metal cations is controlled by a number of factors including cosorbing or complexing. In
this work, the effects of pH, humic acid HA/Co(II) addition orders, ionic strength, concentration of HA, and foreign cations
on the Co(II) sorption on γ-Al2O3 in the presence of HA were investigated. The sorption isotherms of Co(II) on γ-Al2O3 in the absence and presence HA were also studied and described by using S-type sorption model. The experimental results showed
that the Co(II) sorption is strongly dependent on the pH values, concentration of HA, but independent of HA/Co(II) addition
orders, ionic strength, and foreign cations in the presence of HA under our experimental conditions. The results also indicated
that HA enhanced the Co(II) sorption at low pH, but reduced the Co(II) sorption at high pH. It was hypothesized that the significantly
positive influence of HA at low pH on the Co(II) sorption on γ-Al2O3 was attributed to strong surface binding of HA on γ-Al2O3 and subsequently the formation of ternary surface complexes such as ≡S-OOC-R-(COO−)
x
Co2−x
. Chemi-complexation may be the main mechanism of the Co(II) sorption on γ-Al2O3 in the presence of HA. 相似文献
63.
The reaction of Mn(2)(CO)(7)(mu-S2) (1) with [CpMo(CO)(3)](2) (Cp = C(5)H(5)) and [Cp*Mo(CO)(3)](2) (Cp* = C(5)(CH(3))(5)) yielded the new mixed-metal disulfide complexes CpMoMn(CO)(5)(mu-S2) (2) and Cp*MoMn(CO)(5)(mu-S2) (3) by a metal-metal exchange reaction. Compounds 2 and 3 both contain a bridging disulfido ligand lying perpendicular to the Mo-Mn bond. The bond distances are Mo-Mn = 2.8421(10) and 2.8914(5) A and S-S = 2.042(2) and 1.9973(10) A for 2 and 3, respectively. A tetranuclear metal side product CpMoMn(3)(CO)(13)(mu3-S)(mu4-S) (4) was also isolated from the reaction of 1 with [CpMo(CO)(3)](2). Compounds 2 and 3 react with CO to yield the dithiocarbonato complexes CpMoMn(CO)(5)[mu-SC(=O)S] (5) and Cp*MoMn(CO)(5)[mu-SC(=O)S] (6) by insertion of CO into the S-S bond. Similarly, tert-butylisocyanide was inserted into the S-S bond of 2 and 3 to yield the complexes CpMoMn(CO)(5)[mu-S(C=NBu(t))S] (7) and Cp*MoMn(CO)(5)[mu-S(C=NBu(t))S] (8), respectively. Ethylene and dimethylacetylene dicarboxylate also inserted into the S-S bond of 2 and 3 at room temperature to yield the ethanedithiolato ligand bridged complexes CpMoMn(CO)(5)(mu-SCH(2)CH(2)S) (9), Cp*MoMn(CO)(5)(mu-SCH(2)CH(2)S) (10), CpMoMn(CO)(5)[mu-SC(CO(2)Me)=C(CO(2)Me)S] (11), and Cp*MoMn(CO)(5)[mu-SC(CO(2)Me)=C(CO(2)Me)S] (12). Allene was found to insert into the S-S bond of 2 by using one of its two double bonds to yield the complex CpMoMn(CO)(5)[mu-SCH(2)C(=CH(2))S] (13). The molecular structures of the new complexes 2-7 and 9-13 were established by single-crystal X-ray diffraction analyses. 相似文献
64.
本文研究带有五次项的非线性Schrödinger方程初边值问题的有限差分法,其中方程中二阶偏导数项的系数、五次项的系数及初值满足下面的条件(1.6).针对此问题,我们研究了一个守恒差分格式,在条件(1.6)下,差分解的$L^{\infty}$模先验估计被得到.在此基础上,我们得到了差分解最优$L^2$模的误差估计. 相似文献
65.
Journal of Optimization Theory and Applications - This paper proposes a multi-scale method to design a continuous-time distributed algorithm for constrained convex optimization problems by using... 相似文献
66.
67.
Edwards KW Ogg M Bellerive A Britton DI Hyatt ER MacFarlane DB Patel PM Spaan B Sadoff AJ Ammar R Baringer P Bean A Besson D Coppage D Copty N Davis R Hancock N Kelly M Kotov S Kravchenko I Kwak N Lam H Kubota Y Lattery M Momayezi M Nelson JK Patton S Poling R Savinov V Schrenk S Wang R Alam MS Kim IJ Ling Z Mahmood AH O'Neill JJ Severini H Sun CR Wappler F Crawford G Daubenmier CM Fulton R Fujino D Gan KK Honscheid K Kagan H Kass R Lee J Sung M White C Wolf A Zoeller MM Butler F Fu X Nemati B 《Physical review letters》1995,74(17):3331-3335
68.
Kubota Y Lattery M Nelson JK Patton S Perticone D Poling R Savinov V Schrenk S Wang R Alam MS Kim IJ Nemati B O'Neill JJ Severini H Sun CR Zoeller MM Crawford G Daubenmier CM Fulton R Fujino D Gan KK Honscheid K Kagan H Kass R Lee J Malchow R Morrow F Skovpen Y Sung M White C Butler F Fu X Kalbfleisch G Ross WR Skubic P Snow J Wang PL Wood M Brown DN Fast J McIlwain RL Miao T Miller DH Modesitt M Payne D Shibata EI Shipsey IP Wang PN Battle M Ernst J Kwon Y Roberts S Thorndike EH Wang CH 《Physical review letters》1994,72(13):1972-1976
69.
Ammar R Ball S Baringer P Bean A Besson D Coppage D Copty N Davis R Hancock N Kelly M Kwak N Lam H Kubota Y Lattery M Nelson JK Patton S Perticone D Poling R Savinov V Schrenk S Wang R Alam MS Kim IJ Nemati B O'Neill JJ Severini H Sun CR Zoeller MM Crawford G Daubenmier CM Fulton R Fujino D Gan KK Honscheid K Kagan H Kass R Lee J Malchow R Morrow F Skovpen Y Sung M White C Butler F Fu X Kalbfleisch G Ross WR Skubic P Snow J Wang PL Wood M Brown DN Fast J McIlwain RL Miao T Miller DH Modesitt M 《Physical review D: Particles and fields》1994,49(11):5701-5704
70.