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101.
[structure: see text] Two podands, 4,4'-[(ethylenedioxy)bis(ethyleneoxy)]bis[1-(2-imidazo[4,5-f]-1,10-phenanthroline)benzene] (1) and [Ru(phen)(2)](2)(1)(PF(6))(4) (2) complex, were synthesized from 1,10-phenanthroline. The photophysical behavior and the binding ability of 1 and 2 with some alkali metal and alkaline earth cations were investigated by UV-vis and fluorescence spectrometry and (1)H NMR experiments as well as fluorescence lifetime measurements. The complex stability constants (K(S)) and Gibbs free energy changes (DeltaG degrees ) for the stoichiometric 1:1 complexation of 1 and 2 with the cations were obtained by the fluorimetric titrations. The podands 1 and 2 exhibit different fluorescent behavior in the cations examined, i.e., fluorescence quenching for 1, and fluorescence enhancement for 2. In particular, 1 showed responses specific for Mg(2+), resulting in readily distinguishable by eye. 相似文献
102.
The hydrothermal reaction of Ni(NO3)2, NaN3, and nicotinic acid (Hnic) yielded a 3-D supramolecular framework complex, [Ni(1.5)(N3)(nic)2(Hnic)]n (1) with unusual magnetic properties. In 1, Hnic and nic-1 coexist and show different coordination modes (mu2-Hnic-N,O, mu2-nic-N,O, and mu3-nic-N,O,O bridging NiII ions), and azide groups adopt mu-1,1 (EO) bridging mode linking NiII ions with an unusual Ni-N-Ni angle. 相似文献
103.
KONG De-Nian XIE Zai-Lai LI Jian-Rong FENG Mei-Ling HUANG Xiao-Ying 《结构化学》2009,28(11):1373-1380
Two lanthanide selenite-carboxylate (LSC) compounds, namely, [Ln8(SeO3)4(2,6- pdc)8(H2O)10]·2H2O (Ln = Pr 1, Sm 2; 2,6-pdcH2 = pyridine-2,6-dicarboxylic acid) have been hydrothermally synthesized and structurally characterized. Both compounds possess two-dimensional layer structures constructed by Ln8(SeO3)4(2,6-pdc)8(H2O)10 clusters connected to each other via bridging carboxylate groups. The structures are further extended into three-dimensional architectures through extensive inter-layer H-bonding between coordinated water molecules and carboxylate groups. The luminescent properties and thermal stability of both compounds have been investigated. 相似文献
104.
正交投影回归法和HLAE用于解析灰色体系 总被引:1,自引:0,他引:1
提出一种基于正交投影的用于判断未知干扰组分的新方法--正交投影回归法(OrthogonalProjection-basedRregression,OPR),可指示出复杂体系中未知干扰组分存在与否及存在区间;在此基础上,应用最近提出的扩展的HLA算法(HLAE),对一维生素混合体系进行了分析,并与HLA和PLS的结果进行了比较.结果表明,OPR是HLAE得以成功应用的前提;不需待测组分的精确光谱,HLAE可得到优于PLS和至少相当于HLA的结果,在纯光谱不够精确的情况下,完全可以用HLAE代替HLA. 相似文献
105.
106.
A mild, efficient, and general method for the synthesis of benzo[f]quinoline derivatives via three-component reaction of arylaldehyde, naphthalen-2-amine, and acetone or acetophenone is described using iodine as catalyst. The features of this procedure are mild reaction conditions, high yields, and operational simplicity. 相似文献
107.
超声电化学制备PbSe纳米枝晶 总被引:11,自引:0,他引:11
近年来,纳米晶态半导体粒子因其具有大的表面体积比、高的活性、特殊的电学性质和独特的光学性质引起了科学界的广泛关注犤1,2犦。基于半导体纳米粒子的量子尺寸效应和表面效应,半导体纳米粒子在发光材料犤3犦、非线性光学材料犤4犦、光敏传感器材料犤5犦、光催化材料犤6犦等方面具有广阔的应用前景。如何实现对半导体纳米粒子的尺寸大小、粒度分布以及形状和表面修饰的控制,寻找更简便的合成方法以及改善制备环境等是半导体纳米粒子研究的关键。超声电化学是结合了电化学和超声辐照而建立起来的一种新方法,它显示了两者的优点犤… 相似文献
108.
The residual symmetries of the famous modified Korteweg-de Vries (mKdV) equation are researched in this paper. The initial problem on the residual symmetry of the mKdV equation is researched. The residual symmetries for the mKdV equation are proved to be nonlocal and the nonlocal residual symmetries are extended to the local Lie point symmetries by means of enlarging the mKdV equations. One-parameter invariant subgroups and the invariant solutions for the extended system are listed. Eight types of similarity solutions and the reduction equations are demonstrated. It is noted that we researched the twofold residual symmetries by means of taking the mKdV equation as an example. Similarity solutions and the reduction equations are demonstrated for the extended mKdV equations related to the twofold residual symmetries. 相似文献
109.
Transparent Ni^2+-Doped MgO-Al2O3-SiO2 Glass Ceramics with Broadband Infrared Luminescence 下载免费PDF全文
We report on transparent Ni^2+-doped MgO-Al2O3-SiO2 glass ceramics with broadband infrared luminescence. Ni^2+-doped MgO-Al2O3-SiO2 glass is prepared by using the conventional method. After heat treatment at high temperature, MgAl2O4 crystallites are precipitated, and their average size is about 4.3 nm. No luminescence is detected in the as-prepared glass sample, while broadband infrared luminescence centred at around 1315 nm with full width at half maximum (FWHM) of about 300 nm is observed from the glass ceramics. The observed infrared emission could be attributed to the ^3T2g(^3F)→^3A2g(^3F) transition of octahedral Ni^2+ ions in the MgAl2O4 crystallites of the transparent glass ceramics. The product of the fluorescence lifetime and the stimulated emission cross section is about 1.6×10^-24 s cm^2. 相似文献
110.
在氧燃烧方式和空气燃烧方式下对Se的氧化物及其与CaO的混合物进行了热重红外实验,通过TG、DTG、DSC以及X射线衍射分析考察了升温速率、气氛和矿物质对重金属Se在燃烧过程中挥发行为的影响。实验结果显示:氧燃烧气氛下se02的挥发率以及释放总量较之空气气氛发生了较大变化,氧燃烧气氛下,Se化合物的释放总量比空气气氛下低;在同一气氛下,钙硒比越大,钙的固硒效果越明显;升温速率对SeO2挥发的影响较小,主要在于加速或推迟其挥发;氧燃烧方式有助于抑制重金属Se的释放。 相似文献