Grafting of precoordinated Cu(2+)-N-(2-aminoethyl)aminopropylsilane complexes onto mesoporous silicas and the adsorption of aqueous selenate on them.
Grafting of precoordinated Cu(2+)-N-(2-aminoethyl)aminopropylsilane complexes onto mesoporous silicas and the adsorption of aqueous selenate on them.
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将预配位的 Cu(2)-N-(2-氨基乙基)氨基丙基硅烷配合物接枝到介孔二氧化硅上并在其上吸附含水硒酸盐。
DOI：
10.1021/la401823k
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发表时间：
2013
期刊：
影响因子：
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通讯作者：
Ryo Otsuka
中科院分区：
文献类型：
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作者：
H. Yoshitake;Ryo Otsuka
N-（2-氨乙基）氨丙基硅烷（AeAptes）与Cu（2+）以1：1和1：2的Cu：AeAptes比率配位。然后将它们接枝到MCM-41 [产物分别表示为Cu（en）-MCM-41和Cu（en）2-MCM-41]和SBA-15 [产物分别表示为Cu（en）-SBA-15和Cu（en）2-SBA-15]上。这些介孔二氧化硅框架的周期性结构在接枝后得到很好的保留。利用紫外可见光谱和电子顺磁共振光谱分析了Cu（2+）的配位结构，揭示了Cu（2+）与硅烷的比例所预期的结构。我们还通过相同的程序使用Cab-O-sil M7 D二氧化硅制备了Cu（en）-和Cu（en）2-M7 D。Cu（en）2-M7 D和Cu（en）-M7 D的d-d跃迁带位置、g张量和超精细耦合常数与接枝到介孔SiO2上的配合物没有显著差异。其结构参数与Cu（en）-MCM-41和Cu（en）-SBA-15的结构参数基本相同，表明接枝到M7 D上导致了Cu（2+）（AeAptes）2配位结构的转变。利用Langmuir方程分析了硒酸根在吸附剂上的吸附行为。Cu（en）-和Cu（en）2-介孔氧化硅的吸附容量分别为Se/Cu = 0.5和1.0，而Cu（en）2-介孔氧化硅的Langmuir系数是Cu（en）-介孔氧化硅的2倍以上。而Cu（en）-和Cu（en）2-M7 D之间的这两个参数没有显著差异;饱和时Se/Cu = 0.53-0.56，Langmuir系数相同。配位Cu配合物的分解后接枝到M7 D上的二氧化硅表面的结构进行了讨论。利用XANES光谱分析了Cu（en）-和Cu（en）2-介孔氧化硅吸附硒酸根前后Cu的电子态。
N-(2-Aminoethyl)aminopropylsilane (AeAptes) was coordinated with Cu(2+) with Cu:AeAptes ratios of 1:1 and 1:2. These were then grafted onto MCM-41 [the products being denoted as Cu(en)-MCM-41 and Cu(en)2-MCM-41, respectively] and SBA-15 [the products being denoted as Cu(en)-SBA-15 and Cu(en)2-SBA-15, respectively]. The periodic structures of these mesoporous silica frameworks were well-retained after grafting. UV-visible and EPR spectroscopies were used to analyze the coordination structure of Cu(2+), revealing the structure expected from the ratio of Cu(2+) to silane. We also prepared Cu(en)- and Cu(en)2-M7D by the same procedure using Cab-O-sil M7D silica. In contrast to the complexes grafted onto the mesoporous silicas, no significant differences were found in the d-d transition band positions, the g-tensor, and hyperfine coupling constants between Cu(en)-M7D and Cu(en)2-M7D. The structural parameters of these were almost the same as those of Cu(en)-MCM-41 and Cu(en)-SBA-15, suggesting that the grafting onto M7D resulted in the transformation of coordination structure of Cu(2+)(AeAptes)2. The adsorption of selenate was analyzed using the Langmuir equation. The adsorption capacities for Cu(en)- and Cu(en)2-mesoporous silicas were Se/Cu = 0.5 and 1.0, respectively, while the Langmuir coefficients for Cu(en)2-mesoporous silicas were more than twice those for Cu(en)-mesoporous silicas. However, no significant differences in these two parameters were found between Cu(en)- and Cu(en)2-M7D; Se/Cu = 0.53-0.56 at saturation and the Langmuir coefficients were the same. The decomposition of the coordinated Cu complex after grafting onto M7D is discussed with respect to the structure of the silica surface. The electronic state of Cu in Cu(en)- and Cu(en)2-mesoporous silicas was analyzed by XANES spectroscopy before and after the adsorption of selenate.