Improved synthesis, thermal stability and catalytic properties of the metal-organic framework compound CU3(BTC)2
Improved synthesis, thermal stability and catalytic properties of the metal-organic framework compound CU3(BTC)2
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DOI：
10.1016/j.micromeso.2003.12.027
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发表时间：
2004-08-06
影响因子：
5.2
通讯作者：
Kaskel, S
中科院分区：
文献类型：
--
作者：
Schlichte, K;Kratzke, T;Kaskel, S
研究了金属有机骨架化合物Cu-3（BTC）（2）（H2O）（3）（.）xH（2）O（BTC = 1，3，5-三羧酸苯酯）。Cu-3（BTC）（2）（H2O）（3）（.）在393 K水热条件下，采用改进的合成方法合成了xH（2）O。微孔材料具有0.41 cm（3）g（-1）的高比孔体积和10.7埃的孔径（Horvath-Kawazoe）。去除三个铜结合水分子允许进入刘易斯酸铜位点。从化合物的颜色变化中识别出配位水被底物或溶剂分子交换。对于化学吸附的苯甲醛，IR伸缩频率v（C=O）从1702 cm（-1）降低到1687 cm（-1）。化学吸附导致苯甲醛活化用于液相氰硅烷化，在72小时（313 K）后具有50-60%的合理产率和高选择性。过滤实验表明，反应机理是多相的。配位溶剂如THF完全封闭催化剂的刘易斯酸位点。溶剂如CH 2Cl 2或更高的反应温度（353 K）导致催化剂分解。(C)2004年爱思唯尔公司All rights reserved.
The catalytic properties of the metal-organic framework compound Cu-3(BTC)(2)(H2O)(3) (.) xH(2)O (BTC = benzene 1,3,5-tricarboxylate) were explored. Cu2O-free powder samples of Cu-3(BTC)(2)(H2O)(3) (.) xH(2)O were obtained using an improved synthesis at 393 K under hydrothermal conditions. The microporous material has a high specific pore volume of 0.41 cm(3) g(-1) and a pore diameter of 10.7 Angstrom (Horvath-Kawazoe). Removal of the three copper-bound water molecules allows to access the Lewis acid copper sites. The exchange of coordinated water by substrates or solvent molecules is recognized from the color change of the compound. For chemisorbed benzaldehyde, the IR stretching frequency v(C=O) is decreased from 1702 to 1687 cm(-1). The chemisorption results in an activation of benzaldehyde for the liquid phase cyanosilylation with a reasonable yield of 50-60% after 72 h (313 K) and a high selectivity. Filtration experiments demonstrate that the reaction mechanism is heterogeneous. Coordinating solvents such as THF completely block the Lewis acid sites of the catalyst. Solvents such as CH2Cl2 or higher reaction temperatures (353 K) cause decomposition of the catalyst. (C) 2004 Elsevier Inc. All rights reserved.