Molecular interactions with CO2 for controlling the regioselectivity of liquid phase hydrogenation of 2,4-dinitroaniline
Molecular interactions with CO2 for controlling the regioselectivity of liquid phase hydrogenation of 2,4-dinitroaniline
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与CO2的分子相互作用控制2,4-二硝基苯胺液相加氢的区域选择性
DOI：
10.1039/c4cp02114b
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
S. Fujita and M. Arai
中科院分区：
文献类型：
--
作者：
H. Yoshida;A. Tomizawa;H. Tachikawa;S. Fujita and M. Arai
以0.5wt%Pt/TiO 2为催化剂，在323 K、CO2加压下，以四氢呋喃（THF）为多相介质，研究了2，4-二硝基苯胺在不同压力下的催化加氢反应。当CO2压力增加时，氢化的总速率简单地降低，但对所需产物4-硝基-1，2-苯二胺的选择性增加。对4-硝基-1，2-苯二胺的选择性的显着提高可以解释由CO2分子的化学反应性。原位高压FTIR和分子模拟表明，溶解的CO2分子可能与底物的氨基相互作用，削弱氨基和2-硝基之间的氢键，从而改变两个硝基的相对反应活性，以更高的选择性生成目标产物。通过DFT计算，从理论上研究了底物和CO2分子之间的分子内和分子间相互作用的变化。
The catalytic hydrogenation of 2,4-dinitroaniline using a 0.5 wt% Pt/TiO2 catalyst was investigated in a multiphase medium of tetrahydrofuran (THF) pressurized by CO2 at different pressures and at 323 K. When CO2 pressure was increased, the overall rate of hydrogenation simply decreased but the selectivity to the desired product of 4-nitro-1,2-phenylenediamine increased. The noticeable enhancement of the selectivity to 4-nitro-1,2-phenylenediamine can be explained by chemical reactivities of CO2 molecules. In situ high-pressure FTIR and molecular simulations demonstrate that the dissolved CO2 molecules may interact with amino groups of the substrate and weaken the intra-hydrogen bonding between the amino and 2-nitro groups, which results in the change in the relative reactivity of the two nitro groups, yielding the desired product in a higher selectivity. The change in the intra- and inter-molecular interactions between the substrate and CO2 molecules was theoretically examined by DFT calculations.