Katz Michael J, Moon Su-Young, Mondloch Joseph E, Beyzavi M Hassan, Stephenson Casey J, Hupp Joseph T, Farha Omar K
Department of Chemistry , Northwestern University , 2145 Sheridan Road , Evanston , Illinois 60208 , USA . Email:
Chemical Science and Engineering Division , Argonne National Laboratory , 9700 S. Cass Avenue , Argonne , Illinois 60439 , USA.
Chem Sci. 2015 Apr 1;6(4):2286-2291. doi: 10.1039/c4sc03613a. Epub 2015 Feb 24.
The hydrolysis of nerve agents is of primary concern due to the severe toxicity of these agents. Using a MOF-based catalyst (UiO-66), we have previously demonstrated that the hydrolysis can occur with relatively fast half-lives of 50 minutes. However, these rates are still prohibitively slow to be efficiently utilized for some practical applications (, decontamination wipes used to clean exposed clothing/skin/vehicles). We thus turned our attention to derivatives of UiO-66 in order to probe the importance of functional groups on the hydrolysis rate. Three UiO-66 derivatives were explored; UiO-66-NO and UiO-66-(OH) showed little to no change in hydrolysis rate. However, UiO-66-NH showed a 20 fold increase in hydrolysis rate over the parent UiO-66 MOF. Half-lives of 1 minute were observed with this MOF. In order to probe the role of the amino moiety, we turned our attention to UiO-67, UiO-67-NMe and UiO-67-NH. In these MOFs, the amino moiety is in close proximity to the zirconium node. We observed that UiO-67-NH is a faster catalyst than UiO-67 and UiO-67-NMe. We conclude that the role of the amino moiety is to act as a proton-transfer agent during the catalytic cycle and not to hydrogen bond or to form a phosphorane intermediate.
由于神经毒剂具有严重毒性，其水解是首要关注的问题。我们之前使用基于金属有机框架（MOF）的催化剂（UiO - 66）证明，水解能够以相对较快的半衰期（50分钟）发生。然而，对于一些实际应用（如用于清洁暴露衣物/皮肤/车辆的去污擦拭巾）而言，这些速率仍然慢得令人望而却步，无法有效利用。因此，我们将注意力转向UiO - 66的衍生物，以探究官能团对水解速率的重要性。我们研究了三种UiO - 66衍生物；UiO - 66 - NO和UiO - 66 - (OH)的水解速率几乎没有变化。然而，UiO - 66 - NH的水解速率比母体UiO - 66金属有机框架提高了20倍。用这种金属有机框架观察到半衰期为1分钟。为了探究氨基部分的作用，我们将注意力转向UiO - 67、UiO - 67 - NMe和UiO - 67 - NH。在这些金属有机框架中，氨基部分与锆节点紧密相邻。我们观察到UiO - 67 - NH是比UiO - 67和UiO - 67 - NMe更快的催化剂。我们得出结论，氨基部分的作用是在催化循环中充当质子转移剂，而不是形成氢键或磷叶立德中间体。
