A theoretical study on the water-mediated asynchronous addition between urea and formaldehyde

作     者：Tao-Hong Li Xiao-Guang Xie Guan-Ben Du 

作者机构：College of Wood Science and TechnologyNanjing Forestry University Faculty of ChemistrySouthwest Forestry University Department of ChemistryYunnan Univerisity 

出 版 物：《Chinese Chemical Letters》 (中国化学快报（英文版）)

年 卷 期：2013年第24卷第1期

页      面：85-88页

核心收录：

学科分类：081704[工学-应用化学] 07[理学] 08[工学] 0817[工学-化学工程与技术] 070303[理学-有机化学] 0703[理学-化学] 

基　　金：supported by the Programs of the National Science Foundation of China(Nos.51273163 and 30930074) by the Applied Basic Research Project of Yunnan Province(No. S2012FZ0256) 

主　　题：Urea Formaldehyde Water-mediated Asynchronous Addition 

摘      要：The reaction between urea and formaldehyde in water solution was theoretically investigated by using B3LYP and MP2 methods. It was found that the addition of the nitrogen atom in urea to the carbonyl group in formaldehyde precedes the proton transfer and the proton migration from water to the carbonyl group occurs before the proton abstraction from the nitrogen. With one or two water molecules involved in the TS, the activation energy barrier is lowered compared to the TS of the mechanism with no water participation. The energy change along the reaction coordinate clearly shows that a zwitterionic-like intermediate does not exist on the PES. The reaction between urea and formaldehyde occurs in a concerted mechanism but with asynchronous characters, This is different from the stepwise mechanism recently found for the amination reactions of formaldehyde.