Comprehensive DFT Study of the Mechanism of Vanadium-Catalyzed Amination of Benzene with Hydroxylamine

详细信息    查看全文

• 作者：Dianyong Tang ; Liangfang Zhu ; Changwei Hu
• 刊名：Organometallics
• 出版年：2011
• 出版时间：November 14, 2011
• 年：2011
• 卷：30
• 期：21
• 页码：5675-5686
• 全文大小：1272K
• 年卷期：v.30,no.21(November 14, 2011)
• ISSN：1520-6041

文摘

Reaction pathways and free-energy profiles for the conversion of benzene and hydroxylamine to aniline, catalyzed by NaVO₃ and VOSO₄, in acetic acid/water, were discussed using density functional theory calculations. Three model catalysts, namely VO²⁺, VO(H₂O)₅²⁺, and VO(AcO)(H₂O)³⁺, were investigated and compared. The calculations revealed that the addition鈥揺limination pathway was clearly preferred over the C鈥揌 bond activation pathway with VO²⁺ as the catalyst. The rate-determining step for all three catalysts is the formation of the amino radical complex. The existence of water and CH₃COO^{鈥?/sup> effectively reduced the free-energy barriers of the formation of the amino radical complex. Energy decomposition analysis indicated that bonding variations between the solvent (water and CH₃COO鈥?/sup>) and vanadium played an important role in the amination process. The results obtained using VO(AcO)(H₂O)3+ as the catalyst were in good agreement with experimental data.}