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Nb(iPrNPMe2)3Fe–PMe3: A potential high reactivity heterobimetallic catalyst for acetylene cycloadditions |
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| Authors: | Na Zhang Suhong Huo Lingpeng Meng Xiaoyan Li |
| Institution: | 1. College of Chemistry and Material Science, Hebei Normal University, Road East of 2nd Ring South, Shijiazhuang, 050024 China
Contribution: Data curation;2. College of Chemistry and Material Science, Hebei Normal University, Road East of 2nd Ring South, Shijiazhuang, 050024 China Contribution: Formal analysis, Software;3. National Demonstration Center for Experimental Chemistry, Hebei Normal University, Road East of 2nd Ring South, Shijiazhuang, 050024 China;4. College of Chemistry and Material Science, Hebei Normal University, Road East of 2nd Ring South, Shijiazhuang, 050024 China |
| Abstract: | Alkynes cycloaddition reactions are powerful tools for constructing cyclic molecules with optimal atom efficiency, but these reactions cannot proceed at ambient temperature without transition-metal catalysts. In this work, a heterobimetallic complex featuring an Nb–Fe triple bond, Nb(iPrNPMe2)3Fe–PMe3, has been evaluated as the potential catalyst for acetylene cycloaddition, using density functional theory. The calculated results show that the singlet-state (i.e. ground-state) Nb(iPrNPMe2)3Fe–PMe3 can be applied to benzene synthesis, but is not suitable for cyclobutadiene. Benzene can be obtained easily at room temperature and is the unique product on the singlet potential surface. The irradiation of infrared-red light can drive the excitation of singlet Nb(iPrNPMe2)3Fe–PMe3 to its triplet state. Both benzene and cyclobutadiene can be formed on the triplet reaction potential surface due to their low energy barriers. Therefore, Nb(iPrNPMe2)3Fe–PMe3 is a potential high reactivity heterobimetallic catalyst for the cyclotrimerization of alkynes. In the reaction process, the catalytic active site of Nb(iPrNPMe2)3Fe–PMe3 moves from niobium to iron. |
| Keywords: | alkyne cycloaddition carbon–carbon coupling catalytic mechanism density functional theory heterobimetallic compound |