Synthesis of Bis(silylene) Iron Chlorides and Their Catalytic Activity for Dinitrogen Silylation
Wenjing Yang, Xiaomiao Li, Xiaomiao Li, Shengyong Li, Qingshuang Li, Hongjian Sun, Xiaoyan Li, Xiaoyan Li
Abstract
In this study, three tetracoordinated bis(silylene) iron(II) chlorides, namely, [SiCHRSi]FeCl 2 ( 1 ) (R = H), ( 2 ) (R = CH 3 ), and ( 3 ) (R = Ph), were synthesized through the reactions of the three different bis(silylene) ligands [LSiCHRSiL] (L = PhC(NtBu) 2, L1 (R = H), L2 (R = CH 3 ), L3 (R = Ph)) with FeCl 2 ·(THF) 1.5 in THF. The bis(silylene) Fe complexes 1–3 could be used as effective catalysts for dinitrogen silylation, with complex 3 demonstrating the highest turnover number (TON) of 746 equiv among the three complexes. The catalytic mechanism was explored, revealing the involvement of the pentacoordinated bis(dinitrogen) iron(0) complexes [SiCHRSi]Fe(N 2 ) 2 (THF), ( 4 ) − ( 6 ), as the active catalysts in the dinitrogen silylation reaction. Additionally, the cyclic silylene compound 10 was obtained from the reaction of L1 with KC 8 . Single-crystal X-ray diffraction analyses confirmed the molecular structures of complexes 1–3 and 10 in the solid state.