Four- and three-coordinate planar iron(ii) complexes supported by bulky organosilyl ligands

The ligand exchange reaction of (THF)(2)Fe[Si(SiMe3)(3)](2) with 2 equivalents of an N-heterocyclic carbene (NHC) led to the formation of a square-planar iron(ii) complex with trans-oriented -Si(SiMe3)(3) ligands. Conversely, the introduction of a cis-coordinate bidentate organosilyl ligand instead of -Si(SiMe3)(3) resulted in the formation of a square planar iron(ii) complex supported by a cis-coordinate bidentate organosilyl ligand. A three-coordinate planar iron(ii) bis(silyl) complex was also synthesized using a cis-coordinate bidentate organosilyl ligand and a cyclic (alkyl)(amino)carbene auxiliary ligand. Investigation of the catalytic performance of these complexes in the hydrosilylation of acetophenone revealed that the square-planar iron(ii) complex with trans-oriented -Si(SiMe3)(3) ligands exhibits superior reactivity relative to its tetrahedral precursor.

Automated summary

（English Summary:） In this study, several iron complexes were successfully synthesized through ligand exchange reactions and the introduction of different coordinating organosilyl ligands. The catalytic performance of these complexes in the hydrosilylation reaction was investigated, and the results showed that the square-planar iron(ii) complex with trans-oriented organosilyl ligands exhibited superior reactivity.