Reduction-induced hapticity increase in a silacycle-bridged biaryl-based ligand coordinated to an iron center

An Fe(ii) bromide complex supported by a bidentate phosphine ligand and an eta 1(C)-coordinated six-membered silacycle-bridged biphenyl-based ligand is converted upon reduction into an Fe(i) complex in which the hapticity of the silacycle-based ligand increases from eta 1 to eta 5. A six-membered silacycle-based ligand originally coordinated to an Fe(ii) center in an eta 1(C) mode undergoes a hapticity increase upon reduction to afford an Fe(i) complex with the silacycle-based ligand that coordinates in an eta 5 fashion.