Labile Ligand‐Substitution Reactions of Intermediate‐Spin Six‐Coordinate Cobalt(III) Complexes

Abstract

Three intermediate‐spin, six‐coordinate Co(III) complexes, [Co(CNCH2Ph)4{OAs(C6H4Me‐p)3}2](BF4)3, [Co(CNC6H11)4(OSbPh3)2](ClO4)3, and [Co(CNCH2Ph)4(OSbPh3)2](BF4)3, are shown to undergo labile ligand‐substitution reactions with selected trialkylphosphine ligands. Percent yields in reactions of [Co(CNCH2Ph)4{OAs(C6H4Me‐p)3}2](BF4)3 increase significantly when reactions are performed at lowered temperatures. [Co(CNC6H11)4(OSbPh3)2](ClO4)3 and [Co(CNCH2Ph)4(OSbPh3)2](BF4)3 react with P(C3H7‐n)3 and P(C4H9‐n)3 immediately at 0 °C to produce the known complexes, trans‐[Co(CNR)4(PR′3)2]X3, in good yields.