Synthesis and ligand substitution of tetrakis(alkylisocyanide) bis(tri-2-furylphosphine)-cobalt(iii) complexes

Abstract

The complexes [Co(CNC₆H₁₁)₄{P(C₄H₃O)₃}₂](ClO₄)₃ and [Co(CNCH₂Ph)₄{P(C₄H₃O)₃}₂](BF₄)₃ have been synthesized by ligand substitution of tri-2-furylphosphine in the intermediate-spin complexes [Co(CNC₆H₁₁)₄(OSbPh₃)₂](ClO₄)₃ and [Co(CNCH₂Ph)₃(OSbPh₃)₂](BF₄)₃, respectively. Physical properties are reported. These diamagnetic complexes undergo labile ligand-substitution reactions with trialkylphosphines [P(C₃H₇-n)₃, P(C₄H₉-n)₃], producing the complexes [Co(CNR)₄(

)₂]X₃ in good yields at room temperature, This behaviour is in apparent contradiction to the inert nature expected for diamagnetic, six-coordinate Co(III) complexes.

Keywords:

• Tri-2-furylphosphine
• Alkylisocyanide
• Cobalt(III) complexes
• Ligand substitution
• Labile reactions

Acknowledgments

The author wishes to acknowledge the Faculty of Science Research and Publications Committee of the University of Botswana for a grant supporting this research.