biological complexes - haemoglobin

• • Fe(II) in haemoglobin enables oxygen to be transported in the blood .
  • Haem is an iron(II) complex with a multidentate ligand.
  • O2 bonds to Fe2+ ions in the haemoglobin and when required the O2 is released.
• • CO is toxic to humans as CO can from a strong coordinate bond with haemoglobin.
  • This is a stronger bond than that made with oxygen and so it prevents the oxygen attaching to the haemoglobin.
  • With CO, the stability constant is greater than with complex in O2.