1. Pyridine reacts with alkaline haematin to form a dipyridine dihydroxy dimeric haematin in which there is no competition between pyridine and OH for coordination positions on the iron of haematin. 2. Imidazole competes directly with OH to form the monomeric imidazole parahaematin in alkaline media. 3. The monomeric imidazole parahaematin aggregates readily to form a species that is precipitated on standing. 4. A structure is proposed for the haematin–pyridine compound in alkaline media.

This content is only available as a PDF.
You do not currently have access to this content.