hemoglobins

https://doi.org/10.1351/goldbook.H02780
@H02773@ having a @P04898@ chain as axial ligand.
Source:
PAC, 1995, 67, 1307. (Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)) on page 1339 [Terms] [Paper]