Equilibria in complexes of N-heterocyclic molecules. Part 34. Iron binding by caerulomycins

Abstract
Spectroscopic properties of caerulomycin (Hcmn) complexes with iron(II) are discussed. The stoicheiometry of complexation (Job's method) is 2 cmn : 1 Fe; cmn acts as a terdentate ligand. The pKa for the red [Fe( Hcmna)(cmna)]+(Hcmna = caerulomycin A) to form its purple conjugate base [Fe(cmna)2] is 3.5. Solid compounds were made containing both the red cation and the purple uncharged species. Visible c.d. spectra are reported for caerulomycin D and its iron(II) complex.
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