[rms3506]

I am trying to remove all excess Mn(II) from a sample of Mn-porphyrin. The porphyrin contains a short peptide sequence and so is water soluble. After the porphyrin synthesis, I add 100-fold excess Mn-acetate, heat and stir for a few hours, and Mn is fully inserted in the form of Mn(III). I need the sample to contain no Mn(II). I have tried using chelex-100 resin, but still a very small amount of Mn(II) remained. It is possible that not enough batch purifications were done. Are there any other methods for removing Mn(II)?

[kriggy]

Honestly, I think using 100 excess was too much. Have you tried any kind of crystalization? When I was making Mn complex, we mixed ligand with Mn salt in 1:0,9 and then crystalize the complex from methanol solution by slow diffusion of diethylether in cold. I might have some articles regarding Mn porphirine compounds but I think they are only rewievs regarding their structure and antioxidant activity since I worked on non-poprhyrin ligands