I am working on Ir complexes, which have 3+ charged. I am struggling on the purification step. I purified my complexes using SP Sephadex C-25.
I prepared the sephadex media in 0.2 M NaCl for 24 hours, then pack the column normally. My complexes are dissolved in water and added to the column on the Cl- ion forms. The eluent solvent is 1:1 acetone/water (0.025-0.1 M NaCl).
The drawbacks of this method: takes long time up to week, very poor yield, lots and lots of small fractions and the NMR spectrum is not good and no peaks splitting.
Thank you
Could you elaborate on your complexes? Starting with 0.2 M nacl seems a little to high for me. Why do you require the presence of acetone?
Dear Omar,
Thanks a lot for your reply.
I am working on [Ir(C^N)2(N^N)]
The C^N: 2-phenylpyridine. The N^N is bipyridine.
Is it very high to prepare the sefhadex to swill at 0.2 M?
Actually, I am following the literature review and it is said acetone and water. But because I don't have a lot of experience dealing with Sephadex I didn't try to change the conditions before asking.
You want to purify the complex from what? Elaborate in the mixture components please.
Hi Omar,
I am reacting the chloride-bridge dimer with the ligand which is bipyridine in 2-methoxyethanol/water solvent in the presence of AgPF6.
I have an impurities in the NMR spectrum. It is showed as a noise and spread over the spectrum.
Thank you
Yes sure.
The chloride-bridge dimer where the C^N is: 2-phenylpyridine.
an access of: 2,2'-bipyiridine.
AgPF6. The reaction solvent is: 2-methoxyethanol and water.
The reaction refluxed in dark for 36 hours.
First of all, I would not use Sephadex for substances that are not proteins, I would rather use amberlites or similar resins. Anyway if you want to use SP Sephadex and considering that the molecules with positive charges (considering that you have enough water in the system) are: Ag+, 2,2'-bipyiridine, and your complex; I will add the mixture to the column with no NaCl, then add enough water to remove all the 2-methoxyethanol and PF6-. Aftwerwards I will start increasing the NaCl concentration in the running water to selectively remove the adsorbed molecules (your complex should elute with a higher concentration of NaCl.
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