I'm going to be using a finings agent with a positive charge to remove negative trub from a solution (beer).

I would like to keep some chelated zinc in the solution - ideally zinc picolinate - so wondering what its charge is? I'm hoping it's neutral...

Depending on the answer, are there any zinc chelates that carry a neutral charge?

It's all so zinc can remain in the beer after fining to reduce the estrogenic effects of hops.


Zinc picolinate with two ligands per metal ion ($\ce{Zn(C6H4NO2)2}$) is a neutral chelate complex. Deprotonated picolinic acid has one negative charge at the carboxylate group ($\ce{NC5H4-COO^-}$). Two picolinate ligands thus compensate the two positive charges of $\ce{Zn^2+}$, forming a neutral complex in which they act as bidentate ligands. The nitrogen of the pyridine ring and the carboxylate coordinate the Zn center ion.

Image source: http://www.lookchem.com/Zinc-picolinate/

  • $\begingroup$ Could you expand a little bit on your answer, giving the reasons for why the complex is neutral? $\endgroup$
    – tschoppi
    Apr 11 '14 at 15:44
  • $\begingroup$ the complex is neutral because of the 2 negatively charged oxygens and Zn^2+. Thus while 2 oxygens are negative and the zinc is positive, the molecule itself is overall, neutral. $\endgroup$
    – Caters
    Aug 9 '14 at 3:55

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.