# Zinc Picolinate - Positive, negative or neutral charge?

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/

• Could you expand a little bit on your answer, giving the reasons for why the complex is neutral? – tschoppi Apr 11 '14 at 15:44
• 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. – Caters Aug 9 '14 at 3:55