Zinc Picolinate - Positive, negative or neutral charge?
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.



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