The crystal structure of (E)-4-(2-(pyridin-4-ylmethylene)hydrazine-1-carbonyl)pyridin-1-ium-2-olate dihydrate, C12H14N4O4

C12H14N4O4, triclinic, P1‾$P\overline{1}$ (no. 2), a = 6.79127(19) Å, b = 10.0328(3) Å, c = 10.0542(2) Å, α = 90.027(2)°, β = 97.124(2)°, γ = 101.983(3)°, V = 664.71(3) Å3, Z = 2, Rgt(F) = 0.0539, wRref(F2) = 0.1580, T = 292 K.