Taya, Toshiki published the artcileExtraction equilibria of nickel(II) with several heterocyclic substituted hydrazones, Quality Control of 2215-33-0, the publication is Analytical Sciences (1993), 9(6), 835-41, database is CAplus.
The extraction of nickel(II) with seven N,N,N-tridentate heterocyclic hydrazones, a neutral form of which is abbreviated as HL, using chloroform or benzene as an extraction solvent has been studied, the extraction equilibrium being analyzed on the basis of the data for the proton dissociation of H3L2+, the formation of Ni(HL)2+ and Ni(HL)22+ complexes and the proton dissociation of Ni(HL)22+ complexes in aqueous solution Nickel(II) is extracted as NiL2 although it forms such complexing ions an Ni(HL)2+ or Ni(HL)22+ in the aqueous phase. The distribution constants of HL and NiL2 (the abbreviations of which are Kd and Kdm, resp.) have been determined under the same condition as in aqueous solution The logarithmic plots of Kdm vs. Kd displayed two straight lines with slopes of 1.9; one is for hydrazones bearing one pyridyl or one quinolyl ring in the aldehyde moiety and the other for hydrazones bearing another pyridyl ring introduced to the aldehyde moiety. This is attributed to an intramol. hydrogen bond between the imino hydrogen and the nitrogen of pyridine of the latter hydrazones.
Analytical Sciences published new progress about 2215-33-0. 2215-33-0 belongs to pyridine-derivatives, auxiliary class Pyridine,Amine, name is 2-((2-(Pyridin-2-yl)hydrazono)methyl)pyridine, and the molecular formula is C13H16BFO4, Quality Control of 2215-33-0.
Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem