Syntheses, crystal structures and properties of four new coordination polymers involving a schiff base ligand bearing an easily abstracted proton in the hydrazone backbone

Four new complexes, [Mn2(L-H)2Cl4]·CH3CN (1), [Mn(L-H)(NO3)2·CH3OH] (2), [Ni(L-H)2](NO3)2·2H2O (3) and [Zn(L-H)L](NO3) (4) have been synthesized by the reaction of (E)-3-chloro-6-[2-(pyrazin-2-ylmethylene)hydrazinyl]pyridazine (HL) with MnCl2, Mn(NO3)2, Ni(NO3)2 and Zn(NO3)2. Noteworthy, complex 4 is a semi-deprotonated compound. The results signify that the feature of metal salt, such as the size, shape, coordination ability and coordination mode, has significant effects in determining the resulting structure. The magnetic property of 1 and antioxidant activities of HL and 1–4 were also studied.