Nickel(II) and Iron(II) Mononuclear Building Blocks Based on Oximecontaining Schiff Base: Synthesis, Spectroscopy and Structures

Two new mononuclear complexes based on a hydrazine ligand (2E,N'Z)-2-(3,5-dimethyl- 1H-pyrazol-1-yl)-N'-(2-hydroxy-benzylidene)-2-(hydroxyimino)acetohydrazide (H3POAS): [Ni(H2POAS)2]· 2CH3OH·0.5H2O (1) and [Fe(H2POAS)2]·0.5CH3OH·0.5H2O (2) have been synthesized and characterized by IR-spectroscopy, elemental and X-ray single crystal analyses. The reported complexes have similar structures and reveal distorted octahedral N2O4 coordination arrangement of the central atoms formed by the phenolic, the azomethine and the carboxylic groups of the ligand. The molecules of the structures are united by multiple-branched systems of hydrogen bonds, π-stacking and the Van Der Waals forces. In addition, stability of the reported complexes in methanolic solution has been studied by ESI mass-spectrometry.