Synthesis, crystal structure, chromatographic seperation, and thermogravimetric investigation of a ONNO type asymmetric Schiff base and its trinuclear complexes

Abstract

1,3-Propanediamine was put to react with 2-hydroxybenzaldehyde and 2-hydroxyacetophenone sequentially in aprotic medium. The crystalline product was examined by high performance liquid chromatography. The composition was 66% asymmetric Schiff base N(2-hydroxybenzylidene)-N′(2-hydroxyacetophenone)-1,3-propanediamine (SALLACH2) and 33% bis-N,N′(2-hydroxyacetophenylidene)-1,3-propanediamine (LACH2). As the crystals were uniform and of appropriate size, the molecular model of the material was revealed by X-ray diffraction. It was seen that two molecules of SALLACH2 and one molecule of LACH2 formed the mixed crystals. The substance was separated to its components and the asymmetric Schiff base was purified with a silica column. The substance was characterized with elemental analysis, FT-IR, MS, 1HNMR, and 13C NMR. In addition, six tri-nuclear complex with the nuclear structure of NiII-NiII-NiII, NiII-CuII-NiII, NiII-MnII-NiII were prepared from this Schiff base and stoichiometry was determined by elemental analysis, FT-IR and thermogravimetry. Finally, the molecular structures of two complexes were brought to light by XRD which highlights the asymmetry of the ligand more clearly.