In situ ligand and complex transformation of an iron(III) Schiff base complex: structural evidence and theoretical calculations

A C-C coupling reaction has been achieved at room temperature by in situ ligand transformation. The iron(III) complexes before and after the in situ transformation, [FeNaL21(H2O)(4)](2)center dot 2H(2)O (1) (H2L1 = (Z)-2-(2-hydroxyl)benzylideneamino) and [FeL2](2)center dot 7.5H(2)O (2) (H3L2 = (E)-2-(2-hydroxyl-benzylideneamino)-3-hydroxyl-3-(2-hydroxyphenyl), have been studied by elemental analyses, FT-IR, UV-vis, TGA and X-ray single crystal diffraction analysis. The proposed mechanism of this in situ transformation has been determined based on structural evidence and theoretical calculations using the density functional theory (DFT) M06 method.