Synthesis and spectral investigation of manganese(II), cadmium(II) and oxovanadium(IV) complexes with 2,6-diacetylpyridine bis(2-aminobenzoylhydrazone): Crystal structure of manganese(II) and cadmium(II) complexes

The chelating behavior of 2,6-diacetylpyridine bis(2-aminobenzoylhydrazone) (H2dapa) towards manganese(II), cadmium(II) and oxovanadium(IV) ions has been studied by elemental analyses, conductance measurements, magnetic properties and spectral (IR, 1H NMR, UV–Vis and EPR) studies. The IR spectral studies suggest the pentadentate nature of the ligand with pyridine nitrogen, two azomethine nitrogens and two carbonyl oxygen atoms as the ligating sites. Six coordinate structure for [VO(H2dapa)]SO4 · H2O and seven coordinate structures for [Mn(H2dapa)(Cl)(H2O)]Cl · 2H2O and [Cd(H2dapa)Cl2] · H2O complexes have been proposed. Pentagonal bipyramidal geometry for [Mn(H2dapa)(Cl)(H2O)]Cl · 2H2O and [Cd(H2dapa)(Cl2)] · H2O complexes was confirmed by single crystal analysis. The X-band EPR spectra of the oxovanadium(IV) and manganese(II) complexes in the polycrystalline state at room (300 K) and also at liquid nitrogen temperature (77 K) were recorded and their salient features are reported.

Graphical abstractThe chelating behavior of 2,6-diacetylpyridine bis(2-aminobenzoylhydrazone) (H2dapa) towards manganese(II), cadmium(II) and oxovanadium(IV) ions has been studied by elemental analyses, conductance measurements, magnetic properties and spectral (IR, NMR, UV–Vis and EPR) studies. The single crystal analysis of [Mn(H2dapa)(Cl)(H2O)]Cl · 2H2O and [Cd(H2dapa)(Cl2)] · H2O has been performed and refined to an R factor of 0.0796 and 0.0270, respectively. The spectral and single crystal studies suggest the pentadentate nature of the ligand coordinating through pyridine nitrogen, two azomethine nitrogens and two carbonyl oxygen atoms.Figure optionsDownload full-size imageDownload as PowerPoint slide