Equilibrium and spectral studies on ligational behaviour of N,N’-diformylhydrazine
The ligand N,N’-diformylhydrazine (DFH) is a resonance hybrid of its keto- and enol-forms. The resonance structures indicate enolisation of one as well as both the carbonyl groups. This indicates the presence of dissociable protons in the molecule. Equilibrium studies carried out with DFH indicate the presence of one dissociable proton. The solid complexes of Mn(II), Fe(II), Co(II), Ni(II), Cu(II), Zn(II) and Pb(II) with DFH have been synthesized, and have been characterized by elemental analysis, magnetic susceptibility, IR, Far-IR,1H NMR, TGA, FAB and reflectance spectra. IR and1H NMR spectra of the complexes indicate deprotonation of both the enol protons upon complexation. Elemental and TG analyses of Mn(II), Ni(II), Zn(II) DFH complexes indicate 1:1 metal to ligand composition. The dimeric nature of the Mn(II)-DFH complex is supported by its FAB spectrum.
KeywordsN,N’-diformylhydrazine ligational behaviour resonance hybrid keto-enol forms
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