Synthesis and spectral studies of sodium acetato and fluorobis[bis (<i>o-</i>hydroxynaphthaldehyde) oxaloyldihydrazonato]- tetraaquotetrakisdioxouranate(VI) complexes

Abstract

The complexes Na₄[(UO₂)₄(napoxlh)₂(CH₃COO)₄^-(H₂O)4H₂O (1) and Na₄[(UO₂)₄(napoxlh)₂F₄(H₂O)₄] (2) have been synthesized from bis(<i>o</i>-hydroxynaphthaldehyde)oxaloyldihydrazone (napoxlhH₄) and characterized by elemental analysis, molar conductance, electronic. IR and ¹H NMR spectroscopic studies. On the basis of these studies. it is suggested that the fluoro complex exists in chair conformation in which coordination of both azomethine nitrogen atoms of the dihydrazone in <i>cis</i>-configuration to the same metal centre leads to coupling between azomethine protons. In acetato complex, the coordination of two hydrazone parts of the dihydrazone even in <i>cis</i>-configuration to different metal centres eliminates the possibility of azomethine proton coupling and thus its existence in chair conformation. All of the complexes involve eight-coordinated uranium atom with the dihydrazone in the enol form.