Synthesis, Structural, and Thermal Aspects of Dioxouranium(VI) Coordination Compounds of Semicarbazones Derived from 4‐Aminoantipyrine

Abstract

A series of 18 new coordination compounds of dioxouranium(VI) with semicarbazones of 4‐aminoantipyrine, viz., 4[N‐(p‐dimethylaminobenzylidene)amino]antipyrine semicarbazone (DABAAPS), 4[N‐(2′‐nitrobenzylidene)amino]antipyrine semicarbazone (2′‐NO₂BAAPS), and 4[N‐(3′‐nitrobenzylidene)amino]antipyrine semicarbazone (3′‐NO₂BAAPS) of the general composition [UO₂L₂X₂] (X = Br, I, or NCS), [UO₂L₂](ClO₄)₂, [UO₂L(NO₃)₂], and [UO₂L(OOCCH₃)₂] (L = DABAAPS, 2′‐NO₂BAAPS, and 3′‐NO₂BAAPS) were synthesized in non‐aqueous solution and characterized on the basis of elemental analyses, electrical conductivity, magnetic moments, and IR spectral studies. In all of the complexes, these ligands act as neutral tridentate (N, N, O) ligands. In all dioxouranium(VI) complexes, the ν₁ and ν₃ modes are assigned to 845–825 cm⁻¹ and 930–910 cm⁻¹, respectively. Wilson's G‐F matrix method was used to determine the stretching and interaction force constants from which the U–O bond distances were calculated using Badger's formula. The probable coordination number of U(VI) varies from 8–10 in these complexes. The thermal properties of these compounds are also discussed.

Keywords:

• Dioxouranium(IV)
• Semicarbazones
• Coordination compounds

Acknowledgments

One of the authors (R.K.A.) is thankful to University Grant Commission, New Delhi, for financial assistance and Mr. Steven Sutcliffe, Chief Technician, Chemistry Department, The University of the South Pacific, for his assistance in finalizing the manuscript.