Synthesis of N-Methylformohydroxamic Acid and Determination of Stability Constants of Its Complexes With Pu(Ⅳ) and Np(Ⅳ)

The title compound N-methylformohydroxamic acid (NMFHA) was synthesized by the reaction of N-methyl hydroxylamine hydrochloride with ethyl formate in alcohol medium. It was also characterized by element analysis, IR spectrum, mass spectrum and NMR spectrum. In 1.0 mol/L HNO3 solution, stable 1∶2 complexes of NMFHA complexes with Np(Ⅳ) or Pu(Ⅳ) were determined by TTA extraction method, and the stability constants are β₁(Np(Ⅳ))＝8.83×10 ⁹, β₂(Np(Ⅳ))＝1.01×10¹⁹, and β₁(Pu(Ⅳ))＝7.78×10¹⁰, β₂(Pu(Ⅳ))＝5.80×10¹⁹, respectively.