Synthesis and NMR spectroscopic investigation of adducts of neptunyl pivaloyl trifluoroacetonate

Adducts of neptunyl pivaloyl t rifluoroncetanate NpO2(PTFA)2xS, where S-H2O, trimethylphosphate (TMP), dimethylmethylphosphonate (DMMP), trimethylphosphin oxide (TMPO) are prepared, the optimum method of their synthesis is developed. Thermal stability of the adducts in the process of sublimation depending on basicity of neutral ligand is studied. When heated in vacuum, NpO2 (PTFA)2xH2O decomposes completely with the formation of volatile Np(PTFA)4, adducts with TMP and DMMP in the process of sublimation decompose partially with the formation of Np(PTFA)4xNpO2(PTFA)2xTMPO is sublimated completely and the sublimate does not contain Np(4) impurity. The complexes synthesized are characterized by IR spectra. A detailed investigation of NMR spectra of the compounds prepared is conducted. Paramagnetic shifts of 1H and 19F nuclei are determined. In NMR spectra signs of spatial isomerism of neptunyl complexes are manifested. It is shown, that cis- and trans-isometers differ in spatial location of chelate rings as to equatorial plane of group NpO22+. The absence of mutual transformation is characteristic of the isomers. Signs of higher reactivity of trans-isomer in the reactions of exchange and decomposition are obtained