NEPTUNIUM SALTS WITH CERTAIN ACETIC-ACID DERIVATIVES - SYNTHESIS AND PROPERTIES

A study was performed to develop preparation of neptunium(V) salts wit h aminoacetic, glycolic, and trichloroacetic acids. Crystalline NpO2(C H2OHCOO). H2O (I) and NpO2(CCl3COO). H2O (II) were synthesized. Their lattice parameters [I: rhombic, a = 13.440(2), b = 8.755(2), c = 5.711 (1) Angstrom; II: monoclinic, a = 12.836(4), b = 11.308(3), c = 5.875( 1) Angstrom, beta = 99.83(4)degrees] were determined, and IR and elect ronic absorption spectra were measured. The main band of NpO2+ ion (98 0 nm) in electronic absorption spectra of I and II is shifted toward l onger waves by 16 and 21 nm, indicating cation-cation interactions in the lattice. Behavior of the compounds at heating in air was studied. Compound I loses water in the 200-350 degrees C range with simultaneou s decomposition to NpO2. At 210 degrees C, compound II is converted in to intermediate NpOCl2, which then decomposes to NpO2. Main physicoche mical properties of I and II were compared with properties of Np(V) ac etate.