SIMPLE NP(V) BENZOATES

The synthesis of simple Np(V) benzoates for formula NpO2OOCC6H5.nH2O i s described. Their structure and electronic absorption spectra (EAS), IR spectra (NaCl pellets), thermal behavior, and x-ray diffraction pat terns are investigated. It is found that simple neptunyl benzoates cry stallize with 2, 3, and 4 H2O molecules. The individual crystal hydrat es are obtained by hydrothermal synthesis from aqueous-organic solutio ns. The monohydrate is prepared by storing crystalline NpO2OOCC6H5.2H2 O at 120-degrees-C in air. According to EAS, NpO2+ cation-cation inter actions are very important in building the structure of the simple Np( V) benzoates. The cations simultaneously act as ligands and coordinati on centers. The data as a whole indicate that, on one hand, the struct ures of the mono- and dihydrates are different in principle and, on th e other, those of the tri- and tetrahydrates are also.