Authors:S. Nakashima, H. Isobe, N. Akiyama, T. Okuda, and M. Katada
Electronic interaction between two iron atoms was studied in the ferrocene-arene binuclear complexes ([Fc(CH2)nPhFeCp]+PF6-) by using 57Fe Mössbauer spectroscopy and cyclic voltammetry(CV). By comparing the CV data between Fc(CH2)nPh and its arene complexes it was revealed that the considerable electronic interaction between two iron atoms exists in the n = 0 complex and a slight interaction in the n = 1 complex, while no significant interaction exists in n = 2, 3, 4, and 6 complexes. These results were discussed by using MO calculations.
Authors:S. Sahoo, H. Isobe, T. Sato, K. Fujimoto, and Y. Nakamura
A rapid method based on extraction chromatography was developed for the separation of uranium from soil samples for TIMS. The isotope ratios were measured on three standards using a VG 54-30 thermal ionisation mass spectrometer in static mode with Faraday cup and Daly ion counting system. The use of a WARP (Wide Aperture Retardation Potential) energy filter improves abundance sensitivity by an order of magnitude over a conventional VG Sector TIMS. An abundance sensitivity of 28 ppb at mass 237 with respect to 238U can be achieved. By correcting mass bias as a function of ion beam intensity, precision of the 235U/238U ratio was enhanced with a sample load of around 300 ng U. The resulting reproducibility for standards and soil samples was better than 0.2% at two standard deviations. Uranium isotopic compositions have been determined in soil samples and compared between Chernobyl nuclear accident site and the criticality accident, which occurred in Japan at the JCO site.