0000000001151684
AUTHOR
Howard L. Hall
The hydration enthalpies of Md3+ and Lr3+
Lawrencium (3-min 260Lr) and lighter actinides were produced in the bombardment of a 249Bk target with 18O ions and loaded onto a cation exchange column in 0.05 M α-hydroxyisobutyrate solution at pH=4.85, together with the radioactive lanthanide tracers 166Ho, 171Er and 171Tm. In elutions with 0.12 M α=hydroxyisobutyrate solution (pH=4.85), trivalent Lr was eluted exactly together with the Er tracer and Md was eluted close to Ho. Lr elutes much later than expected based on the known elution positions of the lighter actinides and the expected analogy to the elution positions of the homologous lanthanides. From the measured elution positions, ionic radii were calculated for Lr3+ and Md3+. Sem…
Chemical Properties of Element 105 in Aqueous Solution: Halide Complex Formation and Anion Exchange into Triisoctyl Amine
Studies of the halide complexation of element 105 in aqueous solution were performed on 34-s 262Ha produced in the 249Bk(18-O,5n) reaction. The 262Ha was detected by measuring the fission and alpha activities associated with its decay and the alpha decays of its daughter, 4.3-s 258Lr. Time-correlated pairs of parent and daughter alpha particles provided a unique identification of the presence of 262Ha. About 1600 anion exchange separations of 262Ha from HCl and mixed HC1/HF solutions were performed on a one-minute time scale. Reversed-phase micro-chromatographic columns incorporating triisooctyl amine (TIOA) on an inert support were used in the computer-controlled liquid chromatography appa…