Rutherfordium (Rf)

Rutherfordium does not occur naturally in the Earth’s crust. Credit for the first synthesis of this element is given jointly to Albert Ghiorso and his team at the University of California in Berkeley and Georgi Flerov and his team at the Joint Institute for Nuclear Research (JINR) in Dubna, Russia. The element is named for Ernest Rutherford (Fig. IUPAC.104.1), who won the Nobel Prize for developing the theory of radioactive transformations [645].

Rutherfordium is of interest in particle physics research, but it has no commercial applications. 261Rf was one of the decay products used to confirm the synthesis of copernicium in a particle accelerator experiment [634].

Rutherfordium named after Ernest Rutherford.

Scientists working at the Joint Institute for Nuclear Research in Dubna, Russia, first reported the production of rutherfordium in 1964. They bombarded atoms of plutonium-242 with ions of neon-22, forming what they believed to be atoms of rutherfordium-260 and four free neutrons. In 1969, a group of scientists working at the Lawrence Radiation Laboratory, now known as the Lawrence Berkeley Laboratory, in Berkeley, California, attempted to confirm the Dubna group's discovery. Lacking the equipment needed to accelerate neon ions, the Berkeley group, led by Albert Ghiorso, bombarded atoms of californium-248 and californium-249 with ions of carbon-12 and carbon-13, producing atoms of rutherfordium-257, rutherfordium-258, rutherfordium-259 and rutherfordium-261. They were, however, unable to produce the same isotope as the Dubna group. Credit for the discovery of rutherfordium is still under debate. Rutherfordium's most stable isotope, rutherfordium-263, has a half-life of about 10 minutes and decays through spontaneous fission.

In 1964, workers at the Joint Nuclear Research Institute at Dubna (U.S.S.R.) bombarded plutonium with accelerated 113 to 115 MeV neon ions. By measuring fission tracks in a special glass with a microscope, they detected an isotope that decays by spontaneous fission. They suggested that this isotope, which had a half-life of 0.3 +/- 0.1 s might be 260-104, produced by the following reaction: 242Pu + 22Ne >260Rf +4n.

Element 104, the first transactinide element, is expected to have chemical properties similar to those of hafnium. It would, for example, form a relatively volatile compound with chlorine (a tetrachloride).

The Soviet scientists have performed experiments aimed at chemical identification, and have attempted to show that the 0.3-s activity is more volatile than that of the relatively nonvolatile actinide trichlorides. This experiment does not fulfill the test of chemically separating the new element from all others, but it provides important evidence for evaluation. Data issued by Soviet scientists reduced the half-life of the isotope they worked with from 0.3 to 0.15 s.