The synthesis of element 106 was first reported by Soviet scientists in June of 1974. Three months later the Berkeley group claimed positive discovery of the same element. The Soviet claim was based on bombardment of three different isotopes of lead with high energy chromium-54 ions. The American group used a californium target and ions of oxygen-18. The longest lived isotope (which has no known practical uses) has a half-life of 800 milliseconds.
In early1997 the first aqueous chemistry of Sg was reported out of Germany. The most stable oxidation state in aqueous solution appears to be +6 and formation of neutral or anionic oxo or oxohalide compounds occurs just as for Mo or W. The early experiments show, as expected, that Sg is chemically like other members of group 6 and not like uranium [this goes back to an early controversy about the so-called transuranium elements: would they exhibit chemical properties similar to uranium and thus need to be removed to a separate section of the periodic table, or would they--in spite of their radioactivity--exhibit expected chemical properties of their groups? Time and research have shown the latter to be correct].
Like elements 104 and beyond, the controversy over the discovery and therefore the naming of 106 led the IUPAC to adopt the numerical symbol Unh for element 106 (unnilhexium). But in 1993 the Berkeley group gave definitive proof of their priority in synthesis and gave the name Seaborgium (Sg) after Glenn T. Seaborg. While the choice of name was lauded in general, the IUPAC was awaiting a list of names from a committee for elements 104-109. The committee rejected Seaborgium because Seaborg is still living. The Berkeley group pointed out that Einsteinium and Fermium were both named after living scientists at the time (although both died before the names were officially accepted). The committee suggested Rutherfordium (Rf) but after many complaints about the choice of names, reverted to Seaborgium.
Seaborgium is the name which the IUPAC finally approved in August 1997.
Stephen R. Marsden (ChemTopics)