THE PERIODIC TABLE
ELEMENT 110 NAMED DARMSTADTIUM
Name honors German town where the element was discovered
The name was suggested by the team of nuclear scientists who discovered the element in 1994 in Darmstadt, Germany.
The IUPAC Council, the union's highest authority, was scheduled to give formal approval to the name on Aug. 16, after C&EN went to press.
"There is virtually no chance that the name will not be approved," IUPAC Secretary General Edwin D. Becker told C&EN before the meeting. He pointed out that all comments received by IUPAC during its consultation process on the proposed name had been positive. And, unlike the names of some other transfermium elements, no controversy had arisen.
"IUPAC asked us to give a name for element 110," said physicist Sigurd Hofmann, who led the team at the Heavy Ion Research Center (GSI) in Darmstadt that synthesized the element. "Our group had a discussion and decided to follow the old custom of naming the element after the place of discovery.
"We are delighted that we can do something for our town and the people living in this area, many of whom work in our laboratory and contributed to the success of our work," Hofmann told C&EN.
The naming process was managed on behalf of IUPAC by John Corish, professor of physical chemistry at Trinity College, University of Dublin, and past president of IUPAC's Inorganic Chemistry Division.
A joint working party of IUPAC and the International Union of Pure & Applied Physics did "an excellent job" in assessing the competing claims for the discovery of the element and assigning priority for the discovery to GSI, according to Corish.
"I'm very happy with the name suggested by GSI, and it has been well received by the chemistry community throughout the world," he said.
The GSI team initially proposed Da as the element's symbol, Hofmann said. But when they realized that this is the symbol for the atomic mass unit (dalton), they switched to Ds.
Darmstadtium was synthesized by a team of seven GSI researchers, including Hofmann, and six guest scientists from the Joint Institute for Nuclear Research, Dubna, Russia; the department of nuclear physics, Comenius University, Bratislava, Slovakia; and the department of physics, University of Jyväskylä, in Finland [Z. Phys. A, 350, 277 (1995)].
The team created the element by directing a high-energy beam of nickel-62 atoms generated from the GSI heavy-ion accelerator, known as UNILAC, at lead-208 targets on the circumference of a wheel rotating at 1,125 rpm. The rotation kept the temperature of the lead targets below lead's melting point during the two-week experiment.
The team produced two isotopes of the new element: 269Ds and 271Ds, the latter prepared using a 64Ni beam. 269Ds has a half-life of about 270 microseconds.
"From its position in the periodic table, below platinum, this element should have the physical properties of a platinum metal, and were it long-lived enough, it should be possible to make a wide variety of compounds, including several oxides: MO, MO2, and MO3," according to chemist John Emsley's 2001 book "Nature's Building Blocks: An AZ Guide to the Elements."
GSI is the birthplace of six transfermium elements: bohrium (atomic number 107), hassium (108), and meitnerium (109) in 1981, 1984, and 1982, respectively; darmstadtium; and the yet-to-be-named elements 111 and 112 in 1994 and 1996, respectively.
|ELEMENT MAKER GSI's UNILAC accelerator was used to bombard a lead target with a beam of nickel atoms to create darmstadtium.