Darmstadtium

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Darmstadtium
110Ds
Hydrogen (diatomic nonmetal)
Helium (noble gas)
Lithium (alkali metal)
Beryllium (alkaline earth metal)
Boron (metalloid)
Carbon (polyatomic nonmetal)
Nitrogen (diatomic nonmetal)
Oxygen (diatomic nonmetal)
Fluorine (diatomic nonmetal)
Neon (noble gas)
Sodium (alkali metal)
Magnesium (alkaline earth metal)
Aluminium (other metals)
Silicon (metalloid)
Phosphorus (polyatomic nonmetal)
Sulfur (polyatomic nonmetal)
Chlorine (diatomic nonmetal)
Argon (noble gas)
Potassium (alkali metal)
Calcium (alkaline earth metal)
Scandium (transition metal)
Titanium (transition metal)
Vanadium (transition metal)
Chromium (transition metal)
Manganese (transition metal)
Iron (transition metal)
Cobalt (transition metal)
Nickel (transition metal)
Copper (transition metal)
Zinc (transition metal)
Gallium (other metals)
Germanium (metalloid)
Arsenic (metalloid)
Selenium (polyatomic nonmetal)
Bromine (diatomic nonmetal)
Krypton (noble gas)
Rubidium (alkali metal)
Strontium (alkaline earth metal)
Yttrium (transition metal)
Zirconium (transition metal)
Niobium (transition metal)
Molybdenum (transition metal)
Technetium (transition metal)
Ruthenium (transition metal)
Rhodium (transition metal)
Palladium (transition metal)
Silver (transition metal)
Cadmium (transition metal)
Indium (other metals)
Tin (other metals)
Antimony (metalloid)
Tellurium (metalloid)
Iodine (diatomic nonmetal)
Xenon (noble gas)
Caesium (alkali metal)
Barium (alkaline earth metal)
Lanthanum (lanthanide)
Cerium (lanthanide)
Praseodymium (lanthanide)
Neodymium (lanthanide)
Promethium (lanthanide)
Samarium (lanthanide)
Europium (lanthanide)
Gadolinium (lanthanide)
Terbium (lanthanide)
Dysprosium (lanthanide)
Holmium (lanthanide)
Erbium (lanthanide)
Thulium (lanthanide)
Ytterbium (lanthanide)
Lutetium (lanthanide)
Hafnium (transition metal)
Tantalum (transition metal)
Tungsten (transition metal)
Rhenium (transition metal)
Osmium (transition metal)
Iridium (transition metal)
Platinum (transition metal)
Gold (transition metal)
Mercury (transition metal)
Thallium (other metals)
Lead (other metals)
Bismuth (other metals)
Polonium (other metals)
Astatine (metalloid)
Radon (noble gas)
Francium (alkali metal)
Radium (alkaline earth metal)
Actinium (actinide)
Thorium (actinide)
Protactinium (actinide)
Uranium (actinide)
Neptunium (actinide)
Plutonium (actinide)
Americium (actinide)
Curium (actinide)
Berkelium (actinide)
Californium (actinide)
Einsteinium (actinide)
Fermium (actinide)
Mendelevium (actinide)
Nobelium (actinide)
Lawrencium (actinide)
Rutherfordium (transition metal)
Dubnium (transition metal)
Seaborgium (transition metal)
Bohrium (transition metal)
Hassium (transition metal)
Meitnerium (unknown chemical properties)
Darmstadtium (unknown chemical properties)
Roentgenium (unknown chemical properties)
Copernicium (transition metal)
Ununtrium (unknown chemical properties)
Flerovium (unknown chemical properties)
Ununpentium (unknown chemical properties)
Livermorium (unknown chemical properties)
Ununseptium (unknown chemical properties)
Ununoctium (unknown chemical properties)
Pt

Ds

(Uhb)
meitneriumdarmstadtiumroentgenium
Darmstadtium in the periodic table
Appearance
unknown
General properties
Name, symbol, number darmstadtium, Ds, 110
Pronunciation Listeni/dɑrmˈʃtɑːtiəm/
darm-SHTAHT-ee-əm[1]
Element category unknown
but probably a transition metal
Group, period, block 10, 7, d
Standard atomic weight [281]
Electron configuration [Rn] 5f14 6d8 7s2
(predicted)[2]
2, 8, 18, 32, 32, 16, 2
(predicted)[2]
Physical properties
Phase solid (predicted)[3]
Density (near r.t.) 34.8 (predicted)[2] g·cm−3
Atomic properties
Oxidation states 8, 6, 4, 2, 0 (predicted)[2]
Ionization energies
(more)
1st: 955.2 (estimated)[2] kJ·mol−1
2nd: 1891.1 (estimated)[2] kJ·mol−1
3rd: 3029.6 (estimated)[2] kJ·mol−1
Atomic radius 132 (predicted)[2][4] pm
Covalent radius 128 (estimated)[5] pm
Miscellanea
Crystal structure body-centered cubic (predicted)[3]
Darmstadtium has a body-centered cubic crystal structure
CAS registry number 54083-77-1
History
Naming after Darmstadt, Germany, where it was discovered
Discovery Gesellschaft für Schwerionenforschung (1994)
Most stable isotopes
Main article: Isotopes of darmstadtium
iso NA half-life DM DE (MeV) DP
281Ds syn 11 s 94% SF
6% α 8.67 277Hs
281mDs ? syn 3.7 min α 8.77 277mHs ?
279Ds syn 0.20 s 10% α 9.70 275Hs
90% SF
only isotopes with half-lives over 0.1 seconds are included here
· references

Darmstadtium is a chemical element with the symbol Ds and atomic number 110. It is an extremely radioactive synthetic element. The most stable known isotope, darmstadtium-281, has a half-life of approximately 11 seconds, but it is possible that this darmstadtium isotope may have an isomer with a longer half-life, 3.7 minutes. Darmstadtium was first created in 1994 by the GSI Helmholtz Centre for Heavy Ion Research in Darmstadt-Wixhausen part of Darmstadt, Germany. It was named after the city of Darmstadt, where it was discovered.

In the periodic table, it is a d-block transactinide element. It is a member of the 7th period and is placed in the group 10 elements, although no chemical experiments have yet been carried out to confirm that it behaves as the heavier homologue to platinum in group 10. Darmstadtium is calculated to have similar properties to its lighter homologues, nickel, palladium, and platinum.

History[edit]

Discovery[edit]

Darmstadtium was first created on November 9, 1994, at the Institute for Heavy Ion Research (Gesellschaft für Schwerionenforschung) in Darmstadt, Germany, by Peter Armbruster and Gottfried Münzenberg, under the direction of Sigurd Hofmann. The team bombarded a lead-208 target with accelerated nuclei of nickel-62 in a heavy ion accelerator and detected a single atom of the isotope darmstadtium-269:[6]

208
82
Pb + 62
28
Ni → 269
110
Ds + 1
0
n

In the same series of experiments, the same team also carried out the reaction using heavier nickel-64 ions. During two runs, 9 atoms of 271Ds were convincingly detected by correlation with known daughter decay properties:[7]

208
82
Pb + 64
28
Ni → 271
110
Ds + 1
0
n

The IUPAC/IUPAP Joint Working Party (JWP) recognised the GSI team as discoverers in their 2001 report.[8]

Naming[edit]

The name Darmstadtium (Ds) was suggested by the GSI team in honor of the city of Darmstadt, where the element was discovered.[9][10] Before the discovery it was named Ununnilium (Uun). The GSI team originally also considered naming the element wixhausium, after the suburb of Darmstadt known as Wixhausen where the element was discovered, but eventually decided on darmstadtium.[11] The new name was officially recommended by IUPAC on August 16, 2003.[9]

Isotopes[edit]

For a detailed list of information on the discovery of each individual darmstadtium isotope, see isotopes of darmstadtium.
List of darmstadtium isotopes
Isotope
Half-life
[12][13]
Decay
mode[12][13]
Discovery
year
Reaction
267Ds ? 2.8 μs α 1994 209Bi(59Co,n)[14]
268Ds 100? μs α ? unknown
269Ds 179 μs α 1994 208Pb(62Ni,n)[6]
270Ds 100 μs α, SF 2000 207Pb(64Ni,n)[15]
270mDs 6.0 ms α, IT 2000 207Pb(64Ni,n)[15]
271Ds 1.63 ms α 1994 208Pb(64Ni,n)[7]
271mDs 69 ms α 1994 208Pb(64Ni,n)[7]
272Ds 1? s SF ? unknown
273Ds 170 μs α 1996 244Pu(34S,5n)[16]
274Ds 2? s α, SF ? unknown
275Ds 2? s α ? unknown
276Ds 5? s α ? unknown
277Ds 5.7 ms α 2010 285Fl(—,2α)[17]
278Ds 10? s α, SF ? unknown
279Ds 0.18 s SF, α 2002 291Lv(—,3α)[18]
280Ds 11? s SF ? unknown
281Ds 11 s SF, α 1999 289Fl(—,2α)[19]
281mDs ? ~3.7 min α 1999 289Fl(—,2α)[19]

Darmstadtium has no stable or naturally-occurring isotopes. Several radioactive isotopes have been synthesized in the laboratory, either by fusing two atoms or by observing the decay of heavier elements. Eight different isotopes of darmstadtium have been reported with atomic masses 267, 269–271, 273, 277, 279, and 281, although darmstadtium-267 is unconfirmed. Three darmstadtium isotopes, darmstadtium-270, darmstadtium-271, and darmstadtium-281, have known metastable states (although that of darmstadtium-281 is unconfirmed). Most of these decay predominantly through alpha decay, but some undergo spontaneous fission.[12]

Stability and half-lives[edit]

All darmstadtium isotopes are extremely unstable and radioactive; in general, the heavier isotopes are more stable than the lighter. The most stable known darmstadtium isotope, 281Ds, is also the heaviest known darmstadtium isotope; it has a half-life of 11 seconds, although a metastable state, 281mDs, has been reported to have a longer half-life of about 3.7 minutes. The isotope 279Ds has a half-life of 0.18 seconds respectively. The remaining six isotopes and two metastable states have half-lives between 1 microsecond and 70 milliseconds.[12] Some unknown isotopes in this region, such as 272Ds, 274–276Ds, and 280Ds, are predicted to also have rather long half-lives of a few seconds.[12][13] Before its discovery, 277Ds was predicted to also have a long half-life of around 5 seconds; however, it has since been found to have a very short half-life of only 5.7 milliseconds.[12]

The undiscovered isotope 284Ds has been predicted to be the most stable towards beta decay;[20] however, no known darmstadtium isotope has been observed to undergo beta decay.[12] Theoretical calculation in a quantum tunneling model reproduces the experimental alpha decay half-life data for the known darmstadtium isotopes.[21][22] It also predicts that the undiscovered isotope 294Ds, which has a magic number of neutrons (184),[2] would have an alpha decay half-life on the order of 311 years- exactly the same approach as for this latter case also predicts a ~3,500 year half life for the non-neutronically magic 293Ds isotope, however.[23][24]

Predicted properties[edit]

Chemical[edit]

Darmstadtium is the eighth member of the 6d series of transition metals. Since copernicium (element 112) has been shown to be a transition metal, it is expected that all the elements from 104 to 112 would form a fourth transition metal series, with darmstadtium as part of the platinum group metals.[10] Calculations on its ionization potentials and atomic and ionic radii are similar to that of its lighter homologue platinum, thus implying that darmstadtium's basic properties will resemble those of the other group 10 elements, nickel, palladium, and platinum.[2]

Prediction of the probable chemical properties of darmstadtium has not received much attention recently. Darmstadtium is expected to be a noble metal. Based on the most stable oxidation states of the lighter group 10 elements, the most stable oxidation states of darmstadtium are predicted to be the +6, +4, and +2 states; however, the neutral state is predicted to be the most stable in aqueous solutions. In comparison, only palladium and platinum are known to show the maximum oxidation state in the group, +6, while the most stable states are +4 and +2 for both nickel and palladium. It is further expected that the maximum oxidation states of elements from bohrium (element 107) to darmstadtium (element 110) may be stable in the gas phase but not in aqueous solution.[2] Darmstadtium hexafluoride (DsF6) is predicted to have very similar properties to its lighter homologue platinum hexafluoride (PtF6), having very similar electronic structures and ionization potentials.[2][25][26] It is also expected to have the same octahedral molecular geometry as PtF6.[27] Other predicted darmstadtium compounds are darmstadtium carbide (DsC) and darmstadtium tetrachloride (DsCl4), both of which are expected to behave like their lighter homologues.[27]

Physical and atomic[edit]

Darmstadtium is expected to be a solid under normal conditions and to crystallize in the body-centered cubic structure, unlike its lighter congeners which crystallize in the face-centered cubic structure, due to its being expected to have different electron charge densities from them.[3] It should be a very heavy metal with a density of around 34.8 g/cm3. In comparison, the densest known element that has had its density measured, osmium, has a density of only 22.61 g/cm3.[2] This results from darmstadtium's high atomic weight, the lanthanide and actinide contractions, and relativistic effects, although production of enough darmstadtium to measure this quantity would be impractical, and the sample would quickly decay.[2]

The outer electron configuration of darmstadtium is calculated to be 6d87s2, which obeys the Aufbau principle and does not follow platinum's outer electron configuration of 5d96s1. This is due to the relativistic stabilization of the 7s2 electron pair over the whole seventh period, so that none of the elements from 104 to 112 are expected to have electron configurations violating the Aufbau principle. The atomic radius of darmstadtium is expected to be around 132 pm.[2]

Experimental chemistry[edit]

Unambiguous determination of the chemical characteristics of darmstadtium has yet to have been established[28] due to the short half-lives of darmstadtium isotopes and a limited number of likely volatile compounds that could be studied on a very small scale. One of the few darmstadtium compounds that are likely to be sufficiently volatile is darmstadtium hexafluoride (DsF
6
), as its lighter homologue platinum hexafluoride (PtF
6
) is volatile above 60 °C and therefore the analogous compound of darmstadtium might also be sufficiently volatile;[10] a volatile octafluoride (DsF
8
) might also be possible.[2] For chemical studies to be carried out on a transactinide, at least four atoms must be produced, the half-life of the isotope used must be at least 1 second, and the rate of production must be at least one atom per week.[10] Even though the half-life of 281Ds, the most stable confirmed darmstadtium isotope, is 11 seconds, long enough to perform chemical studies, another obstacle is the need to increase the rate of production of darmstadtium isotopes and allow experiments to carry on for weeks or months so that statistically significant results can be obtained. Separation and detection must be carried out continuously to separate out the darmstadtium isotopes and automated systems can then experiment on the gas-phase and solution chemistry of darmstadtium as the yields for heavier elements are predicted to be smaller than those for lighter elements; some of the separation techniques used for bohrium and hassium could be reused. However, the experimental chemistry of darmstadtium has not received as much attention as that of the heavier elements copernicium and flerovium.[2][28]

The more neutron-rich darmstadtium isotopes are the most stable[12] and are thus more promising for chemical studies;[10][2] however, they can only be produced indirectly from the alpha decay of heavier elements,[17][18][19] and indirect synthesis methods are not favourable for chemical studies.[2] The more neutron-rich isotopes 276Ds and 277Ds might be produced directly in the reaction between thorium-232 and calcium-48, but the yield is expected to be low.[2][29][30] Furthermore, this reaction has already been tested without success,[29] and more recent experiments that have successfully synthesized 277Ds using indirect methods show that it has a short half-life of 5.7 ms, not long enough to perform chemical studies.[17]

See also[edit]

References[edit]

  1. ^ "Darmstadtium". Periodic Table of Videos. The University of Nottingham. Retrieved 19 October 2012. 
  2. ^ a b c d e f g h i j k l m n o p q r s t Hoffman, Darleane C.; Lee, Diana M.; Pershina, Valeria (2006). "Transactinides and the future elements". In Morss; Edelstein, Norman M.; Fuger, Jean. The Chemistry of the Actinide and Transactinide Elements (3rd ed.). Dordrecht, The Netherlands: Springer Science+Business Media. ISBN 1-4020-3555-1. 
  3. ^ a b c Östlin, A.; Vitos, L. (2011). "First-principles calculation of the structural stability of 6d transition metals". Physical Review B 84 (11). Bibcode:2011PhRvB..84k3104O. doi:10.1103/PhysRevB.84.113104. 
  4. ^ Fricke, Burkhard (1975). "Superheavy elements: a prediction of their chemical and physical properties". Recent Impact of Physics on Inorganic Chemistry 21: 89–144. doi:10.1007/BFb0116498. Retrieved 4 October 2013. 
  5. ^ Chemical Data. Darmstadtium - Ds, Royal Chemical Society
  6. ^ a b Hofmann, S.; Ninov, V.; Heßberger, F. P.; Armbruster, P.; Folger, H.; Münzenberg, G.; Schött, H. J.; Popeko, A. G. et al. (1995). "Production and decay of 269110". Zeitschrift für Physik A 350 (4): 277. Bibcode:1995ZPhyA.350..277H. doi:10.1007/BF01291181.  edit
  7. ^ a b c Hofmann, S (1998). "New elements – approaching". Reports on Progress in Physics 61 (6): 639. Bibcode:1998RPPh...61..639H. doi:10.1088/0034-4885/61/6/002. 
  8. ^ Karol, P. J.; Nakahara, H.; Petley, B. W.; Vogt, E. (2001). "On the discovery of the elements 110–112 (IUPAC Technical Report)". Pure and Applied Chemistry 73 (6): 959. doi:10.1351/pac200173060959. 
  9. ^ a b Corish, J.; Rosenblatt, G. M. (2003). "Name and symbol of the element with atomic number 110". Pure Appl. Chem. 75 (10): 1613–1615. doi:10.1351/pac200375101613. Retrieved 17 October 2012. 
  10. ^ a b c d e Griffith, W. P. (2008). "The Periodic Table and the Platinum Group Metals". Platinum Metals Review 52 (2): 114. doi:10.1595/147106708X297486. 
  11. ^ "Chemistry in its element – darmstadtium". Chemistry in its element. Royal Society of Chemistry. Retrieved 17 October 2012. 
  12. ^ a b c d e f g h Sonzogni, Alejandro. "Interactive Chart of Nuclides". National Nuclear Data Center: Brookhaven National Laboratory. Retrieved 2008-06-06. 
  13. ^ a b c Gray, Theodore (2002–2010). "The Photographic Periodic Table of the Elements". periodictable.com. Retrieved 16 November 2012. 
  14. ^ Ghiorso, A.; Lee, D.; Somerville, L.; Loveland, W.; Nitschke, J.; Ghiorso, W.; Seaborg, G.; Wilmarth, P.; Leres, R.; Wydler, A.; Nurmia, M.; Gregorich, K.; Czerwinski, K.; Gaylord, R.; Hamilton, T.; Hannink, N. J.; Hoffman, D. C.; Jarzynski, C.; Kacher, C.; Kadkhodayan, B.; Kreek, S.; Lane, M.; Lyon, A.; McMahan, M. A.; Neu, M.; Sikkeland, T.; Swiatecki, W. J.; Türler, A.; Walton, J. T.; Yashita, S. (1995). "Evidence for the possible synthesis of element 110 produced by the 59Co+209Bi reaction". Physical Review C 51 (5): R2293. Bibcode:1995PhRvC..51.2293G. doi:10.1103/PhysRevC.51.R2293. 
  15. ^ a b Hofmann; Heßberger, F.P.; Ackermann, D.; Antalic, S.; Cagarda, P.; Ćwiok, S.; Kindler, B.; Kojouharova, J.; Lommel, B.; Mann, R.; Münzenberg, G.; Popeko, A.G.; Saro, S.; Schött, H.J.; Yeremin, A.V. (2001). "The new isotope 270110 and its decay products 266Hs and 262Sg". Eur. Phys. J. A 10: 5–10. Bibcode:2001EPJA...10....5H. doi:10.1007/s100500170137. 
  16. ^ Lazarev, Yu. A.; Lobanov, Yu.; Oganessian, Yu.; Utyonkov, V.; Abdullin, F.; Polyakov, A.; Rigol, J.; Shirokovsky, I.; Tsyganov, Yu.; Iliev, S.; Subbotin, V. G.; Sukhov, A. M.; Buklanov, G. V.; Gikal, B. N.; Kutner, V. B.; Mezentsev, A. N.; Subotic, K.; Wild, J. F.; Lougheed, R. W.; Moody, K. J. (1996). "α decay of 273110: Shell closure at N=162". Physical Review C 54 (2): 620. Bibcode:1996PhRvC..54..620L. doi:10.1103/PhysRevC.54.620. 
  17. ^ a b c Public Affairs Department (26 October 2010). "Six New Isotopes of the Superheavy Elements Discovered: Moving Closer to Understanding the Island of Stability". Berkeley Lab. Retrieved 2011-04-25. 
  18. ^ a b Yeremin, A. V.; et al. (1999). "Synthesis of nuclei of the superheavy element 114 in reactions induced by 48Ca". Nature 400 (6741): 242. Bibcode:1999Natur.400..242O. doi:10.1038/22281. 
  19. ^ a b c Oganessian, Y. T.; Utyonkov, V.; Lobanov, Y.; Abdullin, F.; Polyakov, A.; Shirokovsky, I.; Tsyganov, Y.; Gulbekian, G.; Bogomolov, S.; Gikal, B. et al. (2004). "Measurements of cross sections for the fusion-evaporation reactions 244Pu(48Ca,xn)292−x114 and 245Cm(48Ca,xn)293−x116". Physical Review C 69 (5): 054607. Bibcode:2004PhRvC..69e4607O. doi:10.1103/PhysRevC.69.054607.  edit
  20. ^ Nie, G. K. (2005). "Charge radii of β-stable nuclei". Modern Physics Letters A 21 (24): 1889. arXiv:nucl-th/0512023. Bibcode:2006MPLA...21.1889N. doi:10.1142/S0217732306020226. 
  21. ^ P. Roy Chowdhury, C. Samanta, and D. N. Basu (2006). "α decay half-lives of new superheavy elements". Phys. Rev. C 73: 014612. arXiv:nucl-th/0507054. Bibcode:2006PhRvC..73a4612C. doi:10.1103/PhysRevC.73.014612. 
  22. ^ C. Samanta, P. Roy Chowdhury and D.N. Basu (2007). "Predictions of alpha decay half lives of heavy and superheavy elements". Nucl. Phys. A 789: 142–154. arXiv:nucl-th/0703086. Bibcode:2007NuPhA.789..142S. doi:10.1016/j.nuclphysa.2007.04.001. 
  23. ^ P. Roy Chowdhury, C. Samanta, and D. N. Basu (2008). "Search for long lived heaviest nuclei beyond the valley of stability". Phys. Rev. C 77 (4): 044603. arXiv:0802.3837. Bibcode:2008PhRvC..77d4603C. doi:10.1103/PhysRevC.77.044603. 
  24. ^ P. Roy Chowdhury, C. Samanta, and D. N. Basu (2008). "Nuclear half-lives for α -radioactivity of elements with 100 ≤ Z ≤ 130". At. Data & Nucl. Data Tables 94 (6): 781. arXiv:0802.4161. Bibcode:2008ADNDT..94..781C. doi:10.1016/j.adt.2008.01.003. 
  25. ^ Rosen, A.; Fricke, B.; Morovic, T.; Ellis, D. E. (1979). J. Phys. C4, Suppl. 4 40: C4/218–219. 
  26. ^ Waber, J. T.; Averill, F. W. (1974). "Molecular orbitals of PtF6 and E110 F6 calculated by the self-consistent multiple scattering Xα method". J. Chem. Phys. 60 (11): 4460–70. Bibcode:1974JChPh..60.4466W. doi:10.1063/1.1680924. 
  27. ^ a b Thayer, John S. (2010). Chemistry of heavier main group elements. p. 82. doi:10.1007/9781402099755_2. 
  28. ^ a b Düllmann, Christoph E. (2012). "Superheavy elements at GSI: a broad research program with element 114 in the focus of physics and chemistry". Radiochimica Acta 100 (2): 67–74. doi:10.1524/ract.2011.1842. 
  29. ^ a b Flerov lab annual report 2004
  30. ^ Feng, Z; Jin, G; Li, J; Scheid, W (2009). "Production of heavy and superheavy nuclei in massive fusion reactions". Nuclear Physics A 816: 33. arXiv:0803.1117. Bibcode:2009NuPhA.816...33F. doi:10.1016/j.nuclphysa.2008.11.003. 

External links[edit]