The document summarizes research on the chemistry of transactinide elements, which are located at the bottom of the periodic table. Key findings include:
1) Experiments have found trends in chemical properties that generally follow the periodic table, such as group membership, but properties can vary more than for lighter elements due to relativistic effects.
2) Research involves innovative experimental setups due to the extremely low production rates and short half-lives of transactinide elements.
3) While the periodic table is generally useful, the chemistry of transactinide elements exhibits subtleties that challenge predictions and require additional experiments to fully understand.
6. Preamble – “As Big as a Barn”
• Low production rates
• Barn = 10-24
cm2
; shed = 10-24
b
Schädel, M. J. Nucl. Radiochem. Sci. 2002, 3(1), 113-120. 6
9. Group 4
• MX4, MX6
2-
, MX7
3-
• Liquid-phase experiments confirm
Haba, H. et al. J. Am. Chem. Soc. 2004, 126, 5219-5224. 9
10. Group 4
• Test with pseudo-homologue Th, Pu
• 8M HNO3
• Chloride complexation Rf>Zr>Hf
Haba, H. et al. J. Nucl. Radiochem. Sci. 2002, 3(1), 143-146. 10
12. Group 5
• Adsorption onto glass surfaces (KCl,
HNO3) (Group 4 = no sorption)
Hoffman, D.C.; Lee, D.M. J. Chem. Educ. 1999, 76(3), 331-347. 12
13. Group 5
• Liquid-liquid extractions of Db, Ta, Nb, Pa in
TiOA, HCl/0.03 M HF
• Ta in organic phase
• Db eluting
between Nb, Pa
Schädel, M.; Angew. Chem. Intl. Ed. 2006, 45, 368-401. 13
15. Group 6
• Group 6 forms neutral or anionic
oxides, oxyhalides
• HNO3/HF[MO3F]-
, [MO2F3]-
, MO2F2
• Pseudo-homologue U UO2
2+
Schädel, M.; J. Alloys Compd. 1998, 271-273, 312-315. 15
16. Group 6
• Volatility MoO2Cl2>WO2Cl2≈SgO2Cl2
• Sg may be least volatile element yet
Türler, A. et al. Angew. Chem. Int. Ed. 1999, 38, 2212-2213. 16
23. Group 12
Eichler, R. et al. Nature, 2007, 447, 72-75.
• Covalent bond with Au
• Relativistic effects?
Eichler, R. et al. Angew. Chem. Int. Ed. 2008, 47, 3262-3266. 23
24. “It’s Just a Phase You’re Going
Through…”
• 112 is more volatile than Hg!
• Gaseous metal?
Eichler, R. et al. Angew. Chem. Int. Ed. 2008, 47, 3262-3266. 24
26. Concluding Remarks
• Periodic table generally good tool
• Lacking for subtle properties
• Innovative experimental set-ups
• Qualitativemore experiments to perform
• 109-114
Nuclear Chemist when asked
to provide a straight answer…
26
Transition: Why would anyone want to study these atoms or try to synthesize them? Well, taking a look at their predicted properties might put a sparkle in your eye!
Spin-orbit coupling is important b/c it changes magic numbers potentially drastically: may make the island of stability less of an island (How will it effect the island of stability??)
Transition: Since we’re chemists, we know that chemical behaviour is dictated more-so by electrons than by isotope (so let’s look at the electrons!)
Concl: The extent to which these effects (nuc/elec) exist in transactinides and the extent to which they affect chemical properties is something theoreticians have been working on, but is ultimately difficult to determine.
Talk about: So how will these electronic and nuclear effects affect the position of SHE in the periodic table? Will these elements behave like d-block elements or like f-block elements or in-between? How exactly do these trends continue?
Transition: since the periodic table can be used to group elements together into their common properties, let’s look at some of the properties of the transactinides to see if they fit their predicted profile.
Make boxes around useful data!
BIGGER photo
Transition: there are characteristic reactions that one can do to ‘test’ for an element of a certain group (based on compounds they form, based on physical properties).