Laboratory for Radiochemistry and Environmental Chemistry

Mendeleev; Dubna 2009

Mendeleev’s principle against Einsteins relativity news from the chemistry of superheavy elements

H.W. Gäggeler

> Reminiscences: from Mendelejeev’s periodic table to the discovery of mendelevium, the last “real” chemical element

> Positioning four new chemical elements into the periodic table during the last decade. Mendelejeevs dreams become true!

> How reliable is single atom chemistry? Proof of principle with elements Hs and 112

> Einsteins influence on the chemistry of heaviest elemenst, so far up to Z=114

Laboratory for Radiochemistry and Environmental Chemistry

Mendelejeev‘s „second“ Periodic Mendelejeev‘s „second“ Periodic Table from 1871Table from 1871

D.I. Mendeleev (8 Feb. 1834 – 2 Feb. 1907)

Predictions by Mendeleev in 1871Predictions by Mendeleev in 1871

Eka-Al: Discovered by P.E. Lecoq de Eka-Al: Discovered by P.E. Lecoq de Boisbaudran in 1875, named GaBoisbaudran in 1875, named Ga

Eka-B: Discovered by L.F. Nilson in Eka-B: Discovered by L.F. Nilson in 1879, named Sc1879, named Sc

Eka-Si: Discovered by C. Winkler in Eka-Si: Discovered by C. Winkler in 18886, named Ge18886, named Ge

Major refinementsMajor refinements

Noble gases: Sir William Ramsey Noble gases: Sir William Ramsey (1894)(1894)

Henry Moseley: Atomic number, Henry Moseley: Atomic number, determined via X-rays, defines determined via X-rays, defines ordering of elements (1914)ordering of elements (1914)

Glenn T. Seaborg: Actinides series Glenn T. Seaborg: Actinides series (1945)(1945)

Periodic Table in the 1930‘sPeriodic Table in the 1930‘s

G.T. Seaborg, W. D. Loveland (1990)

H

Li

Na

K

Rb

Cs

Fr Ra Ac

Ba

Sr

Ca

Mg

Be

Sc

Y

La

Ti

Zr

Hf

V

Nb

Ta

Cr

Mo

W

Mn

Tc

Re

Fe

Ru

Os

Co Ni Cu Zn Ga Ge As

Rh Pd Ag Cd In Sn Sb

Ir Pt Au Hg Tl Pb Bi

Rf Db

B C N O F

Al Si P S Cl

Se Br

Te I

Po At87 88 89-103 104 105

55 56 57-71 72 73 74 75 76 77

37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53

78 79 80 81 82 83 84 85

19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35

11 12 13 14 15 16 17

3 4

1

5 6 7 8 9

1

2

3 4 5 6 7 8 9 10 11 12

13 14 15 16 17

LanthanideLanthanidess

AAcctinidetinidess

114

He

Ne

Ar

Kr

Xe

Rn

54

86

36

18

10

2

18

Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu

Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr

58

90

59 60 61 62

91 92 93 94

63

95 96 97 98 99 100 101

64 65 66 67 68 69

102 103

70 71

La

Ac

57

89

Periodic Periodic TTable todayable today

Mt109 110

Ds111

Rg

Sg106

Bh107

Hs108 112

- -114

116 118113 115 116

Transuranium Elemens

SuperheavyElemens

StableElemens

SphericalShell

SphericalShell

208Pb

298114

Sea of Instability

10 20 30 40

Neutron number

Pro

ton

num

ber

50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200

130

120

110

100

90

80

70

60

50

40

30

20

10

0

LogT (sec)

1/2

14

-2

-6

6

10

2

CHART OF THE NUCLIDES

Courtesy: Yu.Ts. Oganessian

Mendeleev, Dubna 2009

Discovery of new elements – the failure of chemistry!

The heaviest element discovered purely by chemical means: Mendelevium! (1955)

→ Synthesis: bombardment of 253Es with -particles. → Collection of products in a foil. → Separation of products after dissolution of foil on a cation exchange column with -HIB

Elution of actinides on a cation exchange column by -HIB

Elution in drops

Cou

nt r

ate

[cpm

]


Discovery of Mendelevium on the basis of 7 atoms

A. Ghiorso et al., Phys. Rev. 98, 1518 (1955)

Fm

Es Cfunknown

H

Li

Na

K

Rb

Cs

Fr Ra Ac

Ba

Sr

Ca

Mg

Be

Sc

Y

La

Ti

Zr

Hf

V

Nb

Ta

Cr

Mo

W

Mn

Tc

Re

Fe

Ru

Os




Rf Db

B C N O F

Al Si P S Cl

Se Br

Te I

Po At87 88 89-103 104 105

55 56 57-71 72 73 74 75 76 77

37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53

78 79 80 81 82 83 84 85

19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35

11 12 13 14 15 16 17

3 4

1

5 6 7 8 9

1

2

3 4 5 6 7 8 9 10 11 12

13 14 15 16 17


AAcctinidetinidess

114

- -

He

Ne

Ar

Kr

Xe

Rn

54

86

36

18

10

2

18



58

90

59 60 61 62

91 92 93 94

63

95 96 97 98 99 100 101

64 65 66 67 68 69

102 103

70 71

La

Ac

57

89

Positioning of new elements Positioning of new elements during the last decadeduring the last decade

Bh107

Hs108

Mt109 110

Ds111

Rg112

- -

Sg106

1999199919991999

Bh107

Hs108

2002200220022002

112

- -

Techniques developed at PSI and Bern University

116

114

20020077

20020077

20092009??

20092009??


Reactions used and number of atoms found in the „first ever chemical studies“ during the last decade

Bohrium (Z=107); Main experiments at PSI249Bk(22Ne;4n)267Bh (T1/2 = 17 s); 6 atoms (R. Eichler et al., Nature, 407, 64 (2000))

Hassium (Z=108); Main experiments at GSI248Cm(26Mg;5n)269Hs(T1/2 = 15 s); 7 atoms (C.E. Düllmann et al., Nature, 418, 860 (2002))

Element 112; Main experiments at FLNR/JINR242Pu(48Ca,3n)287114 (T1/2 = 0.5 s)283112 (T1/2 = 4 s); 2 atoms (R. Eichler et al., Nature, 447, 72 (2007)). Confirmed with 3 additional atoms (R. Eichler et al., Angew. Chem. Int. Ed., 47(17), 3262 (2008)

Element 114: Main experiments at FLNR/JINR242,244Pu(48Ca;3,4n)287,288,289114 (T1/2 = 0.5s;0.8s;2.6s); 3 – 4 atoms (R. Eichler et al.,submitted to Nature (2008)).


How reliable is single atom chemistry?1st example: hassium chemistry

Investigation of hassium in form of its very volatile molecule HsO4

Applied technique: Thermochromatography

ThermochromatographyThermochromatography

T=100KT=100KT=300KT=300K

detectorsdetectors

Result:Result: TTdepdep HHadsads

Temperature gradient

Tyi

eld

length

Internal chromatogramInternal chromatogram

Tdep

0

10

20

30

40

50

60

70

80

90

1 2 3 4 5 6 7 8 9 10 11 12Detector

Rel.

Yie

ld [

%]

-200

-180

-160

-140

-120

-100

-80

-60

-40

-20

0

Tem

pera

ture

[°C

]

Exp:269Hs (T1/2 =9.7 s)

Exp: 172Os (T1/2=19.2 s) MCS (Os): -39.5 kJ/molMCS (Hs): -46.5 kJ/mol

Temperature profile-82±5 °C

-44±5 °C

HsOHsO44

OsOOsO44

Thermochromatography of Thermochromatography of OsOOsO44 and HsO and HsO44

C.E. Düllmann et al., Nature 418,860 (2002)

1 atom

4 atoms

2 atoms


Nobel Laureate Glenn T. Seaborg, The first human being, able to celebrate „his“ element!


How reliable is single atom chemistry?2nd example: element 112

Element 112 presumably is highly volatile so that it can be separated and analysed in elemental form

Applied technique: Thermochromatography

H

Li

Na

K

Rb

Cs

Fr Ra Ac

Ba

Sr

Ca

Mg

Be

Sc

Y

La

Ti

Zr

Hf

V

Nb

Ta

Cr

Mo

W

Mn

Tc

Re

Fe

Ru

Os




Rf Db

B C N O F

Al Si P S Cl

Se Br

Te I

Po At87 88 89-103 104 105

55 56 57-71 72 73 74 75 76 77

37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53

78 79 80 81 82 83 84 85

19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35

11 12 13 14 15 16 17

3 4

1

5 6 7 8 9

1

2

3 4 5 6 7 8 9 10 11 12

13 14 15 16 17


AAcctinidetinidess

114

He

Ne

Ar

Kr

Xe

Rn

54

86

36

18

10

2

18



58

90

59 60 61 62

91 92 93 94

63

95 96 97 98 99 100 101

64 65 66 67 68 69

102 103

70 71

La

Ac

57

89

Periodic Periodic TTable todayable today

Mt109 110

Ds111

Rg

Sg106

Bh107

Hs108 112

- -114

116 118113 115 116

Trend of sublimation enthalpy within group 12Trend of sublimation enthalpy within group 12

?Mendeleev says: 112 an even more volatile metal compared to Hg!

However,…..

• Pitzer (1975) says: because of relativistic effects element 112 could well behave like a noble gas.

• Reason: E112 has a filled 6d107s2 electronic shell configuration

Relativistic effects

• High atomic number: strong Coulomb attraction causes electrons to move faster.

• Causes relativistic mass increase [m=m0(1-)], withv/c; and, as a consequence, contraction of spherical orbitals (ns, np1/2)

• Energy levels of spherical orbitals are increased• Energy levels of high angular momentum orbitals

are destabilized due to shielding effects by spherical orbitals

• Strong spin-orbit splitting

0.0

0.1

0.2

0.3

0.4

0.5

0 1 2 3 4 5 6 7

r (a.u.)

7sR

7sNR

6sR

6sNR

Example: the relativistic 6s/7s contraction in Au and Rg

a

B

h2

mc2

h2

m0c2

1 v2

c2 a

B0 1

v2

c2

Consequence: Cu, Ag, Au nd10(n+1)s1 Zn+,Cd+,Hg+ however: Rg, 112+ nd9(n+1)s2 (2D5/2)

E.Eliav, U.Kaldor, P.Schwerdtfeger, B.Hess, Y.Ishikawa, Phys. Rev. Lett. 73, 3203 (1994).M.Seth, P.Schwerdtfeger, M.Dolg, K.Faegri, B.A.Hess, U.Kaldor, Chem. Phys. Lett. 250, 461 (1996).

4r 2(r)

Courtesy:P. Schwerdtfeger

direct effect(contraction)

indirect effect(expansion)

relativisticnonrelativistic

Relativistic Effects

M.Kaupp, Spektrum der Wissenschaften, 2005

P. Pyykkö

How to experimentally determine a metallic character of a volatile element at a single

atom level?

→ Determine interaction energy (adsorption enthalpy) with noble metals (e.g. Au)

→ If metallic: strong interaction (adsorption enthalpy) if non-metallic (noble gas like): weak interaction

Metal Surface

Surface: Gold

0

5

10

15

20

25

30

35

40

45

50

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31lenght [cm]

yiel

d [

%]

0

50

100

150

200

250

300

350

400

450

500

tem

per

atu

re [

K]

Hg-192 Hads = -87 kJ/mol

Rn-219 Hads = -27 kJ/mol

Quartz Surface

0

10

20

30

40

50

60

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32lenght [cm]

yiel

d [

%]

0

50

100

150

200

250

300

350

400

450

500

tem

per

atu

re [

K]

Hg-192 Hads = -24.5 kJ/mol

Rn-219 Hads = -20.5 kJ/mol

Tdep. Tl, Po, Pb, Bi ≥ 500 K

The EPIPHANIOMETER

219Rn

211Pb

for 211Pb (via 211Bi)

(Teflon)

No 211Pb detected for clean gas (no aerosol particles)

H.W. Gäggeler et al., J. Aerosol Sci., 20, 557 (1989)

Application to atmospheric aerosol detection at exotic sites

Window/Target (242,244Pu)

Beam (48Ca)

Beam stop

SiO2-FilterTa metal850°C

Quartz column

Cryo On-line Detector (4Cryo On-line Detector (4 COLD)COLD)

Carrier gas He/Ar (70/30)

Teflon capillary

(32 pairs PIN diodes, one side gold covered)

HgHg Loop

Temperature gradient: 35°C to – 180 °C

T

l

RnRn

The element 112,114 experimentsThe element 112,114 experiments(IVO Technique)(IVO Technique)

112,114112,114??Recoil

chamber

Quartz inlay

283112

9.52 MeV

279Ds: 0.088 s

SF94+51 MeV

283112

9.52 MeV

279Ds: 0.072 s

SF112+n.d. MeV

283112

9.38 MeV

279Ds: 0.592 s

SF108+123 MeV

283112

9.47 MeV

279Ds: 0.536 s

SF127+105 MeV

283112

9.35 MeV

279Ds: 0.773 s

SF85+12 MeV

Observed in Chemistry:Observed in Chemistry:

283112

4 s

9.54 MeV

287114

0.51 s

10.02 MeV

279Ds0.18 s

SF(>90%)205 MeV

Reported at FLNR:Reported at FLNR:Oganessian et al. 2004Oganessian et al. 2004

291116

6.3 ms

10.7 MeV

The E112 experiments in 2006/2007The E112 experiments in 2006/2007

242Pu (48Ca, 3n) 2871146.2•1018 48Ca during eff. 32 days

(8 weeks absolute)

NR =0.05NR <1E-5

ResultsResults Monte Carlo simulationfor one single component

Experiment

(-5°C)(-5°C)

(-21°C)(-21°C)(-39°C)(-39°C) (-124°C)(-124°C)

(-28°C)(-28°C)

gas flowgas flow

Courtesy: R. Eichler

-52-52+4+4-3-3 kJ/mol kJ/mol

Trend of sublimation enthalpy within group 12Trend of sublimation enthalpy within group 12

Production of E114Production of E114242Pu (48Ca, 3n) 287114

284112

0.097 sSF

288114

0.8 s

9.95 MeV

2831124 s

9.54 MeV

287114

0.51 s10.02 MeV

279Ds0.2 sSF

285112

29 s

9.16 MeV

289114

2.6 s

9.82 MeV

281Ds11 sSF

244Pu (48Ca, 3-4n) 288-289114

Yu.Ts. Oganessian et al., 2004

0 80604020 120100

0

20

40

60

80

100

120

Standard enthalpies of gaseous monoatomic elements

Atomic number

H° 2

98 [

kcal/m

ol]

B. Eichler, 1974

283112 10.93 s

9.53

287114

10.04 MeV

279Ds: 0.242 s

SF 114+103

284112: 0.11 s

SF 62+n.d.

288114

9.95 MeV

284112

: 0.10 s

SF 108+n.d.

288114

9.81 MeV

242Pu (48Ca, 3n) 287114 244Pu (48Ca, 3-4n) 288-289114

285112

9.20 MeV

289114

281Ds: 3.38 s

SF 106+44

1.43•1019 48Ca during 51 days3.1•1018 48Ca during 16 days

NR=1.8E-3

NR=1.1E-2NR=2E-2

NR=1.5E-3

Results with element 114Results with element 114Dubna 2007Dubna 2007

Det#4

Det#6

- 2008- 2008

-200-150-100-50050

-200-150-100-50050

-200-150-100-50050

0369

1215

(288114)

288114

0369

1215

R

el. y

ield

/ d

ete

cto

r, %

Te

mp

era

ture

, °C

287114

2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 320369

1215

(289114-->285112)

Detector #

goldgold iceice

-88°C-88°C

-90°C-90°C

-93°C-93°C

-4°C-4°C

Results (2007/2008)Results (2007/2008)

Z=112

114Exp(2007/2008)

B. Eichler 2003R. Eichler et al. 2002V.Pershina et al 2008

Prediction and exp. result Prediction and exp. result Dubna 2007/2008Dubna 2007/2008

Strong stabilization of elemental 6d107s27p1/22 atomic state!

How to interpret low adsorption How to interpret low adsorption enthalpy of E114?enthalpy of E114?

Unexpected observation: E114 significantly different to Pb and even more volatile than E112.

Calculated van der Waals energies Calculated van der Waals energies using covalent radiiusing covalent radii11, polarizabilities, polarizabilities2 2

and ionisation potentialsand ionisation potentials22

1P.Pyykkö, M. Atsumi, Chem.Eur. J., 2009, 15, 186

2 E=114: C. Thierfelder, B. Assadollahzadeh, P. Schwerdtfeger,

S. Schäfer, R. Schäfer, Phys. Rev. A 78, 052506 (2008) E=112: V.Pershina, A. Borschevsky, E. Eliav, U. Kaldor, J. Chem. Phys. 128, 024707 (2008)

E112 on Au: -30 kJ/Mol; exp.: -52 kJ/MolE114 on Au: -23 kJ/Mol; exp.: -34 kJ/Mol

(Rn on Au: - 24 kJ/Mol; exp.: -27 kJ/Mol)

Courtesy: R. Eichler

ConclusionConclusion

- On-line gas phase chemistry has reached the sensitivity of about 1 pb

- Month-long beam times at highest possible beam intensities mandatory for chemical studies

- Single atom chemistry yields reliable chemical information

- Elements 112 and 114 surprisingly volatile

- Next: element 113 (eka-Tl). Expected volatility of At.

- Far future: chemistry from actually s-range to ms-range? (e.g. Stern-Gerlach experiment for atomic electronic configuration) [Proposal E.K. Hulet]

Acknowledgement Acknowledgement - Excerpt for Z=112/114 studies -- Excerpt for Z=112/114 studies -

PSI team: R. Eichler et al.

FLNR chemistry: S. Dmitriev, S. Shishkin

FLNR GNS team: V.K. Utyonkov et al.

FLNR VASSILISSA team: A.V. Yeremin et al.

FLNR support: Yu. Ts. Oganessian

LLNR target: K.J.Moody et al.

E112calc

-52-52+4+4-3-3 kJ/mol kJ/mol

Adsorption of E112 on AuAdsorption of E112 on Au

Eichler, R. et al. Nature 487, 72 (2007)

Result can be used to improve the prediction models

B. Eichler 1985B. Eichler 2003V. Pershina et al. 2005/08R. Eichler et al. 2002R. Eichler et al. 2002

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