EVIDENCE OF THE URANIUM III AND URANYL COMPLEXATION BY MACROCYCLES FROM EXAFS

HAL Id: jpa-00226021

https://hal.archives-ouvertes.fr/jpa-00226021

Submitted on 1 Jan 1986

HAL is a multi-disciplinary open access archive for the deposit and dissemination of sci- entific research documents, whether they are pub- lished or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers.

L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d’enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

EVIDENCE OF THE URANIUM III AND URANYL COMPLEXATION BY MACROCYCLES FROM

EXAFS

A. Dejean, P. Charpin, G. Folcher, P. Rigny, A. Navaza, G. Tsoucaris

To cite this version:

A. Dejean, P. Charpin, G. Folcher, P. Rigny, A. Navaza, et al.. EVIDENCE OF THE URANIUM

III AND URANYL COMPLEXATION BY MACROCYCLES FROM EXAFS. Journal de Physique

Colloques, 1986, 47 (C8), pp.C8-645-C8-648. �10.1051/jphyscol:19868122�. �jpa-00226021�

JOURNAL DE PHYSIQUE

Colloque CB, supplement au no 12, Tome 47, decembre 1986

EVIDENCE OF THE URANIUM I11 AND URANYL COMPLEXATION BY MACROCYCLES FROM EXAFS

A. DEJEAN, P. CHARPIN, G. FOLCHER, P. RIGNY, A. NAVAZA* and G. TSOUCARIS*

IRDI/DESICP/DPC/SCM, Centre d l E t u d e s Nucleaires de Saclay, (CNRS - U A 331), F-91191 Gif-sur-Yvette Cedex, France

* ~ a b o r a t o i r e de Physique, Centre Pharmaceutique, (CNRS

-

ER 180), F-92290 Chatenay-Malabry, France

RESUMX : ~ ' a n a l ~ s e EXAFS d'un dchantillon en poudre de U:"(BH~)~ (18-crown-6)2 a montrd la presence d'atomes de carbone au voisinage de l'atome d'uranium, et par la suite prouvz que tous les atomes d'oxygsne du macrocycle sont directement lids au mEtal

.

L'dtude EXAFS du complexe dluranyle ~~'0~(18-crown-6) (C10 ) a pernis de verifier 4 2

l'insertion de l'ion uranyle 3 l'dtat solide et montrd sa ddsinsertion partielle dans une solution dTac6tonitrile.

ABSTRACT : EXAFS analysis performed on powdered sample ~~(BH~)~(18-crown-6)~ has shown the presence of carbon atoms in the vicinity of the uranium atom and hence has proved that all the oxygen atoms of the crown-ether are directly coordinated to the metal.

EXAFS study on the uranyl complex UO~(l8-~rown-6)(ClO~)~ has verified the insertion of the uranyl ion in solid state and given evidence for its partial desinsertion in an acetonitrile solution.

Insertion of uranium in macrocyclic crown-ethers has been proved in solution for the valences VI(l), V(2), IV(3) and III(4). However, insertion in solid phase has been shown only for VI(5) and IV(3,6) valences from X-Ray crystal structures. A va- riety of crown-ether complexes of uranium I11 have been studied in powder state (4,7,8,9,10), but little evidence exists to support the idea that direct coordina- tion of uranium to the oxygen atoms of the crown cavity has been achieved, due to the great difficulty to obtain and keep crystals of these very unstable compounds.

Since no suitable crystal of the compounds either U (BH _{3 4 9} ) ( d ~ c ) ~

-

^{(dcc : dicyclo-}

hexyl-18-crown-6) (4) or U3(BH ) ( ~ r ) ~

-

^{(cr :} 18-crown-6) could be obtained, we 4 9

have studied the latter in powder state with EXAFS analysis at the uranium L I11 absorption edge (LURE); this technique has shown the presence of a carbon shell around the metal, which proves the insertion of the uranium I11 into the crown-ether (fig. ) .

U(BH4)4 (1 1) and UOg (cr) (C1O4)? (1) were chosen as standard compounds. he latter

-

has no X-Ray given distances : the direct complexation of uranyl by the 18-crown-6 is known, but twinned crystals have rendered impossible a structural resolution to determine the U-0 and U-C distances. U.0 distances for this complex have been obtai- ned from EXAFS using U02(CH COO) Na(12) as a standard compound. We have considered

3 3

U-C distances as being the same as those found in the insertion complex ~ O ~ d c c ( C 1 0 ~ ) ~

Article published online by EDP Sciences and available at http://dx.doi.org/10.1051/jphyscol:19868122

C8-646 JOURNAL DE PHYSIQUE

(5). The similar configuration of macrocycles Cr(6) and dcc(7), when they are com- plexed with the cation UC13, justifies this extrapolation. All EXAFS results refer to the parameters attributed to the solid U02(cr)(C104)2. EXAFS spectra of this corn-

-

plex in solid phase and in an acetonitrile solution give evidence for its partial desinsertion in an acetonitrile solution.

The FT of the Uj (BH4)B(db~)Z 111

-

(dbc: dibenzo-18-crown-6)* is shown on figure below. The peak corresponding to U-C pairs is present and proves the insertion of uranium I11 in the crown, but the strong oxydation (first peak) prevents from obtai- ning quantitative results.

-

F T w

9-

0

-

u-0,

w

9-

0

(U

u-o,,

P

9-

0

-

l h ^9-

⁰

1

/

2.00 6.00 2.00 6.00 2.00 6.00

R t i

U02(CH3COO)3Na WZ( 18-~t'own-6)(ClO~)~ UOZ(18-crown-6)~C104)Z (sol Id) (solution i n CH3W)

Fitted parameters of U02(cr)(C10 ) in solid phase with amplitude and phase pa- 4 2

rameters from :

0 0

a) standard U02(CH3C00)3Na (U02 : R = 1.755 A U06 : R = 2.459 A) (12)

0

b) first shell of U02(Cr)(C104)2 (y = 0.4, U02 : R = 1.73 A) (1)

Fitted parameters of U02(Cr)(C10 ) in CH CN saturated solution with amplitude

4 2 3 0

and phase parameters from the same compound in solid state (U02: R = 1.73 A, U06 :

0 0

R = 2.54 A, UC : R = 3.44 A) and from the compound UO (N ) N(C H ) (U02:

o 12 o 2 3 3 2 5 4

R = 1.74A, UN5 : R = 2.46 A)(12).

Pairs UO axial (a)

2

UO equatorial ('a)

6

UO equatorial (b) 6

Fitted parameters of U (BH ) (Cr)2 in solid phase with amplitude and phase para-

3 4 9 0

meters from the solid compound ~0~(18-crown-6)(ClO~)~ : U06 : R = 2.54 A, UC12 :

0 0

R = 3.44(7) (A) and U(BH4)4 : ( U B ~ : R = 2.75 A) ( 1 1 ) . Pairs

U02 axial UO equatorial

6

UCI2 equatorial

uOx

uo

Y

N

1.5

5.2

6.7

lo^;')

0.01

3.39

2.80

a ( ; )

1.73

2.54

2.54

N 2.2

4.8

8.1

3.5 1.7

AEG (eV) 1.2

1.7

5.6

AEa(eV)

-8

+_

1

-6

2

2 R(;)

1.73

2.51

3.44

2.53 2.45

-

no2

( 103i2) 4.7

+

^0.4

3.4

2

^0.4

0.112 0.03 0.00

0

R (A) 2.51

2

^0.01 2.95

2

^0.04

3.47

2

0.03 4.14 5 0.03 Pairs

UO UB

UC

no2

(lo3;')

0.00

0.70

0.00

0.02 0.00

-

N 4.0 4 0.6 3.0

+

^0.4

6.0 f 0.7 2.0

+

^0.2

nEa(eV) '

-

^1.0

0.2

0.1

0.

C8-648 JO.URNAL DE PHYSIQUE

References

1

-

G. FOLCHER, P. CHARPIN, R.M. COSTES, N. KELLER, G.C. de VILLARDI, Inorg. Chim. Acta, 1979, 34, 87-90.

2

-

G. FOLCHER, J. LAMBARD, G.C. de VILLARDI, Inorg. Chim. Acta, 1980, 45, L59

-

^L61.

3

-

G.C. de VILLARDI, P. CHARPIN, R.M. COSTES, G. FOLCHER, P. PLURIEN, P. RIGNY, C. de RANGO,

J.C.S. Chem. Comm., 1978, 90

-

^92.

4.- A. DEJEAN-MEYER, G. FOLCHER, H. MARQUET-ELLIS, J. Chim. Phys., 1983, 80, 579

-

^581.

5

-

A. NAVAZA, F. VILLAIN, P. CHARPIN, Polyhedron, 1984, 3, 143

-

^149.

6

-

G. BOMBIERI, G. de PAOLI, A. IMMIRZI, J. Inorg. Nucl. Chem., 1978, 1889

-

^1894.

7

-

D.C. MOODY, R.A. PENNEMAN, K.V. SALAZAR, Inorg. Chem., 1979, 18, 208

-

^209.

8

-

J.I. BULLOCK, A.E. STOREY,

Inorg. Chim. Acta, 1979, 36, L 399

-

^{L 400.}

9

-

D.C. MOODY, A.J. ZOZULIN, K.V. SALAZAR, Inorg. Chem., 1982, 21, 3856

-

³⁸⁵⁷

10- F.A. HART, M. TAJIK,

Inorg. Chim. Acta, 1983, 71, 169

-

^173.

11- E.R. BERNSTEIN, W.C. HAMILTON, T.A. KEIDERLING, S.J. LA PLACA, S.J. LIPPARD, J. J

.

^MAYERLE

^,

Inorg. Chem., 1972, 11, 3003

-

^3017.

12- P. CHARPIN, A. DEJEAN, G. FOLCHER, P. RIGNY, A. NAVAZA, J. Chimie Physique, 1985, 82, 10, 925

-

^932.