Np(V) complexation with propionate in 0.1 – 4 M NaCl solutions at

20-85°C†

Supporting information

Aleksandr N. Vasiliev1,3, Nidhu L. Banik*,1, Rémi Marsac1, Daniel R. Froehlich1,2, Jörg Rothe1,

Stepan. N. Kalmykov3, Christian M. Marquardt1

*,1Karlsruher Institut für Technologie (KIT), Institut für Nukleare Entsorgung, P.O. Box 3640,

76021 Karlsruhe, Germany.

2Ruprecht-Karls-Universität Heidelberg, Physikalisch Chemisches Institut, Im Neuenheimer Feld

253, 69120 Heidelberg,Germany

3Radiochemistry Division, Chemistry Department, Lomonosov Moscow StateUniversity,

Moscow 119992, Russia.

*Email: nidhu.banik@kit.edu

Electronic Supplementary Material (ESI) for Dalton Transactions.This journal is © The Royal Society of Chemistry 2015

Table caption

Table S1: Stability constants for the formation of 1:1 complex (NpO2+ + Prop- = NpO2(Prop))measured in 0.51 m

NaCl solution as a function of temperature (23–85 °C), and extrapolated to I = 0.

Table S2: Composition of EXAFS samples 1-4.

Temperature /°C [NaCl] / molalLogβ0(T)

Average ± 1σ

20 0.506 1.33 ± 0.10

23 0.506 1.26 ± 0.07

23 0.506 1.31 ± 0.06

40 0.506 1.41± 0.10

60 0.506 1.48 ± 0.10

70 0.506 1.57 ± 0.10

85 0.506 1.67± 0.13

Table S1

Sample [Np(V)] / mmol/L [propionate-] / mol/L pHc [NaCl] / molal

1 0.77 0.48 5.5 0.51

2 0.77 0.48 5.1 1.02

3 0.77 0.48 5.0 2.09

4 0.77 0.48 5.0 4.37

Table S2

Figure caption

Figure S1:(a) Np(V) absorption spectra for various propionate concentration (I = 0.51m; T = 85°C, pHc = 5.0). (b) Example of a deconvoluted spectrum ([Prop] = 0.10m; I = 0.51m; pHc = 5.0, T = 85°C).

Figure S2:(a) Np(V) absorption spectra for various propionate concentration (I = 3.14 m; T = 23°C, pHc = 5.0). (b) Example of a deconvoluted spectrum ([Prop] = 0.14 m; I = 3.2 m; pHc = 5.0, T = 23°C).

Figure S3:Np(V) absorption spectra for NpO2+ aqueous ion and the EXAFS sample 1 (I = 0.51 m; T = 23°C, pHc =

5.0, [Prop]tot = 0.48 M). Deconvolution of the later spectrum shows that approximately 95% of the NpO2(Prop) complex is formed.

Figure S4: Possible structural scheme of Np(V)-propionate complex in the solution a) Bidentate mode b) Monodentate mode.

0.000

0.004

0.008

0.012

0.016

0.020

960 965 970 975 980 985 990 995 1000

Absorptio

n

λ (nm)

0 m

0.04 m

0.05 m

0.10 m

[Prop]tot

(a)[NaCl] = 0.5 mT= 85°C

-0.001

0.001

0.003

0.005

0.007

0.009

0.011

0.013

0.015

960 965 970 975 980 985 990 995 1000

Absorptio

n

λ (nm)

Measured spectrum (symbol)and fitted spectrum (line)

NpO2+

NpO2(Prop)

Residual

(b)[Prop]tot = 0.10 m

(b)[Prop]tot = 0.10 m

Figure S1

-0.001

0.001

0.003

0.005

0.007

0.009

960 965 970 975 980 985 990 995 1000

Absorptio

n

λ (nm)

Measured spectrum (symbol)and fitted spectrum (line)

NpO2+

NpO2(Prop)

Residual

(b)[Prop]tot = 0.10 m

0.000

0.002

0.004

0.006

0.008

0.010

0.012

960 965 970 975 980 985 990 995 1000

Absorptio

n

λ (nm)

0 m

0.02 m

0.03 m

0.07 m

0.10 m

[Prop]tot

(a)[NaCl] = 3.2 mT= 23°C

Figure S2

-0.020.000.020.040.060.080.100.120.140.160.180.200.22

970 975 980 985 990 995 1000

Absorptio

n

λ (nm)

[Prop]tot = 0 M[Np(V)]tot = 0.77 mM[NaCl] = 0.5 MT = 23°C

Residual

[Prop]tot = 0.5 MMeasured spectrum (symbol)

and fitted spectrum (line)

Figure S3

Figure S4

Np

O

O

OH2

O OH2

OH2

O

Np

O

O

OH2

O OH2

OH2

H2O

O

a)

b)