Supplementary information
Spectroscopic Studies on Uranyl Complexes with Tri-nbutyl Phosphate (TBP) in Ionic Liquids
Yue Wang, Yupeng Liu, Taiwei Chu*
Beijing National Laboratory for Molecular Sciences, Radiochemistry and Radiation
Chemistry Key Laboratory of Fundamental Science, College of Chemistry and
Molecular Engineering, Peking University, Beijing 100871, P. R. China
Corresponding Author
* E-mail: twchu@pku.edu.cn
Figures
2-
440
460
480
495.4
420
492.2
400
2+
478.0
380
462.2
(b) [UO2(TBP)4]
475.4
459.6
Absorbance (a.u.)
(a) [UO2Cl4]
500
,nm
Fig. S1. UV-vis absorption spectra of [UO2Cl4]2- and [UO2(TBP)4]2+ in [N4111][NTf2].
Concentrations are c(uranyl) = 0.01 M and c(ligand) = 0.4 M.
Intensity (a.u.)
1500
20
15
10
8
1000
500
0
460
480
500
520
540
560
580
600
620
Wavelength (nm)
Fig. S2. Emission spectra of UO2(ClO4)2 (0.01 M) with 8, 10, 15, and 20 equivalents of
TBP in [N4111][NTf2] at 298 K. λexc=330 nm.
a) [Bmim][NTf2]
Abs.(a.u.)
b) 1M TBP in [Bmim][NTf2]
1261
c) b against a
d) pure TBP
1282
1000
1200
1400
-1
Wavenumbers (cm )
Fig. S3. ATR-FTIR spectra of: a, [Bmim][NTf2]; b, 1M TBP in [Bmim][NTf2]; c, differential
spectrum of b against a; d, pure TBP.
0.05
0.08
0.04
Abs. (a.u.)
0.06
Abs.
0.1 M
0.2 M
0.3 M
0.4 M
0.5 M
Slope = 0.0864 0.0008
2
R =0.9997
0.03
0.02
0.01
0.1
0.2
0.3
0.4
0.5
c(TBP) /M
0.04
0.02
0.00
1240
1260
1280
1300
-1
Wavenumbers (cm )
Fig. S4. Differential ATR-FTIR spectra (in P=O stretching region) of 0.10~0.50 M TBP in
[Bmim][NTf2] againt a [Bmim][NTf2] background. Insert: calibration curve of absorbance at
1261cm-1 versus TBP concentration.
0.20
940
992
1042
1097
1172
1261
Absorbance (a.u.)
0.15
0.10
0.05
0.00
-0.05
-0.10
0.00
0.02
0.04
0.06
0.08
0.10
2+
c(UO2 ) (M)
Fig.S5. The intensity of characteristic peaks of ATR-FTIR spectrum of [UO2(TBP)4]2+ with
c(UO22+).
0.1M UO2(NO3)2
0.1M UO2(ClO4)2
Abs. (a.u.)
1172
bidentate
NO3
1261
1000
1200
1400
1600
Wavenumbers
Fig.S6. Comparison of differential ATR-FTIR spectra of 0.1M UO2(NO3)2 (a) and 0.1M
UO2(ClO4)2 (b) in TBP/[Bmim][NTf2].
By subtracted a straight baseline, the intensities at 992 cm-1 are -0.033 for UO2(NO3)2 and 0.070 for UO2(ClO4)2; and the intensities at 1042 cm-1 are 0.084 for UO2(NO3)2 and 0.190 for
UO2(ClO4)2. Thus the coordination number of TBP to UO2(NO3)2 is estimated to be 1.89
(992 cm-1) or 1.77 (1042 cm-1), close to 2.
Tables
Table S1. UV-vis Absorption data of [UO2(TBP)4]2+ in ILs and in pure TBP (from Figure 2).
band
in [Bmim][NTf2] in [N4111][NTf2]
in [Pyr14][NTf2]
in pure TBP
-1
-1
-1
nm
cm
nm
cm
nm
cm
nm
cm-1
I-1
495.4
20,186 495.4
20,186 495.6
20,178 495.0
20,202
I-2
478.4
20,903 478.2
20,912 478.4
20,903 477.2
20,956
I-3
462.4
21,626 462.4
21,626 462.4
21,626 461.4
21,673
720
720
724
735
avg()
II-1
435.6
22,957 435.6
22,957 435.8
22,946 435.4
22,967
II-2
422.8
23,652 422.8
23,652 423.0
23,640 422.6
23,663
II-3
410.6
24,355 410.6
24,355 410.8
24,343 410.4
24,366
II-4
398.8
25,075 398.8
25,075 399.2
25,050 398.8
25,075
II-5
388.0
25,773 388.0
25,773 388.4
25,745 388.0
25,773
II-6
377.8
26,469 377.8
26,469 378.0
26,455 377.4
26,497
702
702
702
706
avg()
Table S2. UV-vis Absorption data of UO2(NO3)2(TBP)2 in [Bmim][NTf2] and in pure TBP
(from Figure 7).
band
in [Bmim][NTf2]
in pure TBP
-1
nm
cm
nm
cm-1
I-1
485.6
20,593
485.6
20,593
I-2
468.0
21,368
468.2
21,358
I-3
452.0
22,124
452.2
22,114
I-4
436.6
22,904
437.2
22,873
770
760
avg()
II-1(?)*
424.2
23,574
425.8
23,485
II-2
418.0
23,923
414.6
24,120
II-3
406.4
24,606
403.2
24,802
II-4
394.6
25,342
392.2
25,497
II-5
384.2
26,028
381.2
26,233
702
704
avg()
* This band may be a mixture of I-5 and II-1.