1

Electronic supplementary material

Wolfram W. Rudolphand Gert Irmer: A Raman spectroscopic study on aqueous La(CH3CO2)3solutions and La(CH3CO2)3∙1.5 H2O(cr).

Table S1. Raman data ofNaCH3CO2(cr) at 22°C.

no. / peakposition /cm−1 / fwhh / cm−1 / integrated band intensity /a.u. / assignment
1 / 97 / 26 / 77 / lattice mode
2 / 162.5 / 16 / 1713 / lattice mode
3 / 225 / 26 / 79 / ?
4 / 463.6 / 8.4 / 23 / ρ CO2; in plane
5 / 623.5 / 7.2 / 145.7 / ρ CO2
6 / 653.8 / 5.0 / 568.9 / δ CO2
7 / 924.9 / 2.5 / 1508 / ν C–C
8 / 1009 / 17.1 / 83 / ρ CH3
9 / 1046 / 15 / 8 / ρ CH3
10 / 1256 / 7 / 2 / combination band
11 / 1326 / 6 / 2 / combination band
12 / 1340 / 6.8 / 135 / δ CH3
13 / 1409 / 30 / 630 / δ CH3; νsCO2? 1)
14 / 1415.5 / 9.6 / 104 / νsCO2
15 / 1451.8 / 7.4 / 712 / δ CH3
16 / 1568 / 12 / 45 / νasCO2
17 / 1592 / 8.0 / 42 / νasCO2
18 / 1674 / 24 / 28 / combination band
19 / 2560 / 12 / 8 / combination band
20 / 2578 / 13 / 11 / combination band
21 / 2648 / 12 / 30 / combination
22 / 2744 / 14 / 65 / combination
23 / 2840 / 20 / 172 / combination
24 / 2928.6 / 15 / 2754 / ν C–H
25 / 2972 / 44.5 / 563 / ν C–H
26 / 3012 / 42 / 751 / ν C–H

1) This broad and weak band may be due to accidental overlap of two modes
Table S2. Raman data of La(CH3CO2)3 1.5 H2O (cr) at 22 °C.

No. modes / Peak position /cm−1 / fwhh /cm−1 / integrated band intensity /a.u. / assignment
1 / 139.6 / 15.3 / 270.04
2 / 155.6 / 16.44 / 597.7
3 / 187.5 / 9.88 / 88.01
4 / 196.3 / 9.68 / 47.96
5 / 225.2 / 15.75 / 227.95
6 / 249.8 / 13.28 / 22.72
7 / 307.4 / 13 / 25.0 / La–O ?
8 / 333.8 / 18 / 41.0 / La–O ?
9 / 458.32 / 68.6 / 26.68 / ρ CO2
10 / 469.6 / 10.8 / 29.0 / ρ CO2
11 / 478.7 / 5.84 / 40.0 / ρ CO2
12 / 557.2 / 30.0 / 9.0 / libration H2O
13 / 609.6 / 8.9 / 21.8 / ρ CO2
14 / 615.7 / 7.24 / 22.3 / ρ CO2
15 / 666 / 7.33 / 123.8 / δ CO2
16 / 671.3 / 4.2 / 77.8 / δ CO2
17 / 685 / 16.7 / 143.5 / δ CO2
18 / 935.2 / 4.05 / 134.8 / ν C–C
19 / 950.2 / 3.9 / 734.02 / ν C–C
20 / 954.1 / 2.43 / 164.73 / ν C–C
21 / 1015.4 / 7.82 / 11.2 / ρ CH3
22 / 1021.8 / 4.49 / 11.61 / ρ CH3
23 / 1052.6 / 11.2 / 9.92 / ρ CH3
24 / 1086.0 / 27.9 / 13.9 / ρ CH3
25 / 1225.6 / 17.8 / 7.3 / combination band
26 / 1342.3 / 8.06 / 86.44 / δ CH3
27 / 1352.5 / 7.04 / 46.6 / δ CH3
28 / 1424.9 / 18.4 / 638.4 / δ CH2
29 / 1436.8 / 15.15 / 164.9 / δ CH2
30 / 1444.5 / 12.0 / 140.0 / νsCO2
31 / 1470.3 / 14.4 / 457.8 / νsCO2
32 / 1520.0 / 19 / 23.0 / ?
33 / 1548.0 / 18.0 / 46.1 / νasCO2
34 / 1565.7 / 10.4 / 85.9 / νasCO2
35 / 1591 / 10.7 / 41.0 / ?
36 / 1666.6 / 19.8 / 29.2 / δ O–H (H2O)
37 / 2689.1 / 7.3 / 14.0 / combination band
38 / 2844.2 / 49.0 / 48.83 / combination band
39 / 2937.6 / 22.6 / 5034.2 / ν C–H
40 / 2989.7 / 13.4 / 507.75 / ν C–H
41 / 3011.0 / 28.0 / 1100.0 / ν C–H
42 / 3216.8 / 252.0 / 4546.8 / ν O–H (H2O)
43 / 3401.4 / 148.6 / 2469.8 / ν O–H (H2O)
44 / 3505.5 / 94.0 / 386.0 / ν O–H (H2O)

1

Figure S1. Overview Raman spectrum of the crystallineNaCH3CO2(cr) powder at 22°C.

Figure S2A. Overview Raman spectrum of the crystalline La(CH3CO2)3 1.5H2O(cr) powder at 22°C. For clarity not all bands were labeled with the appropriate wavenumber values. For detailed band

parameters see Supplementary Table S2.

Figure S2B. Raman data of La(CH3CO2)3 1.5 H2O (cr) and La(CH3CO2)3 1.5 D2O (cr) in the wavenumber range from 910 – 980 cm−1. Clearly 3 bands are visble in the C–C stretching region for La(CH3CO2)3 1.5H2O(cr) at 935.2 (fwhh = 4.05 cm−1), 950.2 (fwhh = 3.90 cm−1) and 954.1 cm−1 (fwhh = 2.44 cm−1) (see Table 1) and for La(CH3CO2)3 1.5D2O(cr) at 934.7 (fwhh = 3.4 cm−1), 950.1 (fwhh = 3.57 cm−1) and 953.7 cm−1 (fwhh = 2.51 cm−1).

Figure S2C. Raman spectrum and sum curve and component bands of the band fit on La(CH3CO2)3∙ 1.5 H2O (cr)at upper panel and on La(CH3CO2)3∙1.5 D2O (cr) atlower panel.For band parameters of these component bands on La(CH3CO2)3 1.5 H2O (cr), see Table 3 and Table S2.Note that these acetate bands in La(CH3CO2)3∙1.5 H2O (cr) and the deuterated analog are quite comparable.

Figure S3. Stack plot of seven aqueous La(CH3CO2)3 solutions. Spectra from top to bottom: 0.479, 0.398, 0.214,0.110, 0.0584, 0.0345 and 0.0074 mol·L−1. The spectrum at the bottom (0.0074 mol·L−1) is given three times of its original intensity. Spectrum of the most dilute solution at 0.0037 mol·L−1 is given in SupplementaryFig. S8 together with the sum curve of the band fit and the component bands at 928.4 and 939.8 cm−1.

Figure S4.Polarized Raman spectra ofsolutions of La(CH3CO2)3in heavy water in the wavenumber range from 400 – 1780 cm−1. Solution A: 0.432 mol·L−1, B: 0.113 mol·L−1 and C: 0.0344mol·L−1 at 22 °C. Note, the deformation band of D2O at 1202 cm−1whose intensity rises with dilution while the bands of the bound acetate decrease.

Figure S5. Geometric parameters of applying the PC model. The Mullikan charges are given in red.

Figure S6. Geometric parameters of {La3+: −O2CCH3} applying the PC model. The Mullikan charges are given in red.

Figure S7. Discrete cluster model of the [La(OH2)7O2CCH3]2+ specieswith a La(III) : acetate stoichiometry = 1:1.

Figure S8. Discrete cluster model of the [La(OH2)5(O2CCH3)2]+ species with a La(III) : acetate stoichiometry = 1:2.

Figure S9. Isotropic C–C stretching profile of a 0.479 mol·L−1La(CH3CO2)3 solution.Given are the measured profile, the sum profile and the four component bands at 893, 928.5, 939 and 951 cm−1. Underneath is the residue curve, the difference between measured and sum curve presented.

Figure S10. Isotropic C–C stretching profile of a 0.0584 mol·L−1La(CH3CO2)3 solution.Given are the measured profile, the sum profile and the three component bands at 893, 928.2 and 939.1 cm−1. Underneath is the residue curve, the difference between measured and sum curve presented.

Figure S11. Isotropic C–C stretching profile of a 0.0037 mol·L−1La(CH3CO2)3 solution.Given are the measured profile, the sum profile and the three component bands at 928.4 and 939.8 cm−1. Underneath is the residue curve, the difference between measured and sum curve presented.