inorganic compounds
Dieuropium(III) trisulfate octahydrate: a redetermination at 120 K
aSchool of Chemical and Biotechnology, Shanmuga Arts, Science, Technology and Research Academy (SASTRA), Tirumalaisamudram, Thanjavur 613 402, India, bDepartment of Chemistry, Bharathidasan University, Tiruchirappalli, Tamil Nadu 620 024, India, cDepartment of Chemistry, University of Aberdeen, Meston Walk, Old Aberdeen AB24 3UE, Scotland, and dSchool of Chemistry, University of St Andrews, Fife KY16 9ST, Scotland
*Correspondence e-mail: panch_45@yahoo.co.in
The title compound, Eu2(SO4)3·8H2O, crystallizes in C2/c, with one of the anions lying on a twofold rotation axis and the other in a general position, and is best formulated as [Eu(H2O)4/1(SO4)3/3(SO4)1/2]2, where one of the anions lies across a twofold axis. The coordination environment of EuIII consists of four water molecules and four sulfate ions. All the water molecules and sulfate ions are involved in hydrogen-bonding interactions. The structure is similar to that previously determined at 293 K [Wei & Zheng (2003). Z. Kristallogr. New Cryst. Struct. 218, 277–278], but the cell parameters and the interatomic distances are more precise in the present determination.
Comment
Hydrated lanthanide(III) sulfates can adopt a number of different compositions, namely M2(SO4)3·9H2O, M2(SO4)3·8H2O, M2(SO4)3·5H2O and M2(SO4)3·4H2O, and the octahydrated sulfates of lanthanides LnIII exist as coordination polymers in which sulfate ions act as bridging bidentate and tridentate ligands; the presence of four coordinated water molecules leads to a of eight for the lanthanide ion (Wickleder, 2002). The unit-cell dimensions for hydrated europium(III) sulfate were reported many years ago (Geller, 1957), and the in C2/c, has recently been reported using data collected at 293 K (Wei & Zheng, 2003).
We report here the structure at 120 K. The similarity of the unit-cell dimensions and atomic coordinates at 293 and 120 K indicates that the same phase has been utilized in all of these studies. The aims of the present investigation are the determination of more precise metrical parameters and the determination of the extent of hydration. The structure (Table 1 and Fig. 1) indicates the presence of octacoordinate europium, with distorted square antiprismatic coordination by four water molecules, one O atom from a sulfate ion in the μ2 bonding mode and three O atoms from three different anions in the μ3 bonding mode. The triply bridging anions lie in general positions, while the doubly bridging anions lie on twofold rotation axes.
Compound (I) is, in fact, isostructural not only with yttrium(III) sulfate octahydrate (Held & Wickleder, 2003) but also with the analogous lanthanide sulfates Ln2(SO4)3·8H2O, where Ln is Ce (Junk et al., 1999), Pr (Ahmed Farag et al., 1981), Nd (Bartl & Rodek, 1983), Sm (Podberezskaya & Borisov, 1976), Dy (Junk et al., 1999), Er (Wickleder, 1999), Yb (Hiltunen & Niinistö, 1976) or Lu (Junk et al., 1999). The coordination polymer in this structure is most readily envisaged as inversion-related pairs of chains comprising alternating cations and triply bridging anions, themselves generated by translation along the [010] direction, which are then linked into sheets by the doubly bridging anions. The coordination-polymer sheets are linked by hydrogen bonds (Table 2) into a continuous three-dimensional framework structure. As noted for the yttrium analogue (Held & Wickleder, 2003), one of the S—O bonds in the triply bridging anion is significantly longer than the others (Table 1).
Some of the lanthanides, such as europium, can also exhibit lower oxidation states in sulfate salts. Thus, for example, europium(II) sulfate has been shown to be anhydrous and to crystallize in Pnma (Mayer et al., 1964). Accordingly, the of europium in (I) was further confirmed by bond valence sum calculations (Brown, 1992, 2002). A total valence of 3.016 for europium was obtained using the observed Eu—O bond lengths (Table 1) and a bond valence parameter of 2.036 Å for europium (Trzesowska et al., 2004).
Experimental
The title compound was obtained during the attempted preparation of a complex between 2,5-diketopiperazine and europium sulfate, in which 2,5-diketopiperazine (0.228 g, 2 mmol) was heated with europium sulfate (0.736 g, 1 mmol) in water (30 ml). The latter was obtained by the action of sulfuric acid on europium oxide. The crystallization of europium sulfate from solution is facilitated in the presence of other ligands (Held & Wickleder, 2003; Wei & Zheng, 2003).
Crystal data
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Data collection
Refinement
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All H atoms were located in difference maps and then allowed to ride on their parent atoms, with O—H distances of 0.84 Å and with Uiso(H) = 1.2Ueq(O).
Data collection: COLLECT (Hooft, 1999); cell DENZO (Otwinowski & Minor, 1997) and COLLECT; data reduction: DENZO and COLLECT; program(s) used to solve structure: OSCAIL (McArdle, 2003) and SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: OSCAIL and SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2003); software used to prepare material for publication: SHELXL97 and PRPKAPPA (Ferguson, 1999).
Supporting information
https://doi.org/10.1107/S160053680402608X/lh6289sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S160053680402608X/lh6289Isup2.hkl
Data collection: COLLECT (Hooft, 1999); cell
DENZO (Otwinowski & Minor, 1997) and COLLECT; data reduction: DENZO and COLLECT; program(s) used to solve structure: OSCAIL (McArdle, 2003) and SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: OSCAIL and SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2003); software used to prepare material for publication: SHELXL97 and PRPKAPPA (Ferguson, 1999).[Eu2(SO4)3(H2O)8] | F(000) = 1400 |
Mr = 736.26 | Dx = 3.002 Mg m−3 |
Monoclinic, C2/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -C 2yc | Cell parameters from 1869 reflections |
a = 13.5029 (3) Å | θ = 3.1–27.5° |
b = 6.7601 (1) Å | µ = 8.12 mm−1 |
c = 18.2628 (3) Å | T = 120 K |
β = 102.2610 (13)° | Plate, colourless |
V = 1629.02 (5) Å3 | 0.10 × 0.08 × 0.06 mm |
Z = 4 |
Bruker-Nonius 95mm CCD camera on κ-goniostat diffractometer | 1869 independent reflections |
Radiation source: Bruker–Nonius FR591 rotating anode | 1805 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.037 |
Detector resolution: 9.091 pixels mm-1 | θmax = 27.5°, θmin = 3.1° |
φ & ω scans | h = −17→17 |
Absorption correction: multi-scan (SADABS; Sheldrick, 2003) | k = −8→8 |
Tmin = 0.477, Tmax = 0.616 | l = −22→23 |
11784 measured reflections |
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.019 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.054 | H-atom parameters constrained |
S = 1.26 | w = 1/[σ2(Fo2) + (0.0218P)2 + 6.1179P] where P = (Fo2 + 2Fc2)/3 |
1869 reflections | (Δ/σ)max = 0.002 |
114 parameters | Δρmax = 0.71 e Å−3 |
0 restraints | Δρmin = −1.32 e Å−3 |
x | y | z | Uiso*/Ueq | ||
Eu1 | 0.167587 (11) | 0.47732 (2) | 0.392539 (9) | 0.00436 (8) | |
O1 | 0.34495 (19) | 0.5163 (3) | 0.45743 (14) | 0.0075 (5) | |
O2 | 0.01431 (17) | 0.6639 (4) | 0.35904 (14) | 0.0140 (5) | |
O3 | 0.04016 (16) | 0.2634 (3) | 0.43634 (13) | 0.0083 (5) | |
O4 | 0.2592 (2) | 0.5073 (4) | 0.29716 (15) | 0.0123 (5) | |
S1 | 0.21644 (6) | 0.52970 (11) | 0.58924 (5) | 0.00457 (17) | |
O11 | 0.20077 (17) | 0.8241 (3) | 0.39758 (12) | 0.0077 (5) | |
O12 | 0.16150 (18) | 0.5354 (4) | 0.64991 (14) | 0.0097 (5) | |
O13 | 0.14441 (17) | 0.5794 (3) | 0.51715 (12) | 0.0076 (4) | |
O14 | 0.24242 (17) | 0.1670 (3) | 0.41959 (13) | 0.0103 (5) | |
S2 | 0.0000 | 0.17534 (16) | 0.2500 | 0.0053 (2) | |
O21 | 0.08491 (17) | 0.3008 (4) | 0.28701 (13) | 0.0106 (5) | |
O22 | −0.03310 (19) | 0.0515 (3) | 0.30707 (14) | 0.0089 (5) | |
H11 | 0.3814 | 0.4312 | 0.4838 | 0.009* | |
H12 | 0.3610 | 0.6166 | 0.4845 | 0.009* | |
H21 | −0.0434 | 0.6132 | 0.3549 | 0.017* | |
H22 | 0.0076 | 0.7843 | 0.3477 | 0.017* | |
H31 | 0.0064 | 0.1908 | 0.4028 | 0.010* | |
H32 | −0.0066 | 0.3184 | 0.4527 | 0.010* | |
H41 | 0.2369 | 0.4741 | 0.2524 | 0.015* | |
H42 | 0.3197 | 0.5429 | 0.3007 | 0.015* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Eu1 | 0.00432 (12) | 0.00358 (11) | 0.00492 (12) | −0.00052 (5) | 0.00041 (8) | −0.00030 (5) |
O1 | 0.0081 (12) | 0.0060 (11) | 0.0069 (12) | 0.0006 (8) | −0.0017 (10) | −0.0003 (8) |
O2 | 0.0059 (11) | 0.0084 (12) | 0.0258 (14) | −0.0008 (9) | −0.0012 (10) | 0.0046 (10) |
O3 | 0.0067 (11) | 0.0085 (11) | 0.0095 (11) | −0.0019 (9) | 0.0008 (9) | −0.0017 (9) |
O4 | 0.0083 (13) | 0.0217 (13) | 0.0073 (13) | −0.0068 (9) | 0.0029 (11) | −0.0032 (9) |
S1 | 0.0046 (4) | 0.0032 (4) | 0.0057 (4) | −0.0001 (3) | 0.0007 (3) | 0.0002 (3) |
O11 | 0.0066 (11) | 0.0053 (11) | 0.0107 (12) | −0.0019 (9) | 0.0008 (9) | −0.0003 (9) |
O12 | 0.0072 (13) | 0.0157 (12) | 0.0066 (13) | −0.0018 (9) | 0.0021 (10) | −0.0016 (9) |
O13 | 0.0076 (11) | 0.0081 (11) | 0.0059 (11) | 0.0001 (9) | −0.0010 (9) | 0.0001 (9) |
O14 | 0.0115 (12) | 0.0029 (11) | 0.0158 (12) | 0.0019 (9) | 0.0012 (9) | −0.0003 (9) |
S2 | 0.0052 (5) | 0.0049 (5) | 0.0053 (5) | 0.000 | −0.0004 (4) | 0.000 |
O21 | 0.0094 (11) | 0.0139 (12) | 0.0078 (11) | −0.0078 (9) | 0.0006 (9) | −0.0041 (9) |
O22 | 0.0104 (12) | 0.0071 (11) | 0.0091 (12) | −0.0008 (9) | 0.0022 (10) | 0.0023 (9) |
Eu1—O1 | 2.450 (3) | O3—H31 | 0.84 |
Eu1—O2 | 2.390 (2) | O3—H32 | 0.84 |
Eu1—O3 | 2.505 (2) | O4—H41 | 0.84 |
Eu1—O4 | 2.350 (3) | O4—H42 | 0.84 |
Eu1—O11 | 2.384 (2) | S1—O11i | 1.473 (2) |
Eu1—O13 | 2.461 (2) | S1—O12 | 1.459 (3) |
Eu1—O14 | 2.336 (2) | S1—O13 | 1.499 (2) |
Eu1—O21 | 2.339 (2) | S1—O14ii | 1.463 (2) |
O1—H11 | 0.84 | S2—O21 | 1.470 (2) |
O1—H12 | 0.84 | S2—O21iii | 1.470 (2) |
O2—H21 | 0.84 | S2—O22 | 1.478 (2) |
O2—H22 | 0.84 | S2—O22iii | 1.478 (2) |
O14—Eu1—O21 | 79.93 (8) | O1—Eu1—S1 | 62.92 (6) |
O14—Eu1—O4 | 87.81 (8) | O13—Eu1—S1 | 20.55 (5) |
O21—Eu1—O4 | 70.58 (8) | O3—Eu1—S1 | 74.07 (5) |
O14—Eu1—O11 | 143.67 (8) | Eu1—O1—H11 | 126.7 |
O21—Eu1—O11 | 125.90 (8) | Eu1—O1—H12 | 118.4 |
O4—Eu1—O11 | 79.62 (8) | H11—O1—H12 | 99.7 |
O14—Eu1—O2 | 147.20 (8) | Eu1—O2—H21 | 122.9 |
O21—Eu1—O2 | 79.78 (8) | Eu1—O2—H22 | 128.1 |
O4—Eu1—O2 | 109.18 (9) | H21—O2—H22 | 108.9 |
O11—Eu1—O2 | 68.68 (8) | Eu1—O3—H31 | 114.0 |
O14—Eu1—O1 | 70.11 (8) | Eu1—O3—H32 | 118.4 |
O21—Eu1—O1 | 134.41 (8) | H31—O3—H32 | 100.7 |
O4—Eu1—O1 | 74.62 (9) | Eu1—O4—H41 | 124.2 |
O11—Eu1—O1 | 73.70 (7) | Eu1—O4—H42 | 128.6 |
O2—Eu1—O1 | 140.48 (8) | H41—O4—H42 | 107.1 |
O14—Eu1—O13 | 100.98 (8) | O12—S1—O14ii | 111.97 (14) |
O21—Eu1—O13 | 140.61 (8) | O12—S1—O11i | 110.40 (14) |
O4—Eu1—O13 | 148.41 (8) | O14ii—S1—O11i | 109.58 (13) |
O11—Eu1—O13 | 75.44 (8) | O12—S1—O13 | 108.74 (14) |
O2—Eu1—O13 | 79.37 (8) | O14ii—S1—O13 | 107.30 (14) |
O1—Eu1—O13 | 79.97 (8) | O11i—S1—O13 | 108.75 (13) |
O14—Eu1—O3 | 73.11 (8) | O12—S1—Eu1 | 139.49 (10) |
O21—Eu1—O3 | 74.25 (8) | O14ii—S1—Eu1 | 77.87 (10) |
O4—Eu1—O3 | 142.36 (8) | O11i—S1—Eu1 | 101.82 (9) |
O11—Eu1—O3 | 133.73 (7) | S1i—O11—Eu1 | 142.72 (14) |
O2—Eu1—O3 | 76.72 (8) | S1—O13—Eu1 | 124.27 (13) |
O1—Eu1—O3 | 125.08 (8) | S1ii—O14—Eu1 | 161.88 (15) |
O13—Eu1—O3 | 68.63 (8) | O21—S2—O21iii | 109.6 (2) |
O14—Eu1—S1 | 84.02 (6) | O21—S2—O22 | 108.99 (13) |
O21—Eu1—S1 | 147.46 (6) | O21—S2—O22iii | 109.13 (13) |
O4—Eu1—S1 | 137.03 (7) | O22—S2—O22iii | 111.0 (2) |
O11—Eu1—S1 | 82.48 (5) | S2—O21—Eu1 | 149.58 (14) |
O2—Eu1—S1 | 99.91 (6) | ||
O14—Eu1—S1—O12 | −108.91 (17) | O2—Eu1—O11—S1i | −175.9 (2) |
O21—Eu1—S1—O12 | −48.3 (2) | O1—Eu1—O11—S1i | 16.4 (2) |
O4—Eu1—S1—O12 | 170.80 (18) | O13—Eu1—O11—S1i | 100.0 (2) |
O11—Eu1—S1—O12 | 104.91 (17) | O3—Eu1—O11—S1i | 139.71 (19) |
O2—Eu1—S1—O12 | 38.20 (17) | S1—Eu1—O11—S1i | 80.3 (2) |
O1—Eu1—S1—O12 | −179.60 (17) | O12—S1—O13—Eu1 | −155.83 (14) |
O13—Eu1—S1—O12 | 36.7 (2) | O14ii—S1—O13—Eu1 | −34.53 (19) |
O3—Eu1—S1—O12 | −34.81 (17) | O11i—S1—O13—Eu1 | 83.92 (17) |
O14—Eu1—S1—O14ii | 0.82 (15) | O14—Eu1—O13—S1 | 34.95 (17) |
O21—Eu1—S1—O14ii | 61.43 (15) | O21—Eu1—O13—S1 | 122.42 (16) |
O4—Eu1—S1—O14ii | −79.46 (13) | O4—Eu1—O13—S1 | −69.0 (2) |
O11—Eu1—S1—O14ii | −145.36 (11) | O11—Eu1—O13—S1 | −107.93 (16) |
O2—Eu1—S1—O14ii | 147.93 (11) | O2—Eu1—O13—S1 | −178.45 (17) |
O1—Eu1—S1—O14ii | −69.87 (11) | O1—Eu1—O13—S1 | −32.33 (15) |
O13—Eu1—S1—O14ii | 146.39 (19) | O3—Eu1—O13—S1 | 101.77 (16) |
O3—Eu1—S1—O14ii | 74.93 (11) | O21—Eu1—O14—S1ii | 31.0 (5) |
O14—Eu1—S1—O11i | 108.59 (11) | O4—Eu1—O14—S1ii | −39.7 (5) |
O21—Eu1—S1—O11i | 169.20 (14) | O11—Eu1—O14—S1ii | −108.8 (5) |
O4—Eu1—S1—O11i | 28.30 (14) | O2—Eu1—O14—S1ii | 83.6 (5) |
O11—Eu1—S1—O11i | −37.59 (14) | O1—Eu1—O14—S1ii | −114.1 (5) |
O2—Eu1—S1—O11i | −104.30 (11) | O13—Eu1—O14—S1ii | 170.9 (5) |
O1—Eu1—S1—O11i | 37.90 (11) | O3—Eu1—O14—S1ii | 107.5 (5) |
O13—Eu1—S1—O11i | −105.84 (19) | S1—Eu1—O14—S1ii | −177.4 (5) |
O3—Eu1—S1—O11i | −177.30 (11) | O21iii—S2—O21—Eu1 | 88.2 (3) |
O14—Eu1—S1—O13 | −145.56 (17) | O22—S2—O21—Eu1 | −31.1 (3) |
O21—Eu1—S1—O13 | −84.96 (19) | O22iii—S2—O21—Eu1 | −152.5 (3) |
O4—Eu1—S1—O13 | 134.15 (18) | O14—Eu1—O21—S2 | 88.9 (3) |
O11—Eu1—S1—O13 | 68.25 (17) | O4—Eu1—O21—S2 | −179.9 (3) |
O2—Eu1—S1—O13 | 1.54 (17) | O11—Eu1—O21—S2 | −119.3 (3) |
O1—Eu1—S1—O13 | 143.74 (17) | O2—Eu1—O21—S2 | −65.2 (3) |
O3—Eu1—S1—O13 | −71.46 (17) | O1—Eu1—O21—S2 | 137.7 (3) |
O14—Eu1—O11—S1i | 11.2 (3) | O13—Eu1—O21—S2 | −6.2 (4) |
O21—Eu1—O11—S1i | −117.1 (2) | O3—Eu1—O21—S2 | 13.7 (3) |
O4—Eu1—O11—S1i | −60.4 (2) | S1—Eu1—O21—S2 | 27.2 (4) |
Symmetry codes: (i) −x+1/2, −y+3/2, −z+1; (ii) −x+1/2, −y+1/2, −z+1; (iii) −x, y, −z+1/2. |
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H11···O3ii | 0.84 | 2.08 | 2.910 (3) | 170 |
O1—H12···O13i | 0.84 | 2.06 | 2.771 (3) | 143 |
O2—H21···O12iv | 0.84 | 1.87 | 2.704 (4) | 171 |
O2—H22···O22v | 0.84 | 1.99 | 2.814 (3) | 169 |
O3—H31···O22 | 0.84 | 1.96 | 2.759 (3) | 159 |
O3—H32···O13iv | 0.84 | 2.16 | 2.994 (3) | 170 |
O4—H41···O12vi | 0.84 | 1.93 | 2.748 (4) | 163 |
O4—H42···O22vii | 0.84 | 1.97 | 2.788 (4) | 165 |
Symmetry codes: (i) −x+1/2, −y+3/2, −z+1; (ii) −x+1/2, −y+1/2, −z+1; (iv) −x, −y+1, −z+1; (v) x, y+1, z; (vi) x, −y+1, z−1/2; (vii) x+1/2, y+1/2, z. |
Footnotes
‡Postal address: Department of Electrical Engineering and Physics, University of Dundee, Dundee DD1 4HN, Scotland.
Acknowledgements
X-ray data were collected at the EPSRC X-ray Crystallographic Service, University of Southampton, England; the authors thank the staff for all their help and advice. JNL thanks NCR Self-Service, Dundee, for grants which have provided computing facilities for this work.
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