Hexa­aqua­bis­(di­methyl sulfoxide)­yttrium(III) trichloride

The title compound, [Y(C₂H₆OS)₂(H₂O)₆]Cl₃, contains the cation [Y(H₂O)₆{(CH₃)₂SO}₂]³⁺ with a distorted square antiprismatic geometry of the eight coordinated O atoms. The six water mol­ecules are coordinated with an average Y-O distance of 2.38 (2) Å, ranging from 2.360 (3) to 2.404 (3) Å. Each water mol­ecule forms two hydrogen bonds to the chloride anions with O-Cl distances ranging from 3.068 (4) to 3.422 (4) Å. The two di­methyl­ sulfoxide ligands, situated in the cis position with the O-Y-O angle equal to 83.22 (11)°, have Y-O distances of 2.269 (3) and 2.278 (3) Å.

S1. Comment

Diffraction from ionic solutions often gives restricted structural information since the two-dimensional radial distribution function obtained can not normally be separated into individual pair distribution functions unless further experiments are made. In some cases, where suitable pairs of isotopes are available, the spatial correlation between an ion and its surrounding solvent molecules may be unambigously determined by isotopic substitution neutron diffraction (Soper et al., 1977). The characterization of crystalline solvated salts is one of the most important sources of information for the structure of liquid solutions since the liquid phase may, in many cases, be regarded as the dynamic analogue of the crystalline phase. The crystalline structure may therefore serve as model for the local structure of the metal ion in solution. For example, crystalline alum salts, CsM(SO₄)₂(H₂O)₁₂, are ideal to model the first hydration sphere of the hexa-aqua chromium(III), gallium(III) and indium(III) cations in aqueous solution (Lindqvist-Reis et al., 1998). It has recently been shown, by high resolution EXAFS measurements, that the local environment of the yttrium(III) ion in aqueous solution is very similar to that observed in crystalline [Y(H₂O)₈]Cl₃ (15-crown-5), where the water molecules are coordinated to the yttrium(III) ion to form a distorted dodecahedron with Y—O distances ranging from 2.322 (6) to 2.432 (7) Å (Lindqvist-Reis, Pattanaik et al., 1999). The 15-crown-5 molecules form hydrogen bonds to the hydrated cation and the chloride anions and, in that respect, mimic a second hydration sphere in solution. In dimethylsulphoxide (DMSO) solutions, the yttrium(III) ion coordinates dmso molecules with an average Y—O distance of 2.36 (1) Å as compared to crystalline [Y(CH₃)₂SO)₈]I₃ where the dmso molecules are distributed into two groups, one with Y—O distances ranging from 2.311 (4) to 2.320 (4) Å while in the other group Y—O distances between 2.352 (4) and 2.368 (4) Å are observed (Lindqvist-Reis, Naslund et al., 1999).

In the present contribution we wish to present the structure of the mixed aqua/dmso complex cation [Y(H₂O)₆((CH₃)₂SO)₂]³⁺ where the two different oxygen donating ligands form a distorted square antiprism (Fig. 1). The six water molecules are coordinated with an average Y—O distance of 2.38 (2) Å, ranging from 2.360 (3) to 2.404 (3) Å. No significant trans influence produced by the dmso ligands can be observed. Each water molecule forms two hydrogen bonds to the chloride ions. The average hydrogen-bonded O—Cl distance is 3.18 (9) Å, ranging from 3.068 (4) to 3.422 (4) Å. The two dmso molecules, situated at cis positions with the O1—Y—O2 angle equal to 83.22 (11)°, have Y—O distances of 2.269 (3) and 2.278 (3) Å, significantly shorter than those observed in the [Y(CH₃)₂SO)₈]³⁺ cation (Lindqvist-Reis, Naslund et al., 1999). At room temperature, both dmso molecules are disordered in two positions which were both resolved and independently refined. The main form (84.304 and 86.482% for S1 and S2, respectively) is transformed into the other by an inversion of the sulfur atom through the plane defined by C1, C2, O1 and Y1 (mean deviation from plane = 0.007 Å). The perpendicular distance of the S1 and S1A atoms to this plane is −0.71 and + 0.65 Å, respectively (Figure 2).

S2. Experimental

The title compound was synthesized by dissolving yttrium oxide in dilute hydrochloric acid on stirring and heating. The solution was concentrated by slow evaporation followed by addition of DMSO (DMSO:H₂O = 1:3). After further evaporation in excicator, crystals of X-ray quality were obtained.

The yttrium and chloride content was determined by edta titration and by anion exchange (Dowex 50 W-X8, H⁺-form), respectively. Identification of the coordinated DMSO molecules was achieved by comparing the Raman spectrum (BioRad FTS 6000 spectrometer) of the crystals with that of liquid DMSO.

S3. Refinement

Water-H atoms were located on difference Fourier maps but the O—H distances were constrained to 0.82 Å. Methyl-H atoms were generated in ideal positions and were riding on their respective carbon atom.

Computing details

Data collection: SMART (Bruker, 1998b); cell refinement: SMART and SAINT (Bruker, 1998b); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Bruker, 1998a); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Figures

	Fig. 1. The molecular structure of [Y(H2O)6{(CH3)2SO}2]^3+ with displacement ellipsoids drawn at the 30% probability level for all non-H atoms.
	Fig. 2. One dmso ligand coordinated to the Y^3+ cation showing the two disordered positions of the sulfur atom. The displacement ellipsoids are drawn at the 30% probability level. Hydrogen atoms are not shown for clarity.

Hexaaquabis(dimethylsulphoxide)yttrium(III) Chloride

Crystal data

[Y(C2H6OS)2(H2O)6]Cl3	F(000) = 936
Mr = 459.61	Dx = 1.659 Mg m^−3 Dm = 1.658 Mg m^−3 Dm measured by flotation in tetrabromoethane/dichloromethane mixtures
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 8.7942 (11) Å	Cell parameters from 2682 reflections
b = 12.3337 (15) Å	θ = 2.0–28.5°
c = 17.291 (2) Å	µ = 3.85 mm^−1
β = 101.201 (2)°	T = 298 K
V = 1839.7 (4) Å^3	Prism, colourless
Z = 4	0.22 × 0.20 × 0.18 mm

Data collection

Bruker SMART CCD diffractometer	4261 independent reflections
Radiation source: fine-focus sealed tube	2682 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.055
ω scans	θmax = 28.5°, θmin = 2.0°
Absorption correction: empirical (using intensity measurements) Bruker SADABS (1998c)	h = −11→10
Tmin = 0.445, Tmax = 0.500	k = −16→15
10933 measured reflections	l = −22→19

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.044	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.099	w = 1/[σ^2(Fo^2) + (0.0432P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 0.94	(Δ/σ)max < 0.001
4261 reflections	Δρmax = 0.49 e Å^−3
233 parameters	Δρmin = −0.38 e Å^−3
12 restraints	Extinction correction: SHELXL (Bruker, 1998a), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0007 (3)

Special details

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

A hemisphere of data (1375 frames) was collected with 0.3 ° frame width and a detector - crystal distance of 5.00 cm. The detector was positioned with Θ = 28.0 °. Data were recorded in three series with ϕ = 0, 88 and 180 ° with 20 s exposure time. The data set is complete to 95.0% to Θ = 28.0 °.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq	Occ. (<1)
Y1	0.75788 (5)	0.57626 (3)	0.14854 (2)	0.02824 (13)
S1	0.77629 (17)	0.47428 (12)	0.34419 (8)	0.0456 (5)	0.843 (3)
S1A	0.6862 (9)	0.5642 (6)	0.3411 (4)	0.044 (3)	0.157 (3)
S2	0.71144 (16)	0.27436 (10)	0.13828 (8)	0.0375 (5)	0.865 (4)
S2A	0.7933 (15)	0.3034 (8)	0.2018 (7)	0.066 (4)	0.135 (4)
O1	0.7865 (4)	0.5578 (2)	0.28167 (16)	0.0422 (8)
O2	0.7052 (4)	0.3962 (2)	0.1489 (2)	0.0494 (9)
C1	0.8332 (8)	0.5467 (5)	0.4330 (3)	0.086 (2)
H1A	0.9165	0.5090	0.4664	0.129*
H1B	0.7469	0.5526	0.4592	0.129*
H1C	0.8673	0.6179	0.4217	0.129*
C2	0.5788 (6)	0.4571 (5)	0.3454 (4)	0.0793 (19)
H2A	0.5558	0.3812	0.3473	0.119*
H2B	0.5179	0.4883	0.2986	0.119*
H2C	0.5545	0.4925	0.3909	0.119*
C3	0.6727 (7)	0.2175 (4)	0.2241 (3)	0.0732 (18)
H3A	0.5880	0.1674	0.2111	0.110*
H3B	0.6456	0.2737	0.2574	0.110*
H3C	0.7629	0.1798	0.2512	0.110*
C4	0.9105 (6)	0.2428 (4)	0.1513 (3)	0.0617 (15)
H4A	0.9300	0.2052	0.1056	0.093*
H4B	0.9398	0.1976	0.1969	0.093*
H4C	0.9701	0.3085	0.1584	0.093*
O3	0.6020 (4)	0.6711 (4)	0.0398 (2)	0.0624 (11)
O4	0.9235 (4)	0.7115 (3)	0.1134 (2)	0.0555 (10)
O5	0.8361 (4)	0.5116 (3)	0.03386 (19)	0.0475 (9)
O6	1.0152 (4)	0.5118 (3)	0.1916 (2)	0.0462 (8)
O7	0.6925 (4)	0.7425 (3)	0.2028 (2)	0.0429 (8)
O8	0.4936 (4)	0.5540 (3)	0.1564 (2)	0.0454 (8)
H31	0.517 (3)	0.700 (3)	0.036 (2)	0.041 (14)*
H32	0.621 (6)	0.668 (4)	−0.0035 (17)	0.067 (18)*
H41	1.008 (3)	0.695 (4)	0.104 (3)	0.062 (17)*
H42	0.910 (6)	0.775 (2)	0.124 (3)	0.08 (2)*
H51	0.838 (7)	0.546 (4)	−0.007 (2)	0.07 (2)*
H52	0.826 (5)	0.450 (2)	0.016 (3)	0.045 (15)*
H61	1.058 (6)	0.498 (4)	0.2367 (15)	0.064 (18)*
H62	1.063 (5)	0.482 (4)	0.163 (2)	0.057 (17)*
H71	0.703 (6)	0.746 (4)	0.2506 (12)	0.08 (2)*
H72	0.723 (8)	0.801 (3)	0.188 (4)	0.13 (3)*
H81	0.430 (4)	0.597 (3)	0.134 (3)	0.051 (17)*
H82	0.453 (5)	0.495 (2)	0.155 (2)	0.037 (13)*
Cl1	0.81849 (15)	0.94934 (9)	0.13944 (7)	0.0453 (3)
Cl2	0.72359 (14)	0.85052 (10)	0.37717 (7)	0.0480 (3)
Cl3	0.75603 (14)	0.20499 (9)	0.44176 (7)	0.0478 (3)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Y1	0.0302 (2)	0.0302 (2)	0.0253 (2)	−0.00162 (19)	0.00782 (15)	−0.00031 (18)
S2	0.0428 (9)	0.0302 (8)	0.0400 (10)	−0.0001 (6)	0.0095 (7)	0.0032 (6)
Cl3	0.0457 (7)	0.0514 (7)	0.0473 (7)	−0.0071 (6)	0.0117 (6)	0.0110 (6)
Cl2	0.0553 (8)	0.0532 (7)	0.0367 (6)	0.0132 (6)	0.0120 (5)	−0.0069 (5)
S1	0.0476 (10)	0.0485 (10)	0.0446 (9)	0.0059 (7)	0.0181 (7)	0.0154 (7)
O8	0.033 (2)	0.036 (2)	0.069 (2)	−0.0022 (17)	0.0110 (17)	0.0005 (18)
O7	0.063 (2)	0.0326 (19)	0.038 (2)	−0.0008 (16)	0.0216 (18)	−0.0007 (16)
O1	0.052 (2)	0.047 (2)	0.0282 (16)	−0.0027 (15)	0.0090 (14)	0.0066 (14)
O6	0.039 (2)	0.065 (2)	0.036 (2)	0.0099 (18)	0.0082 (17)	0.0011 (19)
O5	0.077 (3)	0.037 (2)	0.0308 (19)	−0.0024 (18)	0.0182 (17)	−0.0052 (17)
O4	0.051 (2)	0.036 (2)	0.090 (3)	−0.0017 (19)	0.040 (2)	0.000 (2)
O3	0.049 (2)	0.107 (3)	0.033 (2)	0.028 (2)	0.0120 (18)	0.022 (2)
Cl1	0.0545 (8)	0.0384 (7)	0.0441 (7)	−0.0065 (5)	0.0122 (5)	−0.0004 (5)
O	0.047 (2)	0.0274 (17)	0.075 (3)	0.0042 (14)	0.0148 (17)	0.0070 (16)
C4	0.050 (3)	0.046 (3)	0.095 (4)	0.010 (3)	0.027 (3)	0.019 (3)
C3	0.082 (5)	0.055 (3)	0.092 (5)	0.010 (3)	0.043 (4)	0.022 (3)
C2	0.060 (4)	0.104 (5)	0.079 (4)	−0.004 (3)	0.026 (3)	0.037 (4)
C1	0.093 (5)	0.137 (6)	0.027 (3)	−0.008 (4)	0.009 (3)	0.010 (3)
S1A	0.048 (5)	0.049 (5)	0.035 (4)	0.006 (4)	0.010 (3)	0.009 (3)
S2A	0.103 (10)	0.035 (6)	0.062 (8)	0.008 (6)	0.024 (7)	−0.003 (5)

Geometric parameters (Å, º)

Y1—O2	2.269 (3)	S2—O2	1.516 (3)
Y1—O1	2.278 (3)	S2—C3	1.734 (5)
Y1—O5	2.360 (3)	S2—C4	1.765 (5)
Y1—O4	2.370 (3)	S1—S1A	1.358 (8)
Y1—O8	2.371 (3)	S1—O1	1.508 (3)
Y1—O7	2.372 (3)	S1—C2	1.754 (6)
Y1—O6	2.377 (3)	S1—C1	1.763 (6)
Y1—O3	2.404 (4)	O1—S1A	1.481 (8)
S2—S2A	1.244 (13)	O—S2A	1.572 (11)
O2—Y1—O1	83.22 (11)	O4—Y1—O3	75.10 (14)
O2—Y1—O5	76.38 (12)	O8—Y1—O3	71.64 (13)
O1—Y1—O5	145.31 (12)	O7—Y1—O3	75.16 (14)
O2—Y1—O4	145.65 (12)	O6—Y1—O3	140.45 (12)
O1—Y1—O4	112.12 (13)	S2A—S2—O2	68.6 (5)
O5—Y1—O4	74.25 (13)	S2A—S2—C3	62.4 (5)
O2—Y1—O8	71.54 (12)	O2—S2—C3	106.3 (2)
O1—Y1—O8	81.21 (12)	S2A—S2—C4	64.0 (6)
O5—Y1—O8	117.28 (13)	O2—S2—C4	105.1 (2)
O4—Y1—O8	139.00 (13)	C3—S2—C4	99.0 (3)
O2—Y1—O7	141.23 (12)	S1A—S1—O1	62.0 (3)
O1—Y1—O7	70.98 (11)	S1A—S1—C2	61.8 (4)
O5—Y1—O7	139.22 (12)	O1—S1—C2	106.7 (2)
O4—Y1—O7	72.62 (12)	S1A—S1—C1	71.7 (4)
O8—Y1—O7	76.20 (12)	O1—S1—C1	103.4 (2)
O2—Y1—O6	81.61 (12)	C2—S1—C1	99.5 (3)
O1—Y1—O6	74.83 (12)	S1A—O1—S1	54.0 (3)
O5—Y1—O6	74.65 (13)	S1A—O1—Y1	137.1 (4)
O4—Y1—O6	73.79 (13)	S1—O1—Y1	141.45 (18)
O8—Y1—O6	145.82 (12)	S2—O2—S2A	47.5 (4)
O7—Y1—O6	117.02 (13)	S2—O2—Y1	163.3 (2)
O2—Y1—O3	113.11 (14)	S2A—O2—Y1	129.5 (5)
O1—Y1—O3	140.64 (12)	S1—S1A—O1	64.0 (4)
O5—Y1—O3	73.87 (13)	S2—S2A—O2	63.9 (6)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O8—H82···Cl2^i	0.81 (2)	2.35 (2)	3.138 (4)	162 (4)
O5—H52···Cl3^ii	0.82 (2)	2.31 (2)	3.120 (4)	167 (4)
O8—H81···Cl3^iii	0.82 (2)	2.30 (2)	3.118 (4)	174 (5)
O5—H51···Cl2^iv	0.82 (2)	2.43 (3)	3.189 (4)	155 (5)
O3—H32···Cl2^iv	0.80 (2)	2.42 (2)	3.207 (4)	170 (5)
O3—H31···Cl3^iii	0.82 (2)	2.51 (3)	3.253 (4)	152 (4)
O6—H62···Cl2^v	0.80 (2)	2.67 (3)	3.422 (4)	157 (5)
O7—H72···Cl1	0.83 (2)	2.25 (2)	3.068 (4)	174 (7)
O6—H61···Cl1^v	0.81 (2)	2.29 (2)	3.099 (4)	176 (5)
O4—H42···Cl1	0.81 (2)	2.33 (2)	3.134 (4)	168 (6)
O7—H71···Cl2	0.81 (2)	2.52 (3)	3.258 (4)	152 (5)
O4—H41···Cl3^vi	0.81 (2)	2.37 (2)	3.147 (4)	161 (5)

Symmetry codes: (i) −x+1, y−1/2, −z+1/2; (ii) x, −y+1/2, z−1/2; (iii) −x+1, y+1/2, −z+1/2; (iv) x, −y+3/2, z−1/2; (v) −x+2, y−1/2, −z+1/2; (vi) −x+2, y+1/2, −z+1/2.