Sodium trichloro­methane­sulfonate monohydrate

Sodium trichloro­methane­sulfonate monohydrate, Na⁺·CCl₃SO₃⁻·H₂O, crystallizes in P2₁/a with all the atoms located in general positions. The trichloro­methane­sulfonate (trichlate) anion consists of pyramidal SO₃ and CCl₃ groups connected via an S—C bond in a staggered conformation with approximate C_3v symmetry. The water mol­ecule is hydrogen bonded to the sulfonate O atoms, with one water H atom forming weak bifurcated O—H...O hydrogen bonds to two different trichlate ions. Two water O atoms and three O atoms from different SO₃ groups form a square-pyramidal arrangement around the sodium ion.

S1. Comment

Trichloromethanesulfonate (CCl₃SO₃^-) salts were first prepared more than 150 years ago (Kolbe, 1845). The trichlate and the related trifluoromethanesulfonate (CF₃SO₃^-) and mesylate (CH₃SO₃^-) anions have been studied by means of vibrational spectroscopy complemented by normal coordinate analysis (Miles et al., 1969; Bürger et al., 1970). Gejji et al. (1994) performed quantum chemical calculations of the structure and vibrational frequencies of trichloromethanesulfonic acid, CCl₃SO₃H, and its anion. Edwards & Smith (1991) reported vibrational assignments of the acid and determined its dissociation constant in 2 mol dm^-3 aqueous solution by Raman measurements. A recent ³⁵Cl nuclear quadrupole resonance study concluded that the trichlate anion has weaker coordination ability than several chloroacetate anions (Wulfsberg et al., 2004). The present study of sodium trichloromethanesulfonate monohydrate (CCl₃SO₃Na·H₂O) seems to be the first crystal structure reported containing a trichlate anion.

The crystal structure is described in the space group P2₁/a with all atoms located in general sites (4e). The pyramidal SO₃ and CCl₃ groups of the triclate anion are in a staggered conformation (Fig. 1 and Table 1). One water H atom (H42) is involved in a weak, bifurcated hydrogen bond to two O atoms, O1 and O2, of different trichlate ions, while the other H atom (H41) forms a shorter hydrogen bond (Fig. 1 and Table 2). The Na⁺ ion has an almost square-pyramidal environment of O atoms from two water molecules and three different SO₃ groups, with a mean Na⁺···O distance of 2.38 Å.

As shown in Table 3, the mean S—O bond distance is not significantly influenced by hydrogen bonding or by replacing the –CCl₃ group with –CH₃ or –CF₃. The C—S bond increases considerably from the mesylate (H₃C—SO₃^-) to the trifluoromethanesulfonate (F₃C—SO₃^-) ion, with an even longer C—S bond for the trichlate (Cl₃C—SO₃^-), as predicted by theoretical studies. The electron-withdrawing effect of the electronegative Cl and F atoms evidently weakens the C—S bond and makes the O—S—O angles about two degrees larger than in the mesylate ion. The mean C—Cl bond length and Cl—C—Cl angle determined in this work agree well with the values found for trichloromethane (Sutton, 1965). Please check all of the values in Table 2 carefully; O4—H42 distance in _geom_bond loop in CIF is 0.74 (5).

S2. Experimental

CCl₃SO₃Na·H₂O was obtained from a solution prepared by stirring and heating [323 (2) K] wax-like crystals of trichloromethanesulfonyl chloride (CCl₃SO₂Cl, 2.547 g, Aldrich) in an excess (36 ml) of 1 mol dm^-3 sodium hydroxide solution (Edwards & Smith, 1991). After evaporating the solvent, first in a rotary evaporator at 355 (2) K and then at reduced pressure in a vacuum desiccator, colourless crystals were obtained, which recrystallized from water.

Computing details

Data collection: EXPOSE in IPDS Software (Stoe & Cie, 1997); cell refinement: CELL in IPDS Software (Stoe & Cie, 1997); data reduction: INTEGRATE in IPDS Software (Stoe & Cie, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: DIAMOND (Bergerhoff, 1996); software used to prepare material for publication: SHELXL97 (Sheldrick, 1997) and PLATON (Spek, 2003).

Figures

Fig. 1. The trichlate ion and the environment of the sodium ion and the water molecule (40% probability displacement ellipsoids). Broken lines indicate hydrogen bonds (see Table 2 for geometric details).

Sodium trichloromethanesulfonate monohydrate

Crystal data

Na^+·CCl3O3S^−·H2O	F(000) = 472
Mr = 239.43	Dx = 2.072 Mg m^−3
MonoclinicP21/a	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yab	Cell parameters from 221 reflections
a = 10.727 (7) Å	θ = 3.5–27.1°
b = 5.828 (3) Å	µ = 1.47 mm^−1
c = 12.613 (9) Å	T = 291 K
β = 103.24 (8)°	Pentagonal prism, colourless
V = 767.6 (9) Å^3	0.5 × 0.3 × 0.1 mm
Z = 4

Data collection

Stoe IPDS diffractometer	1805 independent reflections
Radiation source: fine-focus sealed tube	1312 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.100
Detector resolution: 6.67 pixels mm^-1	θmax = 27.8°, θmin = 3.3°
φ scans	h = −14→14
Absorption correction: numerical (X-RED; Stoe & Cie, 1997)	k = −7→7
Tmin = 0.579, Tmax = 0.953	l = −16→16
6794 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.048	Hydrogen site location: difference Fourier map
wR(F^2) = 0.127	All H-atom parameters refined
S = 0.96	w = 1/[σ^2(Fo^2) + (0.0767P)^2] where P = (Fo^2 + 2Fc^2)/3
1805 reflections	(Δ/σ)max < 0.001
99 parameters	Δρmax = 0.86 e Å^−3
0 restraints	Δρmin = −0.43 e Å^−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.

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

	x	y	z	Uiso*/Ueq
S	0.05676 (7)	0.04739 (11)	0.17539 (7)	0.0266 (2)
O1	−0.0697 (2)	0.1198 (4)	0.1188 (2)	0.0379 (6)
O2	0.1600 (2)	0.1947 (4)	0.1607 (2)	0.0401 (6)
O3	0.0811 (2)	−0.1956 (4)	0.1632 (2)	0.0333 (5)
C	0.0572 (3)	0.0779 (5)	0.3212 (3)	0.0317 (7)
Cl1	−0.07508 (10)	−0.07896 (17)	0.34637 (9)	0.0490 (3)
Cl2	0.20084 (10)	−0.02867 (19)	0.40237 (9)	0.0544 (3)
Cl3	0.03900 (10)	0.37046 (15)	0.35018 (9)	0.0504 (3)
Na	−0.27893 (13)	−0.0510 (2)	0.09992 (13)	0.0393 (4)
O4	−0.3336 (3)	0.1051 (4)	−0.0781 (2)	0.0391 (6)
H41	−0.409 (5)	0.124 (7)	−0.116 (4)	0.045 (12)*
H42	−0.315 (5)	0.003 (9)	−0.107 (4)	0.057 (16)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
S	0.0232 (4)	0.0190 (4)	0.0403 (5)	−0.0016 (3)	0.0132 (3)	−0.0001 (3)
O1	0.0295 (12)	0.0314 (12)	0.0515 (15)	0.0041 (9)	0.0066 (10)	0.0024 (11)
O2	0.0377 (13)	0.0285 (12)	0.0617 (17)	−0.0095 (9)	0.0271 (12)	−0.0012 (11)
O3	0.0315 (11)	0.0195 (10)	0.0525 (15)	0.0002 (8)	0.0170 (10)	−0.0057 (10)
C	0.0335 (16)	0.0222 (13)	0.0419 (18)	0.0024 (12)	0.0142 (14)	−0.0014 (13)
Cl1	0.0537 (6)	0.0431 (5)	0.0606 (6)	−0.0089 (4)	0.0349 (5)	0.0012 (4)
Cl2	0.0479 (6)	0.0595 (6)	0.0507 (6)	0.0182 (4)	0.0007 (4)	−0.0009 (5)
Cl3	0.0650 (6)	0.0248 (4)	0.0639 (7)	0.0042 (4)	0.0201 (5)	−0.0117 (4)
Na	0.0325 (7)	0.0251 (6)	0.0652 (10)	0.0040 (5)	0.0211 (7)	0.0080 (6)
O4	0.0313 (13)	0.0244 (12)	0.0607 (18)	0.0029 (9)	0.0087 (12)	−0.0037 (11)

Geometric parameters (Å, º)

S—O1	1.444 (3)	Na—O2^iii	2.358 (3)
S—O2	1.446 (2)	Na—O4	2.368 (4)
S—O3	1.455 (2)	Na—O3^iv	2.371 (3)
S—C	1.847 (4)	Na—O4^v	2.388 (3)
O1—Na	2.417 (3)	Na—Na^v	3.993 (3)
O2—Na^i	2.358 (3)	Na—Na^vi	3.993 (3)
O3—Na^ii	2.371 (3)	Na—H42	2.57 (5)
C—Cl2	1.757 (4)	O4—Na^vi	2.388 (3)
C—Cl3	1.764 (3)	O4—H41	0.85 (5)
C—Cl1	1.777 (3)	O4—H42	0.74 (5)
O1—S—O2	115.05 (15)	O2^iii—Na—Na^v	160.53 (10)
O1—S—O3	113.80 (14)	O4—Na—Na^v	73.89 (10)
O2—S—O3	113.77 (13)	O3^iv—Na—Na^v	87.72 (8)
O1—S—C	104.58 (17)	O4^v—Na—Na^v	32.74 (8)
O2—S—C	104.09 (16)	O1—Na—Na^v	95.04 (9)
O3—S—C	103.84 (14)	O2^iii—Na—Na^vi	69.96 (7)
S—O1—Na	132.41 (15)	O4—Na—Na^vi	33.05 (7)
S—O2—Na^i	147.40 (16)	O3^iv—Na—Na^vi	150.34 (9)
S—O3—Na^ii	141.68 (13)	O4^v—Na—Na^vi	112.57 (10)
Cl2—C—Cl3	110.18 (19)	O1—Na—Na^vi	59.10 (8)
Cl2—C—Cl1	110.11 (19)	Na^v—Na—Na^vi	93.72 (8)
Cl3—C—Cl1	109.25 (17)	O2^iii—Na—H42	103.5 (12)
Cl2—C—S	110.37 (18)	O4—Na—H42	16.8 (12)
Cl3—C—S	108.92 (18)	O3^iv—Na—H42	117.3 (11)
Cl1—C—S	107.97 (19)	O4^v—Na—H42	87.1 (12)
O2^iii—Na—O4	86.72 (11)	O1—Na—H42	88.3 (11)
O2^iii—Na—O3^iv	101.21 (10)	Na^v—Na—H42	57.2 (12)
O4—Na—O3^iv	121.34 (12)	Na^vi—Na—H42	43.8 (11)
O2^iii—Na—O4^v	164.20 (12)	Na—O4—Na^vi	114.21 (13)
O4—Na—O4^v	103.58 (9)	Na—O4—H41	125 (3)
O3^iv—Na—O4^v	83.81 (10)	Na^vi—O4—H41	106 (3)
O2^iii—Na—O1	85.76 (10)	Na—O4—H42	97 (4)
O4—Na—O1	87.58 (12)	Na^vi—O4—H42	115 (4)
O3^iv—Na—O1	150.33 (11)	H41—O4—H42	99 (5)
O4^v—Na—O1	82.80 (10)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O4—H41···O3^vi	0.85 (5)	2.09 (5)	2.871 (4)	153 (4)
O4—H42···O1^v	0.75 (5)	2.54 (5)	3.016 (4)	123 (5)
O4—H42···O2^vii	0.75 (5)	2.25 (5)	2.915 (4)	148 (5)

Symmetry codes: (v) −x−1/2, y−1/2, −z; (vi) −x−1/2, y+1/2, −z; (vii) −x, −y, −z.