Potassium sodium (2R,3R)-tartrate tetra-hydrate: the paraelectric phase of Rochelle salt at 105 K.

Rochelle salt, K(+)·Na(+)·C(4)H(4)O(6) (2-)·4H(2)O, is known for its remarkable ferroelectric state between 255 and 297 K. The current investigation, based on data collected at 105 K, provides very accurate structural information for the low-temperature paraelectric form. Unlike the ferroelectric form, there is only one tartrate molecule in the asymmetric unit, and the structure displays no disorder to large anisotropic atomic displacements.

Related literature

For previous and related structures, see: Beevers & Hughes (1941 ▶); Iwata et al. (1989 ▶); Solans et al. (1997 ▶); Ottenz et al. (1998 ▶); Hinazumi & Mitsui (1972 ▶); Kay (1978 ▶); Kuroda & Mason (1981 ▶); Brożek & Stadnicka (1994 ▶); Suzuki et al. (1996a ▶,b ▶); Ambady & Kartha (1968 ▶); Boese et al. (1995 ▶). For irradiation studies, see: Suzuki (1974 ▶); Treeck, van & Windsch (1977 ▶). For a description of the Cambridge Structural Database, see: Allen (2002 ▶).

Experimental

Crystal data

K+·Na+·C4H4O6 2−·4H2O

M = 282.23

Orthorhombic,

a = 11.7859 (6) Å

b = 14.1972 (7) Å

c = 6.1875 (3) Å

V = 1035.33 (9) Å3

Z = 4

Mo Kα radiation

μ = 0.60 mm−1

T = 105 (2) K

0.5 mm (radius)

Data collection

Siemens SMART CCD diffractometer

Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T min = 0.398, T max = 0.551 (expected range = 0.722–1.000)

33523 measured reflections

10040 independent reflections

8947 reflections with I > 2σ(I)

R int = 0.037

Refinement

R[F 2 > 2σ(F 2)] = 0.029

wR(F 2) = 0.069

S = 1.06

10040 reflections

195 parameters

12 restraints

All H-atom parameters refined

Δρmax = 0.50 e Å−3

Δρmin = −0.73 e Å−3

Absolute structure: Flack, 1983 ▶, 4266 Friedel pairs

Flack parameter: 0.044 (14)

Data collection: SMART (Bruker, 1998 ▶); cell refinement: SAINT-Plus (Bruker, 2001 ▶); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808005266/bg2163sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808005266/bg2163Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

K+·Na+·C4H4O62–·4H2O	Dx = 1.811 Mg m−3
Mr = 282.23	Mo Kα radiation λ = 0.71073 Å
Orthorhombic, P21212	Cell parameters from 10000 reflections
a = 11.7859 (6) Å	θ = 2.9–49.7º
b = 14.1972 (7) Å	µ = 0.60 mm−1
c = 6.1875 (3) Å	T = 105 (2) K
V = 1035.33 (9) Å3	Sphere, colourless
Z = 4	0.5 mm (radius)
F000 = 584

Siemens SMART CCD diffractometer	10040 independent reflections
Radiation source: fine-focus sealed tube	8947 reflections with I > 2σ(I)
Monochromator: graphite	Rint = 0.037
Detector resolution: 8.3 pixels mm-1	θmax = 49.7º
T = 105(2) K	θmin = 2.9º
sets of exposures each taken over 0.3° ω rotation scans	h = −25→25
Absorption correction: multi-scan(SADABS; Sheldrick, 1996)	k = −28→30
Tmin = 0.398, Tmax = 0.551	l = −12→12
33523 measured reflections

Refinement on F2	All H-atom parameters refined
Least-squares matrix: full	w = 1/[σ2(Fo2) + (0.0324P)2 + 0.0088P] where P = (Fo2 + 2Fc2)/3
R[F2 > 2σ(F2)] = 0.029	(Δ/σ)max = 0.002
wR(F2) = 0.069	Δρmax = 0.50 e Å−3
S = 1.06	Δρmin = −0.73 e Å−3
10040 reflections	Extinction correction: SHELXTL (Bruker, 2000), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
195 parameters	Extinction coefficient: 0.132 (3)
12 restraints	Absolute structure: Flack, 1983, 4266 Friedel pairs
Primary atom site location: structure-invariant direct methods	Flack parameter: 0.044 (14)
Hydrogen site location: difference Fourier map

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. Data were collected by measuring six sets of exposures with the detector set at 2θ = 29° and 65°, crystal-to-detector distance 5.00 cm. Refinement of F2 against ALL reflections.

	x	y	z	Uiso*/Ueq
K1	0.0000	0.0000	0.04255 (4)	0.02054 (4)
K2	0.5000	0.0000	0.83902 (3)	0.01318 (3)
Na	0.23248 (2)	−0.007143 (18)	0.51526 (4)	0.01041 (4)
O1	0.12000 (3)	0.10859 (3)	0.34799 (7)	0.01016 (5)
O2	0.21269 (4)	0.20379 (3)	0.11755 (7)	0.01211 (6)
O3	0.22830 (4)	0.40729 (3)	0.82011 (8)	0.01585 (7)
O4	0.04765 (4)	0.35891 (3)	0.84893 (8)	0.01439 (7)
O5	0.16547 (4)	0.35790 (3)	0.32421 (7)	0.01060 (5)
H5	0.1932 (12)	0.3393 (11)	0.216 (3)	0.021 (3)*
O6	0.29638 (3)	0.24888 (3)	0.63394 (7)	0.01132 (6)
H6	0.3284 (13)	0.2989 (11)	0.584 (3)	0.025 (3)*
C1	0.15538 (4)	0.18798 (3)	0.28320 (8)	0.00798 (6)
C2	0.12505 (4)	0.27375 (3)	0.42269 (8)	0.00802 (6)
H2	0.0351 (13)	0.2714 (11)	0.429 (3)	0.024 (3)*
C3	0.17752 (4)	0.26353 (3)	0.64784 (8)	0.00867 (6)
H3	0.1368 (13)	0.2117 (11)	0.726 (3)	0.027 (4)*
C4	0.14865 (5)	0.35032 (4)	0.78496 (9)	0.01035 (6)
O1W	0.39615 (4)	0.08350 (3)	0.48487 (8)	0.01405 (7)
H11W	0.3642 (12)	0.1317 (8)	0.527 (2)	0.023 (3)*
H12W	0.4433 (14)	0.0974 (13)	0.388 (3)	0.058 (6)*
O2W	0.23689 (6)	0.04149 (3)	0.87925 (8)	0.02083 (10)
H21W	0.2524 (16)	0.0009 (10)	0.980 (2)	0.045 (5)*
H22W	0.2331 (16)	0.0930 (8)	0.953 (3)	0.044 (5)*
O3W	0.05896 (4)	−0.19201 (4)	−0.03036 (10)	0.01860 (8)
H31W	0.1210 (11)	−0.2072 (13)	0.028 (3)	0.051 (6)*
H32W	0.0307 (13)	−0.2458 (8)	−0.066 (3)	0.037 (5)*
O4W	0.07835 (4)	−0.10799 (4)	0.57031 (9)	0.01684 (8)
H41W	0.0099 (9)	−0.1009 (14)	0.526 (3)	0.054 (6)*
H42W	0.0734 (12)	−0.1431 (10)	0.6784 (19)	0.026 (4)*

	U11	U22	U33	U12	U13	U23
K1	0.02786 (8)	0.01565 (7)	0.01810 (8)	−0.00967 (7)	0.000	0.000
K2	0.01563 (5)	0.01227 (5)	0.01164 (6)	−0.00229 (5)	0.000	0.000
Na	0.01174 (8)	0.00770 (8)	0.01179 (9)	−0.00031 (6)	−0.00041 (6)	0.00065 (7)
O1	0.01294 (12)	0.00587 (11)	0.01166 (15)	−0.00070 (9)	−0.00034 (11)	0.00031 (10)
O2	0.01710 (14)	0.00966 (13)	0.00956 (15)	−0.00019 (11)	0.00367 (11)	−0.00079 (10)
O3	0.02292 (18)	0.01090 (15)	0.01373 (18)	−0.00454 (13)	−0.00006 (14)	−0.00398 (12)
O4	0.01600 (14)	0.01549 (16)	0.01168 (16)	0.00482 (12)	0.00046 (12)	−0.00285 (13)
O5	0.01694 (14)	0.00605 (12)	0.00880 (14)	−0.00054 (10)	−0.00024 (11)	0.00062 (9)
O6	0.01094 (12)	0.00955 (13)	0.01345 (16)	0.00182 (10)	−0.00145 (10)	0.00072 (11)
C1	0.01007 (13)	0.00605 (13)	0.00782 (15)	0.00050 (11)	−0.00097 (11)	−0.00050 (10)
C2	0.01034 (13)	0.00591 (13)	0.00780 (16)	0.00042 (11)	−0.00044 (11)	−0.00038 (10)
C3	0.01152 (13)	0.00669 (14)	0.00780 (16)	0.00042 (11)	−0.00063 (12)	−0.00042 (11)
C4	0.01571 (16)	0.00818 (15)	0.00715 (16)	0.00110 (13)	−0.00097 (13)	−0.00082 (11)
O1W	0.01351 (14)	0.01088 (14)	0.01774 (19)	−0.00051 (11)	0.00272 (12)	0.00068 (12)
O2W	0.0434 (3)	0.00952 (15)	0.00958 (18)	0.00494 (17)	0.00155 (17)	−0.00014 (11)
O3W	0.01445 (15)	0.0230 (2)	0.0183 (2)	0.00034 (14)	−0.00277 (14)	0.00046 (16)
O4W	0.01251 (14)	0.01583 (17)	0.0222 (2)	−0.00316 (12)	−0.00284 (13)	0.00420 (15)

K1—O1	2.8194 (4)	O2—C1	1.2479 (6)
K1—O1i	2.8194 (4)	O3—C4	1.2581 (7)
K1—O3Wi	2.8491 (6)	O4—C4	1.2604 (7)
K1—O3W	2.8491 (6)	O5—C2	1.4232 (6)
K1—O2Wii	3.0271 (7)	O5—H5	0.789 (17)
K1—O2Wiii	3.0270 (7)	O6—C3	1.4188 (6)
K2—O1W	2.7758 (5)	O6—H6	0.861 (16)
K2—O1Wiv	2.7758 (5)	C1—C2	1.5348 (7)
K2—O4v	2.8383 (5)	C2—C3	1.5311 (7)
K2—O4vi	2.8383 (5)	C2—H2	1.062 (15)
K2—O5vii	2.9822 (4)	C3—C4	1.5342 (7)
K2—O5viii	2.9822 (4)	C3—H3	1.004 (17)
K2—O2W	3.1662 (7)	O1W—H11W	0.824 (8)
K2—O2Wiv	3.1662 (7)	O1W—H12W	0.843 (9)
Na—O1W	2.3264 (5)	O2W—H21W	0.868 (9)
Na—O4W	2.3379 (5)	O2W—H22W	0.862 (9)
Na—O1	2.3512 (5)	O3W—H31W	0.843 (9)
Na—O2W	2.3562 (6)	O3W—H32W	0.862 (8)
Na—O3vii	2.4485 (6)	O4W—H41W	0.858 (9)
Na—O5vii	2.4707 (5)	O4W—H42W	0.836 (8)
O1—C1	1.2668 (6)
O2—C1—O1	126.74 (5)	C2—C3—C4	109.72 (4)
O2—C1—C2	116.44 (4)	O6—C3—H3	113.2 (9)
O1—C1—C2	116.82 (4)	C2—C3—H3	108.4 (10)
O5—C2—C3	109.50 (4)	C4—C3—H3	102.5 (10)
O5—C2—C1	110.32 (4)	O3—C4—O4	126.03 (5)
C3—C2—C1	110.02 (4)	O3—C4—C3	116.52 (5)
O5—C2—H2	112.1 (8)	O4—C4—C3	117.44 (5)
C3—C2—H2	111.5 (9)	H11W—O1W—H12W	109.6 (12)
C1—C2—H2	103.2 (9)	H21W—O2W—H22W	101.2 (11)
O6—C3—C2	110.95 (4)	H31W—O3W—H32W	102.7 (11)
O6—C3—C4	111.73 (4)	H41W—O4W—H42W	105.2 (11)
O2—C1—C2—O5	3.05 (6)	O5—C2—C3—C4	57.57 (5)
O1—C1—C2—O5	−177.09 (4)	C1—C2—C3—C4	178.98 (4)
O2—C1—C2—C3	−117.87 (5)	O6—C3—C4—O3	16.43 (7)
O1—C1—C2—C3	61.98 (5)	C2—C3—C4—O3	−107.06 (5)
O5—C2—C3—O6	−66.37 (5)	O6—C3—C4—O4	−164.68 (5)
C1—C2—C3—O6	55.04 (5)	C2—C3—C4—O4	71.84 (6)

D—H···A	D—H	H···A	D···A	D—H···A
O5—H5···O2	0.789 (17)	2.031 (16)	2.5946 (6)	128.2 (14)
O6—H6···O4Wix	0.861 (16)	1.968 (16)	2.8119 (7)	166.5 (16)
O1W—H11W···O6	0.824 (8)	1.960 (8)	2.7832 (6)	176.8 (15)
O1W—H12W···O4viii	0.843 (9)	2.010 (9)	2.8500 (7)	174.8 (18)
O2W—H21W···O3vi	0.868 (9)	1.830 (9)	2.6941 (7)	173.4 (19)
O2W—H22W···O2x	0.862 (9)	1.890 (9)	2.7505 (7)	175.5 (19)
O3W—H31W···O6vii	0.843 (9)	2.391 (15)	3.1029 (7)	142.5 (19)
O3W—H31W···O2xi	0.843 (9)	2.499 (17)	3.1181 (7)	131.0 (17)
O3W—H31W···O3vii	0.843 (9)	2.584 (14)	3.1569 (8)	126.2 (15)
O3W—H32W···O4ii	0.862 (8)	1.926 (8)	2.7842 (8)	173.8 (16)
O4W—H41W···O1i	0.858 (9)	1.888 (10)	2.7124 (6)	160.4 (19)
O4W—H42W···O3Wx	0.836 (8)	1.939 (9)	2.7532 (8)	164.4 (16)

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O5—H5⋯O2	0.789 (17)	2.031 (16)	2.5946 (6)	128.2 (14)
O6—H6⋯O4Wi	0.861 (16)	1.968 (16)	2.8119 (7)	166.5 (16)
O1W—H11W⋯O6	0.824 (8)	1.960 (8)	2.7832 (6)	176.8 (15)
O1W—H12W⋯O4ii	0.843 (9)	2.010 (9)	2.8500 (7)	174.8 (18)
O2W—H21W⋯O3iii	0.868 (9)	1.830 (9)	2.6941 (7)	173.4 (19)
O2W—H22W⋯O2iv	0.862 (9)	1.890 (9)	2.7505 (7)	175.5 (19)
O3W—H31W⋯O6v	0.843 (9)	2.391 (15)	3.1029 (7)	142.5 (19)
O3W—H31W⋯O2vi	0.843 (9)	2.499 (17)	3.1181 (7)	131.0 (17)
O3W—H31W⋯O3v	0.843 (9)	2.584 (14)	3.1569 (8)	126.2 (15)
O3W—H32W⋯O4vii	0.862 (8)	1.926 (8)	2.7842 (8)	173.8 (16)
O4W—H41W⋯O1viii	0.858 (9)	1.888 (10)	2.7124 (6)	160.4 (19)
O4W—H42W⋯O3Wiv	0.836 (8)	1.939 (9)	2.7532 (8)	164.4 (16)

Symmetry codes: (i) ; (ii) ; (iii) ; (iv) ; (v) ; (vi) ; (vii) ; (viii) .