metal-organic compounds
Potassium sodium (2R,3R)-tartrate tetrahydrate: the paraelectric phase of Rochelle salt at 105 K
aDepartment of Chemistry, University of Oslo, PO Box 1033 Blindern, N-0315 Oslo, Norway, and bDepartment of Physics, University of Oslo, PO Box 1048 Blindern, N-0316 Oslo, Norway
*Correspondence e-mail: c.h.gorbitz@kjemi.uio.no
Rochelle salt, K+·Na+·C4H4O62−·4H2O, 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 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
|
Data collection: SMART (Bruker, 1998); cell 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.
Supporting information
10.1107/S1600536808005266/bg2163sup1.cif
contains datablocks I, global. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536808005266/bg2163Isup2.hkl
Rochelle salt was obtained from Sigma-Aldrich and tetrahydrate crystals were grown from saturated aqueous solutions. A large block-shaped speciemen was ground into a sphere in a mill and used for data collection.
Data collection: SMART (Bruker, 1998); cell
SAINT-Plus (Bruker, 2001); data reduction: SAINT-Plus (Bruker, 2001); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).Fig. 1. : The molecular structure of (I). Displacement ellipsoids are shown at the 50% probability level. Metal ccordination has been indicated by dashed lines. | |
Fig. 2. : Crystal packing arrangement viewed approximately along the c axis. H atoms bonded to C have been left out for clarity. Na+ is yellow, K+ is light blue with K1 at the centre of the unit cell and K2 at the cell edge. Hydrogen bonds are shown as black dotted lines while ligand coordination is indicated in orange for three selected metal ions. The arrow points to H31W, which is involved in a four-center hydrogen bond. |
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 = 2.9–49.7° |
b = 14.1972 (7) Å | µ = 0.60 mm−1 |
c = 6.1875 (3) Å | T = 105 K |
V = 1035.33 (9) Å3 | Sphere, colourless |
Z = 4 | 0.5 mm (radius) |
F(000) = 584 |
Siemens SMART CCD diffractometer | 10040 independent reflections |
Radiation source: fine-focus sealed tube | 8947 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.037 |
Detector resolution: 8.3 pixels mm-1 | θmax = 49.7°, θmin = 2.9° |
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 | Absolute structure parameter: 0.044 (14) |
Hydrogen site location: difference Fourier map |
K+·Na+·C4H4O62−·4H2O | V = 1035.33 (9) Å3 |
Mr = 282.23 | Z = 4 |
Orthorhombic, P21212 | Mo Kα radiation |
a = 11.7859 (6) Å | µ = 0.60 mm−1 |
b = 14.1972 (7) Å | T = 105 K |
c = 6.1875 (3) Å | 0.5 mm (radius) |
Siemens SMART CCD diffractometer | 10040 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | 8947 reflections with I > 2σ(I) |
Tmin = 0.398, Tmax = 0.551 | Rint = 0.037 |
33523 measured reflections |
R[F2 > 2σ(F2)] = 0.029 | All H-atom parameters refined |
wR(F2) = 0.069 | Δρmax = 0.50 e Å−3 |
S = 1.06 | Δρmin = −0.73 e Å−3 |
10040 reflections | Absolute structure: Flack, 1983, 4266 Friedel pairs |
195 parameters | Absolute structure parameter: 0.044 (14) |
12 restraints |
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) |
Symmetry codes: (i) −x, −y, z; (ii) −x, −y, z−1; (iii) x, y, z−1; (iv) −x+1, −y, z; (v) x+1/2, −y+1/2, −z+2; (vi) −x+1/2, y−1/2, −z+2; (vii) −x+1/2, y−1/2, −z+1; (viii) x+1/2, −y+1/2, −z+1. |
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 | 0.82 (1) | 1.96 (1) | 2.7832 (6) | 177 (2) |
O1W—H12W···O4viii | 0.84 (1) | 2.01 (1) | 2.8500 (7) | 175 (2) |
O2W—H21W···O3vi | 0.87 (1) | 1.83 (1) | 2.6941 (7) | 173 (2) |
O2W—H22W···O2x | 0.86 (1) | 1.89 (1) | 2.7505 (7) | 176 (2) |
O3W—H31W···O6vii | 0.84 (1) | 2.39 (2) | 3.1029 (7) | 143 (2) |
O3W—H31W···O2xi | 0.84 (1) | 2.50 (2) | 3.1181 (7) | 131 (2) |
O3W—H31W···O3vii | 0.84 (1) | 2.58 (1) | 3.1569 (8) | 126 (2) |
O3W—H32W···O4ii | 0.86 (1) | 1.93 (1) | 2.7842 (8) | 174 (2) |
O4W—H41W···O1i | 0.86 (1) | 1.89 (1) | 2.7124 (6) | 160 (2) |
O4W—H42W···O3Wx | 0.84 (1) | 1.94 (1) | 2.7532 (8) | 164 (2) |
Symmetry codes: (i) −x, −y, z; (ii) −x, −y, z−1; (vi) −x+1/2, y−1/2, −z+2; (vii) −x+1/2, y−1/2, −z+1; (viii) x+1/2, −y+1/2, −z+1; (ix) −x+1/2, y+1/2, −z+1; (x) x, y, z+1; (xi) −x+1/2, y−1/2, −z. |
Experimental details
Crystal data | |
Chemical formula | K+·Na+·C4H4O62−·4H2O |
Mr | 282.23 |
Crystal system, space group | Orthorhombic, P21212 |
Temperature (K) | 105 |
a, b, c (Å) | 11.7859 (6), 14.1972 (7), 6.1875 (3) |
V (Å3) | 1035.33 (9) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.60 |
Crystal size (mm) | 0.5 (radius) |
Data collection | |
Diffractometer | Siemens SMART CCD diffractometer |
Absorption correction | Multi-scan (SADABS; Sheldrick, 1996) |
Tmin, Tmax | 0.398, 0.551 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 33523, 10040, 8947 |
Rint | 0.037 |
(sin θ/λ)max (Å−1) | 1.072 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.029, 0.069, 1.06 |
No. of reflections | 10040 |
No. of parameters | 195 |
No. of restraints | 12 |
H-atom treatment | All H-atom parameters refined |
Δρmax, Δρmin (e Å−3) | 0.50, −0.73 |
Absolute structure | Flack, 1983, 4266 Friedel pairs |
Absolute structure parameter | 0.044 (14) |
Computer programs: SMART (Bruker, 1998), SAINT-Plus (Bruker, 2001), SHELXTL (Sheldrick, 2008).
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) −x+1/2, y+1/2, −z+1; (ii) x+1/2, −y+1/2, −z+1; (iii) −x+1/2, y−1/2, −z+2; (iv) x, y, z+1; (v) −x+1/2, y−1/2, −z+1; (vi) −x+1/2, y−1/2, −z; (vii) −x, −y, z−1; (viii) −x, −y, z. |
Acknowledgements
The purchase of the Siemens SMART CCD diffractometer was made possible through support from the Research Council of Norway (NFR)
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The radiation-induced free radical chemistry of dicarboxylic acids and their salts has received attention for several decades. The Rochelle salt, is of particular interest as it as it exhibits a ferroelectric phase between 255 and 297 K, where the structure is monoclinic, space group P21; outside this temperature range the compound is paraelectric and presents orthorhombic phases in space group P21212. The nature of the radicals formed in Rochelle salt is currently investigated in order to understand the mechanisms producing changes in the ferroelectric properties of this compound upon irradiation (Suzuki, 1974; Treeck, van & Windsch, 1977). For the analysis of the electron magnetic resonance data, precise knowledge of the low-temperature orthorhombic form is necessary. Structural data for the high-temperature orthorhombic form were first provided by Beevers & Hughes (1941). Iwata et al. (1989) carried out a neutron diffraction study for both orthorhombic forms; more accurate X-ray diffraction studies were later presented by Solans et al. (1997), who concluded that differences between the two P21212 states are "small but significant". None of these structures are, however, available in the Cambridge Structural Database (Version 5.29 of November 2007; Allen, 2002). A high-precision redetermination of Rochelle salt at low temperature has therefore been executed.
The molecular structure of (I) is shown in Fig. 1. The crystal packing arrangement, illustrated in Fig. 2, is very similar to those found in the P21212 structures of other salts of tartaric acid in which Na+ is replaced by Li+ and/or K+ by NH4+ or Tl+ [Li+/K+: Ottenz et al., 1998; Li+/NH4+: Hinazumi & Mitsui, 1972; Li+/Tl+: Kay, 1978; Na+/NH4+ (II): Kuroda & Mason, 1981; Brożek & Stadnicka, 1994; Suzuki et al., 1996a] as well as in salts where K+ has been only partly replaced by NH4+ (Suzuki et al., 1996a; Suzuki et al., 1996b). The pure sodium (Ambady & Kartha, 1968) or potassium salts (Boese et al., 1995) on the other hand, have completely different structures.
Hydrogen bonds are listed in Table 1, the most unusual feature is the almost symmetric four-center interaction involving H31W.
When K+ is replaced by NH4+ [as, for instance, in II] the four shortest K2···O contacts are converted into hydrogen bonds, while only the two K1···O4 interactions are transformed into short hydrogen bonds, the K1···O1W and K1···O2W contacts being replaced by a three-center hydrogen bond.