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Supporting information
![]() | Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270103021693/sk1657sup1.cif |
![]() | Structure factor file (CIF format) https://doi.org/10.1107/S0108270103021693/sk1657Isup2.hkl |
α-LiRb2(SO3CF3)3 was prepared from mixtures of solid LiSO3CF3 (Aldrich, 99.995%) and RbSO3CF3. Details concerning the synthesis are given in Pompetzki et al. (2003). The `single-crystal' investigated in the present work was found within a diphasic product consisting of LiRb2(SO3CF3)3 and Li0.55Rb0.45SO3CF3, which had formed on annealing (533 K, 7 d, cooling rate 5 K h−1) a mixture of LiSO3CF3 (40 mol%) and RbSO3CF3 (60 mol%). The crystal was selected in a glove box under dry argon.
The structure was solved in space group P21/n via direct methods and the solution yielded the positions of the heavy atoms. The positions of the light atoms were found using a difference Fourier synthesis. Refinement as a single-crystal stuck at an overall agreement factor of about 23%, and no satisfactory structural model could be obtained. Of course, the pseudo-orthorhombic metrics implied the possibility of twinning. Furthermore, the fact that differential scanning calorimetry measurements and X-ray powder diffraction studies confirmed a phase transition at approximately 383 K to a β phase with orthorhombic metrics (a = 5.476 (2), b = 16.554 (18) and c = 20.177 (11) Å) suggested the introduction of an additional mirror plane from the orthorhombic system as a twinning operation. Consequently, we chose a mirror plane perpendicular to the a axis and introduced the corresponding twin matrix. The refinement converged satisfactorily after taking the twinning into account. The twin matrix was given by (100/010/001). The volume fractions of the twin individuals are tI = 0.515 (2) and tII = 0.485 (2).
Data collection: SMART (Bruker, 1997); cell refinement: SMART; data reduction: SAINT (Bruker, 1999); program(s) used to solve structure: SIR97 (Altomare et al., 1997); program(s) used to refine structure: JANA2000 (Petřiček & Dušek, 2000); molecular graphics: DIAMOND (Bergerhoff et al., 1996) and ORTEP-3 for Windows (Farrugia, 1996); software used to prepare material for publication: Details?.
LiRb2(SO3CF3)3 | F(000) = 1184 |
Mr = 625.12 | Dx = 2.42 Mg m−3 |
Monoclinic, P21/n | Mo Kα radiation, λ = 0.71069 Å |
Hall symbol: -P 2yn | Cell parameters from 3752 reflections |
a = 5.3408 (9) Å | θ = 4.8–59.1° |
b = 16.286 (2) Å | µ = 6.20 mm−1 |
c = 19.721 (3) Å | T = 293 K |
β = 90.48 (1)° | Irregular, colourless |
V = 1715.3 (4) Å3 | 0.15 × 0.12 × 0.08 mm |
Z = 4 |
Bruker SMART-APEX CCD area-detector diffractometer | 5010 independent reflections |
Radiation source: fine-focus sealed tube | 2625 reflections with I > 3σ(I) |
Graphite monochromator | Rint = 0.114 |
ω scans | θmax = 30.1°, θmin = 1.6° |
Absorption correction: multi-scan (SADABS; Sheldrick, 1998) | h = −7→7 |
Tmin = 0.062, Tmax = 0.155 | k = −22→22 |
21958 measured reflections | l = −27→27 |
Refinement on F2 | 0 restraints |
Least-squares matrix: full | Primary atom site location: structure-invariant direct methods |
R[F2 > 2σ(F2)] = 0.068 | Secondary atom site location: difference Fourier map |
wR(F2) = 0.061 | w = 1/[σ2(Fo2)] |
S = 4.17 | (Δ/σ)max = 0.0004 |
5010 reflections | Δρmax = 1.86 e Å−3 |
245 parameters | Δρmin = −2.05 e Å−3 |
LiRb2(SO3CF3)3 | V = 1715.3 (4) Å3 |
Mr = 625.12 | Z = 4 |
Monoclinic, P21/n | Mo Kα radiation |
a = 5.3408 (9) Å | µ = 6.20 mm−1 |
b = 16.286 (2) Å | T = 293 K |
c = 19.721 (3) Å | 0.15 × 0.12 × 0.08 mm |
β = 90.48 (1)° |
Bruker SMART-APEX CCD area-detector diffractometer | 5010 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 1998) | 2625 reflections with I > 3σ(I) |
Tmin = 0.062, Tmax = 0.155 | Rint = 0.114 |
21958 measured reflections |
R[F2 > 2σ(F2)] = 0.068 | 245 parameters |
wR(F2) = 0.061 | 0 restraints |
S = 4.17 | Δρmax = 1.86 e Å−3 |
5010 reflections | Δρmin = −2.05 e Å−3 |
Experimental. δω=0.3° per frame; 1800 frames; 45 sec per frame. |
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 as twin. Twin matrix (100/010/001). Twin volumes tI = 0.515 (2), tII = 0.485 (2). Maximum angular difference for twin overlap = 0.2. |
x | y | z | Uiso*/Ueq | ||
Rb1 | 0.0264 (3) | 0.87556 (9) | 0.01184 (7) | 0.0367 (5) | |
Rb2 | −0.1026 (4) | 1.15805 (12) | −0.22444 (9) | 0.0654 (8) | |
S1 | 0.0316 (8) | 0.6932 (2) | −0.13409 (19) | 0.0310 (14) | |
S2 | 0.5460 (8) | 0.7516 (3) | 0.09017 (19) | 0.0344 (15) | |
S3 | −0.4912 (9) | 0.9677 (2) | −0.10632 (18) | 0.0320 (14) | |
O1 | 0.180 (2) | 0.7391 (6) | −0.0899 (5) | 0.038 (4) | |
O2 | 0.124 (2) | 0.6834 (7) | −0.1986 (5) | 0.053 (4) | |
O3 | −0.2256 (18) | 0.7116 (6) | −0.1317 (5) | 0.037 (4) | |
O4 | 0.282 (2) | 0.7632 (7) | 0.1033 (7) | 0.066 (6) | |
O5 | 0.713 (2) | 0.7910 (7) | 0.1325 (6) | 0.044 (4) | |
O6 | 0.6150 (19) | 0.7502 (6) | 0.0198 (5) | 0.049 (4) | |
O7 | −0.292 (2) | 1.0237 (8) | −0.1186 (6) | 0.066 (6) | |
O8 | −0.420 (2) | 0.8854 (6) | −0.0847 (5) | 0.054 (4) | |
O9 | −0.698 (2) | 0.9992 (7) | −0.0719 (5) | 0.052 (5) | |
C1 | −0.595 (4) | 0.9478 (13) | −0.1964 (8) | 0.061 (9) | |
C2 | −0.548 (4) | 1.0889 (10) | −0.4053 (11) | 0.068 (9) | |
C3 | 0.577 (4) | 0.6385 (12) | 0.1075 (9) | 0.060 (8) | |
F1 | −0.679 (2) | 1.0173 (7) | −0.2233 (6) | 0.118 (7) | |
F2 | −0.426 (3) | 0.9161 (9) | −0.2327 (6) | 0.146 (8) | |
F3 | −0.791 (3) | 0.9015 (8) | −0.1917 (6) | 0.113 (7) | |
F4 | −0.780 (2) | 1.0659 (7) | −0.4022 (7) | 0.098 (7) | |
F5 | −0.468 (4) | 1.0886 (6) | −0.4642 (5) | 0.126 (7) | |
F6 | −0.412 (3) | 1.0404 (6) | −0.3659 (6) | 0.103 (6) | |
F7 | 0.502 (3) | 0.6303 (6) | 0.1696 (5) | 0.117 (6) | |
F8 | 0.457 (3) | 0.5964 (7) | 0.0681 (6) | 0.110 (6) | |
F9 | 0.8187 (19) | 0.6242 (8) | 0.1085 (7) | 0.114 (7) | |
Li1 | 0.534 (5) | 0.7604 (12) | −0.0743 (11) | 0.027 (8) |
U11 | U22 | U33 | U12 | U13 | U23 | |
Rb1 | 0.0342 (9) | 0.0356 (9) | 0.0403 (9) | −0.0022 (9) | 0.0000 (9) | −0.0031 (8) |
Rb2 | 0.0454 (12) | 0.1113 (18) | 0.0393 (10) | −0.0068 (11) | −0.0093 (10) | 0.0037 (12) |
S1 | 0.030 (3) | 0.034 (2) | 0.029 (2) | 0.001 (2) | 0.002 (2) | −0.0091 (17) |
S2 | 0.031 (3) | 0.046 (3) | 0.026 (2) | 0.003 (2) | −0.004 (2) | 0.0054 (19) |
S3 | 0.033 (3) | 0.026 (2) | 0.038 (2) | 0.001 (2) | −0.001 (2) | −0.0018 (18) |
O1 | 0.037 (8) | 0.029 (7) | 0.048 (8) | 0.007 (5) | −0.010 (6) | −0.026 (6) |
O2 | 0.061 (8) | 0.061 (8) | 0.038 (7) | −0.001 (7) | 0.013 (6) | −0.022 (6) |
O3 | 0.025 (7) | 0.045 (8) | 0.042 (7) | 0.001 (5) | −0.002 (6) | −0.004 (6) |
O4 | 0.022 (8) | 0.080 (12) | 0.096 (13) | 0.009 (6) | 0.005 (7) | 0.002 (9) |
O5 | 0.042 (7) | 0.042 (8) | 0.047 (8) | −0.009 (6) | −0.008 (6) | −0.004 (7) |
O6 | 0.067 (8) | 0.045 (7) | 0.036 (6) | −0.029 (6) | 0.012 (7) | 0.008 (6) |
O7 | 0.036 (8) | 0.072 (10) | 0.091 (11) | −0.002 (7) | −0.010 (8) | −0.019 (9) |
O8 | 0.067 (9) | 0.039 (7) | 0.055 (7) | 0.008 (7) | −0.038 (6) | −0.005 (6) |
O9 | 0.039 (7) | 0.078 (10) | 0.040 (8) | −0.002 (7) | 0.002 (6) | 0.008 (7) |
C1 | 0.079 (17) | 0.071 (17) | 0.031 (11) | −0.020 (13) | −0.034 (11) | −0.001 (11) |
C2 | 0.064 (16) | 0.028 (11) | 0.112 (18) | 0.000 (11) | −0.002 (16) | 0.026 (12) |
C3 | 0.086 (17) | 0.054 (15) | 0.040 (12) | 0.000 (12) | 0.025 (12) | 0.037 (10) |
F1 | 0.186 (14) | 0.081 (10) | 0.087 (9) | 0.032 (9) | −0.037 (10) | 0.029 (8) |
F2 | 0.146 (14) | 0.213 (17) | 0.078 (9) | 0.092 (12) | −0.037 (11) | −0.079 (10) |
F3 | 0.151 (14) | 0.111 (12) | 0.077 (9) | −0.026 (10) | −0.079 (9) | 0.004 (8) |
F4 | 0.087 (10) | 0.060 (9) | 0.146 (14) | −0.029 (7) | −0.014 (9) | 0.000 (8) |
F5 | 0.233 (17) | 0.081 (9) | 0.063 (8) | −0.031 (12) | 0.030 (12) | −0.037 (6) |
F6 | 0.138 (12) | 0.040 (7) | 0.133 (11) | 0.030 (8) | 0.018 (10) | 0.025 (7) |
F7 | 0.162 (13) | 0.093 (9) | 0.098 (9) | −0.003 (11) | −0.008 (11) | 0.050 (8) |
F8 | 0.137 (13) | 0.075 (9) | 0.118 (10) | −0.011 (10) | −0.027 (12) | −0.017 (7) |
F9 | 0.078 (9) | 0.075 (10) | 0.189 (15) | 0.042 (8) | −0.011 (9) | 0.043 (10) |
Li1 | 0.031 (17) | 0.016 (13) | 0.033 (14) | 0.006 (13) | 0.011 (13) | 0.007 (10) |
Rb1—O4 | 2.904 (12) | S2—O5 | 1.376 (12) |
Rb1—O9i | 2.944 (11) | S2—O6 | 1.439 (11) |
Rb1—O9ii | 2.998 (11) | S2—O4 | 1.445 (12) |
Rb1—O6iii | 3.004 (10) | S2—C3 | 1.88 (2) |
Rb1—O7iv | 3.014 (12) | S2—Rb1ii | 3.620 (5) |
Rb1—O8 | 3.043 (10) | S2—Rb2iv | 3.859 (5) |
Rb1—O1 | 3.108 (10) | S3—O9 | 1.400 (12) |
Rb1—O5iii | 3.228 (11) | S3—O7 | 1.425 (13) |
Rb1—S2iii | 3.620 (5) | S3—O8 | 1.456 (10) |
Rb1—Li1iii | 3.64 (2) | S3—C1 | 1.885 (18) |
Rb1—Li1 | 3.72 (2) | S3—Rb1iii | 3.798 (4) |
Rb2—O5v | 2.870 (11) | S3—Rb1iv | 4.009 (4) |
Rb2—O4iv | 2.883 (13) | C1—F2 | 1.27 (3) |
Rb2—O2vi | 3.011 (11) | C1—F3 | 1.29 (3) |
Rb2—O3vii | 3.100 (11) | C1—F1 | 1.33 (2) |
Rb2—O2vii | 3.188 (11) | C2—F5 | 1.24 (2) |
Rb2—O7 | 3.193 (13) | C2—F4 | 1.29 (2) |
Rb2—F1ii | 3.221 (12) | C2—F6 | 1.32 (2) |
Rb2—S1vii | 3.641 (4) | C3—F8 | 1.21 (2) |
Rb2—S2iv | 3.859 (5) | C3—F7 | 1.30 (2) |
Rb2—Rb1iv | 4.244 (2) | C3—F9 | 1.31 (2) |
S1—O2 | 1.378 (10) | Li1—O3ii | 1.89 (3) |
S1—O1 | 1.390 (11) | Li1—O6 | 1.91 (2) |
S1—O3 | 1.407 (11) | Li1—O1 | 1.94 (3) |
S1—C2viii | 1.870 (18) | Li1—O8ii | 2.06 (2) |
S1—Rb2viii | 3.641 (4) | Li1—Rb1ii | 3.64 (2) |
O4—Rb1—O9i | 117.7 (3) | O2—S1—C2viii | 105.3 (8) |
O4—Rb1—O9ii | 122.3 (3) | O1—S1—C2viii | 101.8 (8) |
O9i—Rb1—O9ii | 93.0 (3) | O3—S1—C2viii | 102.9 (8) |
O4—Rb1—O6iii | 83.1 (3) | O2—S1—Rb2viii | 60.2 (5) |
O9i—Rb1—O6iii | 90.7 (3) | O1—S1—Rb2viii | 156.3 (4) |
O9ii—Rb1—O6iii | 148.0 (3) | O3—S1—Rb2viii | 56.7 (4) |
O4—Rb1—O7iv | 72.1 (3) | C2viii—S1—Rb2viii | 101.7 (7) |
O9i—Rb1—O7iv | 67.7 (3) | O5—S2—O6 | 115.0 (7) |
O9ii—Rb1—O7iv | 77.8 (3) | O5—S2—O4 | 117.3 (7) |
O6iii—Rb1—O7iv | 132.3 (3) | O6—S2—O4 | 115.7 (7) |
O4—Rb1—O8 | 141.7 (3) | O5—S2—C3 | 106.9 (8) |
O9i—Rb1—O8 | 75.5 (3) | O6—S2—C3 | 97.8 (7) |
O9ii—Rb1—O8 | 90.3 (3) | O4—S2—C3 | 100.4 (8) |
O6iii—Rb1—O8 | 59.9 (3) | O5—S2—Rb1ii | 62.6 (5) |
O7iv—Rb1—O8 | 140.4 (3) | O6—S2—Rb1ii | 53.8 (4) |
O4—Rb1—O1 | 80.0 (3) | O4—S2—Rb1ii | 134.3 (5) |
O9i—Rb1—O1 | 156.3 (3) | C3—S2—Rb1ii | 124.1 (7) |
O9ii—Rb1—O1 | 89.5 (3) | O5—S2—Rb1 | 118.2 (5) |
O6iii—Rb1—O1 | 75.2 (3) | O6—S2—Rb1 | 78.8 (4) |
O7iv—Rb1—O1 | 135.7 (3) | C3—S2—Rb1 | 131.7 (7) |
O8—Rb1—O1 | 80.9 (3) | Rb1ii—S2—Rb1 | 92.80 (10) |
O4—Rb1—O5iii | 61.2 (3) | O5—S2—Rb2iv | 78.8 (5) |
O9i—Rb1—O5iii | 71.6 (3) | O6—S2—Rb2iv | 146.3 (5) |
O9ii—Rb1—O5iii | 162.2 (3) | C3—S2—Rb2iv | 107.6 (6) |
O6iii—Rb1—O5iii | 44.6 (3) | Rb1ii—S2—Rb2iv | 121.43 (12) |
O7iv—Rb1—O5iii | 87.7 (3) | Rb1—S2—Rb2iv | 67.76 (8) |
O8—Rb1—O5iii | 94.3 (3) | O9—S3—O7 | 116.2 (7) |
O1—Rb1—O5iii | 108.2 (3) | O9—S3—O8 | 113.6 (7) |
O4—Rb1—O8ii | 88.4 (3) | O7—S3—O8 | 116.5 (7) |
O9i—Rb1—O8ii | 133.5 (3) | O9—S3—C1 | 107.0 (9) |
O9ii—Rb1—O8ii | 41.9 (3) | O7—S3—C1 | 99.4 (9) |
O6iii—Rb1—O8ii | 132.4 (3) | O8—S3—C1 | 101.1 (8) |
O7iv—Rb1—O8ii | 87.8 (3) | O9—S3—Rb1iii | 45.9 (5) |
O8—Rb1—O8ii | 108.4 (2) | O7—S3—Rb1iii | 150.4 (5) |
O1—Rb1—O8ii | 57.2 (2) | O8—S3—Rb1iii | 68.5 (4) |
O5iii—Rb1—O8ii | 149.0 (2) | C1—S3—Rb1iii | 108.3 (7) |
O4—Rb1—S2iii | 73.5 (2) | O9—S3—Rb1 | 114.2 (5) |
O9i—Rb1—S2iii | 77.8 (2) | O7—S3—Rb1 | 79.7 (5) |
O9ii—Rb1—S2iii | 164.2 (2) | C1—S3—Rb1 | 134.3 (7) |
O6iii—Rb1—S2iii | 22.7 (2) | Rb1iii—S3—Rb1 | 87.85 (8) |
O7iv—Rb1—S2iii | 109.6 (2) | S1—O1—Li1 | 137.9 (9) |
O8—Rb1—S2iii | 75.1 (2) | S1—O1—Rb1 | 129.7 (6) |
O1—Rb1—S2iii | 93.9 (2) | Li1—O1—Rb1 | 91.8 (7) |
O5iii—Rb1—S2iii | 22.2 (2) | S1—O2—Rb2ix | 142.5 (6) |
O8ii—Rb1—S2iii | 148.7 (2) | S1—O2—Rb2viii | 97.8 (5) |
O4—Rb1—Li1iii | 107.5 (4) | Rb2ix—O2—Rb2viii | 118.9 (3) |
O9i—Rb1—Li1iii | 96.6 (4) | S1—O3—Li1iii | 141.0 (10) |
O9ii—Rb1—Li1iii | 116.4 (4) | S1—O3—Rb2viii | 101.0 (5) |
O6iii—Rb1—Li1iii | 31.6 (4) | Li1iii—O3—Rb2viii | 117.8 (8) |
O7iv—Rb1—Li1iii | 160.1 (4) | S2—O4—Rb2iv | 122.6 (7) |
O8—Rb1—Li1iii | 34.5 (4) | S2—O4—Rb1 | 115.1 (7) |
O1—Rb1—Li1iii | 61.5 (4) | Rb2iv—O4—Rb1 | 94.3 (3) |
O5iii—Rb1—Li1iii | 75.4 (4) | S2—O5—Rb2v | 168.9 (7) |
O8ii—Rb1—Li1iii | 112.1 (4) | S2—O5—Rb1ii | 95.1 (5) |
S2iii—Rb1—Li1iii | 53.1 (4) | Rb2v—O5—Rb1ii | 88.0 (3) |
O4—Rb1—Li1 | 68.0 (4) | S2—O6—Li1 | 151.4 (11) |
O9i—Rb1—Li1 | 166.4 (4) | S2—O6—Rb1ii | 103.5 (5) |
O9ii—Rb1—Li1 | 74.0 (4) | Li1—O6—Rb1ii | 92.9 (8) |
O6iii—Rb1—Li1 | 102.5 (4) | S3—O7—Rb1iv | 125.3 (7) |
O7iv—Rb1—Li1 | 104.7 (4) | S3—O7—Rb2 | 142.3 (7) |
O8—Rb1—Li1 | 108.1 (4) | Rb1iv—O7—Rb2 | 86.2 (3) |
O1—Rb1—Li1 | 31.5 (4) | S3—O8—Li1iii | 155.1 (10) |
O5iii—Rb1—Li1 | 120.4 (4) | S3—O8—Rb1 | 115.7 (5) |
O8ii—Rb1—Li1 | 32.9 (4) | Li1iii—O8—Rb1 | 88.9 (8) |
S2iii—Rb1—Li1 | 115.8 (3) | S3—O8—Rb1iii | 89.0 (5) |
Li1iii—Rb1—Li1 | 93.1 (5) | Li1iii—O8—Rb1iii | 78.5 (8) |
O5v—Rb2—O4iv | 66.0 (3) | Rb1—O8—Rb1iii | 108.4 (3) |
O5v—Rb2—O2vi | 70.5 (3) | S3—O9—Rb1i | 157.6 (7) |
O4iv—Rb2—O2vi | 130.3 (3) | S3—O9—Rb1iii | 114.5 (6) |
O5v—Rb2—O3vii | 134.8 (3) | Rb1i—O9—Rb1iii | 87.0 (3) |
O4iv—Rb2—O3vii | 122.3 (3) | F2—C1—F3 | 112.5 (18) |
O2vi—Rb2—O3vii | 75.3 (3) | F2—C1—F1 | 111.3 (16) |
O5v—Rb2—O2vii | 152.7 (3) | F3—C1—F1 | 104.8 (18) |
O4iv—Rb2—O2vii | 92.3 (3) | F2—C1—S3 | 113.4 (16) |
O2vi—Rb2—O2vii | 118.9 (3) | F3—C1—S3 | 105.3 (12) |
O3vii—Rb2—O2vii | 43.7 (3) | F1—C1—S3 | 109.0 (13) |
O5v—Rb2—O7 | 91.0 (3) | F5—C2—F4 | 112.4 (19) |
O4iv—Rb2—O7 | 69.8 (3) | F5—C2—F6 | 110.9 (18) |
O2vi—Rb2—O7 | 134.3 (3) | F4—C2—F6 | 108.7 (16) |
O3vii—Rb2—O7 | 134.3 (3) | F5—C2—S1vii | 112.2 (13) |
O2vii—Rb2—O7 | 96.9 (3) | F4—C2—S1vii | 106.5 (13) |
O5v—Rb2—F1ii | 72.3 (3) | F6—C2—S1vii | 105.9 (14) |
O4iv—Rb2—F1ii | 123.3 (3) | F8—C3—F7 | 112.3 (18) |
O2vi—Rb2—F1ii | 60.1 (3) | F8—C3—F9 | 115.1 (17) |
O3vii—Rb2—F1ii | 114.2 (3) | F7—C3—F9 | 106.2 (16) |
O2vii—Rb2—F1ii | 135.0 (3) | F8—C3—S2 | 113.0 (14) |
O7—Rb2—F1ii | 74.6 (3) | F7—C3—S2 | 104.1 (12) |
O5v—Rb2—S1vii | 152.5 (2) | F9—C3—S2 | 105.2 (13) |
O4iv—Rb2—S1vii | 110.7 (2) | C1—F1—Rb2iii | 147.7 (12) |
O2vi—Rb2—S1vii | 97.1 (2) | O3ii—Li1—O6 | 113.2 (13) |
O3vii—Rb2—S1vii | 22.30 (19) | O3ii—Li1—O1 | 119.7 (12) |
O2vii—Rb2—S1vii | 22.02 (19) | O6—Li1—O1 | 110.6 (12) |
O7—Rb2—S1vii | 114.1 (2) | O3ii—Li1—O8ii | 105.8 (12) |
F1ii—Rb2—S1vii | 123.7 (2) | O6—Li1—O8ii | 99.0 (10) |
O5v—Rb2—S2iv | 84.4 (2) | O1—Li1—O8ii | 106.1 (11) |
O4iv—Rb2—S2iv | 18.4 (2) | O3ii—Li1—Rb1ii | 90.2 (9) |
O2vi—Rb2—S2iv | 145.3 (2) | O6—Li1—Rb1ii | 55.5 (7) |
O3vii—Rb2—S2iv | 110.0 (2) | O1—Li1—Rb1ii | 149.7 (10) |
O2vii—Rb2—S2iv | 74.84 (19) | O8ii—Li1—Rb1ii | 56.7 (6) |
O7—Rb2—S2iv | 67.2 (2) | O3ii—Li1—Rb1 | 170.2 (10) |
F1ii—Rb2—S2iv | 134.5 (2) | O6—Li1—Rb1 | 76.1 (8) |
S1vii—Rb2—S2iv | 94.60 (10) | O1—Li1—Rb1 | 56.7 (7) |
O2—S1—O1 | 115.7 (7) | O8ii—Li1—Rb1 | 68.6 (7) |
O2—S1—O3 | 114.4 (7) | Rb1ii—Li1—Rb1 | 93.1 (5) |
O1—S1—O3 | 114.4 (6) |
Symmetry codes: (i) −x−1, −y+2, −z; (ii) x+1, y, z; (iii) x−1, y, z; (iv) −x, −y+2, −z; (v) −x+1, −y+2, −z; (vi) −x+1/2, y+1/2, −z−1/2; (vii) −x−1/2, y+1/2, −z−1/2; (viii) −x−1/2, y−1/2, −z−1/2; (ix) −x+1/2, y−1/2, −z−1/2. |
Experimental details
Crystal data | |
Chemical formula | LiRb2(SO3CF3)3 |
Mr | 625.12 |
Crystal system, space group | Monoclinic, P21/n |
Temperature (K) | 293 |
a, b, c (Å) | 5.3408 (9), 16.286 (2), 19.721 (3) |
β (°) | 90.48 (1) |
V (Å3) | 1715.3 (4) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 6.20 |
Crystal size (mm) | 0.15 × 0.12 × 0.08 |
Data collection | |
Diffractometer | Bruker SMART-APEX CCD area-detector diffractometer |
Absorption correction | Multi-scan (SADABS; Sheldrick, 1998) |
Tmin, Tmax | 0.062, 0.155 |
No. of measured, independent and observed [I > 3σ(I)] reflections | 21958, 5010, 2625 |
Rint | 0.114 |
(sin θ/λ)max (Å−1) | 0.707 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.068, 0.061, 4.17 |
No. of reflections | 5010 |
No. of parameters | 245 |
Δρmax, Δρmin (e Å−3) | 1.86, −2.05 |
Computer programs: SMART (Bruker, 1997), SMART, SAINT (Bruker, 1999), SIR97 (Altomare et al., 1997), JANA2000 (Petřiček & Dušek, 2000), DIAMOND (Bergerhoff et al., 1996) and ORTEP-3 for Windows (Farrugia, 1996), Details?.
Rb1—O4 | 2.904 (12) | Rb2—O2vi | 3.011 (11) |
Rb1—O9i | 2.944 (11) | Rb2—O3vii | 3.100 (11) |
Rb1—O9ii | 2.998 (11) | Rb2—O2vii | 3.188 (11) |
Rb1—O6iii | 3.004 (10) | Rb2—O7 | 3.193 (13) |
Rb1—O7iv | 3.014 (12) | Rb2—F1ii | 3.221 (12) |
Rb1—O8 | 3.043 (10) | Li1—O3ii | 1.89 (3) |
Rb1—O1 | 3.108 (10) | Li1—O6 | 1.91 (2) |
Rb1—O5iii | 3.228 (11) | Li1—O1 | 1.94 (3) |
Rb2—O5v | 2.870 (11) | Li1—O8ii | 2.06 (2) |
Rb2—O4iv | 2.883 (13) | ||
O3ii—Li1—O6 | 113.2 (13) | O3ii—Li1—O8ii | 105.8 (12) |
O3ii—Li1—O1 | 119.7 (12) | O6—Li1—O8ii | 99.0 (10) |
O6—Li1—O1 | 110.6 (12) | O1—Li1—O8ii | 106.1 (11) |
Symmetry codes: (i) −x−1, −y+2, −z; (ii) x+1, y, z; (iii) x−1, y, z; (iv) −x, −y+2, −z; (v) −x+1, −y+2, −z; (vi) −x+1/2, y+1/2, −z−1/2; (vii) −x−1/2, y+1/2, −z−1/2. |
Salts consisting of complex anions often show phase transitions to rotationally disordered modifications. As a rule, these phase transitions are accompanied by an increase of the ionic conductivity (Jansen, 1991). Alkali metal salts of the trifluoromethylsulfonate (trifluoromethanesulfonate) ion belong to these so-called rotator phases. Due to their interesting properties, the ionic conductivities and crystal structures of, for example, β-LiSO3CF3 (Tremayne et al., 1992; Bolte & Lerner, 2001), α-NaSO3CF3 (Sofina et al., 2003) and RT-KSO3CF3 (Korus & Jansen, 2001) have been studied in detail. Furthermore, mixed alkali trifluoromethanesulfonates offer the possibility of exploring the `mixed cation effect', which can be observed in ion-conducting systems containing more than one mobile cation (Yanija & Secco, 1995). The ionic conductivity of compounds in such systems can generally be varied by adjusting the ratio of the cations.
Against this background, we have carried out systematic investigations of the phase diagram of the LiSO3CF3/RbSO3CF3 system. In the course of these investigations, crystals of α-LiRb2(SO3CF3)3 were found and the structure is presented here. The structure determination was rendered complicated due to underlying twinning.
In the structure of α-LiRb2(SO3CF3)3, three crystallographically independent trifluoromethanesulfonate ions can be distinguished. Their conformation is staggered and the observed bond lengths and angles are comparable to those in β-LiSO3CF3 (Bolte & Lerner, 2001), α-NaSO3CF3(Sofina et al., 2003), the low- and room-temperature modifications of NaSO3CF3·H2O (Korus & Jansen, 1997), NaSO3CF3·3HSO3CF3 (Korus & Jansen, 1998) and RT-KSO3CF3 (Korus & Jansen, 2001).
In α-LiRb2(SO3CF3)3, atom Rb1 is coordinated by O atoms in the form of a distorted square antiprism (Fig. 1). The cation is displaced towards the plane formed by atoms O1, O4, O7iv and O9ii [symmetry codes: (ii) 1 + x, y, z; (iv) −x, 2 − y, −z]. Atom O5iii is shifted from the ideal position and approaches atom O6iii, as both atoms are bridged by an S atom [symmetry code: (iii) x − 1, y, z]. Each of the remaining O atoms forms part of a different trifluoromethanesulfonate ion. Please check that added symmetry codes, here and elsewhere, are correct.
Atom Rb2 is coordinated by five O atoms to form a distorted pentagonal plane (Fig. 1). The O2vi—Rb2—O4iv angle is widened, as the atoms O2vi and O4iv are again bridged by an S atom [symmetry code: (vi) 1/2 − x, 1/2 + y, −1/2 − z]. The nearest atoms above the pentagonal plane are O7 and F1ii; below the plane is atom F7, with a large distance to the central atom (4.20 Å).
The Li atom is surrounded by O atoms in the form of a strongly distorted tetrahedron, with Li—O distances as large as 1.95 Å on average (Fig. 1). This value is only slightly different from that observed in β-LiSO3CF3 (1.94 Å; Bolte & Lerner, 2001).
In the structures of the pure alkali trifluoromethanesulfonates MSO3CF3 (M is Li or Na) which have been characterized to date (Bolte & Lerner, 2001; Sofina et al., 2003), as well as in the structure of NaSO3CF3·H2O; (Korus & Jansen, 1997), the nonpolar CF3 groups point towards each other and form double layers which are linked by cations. In α-LiRb2(SO3CF3)3 and RT-KSO3CF3 (Korus & Jansen, 2001), on the other hand, the CF3 groups build up channel-like patterns along the crystallographic a axis (Fig. 2) and the polar interstices between these channels are filled with cations (Fig. 3).