Acta Cryst. (2013). E69, i38 [ doi:10.1107/S1600536813013603 ]
The crystal structure of trisodium potassium dodecamolybdenum tetradecasulfide, Na_{2.9 (2)}KMo_{12}S_{14}, consists of Mo_{12}S_{14}S_{6} cluster units interconnected through interunit Mo-S bonds and delimiting channels in which the Na^{+} cations are disordered. The cluster units are centered at Wyckoff positions 2d and have point-group symmetry 3.2. The K atom lies on sites with 3.2 symmetry (Wyckoff site 2c) between two consecutive Mo_{12}S_{14}S_{6} units. One of the three independent S atoms and one Na atom lie on sites with 3.. symmetry (Wyckoff sites 4e and 4f). The other Na atom occupies a 2b position with -3.. symmetry. The crystal studied was a merohedral twin with refined components of 0.4951 (13) and 0.5049 (13).
Single crystals of Na_{2.9}KMo_{12}S_{14} were obtained by treating crystals of KMo_{12}S_{14} in a basic reducing solution of Na_{2}S_{2}O_{3}/NaOH at 333 K for 3 days. The KMo_{12}S_{14} compound was prepared by oxidation of single crystals of K_{2.3}Mo_{12}S_{14} in an aqueous solution of iodine at 363 K for 48 h. Single crystals of K_{2.3}Mo_{12}S_{14} were prepared from a mixture of K_{2}MoS_{4}, MoS_{2}, and Mo with the nominal composition K_{2}Mo_{3}S_{4}. The initial mixture (ca 5 g) was cold pressed and loaded into a molybdenum crucible, which was sealed under a low argon pressure using an arc welding system. The charge was heated at the rate of 300 K/h up to 1773 K, temperature which was held for 6 h, then cooled at 100 K/h down to 1373 K and finally furnace cooled. All handlings of materials were done in an argon-filled glove box.
In the first stage of the refinement, the atomic positions of the Mo and S atoms were deduced from those in KMo_{12}S_{14} (Picard et al., 2006). A subsequent difference-Fourier synthesis reveals the potassium atom and a quasi-continuous electron density along the c axis due to the sodium atoms. The latter was modelled with two partly occupied sodium sites (4 e and 2 b positions) using second-order tensors for the anisotropic displacement parameters. Anharmonic treatment of the Na1 and Na2 atoms using the program JANA2000 (Petříček & Dušek, 2000) was unsuccessful. The final occupation factors for the Na atoms were refined freely. The highest peak and the deepest hole in the final Fourier map are located 1.07 Å from Na2 and 0.58 Å from Mo2, respectively. Analysis of the intensity data using the TwinRotMat routine of PLATON (Spek, 2009) revealed the studied crystal was twinned by merohedry with [100, 010, 001]as the twin matrix. The ratio of the twin components was refined to 0.4951 (13):0.5049 (13). The Na content found seems reliable since the cationic electron transfer towards the Mo_{12} cluster deduced from our refinement is +3.9 and is in agreement with the maximal limit of +4 that the Mo_{12} cluster can accept to be well bonded and with the semi-conductor behavior observed on a single-crystal. Indeed, a lower stoichiometry in Na would lead to a metallic behavior. This is also confirmed by semi-quantitative analyses by energy dispersive spectroscopy (eds) which indicated roughly stoichiometries comprised between 2.6 and 3.2 for the Na content.
Data collection: COLLECT (Nonius, 1998); cell refinement: COLLECT (Nonius, 1998); data reduction: EVALCCD (Duisenberg, 1998); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Bergerhoff, 1996); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).
Na_{2.90}KMo_{12}S_{14} | D_{x} = 4.575 Mg m^{−}^{3} |
M_{r} = 1705.89 | Mo Kα radiation, λ = 0.71069 Å |
Trigonal, P3_{1}c | Cell parameters from 5780 reflections |
a = 9.3664 (1) Å | θ = 3.5–39.8° |
c = 16.2981 (2) Å | µ = 7.24 mm^{−}^{1} |
V = 1238.26 (2) Å^{3} | T = 100 K |
Z = 2 | Multi-faceted crystal, black |
F(000) = 1558 | 0.08 × 0.07 × 0.07 mm |
Nonius KappaCCD diffractometer | 2536 independent reflections |
Radiation source: fine-focus sealed tube | 2376 reflections with I > 2σ(I) |
Graphite monochromator | R_{int} = 0.056 |
ϕ scans (κ = 0) + additional ω scans | θ_{max} = 39.8°, θ_{min} = 3.5° |
Absorption correction: analytical (de Meulenaer & Tompa, 1965) | h = −16→16 |
T_{min} = 0.550, T_{max} = 0.572 | k = −16→16 |
37291 measured reflections | l = −29→27 |
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})] = 0.027 | w = 1/[σ^{2}(F_{o}^{2}) + (0.029P)^{2} + 4.9317P] where P = (F_{o}^{2} + 2F_{c}^{2})/3 |
wR(F^{2}) = 0.073 | (Δ/σ)_{max} = 0.001 |
S = 1.13 | Δρ_{max} = 2.74 e Å^{−}^{3} |
2536 reflections | Δρ_{min} = −1.84 e Å^{−}^{3} |
52 parameters | Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^{*}=kFc[1+0.001xFc^{2}λ^{3}/sin(2θ)]^{-1/4} |
0 restraints | Extinction coefficient: 0.00032 (9) |
Na_{2.90}KMo_{12}S_{14} | Z = 2 |
M_{r} = 1705.89 | Mo Kα radiation |
Trigonal, P3_{1}c | µ = 7.24 mm^{−}^{1} |
a = 9.3664 (1) Å | T = 100 K |
c = 16.2981 (2) Å | 0.08 × 0.07 × 0.07 mm |
V = 1238.26 (2) Å^{3} |
Nonius KappaCCD diffractometer | 2536 independent reflections |
Absorption correction: analytical (de Meulenaer & Tompa, 1965) | 2376 reflections with I > 2σ(I) |
T_{min} = 0.550, T_{max} = 0.572 | R_{int} = 0.056 |
37291 measured reflections |
R[F^{2} > 2σ(F^{2})] = 0.027 | 52 parameters |
wR(F^{2}) = 0.073 | 0 restraints |
S = 1.13 | Δρ_{max} = 2.74 e Å^{−}^{3} |
2536 reflections | Δρ_{min} = −1.84 e Å^{−}^{3} |
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 F^{2} against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F^{2}, conventional R-factors R are based on F, with F set to zero for negative F^{2}. The threshold expression of F^{2} > σ(F^{2}) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F^{2} are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. |
x | y | z | U_{iso}*/U_{eq} | Occ. (<1) | |
Mo1 | 0.50983 (3) | 0.16646 (3) | 0.043656 (15) | 0.00973 (6) | |
Mo2 | 0.66853 (3) | 0.16929 (3) | 0.183610 (15) | 0.00826 (5) | |
S1 | 0.68780 (10) | 0.04088 (9) | 0.05564 (4) | 0.01069 (11) | |
S2 | 0.36482 (9) | 0.02520 (9) | 0.17966 (4) | 0.01064 (11) | |
S3 | 0.6667 | 0.3333 | −0.06924 (8) | 0.0129 (2) | |
K1 | 0.6667 | 0.3333 | −0.2500 | 0.0195 (3) | |
Na1 | 0.0000 | 0.0000 | 0.1936 (13) | 0.36 (4) | 0.71 (5) |
Na2 | 0.0000 | 0.0000 | 0.099 (3) | 0.40 (4) | 0.74 (4) |
U^{11} | U^{22} | U^{33} | U^{12} | U^{13} | U^{23} | |
Mo1 | 0.01224 (10) | 0.01354 (11) | 0.00434 (9) | 0.00714 (8) | −0.00045 (7) | 0.00041 (7) |
Mo2 | 0.01081 (9) | 0.01033 (10) | 0.00371 (9) | 0.00535 (8) | −0.00034 (6) | −0.00060 (7) |
S1 | 0.0143 (3) | 0.0125 (3) | 0.0063 (2) | 0.0074 (2) | −0.0003 (2) | −0.00134 (19) |
S2 | 0.0121 (2) | 0.0118 (2) | 0.0064 (2) | 0.0047 (2) | −0.0014 (2) | −0.0007 (2) |
S3 | 0.0172 (3) | 0.0172 (3) | 0.0044 (4) | 0.00859 (16) | 0.000 | 0.000 |
K1 | 0.0264 (5) | 0.0264 (5) | 0.0058 (6) | 0.0132 (3) | 0.000 | 0.000 |
Na1 | 0.47 (6) | 0.47 (6) | 0.12 (2) | 0.24 (3) | 0.000 | 0.000 |
Na2 | 0.045 (4) | 0.045 (4) | 1.12 (12) | 0.023 (2) | 0.000 | 0.000 |
Mo1—S3 | 2.3855 (10) | S3—Mo1^{iii} | 2.3855 (10) |
Mo1—S1^{i} | 2.4620 (8) | S3—Mo1^{i} | 2.3855 (10) |
Mo1—S1 | 2.4822 (8) | K1—S3 | 2.9460 (13) |
Mo1—S1^{ii} | 2.4944 (8) | K1—S3^{vii} | 2.9460 (13) |
Mo1—S2 | 2.5907 (7) | K1—S2^{viii} | 3.4188 (7) |
Mo1—Mo1^{iii} | 2.6296 (5) | K1—S2^{ix} | 3.4188 (7) |
Mo1—Mo1^{i} | 2.6296 (5) | K1—S2^{x} | 3.4188 (7) |
Mo1—Mo2 | 2.7155 (4) | K1—S2^{ii} | 3.4188 (7) |
Mo1—Mo2^{i} | 2.7803 (4) | K1—S2^{xi} | 3.4188 (7) |
Mo2—S1 | 2.4589 (7) | K1—S2^{xii} | 3.4188 (7) |
Mo2—S2 | 2.4655 (7) | Na1—Na2 | 1.55 (5) |
Mo2—S2^{iii} | 2.4904 (8) | Na1—Na1^{xiii} | 1.84 (4) |
Mo2—S2^{iv} | 2.5866 (7) | Na1—S2^{xiv} | 3.3131 (17) |
Mo2—Mo2^{v} | 2.6440 (5) | Na1—S2^{xv} | 3.3131 (17) |
Mo2—Mo2^{iv} | 2.6745 (5) | Na1—S1^{xvi} | 3.856 (12) |
Mo2—Mo2^{iii} | 2.6765 (4) | Na1—S1^{xvii} | 3.856 (12) |
Mo2—Mo2^{i} | 2.6765 (4) | Na1—S1^{i} | 3.856 (12) |
Mo2—Mo1^{iii} | 2.7803 (4) | Na1—S2^{xviii} | 3.898 (11) |
S1—Mo1^{iii} | 2.4620 (8) | Na1—S2^{xiii} | 3.898 (11) |
S1—Mo1^{ii} | 2.4944 (8) | Na1—S2^{xix} | 3.898 (11) |
S1—Na2^{vi} | 3.210 (12) | Na2—S1^{i} | 3.210 (12) |
S2—Mo2^{i} | 2.4904 (8) | Na2—S1^{xvi} | 3.210 (12) |
S2—Mo2^{iv} | 2.5866 (7) | Na2—S1^{xvii} | 3.210 (12) |
S2—Na1 | 3.3131 (17) | Na2—S2^{xiv} | 3.56 (2) |
S2—K1^{ii} | 3.4188 (7) | Na2—S2^{xv} | 3.56 (2) |
S3—Mo1—S1^{i} | 92.320 (19) | Mo1^{iii}—S1—Mo1^{ii} | 127.81 (3) |
S3—Mo1—S1 | 91.819 (19) | Mo1—S1—Mo1^{ii} | 84.55 (3) |
S1^{i}—Mo1—S1 | 169.89 (3) | Mo2—S1—Na2^{vi} | 99.6 (9) |
S3—Mo1—S1^{ii} | 89.07 (3) | Mo1^{iii}—S1—Na2^{vi} | 98.08 (6) |
S1^{i}—Mo1—S1^{ii} | 93.84 (4) | Mo1—S1—Na2^{vi} | 160.3 (4) |
S1—Mo1—S1^{ii} | 95.45 (3) | Mo1^{ii}—S1—Na2^{vi} | 114.5 (6) |
S3—Mo1—S2 | 171.28 (3) | Mo2—S2—Mo2^{i} | 65.37 (2) |
S1^{i}—Mo1—S2 | 84.81 (3) | Mo2—S2—Mo2^{iv} | 63.873 (19) |
S1—Mo1—S2 | 89.74 (2) | Mo2^{i}—S2—Mo2^{iv} | 62.735 (18) |
S1^{ii}—Mo1—S2 | 99.32 (2) | Mo2—S2—Mo1 | 64.912 (19) |
S3—Mo1—Mo1^{iii} | 56.554 (16) | Mo2^{i}—S2—Mo1 | 66.315 (19) |
S1^{i}—Mo1—Mo1^{iii} | 118.03 (2) | Mo2^{iv}—S2—Mo1 | 118.36 (3) |
S1—Mo1—Mo1^{iii} | 57.50 (2) | Mo2—S2—Na1 | 154.66 (8) |
S1^{ii}—Mo1—Mo1^{iii} | 131.58 (2) | Mo2^{i}—S2—Na1 | 89.74 (2) |
S2—Mo1—Mo1^{iii} | 117.822 (17) | Mo2^{iv}—S2—Na1 | 101.5 (3) |
S3—Mo1—Mo1^{i} | 56.554 (16) | Mo1—S2—Na1 | 110.7 (3) |
S1^{i}—Mo1—Mo1^{i} | 58.24 (2) | Mo2—S2—K1^{ii} | 92.19 (2) |
S1—Mo1—Mo1^{i} | 117.29 (2) | Mo2^{i}—S2—K1^{ii} | 150.01 (3) |
S1^{ii}—Mo1—Mo1^{i} | 130.870 (19) | Mo2^{iv}—S2—K1^{ii} | 90.10 (2) |
S2—Mo1—Mo1^{i} | 115.293 (18) | Mo1—S2—K1^{ii} | 123.66 (3) |
Mo1^{iii}—Mo1—Mo1^{i} | 60.0 | Na1—S2—K1^{ii} | 109.13 (14) |
S3—Mo1—Mo2 | 119.13 (2) | Mo1^{iii}—S3—Mo1 | 66.89 (3) |
S1^{i}—Mo1—Mo2 | 113.78 (2) | Mo1^{iii}—S3—Mo1^{i} | 66.89 (3) |
S1—Mo1—Mo2 | 56.254 (17) | Mo1—S3—Mo1^{i} | 66.89 (3) |
S1^{ii}—Mo1—Mo2 | 137.91 (2) | Mo1^{iii}—S3—K1 | 140.47 (2) |
S2—Mo1—Mo2 | 55.315 (17) | Mo1—S3—K1 | 140.47 (2) |
Mo1^{iii}—Mo1—Mo2 | 62.662 (9) | Mo1^{i}—S3—K1 | 140.47 (2) |
Mo1^{i}—Mo1—Mo2 | 91.183 (8) | S3—K1—S3^{vii} | 180.0 |
S3—Mo1—Mo2^{i} | 116.65 (2) | S3—K1—S2^{viii} | 70.407 (11) |
S1^{i}—Mo1—Mo2^{i} | 55.546 (18) | S3^{vii}—K1—S2^{viii} | 109.593 (11) |
S1—Mo1—Mo2^{i} | 114.41 (2) | S3—K1—S2^{ix} | 109.593 (11) |
S1^{ii}—Mo1—Mo2^{i} | 138.42 (2) | S3^{vii}—K1—S2^{ix} | 70.407 (11) |
S2—Mo1—Mo2^{i} | 55.112 (17) | S2^{viii}—K1—S2^{ix} | 171.43 (2) |
Mo1^{iii}—Mo1—Mo2^{i} | 89.759 (7) | S3—K1—S2^{x} | 109.593 (11) |
Mo1^{i}—Mo1—Mo2^{i} | 60.181 (8) | S3^{vii}—K1—S2^{x} | 70.407 (11) |
Mo2—Mo1—Mo2^{i} | 58.275 (11) | S2^{viii}—K1—S2^{x} | 63.43 (2) |
S1—Mo2—S2 | 93.26 (3) | S2^{ix}—K1—S2^{x} | 109.349 (11) |
S1—Mo2—S2^{iii} | 87.06 (3) | S3—K1—S2^{ii} | 70.407 (11) |
S2—Mo2—S2^{iii} | 173.83 (2) | S3^{vii}—K1—S2^{ii} | 109.593 (11) |
S1—Mo2—S2^{iv} | 117.76 (2) | S2^{viii}—K1—S2^{ii} | 109.349 (11) |
S2—Mo2—S2^{iv} | 90.68 (3) | S2^{ix}—K1—S2^{ii} | 63.43 (2) |
S2^{iii}—Mo2—S2^{iv} | 94.62 (3) | S2^{x}—K1—S2^{ii} | 78.22 (2) |
S1—Mo2—Mo2^{v} | 144.46 (2) | S3—K1—S2^{xi} | 109.593 (11) |
S2—Mo2—Mo2^{v} | 120.668 (19) | S3^{vii}—K1—S2^{xi} | 70.407 (11) |
S2^{iii}—Mo2—Mo2^{v} | 60.414 (17) | S2^{viii}—K1—S2^{xi} | 78.22 (2) |
S2^{iv}—Mo2—Mo2^{v} | 56.852 (18) | S2^{ix}—K1—S2^{xi} | 109.349 (11) |
S1—Mo2—Mo2^{iv} | 150.83 (2) | S2^{x}—K1—S2^{xi} | 109.349 (12) |
S2—Mo2—Mo2^{iv} | 60.265 (17) | S2^{ii}—K1—S2^{xi} | 171.43 (2) |
S2^{iii}—Mo2—Mo2^{iv} | 120.634 (19) | S3—K1—S2^{xii} | 70.407 (11) |
S2^{iv}—Mo2—Mo2^{iv} | 55.862 (18) | S3^{vii}—K1—S2^{xii} | 109.593 (11) |
Mo2^{v}—Mo2—Mo2^{iv} | 60.428 (12) | S2^{viii}—K1—S2^{xii} | 109.349 (11) |
S1—Mo2—Mo2^{iii} | 115.260 (19) | S2^{ix}—K1—S2^{xii} | 78.22 (2) |
S2—Mo2—Mo2^{iii} | 117.738 (19) | S2^{x}—K1—S2^{xii} | 171.43 (2) |
S2^{iii}—Mo2—Mo2^{iii} | 56.865 (19) | S2^{ii}—K1—S2^{xii} | 109.349 (11) |
S2^{iv}—Mo2—Mo2^{iii} | 117.009 (17) | S2^{xi}—K1—S2^{xii} | 63.43 (2) |
Mo2^{v}—Mo2—Mo2^{iii} | 60.350 (10) | Na2—Na1—Na1^{xiii} | 180.000 (2) |
Mo2^{iv}—Mo2—Mo2^{iii} | 89.670 (5) | Na2—Na1—S2^{xiv} | 86.1 (4) |
S1—Mo2—Mo2^{i} | 119.02 (2) | Na1^{xiii}—Na1—S2^{xiv} | 93.9 (4) |
S2—Mo2—Mo2^{i} | 57.760 (19) | Na2—Na1—S2 | 86.1 (4) |
S2^{iii}—Mo2—Mo2^{i} | 116.843 (19) | Na1^{xiii}—Na1—S2 | 93.9 (4) |
S2^{iv}—Mo2—Mo2^{i} | 115.061 (17) | S2^{xiv}—Na1—S2 | 119.54 (9) |
Mo2^{v}—Mo2—Mo2^{i} | 90.323 (5) | Na2—Na1—S2^{xv} | 86.1 (4) |
Mo2^{iv}—Mo2—Mo2^{i} | 59.222 (10) | Na1^{xiii}—Na1—S2^{xv} | 93.9 (4) |
Mo2^{iii}—Mo2—Mo2^{i} | 60.0 | S2^{xiv}—Na1—S2^{xv} | 119.54 (9) |
S1—Mo2—Mo1 | 57.07 (2) | S2—Na1—S2^{xv} | 119.54 (9) |
S2—Mo2—Mo1 | 59.773 (17) | Na2—Na1—Na2^{xiii} | 180.000 (2) |
S2^{iii}—Mo2—Mo1 | 115.73 (2) | Na1^{xiii}—Na1—Na2^{xiii} | 0.000 (2) |
S2^{iv}—Mo2—Mo1 | 147.71 (2) | S2^{xiv}—Na1—Na2^{xiii} | 93.9 (4) |
Mo2^{v}—Mo2—Mo1 | 147.951 (10) | S2—Na1—Na2^{xiii} | 93.9 (4) |
Mo2^{iv}—Mo2—Mo1 | 111.157 (13) | S2^{xv}—Na1—Na2^{xiii} | 93.9 (4) |
Mo2^{iii}—Mo2—Mo1 | 90.180 (8) | Na1—Na2—S1^{i} | 102.6 (9) |
Mo2^{i}—Mo2—Mo1 | 62.075 (8) | Na1—Na2—S1^{xvii} | 102.6 (9) |
S1—Mo2—Mo1^{iii} | 55.650 (19) | S1^{i}—Na2—S1^{xvii} | 115.4 (7) |
S2—Mo2—Mo1^{iii} | 116.776 (19) | Na1—Na2—S1^{xvi} | 102.6 (9) |
S2^{iii}—Mo2—Mo1^{iii} | 58.573 (17) | S1^{i}—Na2—S1^{xvi} | 115.4 (7) |
S2^{iv}—Mo2—Mo1^{iii} | 151.11 (2) | S1^{xvii}—Na2—S1^{xvi} | 115.4 (7) |
Mo2^{v}—Mo2—Mo1^{iii} | 110.082 (13) | Na1—Na2—Na2^{xx} | 180.000 (2) |
Mo2^{iv}—Mo2—Mo1^{iii} | 144.903 (10) | S1^{i}—Na2—Na2^{xx} | 77.4 (9) |
Mo2^{iii}—Mo2—Mo1^{iii} | 59.650 (8) | S1^{xvii}—Na2—Na2^{xx} | 77.4 (9) |
Mo2^{i}—Mo2—Mo1^{iii} | 88.804 (7) | S1^{xvi}—Na2—Na2^{xx} | 77.4 (9) |
Mo1—Mo2—Mo1^{iii} | 57.157 (12) | Na1—Na2—Na1^{xiii} | 0.000 (1) |
Mo2—S1—Mo1^{iii} | 68.80 (2) | S1^{i}—Na2—Na1^{xiii} | 102.6 (9) |
Mo2—S1—Mo1 | 66.67 (2) | S1^{xvii}—Na2—Na1^{xiii} | 102.6 (9) |
Mo1^{iii}—S1—Mo1 | 64.26 (2) | S1^{xvi}—Na2—Na1^{xiii} | 102.6 (9) |
Mo2—S1—Mo1^{ii} | 136.36 (4) | Na2^{xx}—Na2—Na1^{xiii} | 180.000 (1) |
Symmetry codes: (i) −x+y+1, −x+1, z; (ii) −x+1, −y, −z; (iii) −y+1, x−y, z; (iv) −x+y+1, y, −z+1/2; (v) −y+1, −x+1, −z+1/2; (vi) x+1, y, z; (vii) −y+1, −x+1, −z−1/2; (viii) y+1, −x+y+1, −z; (ix) x−y, −y, z−1/2; (x) y+1, x, z−1/2; (xi) −x+1, −x+y+1, z−1/2; (xii) x−y, x, −z; (xiii) −y, −x, −z+1/2; (xiv) −x+y, −x, z; (xv) −y, x−y, z; (xvi) −y, x−y−1, z; (xvii) x−1, y, z; (xviii) x, x−y, −z+1/2; (xix) −x+y, y, −z+1/2; (xx) −x, −y, −z. |
Experimental details
Crystal data | |
Chemical formula | Na_{2.90}KMo_{12}S_{14} |
M_{r} | 1705.89 |
Crystal system, space group | Trigonal, P3_{1}c |
Temperature (K) | 100 |
a, c (Å) | 9.3664 (1), 16.2981 (2) |
V (Å^{3}) | 1238.26 (2) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm^{−}^{1}) | 7.24 |
Crystal size (mm) | 0.08 × 0.07 × 0.07 |
Data collection | |
Diffractometer | Nonius KappaCCD diffractometer |
Absorption correction | Analytical (de Meulenaer & Tompa, 1965) |
T_{min}, T_{max} | 0.550, 0.572 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 37291, 2536, 2376 |
R_{int} | 0.056 |
(sin θ/λ)_{max} (Å^{−}^{1}) | 0.900 |
Refinement | |
R[F^{2} > 2σ(F^{2})], wR(F^{2}), S | 0.027, 0.073, 1.13 |
No. of reflections | 2536 |
No. of parameters | 52 |
Δρ_{max}, Δρ_{min} (e Å^{−}^{3}) | 2.74, −1.84 |
Computer programs: COLLECT (Nonius, 1998), EVALCCD (Duisenberg, 1998), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), DIAMOND (Bergerhoff, 1996).
Mo1—S3 | 2.3855 (10) | Mo2—Mo2^{v} | 2.6440 (5) |
Mo1—S1^{i} | 2.4620 (8) | Mo2—Mo2^{iv} | 2.6745 (5) |
Mo1—S1 | 2.4822 (8) | Mo2—Mo2^{i} | 2.6765 (4) |
Mo1—S1^{ii} | 2.4944 (8) | K1—S3 | 2.9460 (13) |
Mo1—S2 | 2.5907 (7) | K1—S2^{vi} | 3.4188 (7) |
Mo1—Mo1^{iii} | 2.6296 (5) | K1—S2^{vii} | 3.4188 (7) |
Mo1—Mo2 | 2.7155 (4) | K1—S2^{viii} | 3.4188 (7) |
Mo1—Mo2^{i} | 2.7803 (4) | Na1—S2^{ix} | 3.3131 (17) |
Mo2—S1 | 2.4589 (7) | Na1—S1^{x} | 3.856 (12) |
Mo2—S2 | 2.4655 (7) | Na1—S2^{xi} | 3.898 (11) |
Mo2—S2^{iii} | 2.4904 (8) | Na2—S1^{xii} | 3.210 (12) |
Mo2—S2^{iv} | 2.5866 (7) | Na2—S2^{xiii} | 3.56 (2) |
Symmetry codes: (i) −x+y+1, −x+1, z; (ii) −x+1, −y, −z; (iii) −y+1, x−y, z; (iv) −x+y+1, y, −z+1/2; (v) −y+1, −x+1, −z+1/2; (vi) y+1, −x+y+1, −z; (vii) −x+1, −x+y+1, z−1/2; (viii) x−y, x, −z; (ix) −x+y, −x, z; (x) −y, x−y−1, z; (xi) x, x−y, −z+1/2; (xii) x−1, y, z; (xiii) −y, x−y, z. |
Intensity data were collected on the Nonius KappaCCD X-ray diffactometer system of the Centre de Diffractométrie de l'Université de Rennes I (www.cdifx.univ-rennes1.fr).
In a previous paper, we reported the synthesis, the crystal structures and, the physical properties of the compounds K_{1 +} _{x}Mo_{12}S_{14} (x= 0, 1.1, 1.3, and 1.6) which crystallize in a new structural type only based on the Mo_{12} cluster (Picard et al., 2006). We present here the crystal structure of the sulfide Na_{2.9}KMo_{12}S_{14} which is isomorphous with the latter compounds (Picard et al., 2006). Its crystal structure (Fig. 1) contains Mo_{12}S^{i}_{14}S^{a}_{6} cluster units (for details of the i- and a-type ligand notation, see Schäfer & von Schnering (1964)). The i-type ligands cap Mo triangular faces and the a-type ones are in apical position for the external Mo1 atoms (Fig. 2). The Mo_{12}S_{14} cluster unit is centred at a 2 d (D_{3} or 32 symmetry) position. The Mo—Mo distances within the Mo_{12} clusters are 2.6296 (5) Å for the distances in the triangles formed by the Mo1 related through the threefold axis and 2.6764 (4) in the triangles formed by the Mo2 atoms. The distances between the triangles formed by the Mo1 and Mo2 atoms are 2.7155 (4) and 2.7803 (4) Å and those between the two Mo2_{3} triangles, 2.6440 (5) and 2.6745 (5) Å. The sulfur atoms bridge either one [S1 and S3] or two [S2] Mo triangular faces of the clusters. Moreover the S1 atoms are linked to a Mo atom of a neighboring cluster. The Mo—S bond distances range from 2.3855 (10) to 2.5907 (7) Å. Each Mo_{12}S_{14} unit is interconnected to 6 adjacent ones via Mo1—S1 bonds to form the three-dimensional Mo—S framework, the connective formula of which is Mo_{12}S^{i}_{8}S^{i-a}_{6/2}S^{a-i}_{6/2}. It results from this arrangement that the shortest intercluster Mo1—Mo1 distance between the Mo_{12} clusters is 3.4025 (3) Å, indicating only weak metal-metal interaction. The Na cations reside in large channels extending along the c axis (Fig. 3). The Na1 cations occupied distorted tri-capped trigonal prismatic cavities of sulfur atoms and the Na2 are in an octahedron compressed along the threefold axis. The Na—S distances spread over a wide range 3.210 (12) - 3.898 (11) Å. The K cation is eight-coordinated with six S2 atoms at 3.4188 (7), forming an octahedron compressed along the threefold axis, and the remaining two S3 atoms capping two opposite faces of the octahedron at 2.9460 (13).