Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270108005179/iz3045sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270108005179/iz3045Isup2.hkl |
All chemicals used were of analytical grade (Merck) and employed without further purification. The title compound was obtained on dissolution of freshly precipitated HgO (25 mg, 0.115 mmol) in a boiling aqueous solution of K2SO3 (50 ml, 180 mg, 1.1 mmol). After cooling to ambient temperature, aggregated yellowish crystals with a lancet-like habit and of up to 2 mm in length were formed within 2 d. The crystals were not stable over a long period and decomposed within a few days under formation of elemental mercury and SO2. However, when the crystals were embedded in perfluorinated ether, collection of a complete data set with high redundancy was possible without difficulty.
Structure data were standardized using STRUCTURETIDY (Gelato & Parthé, 1987). The highest remaining peak in the final difference Fourier map is 0.76 Å from atom Hg2 and the deepest hole is 0.90 Å from atom Hg1.
Data collection: SMART (Bruker, 2003); cell refinement: SAINT (Bruker, 2003); data reduction: SAINT (Bruker, 2003); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ATOMS (Dowty, 2006); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).
K2[O(HgSO3)3] | F(000) = 1624 |
Mr = 936.15 | Dx = 5.243 Mg m−3 |
Orthorhombic, Pnma | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ac 2n | Cell parameters from 4956 reflections |
a = 7.352 (4) Å | θ = 2.8–30.0° |
b = 20.734 (11) Å | µ = 40.01 mm−1 |
c = 7.780 (4) Å | T = 298 K |
V = 1185.9 (11) Å3 | Plate, light yellow |
Z = 4 | 0.12 × 0.11 × 0.04 mm |
Bruke SMART APEX CCD area-detector diffractometer | 1763 independent reflections |
Radiation source: fine-focus sealed tube | 1612 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.046 |
ω scans | θmax = 30.0°, θmin = 2.8° |
Absorption correction: numerical (HABITUS; Herrendorf, 1997) | h = −10→10 |
Tmin = 0.086, Tmax = 0.327 | k = −28→25 |
12066 measured reflections | l = −10→10 |
Refinement on F2 | 0 restraints |
Least-squares matrix: full | Primary atom site location: structure-invariant direct methods |
R[F2 > 2σ(F2)] = 0.023 | Secondary atom site location: difference Fourier map |
wR(F2) = 0.055 | w = 1/[σ2(Fo2) + (0.0284P)2 + 1.2995P] where P = (Fo2 + 2Fc2)/3 |
S = 1.06 | (Δ/σ)max = 0.002 |
1763 reflections | Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
89 parameters | Extinction coefficient: 0.00048 (6) |
K2[O(HgSO3)3] | V = 1185.9 (11) Å3 |
Mr = 936.15 | Z = 4 |
Orthorhombic, Pnma | Mo Kα radiation |
a = 7.352 (4) Å | µ = 40.01 mm−1 |
b = 20.734 (11) Å | T = 298 K |
c = 7.780 (4) Å | 0.12 × 0.11 × 0.04 mm |
Bruke SMART APEX CCD area-detector diffractometer | 1763 independent reflections |
Absorption correction: numerical (HABITUS; Herrendorf, 1997) | 1612 reflections with I > 2σ(I) |
Tmin = 0.086, Tmax = 0.327 | Rint = 0.046 |
12066 measured reflections |
R[F2 > 2σ(F2)] = 0.023 | 1763 reflections |
wR(F2) = 0.055 | 89 parameters |
S = 1.06 | 0 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. 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. |
x | y | z | Uiso*/Ueq | ||
Hg1 | 0.22565 (3) | 0.170861 (10) | 0.76734 (3) | 0.01824 (8) | |
Hg2 | 0.05090 (3) | 0.2500 | 0.41045 (3) | 0.01651 (9) | |
K | −0.13687 (15) | 0.05982 (6) | 0.13114 (18) | 0.0265 (3) | |
S1 | 0.36893 (15) | 0.08535 (6) | 0.90930 (16) | 0.0168 (2) | |
S2 | 0.0100 (2) | 0.2500 | 0.1142 (2) | 0.0141 (3) | |
O1 | 0.5250 (5) | 0.1127 (2) | 1.0028 (6) | 0.0271 (9) | |
O2 | 0.4237 (6) | 0.0389 (2) | 0.7793 (6) | 0.0331 (10) | |
O3 | 0.2341 (5) | 0.0593 (2) | 1.0274 (6) | 0.0285 (9) | |
O4 | −0.0900 (5) | 0.1915 (2) | 0.0636 (5) | 0.0260 (8) | |
O5 | 0.0828 (6) | 0.2500 | 0.6721 (6) | 0.0157 (9) | |
O6 | 0.1939 (7) | 0.2500 | 0.0394 (6) | 0.0260 (13) |
U11 | U22 | U33 | U12 | U13 | U23 | |
Hg1 | 0.02221 (11) | 0.01385 (12) | 0.01866 (12) | 0.00044 (6) | −0.00345 (7) | 0.00189 (7) |
Hg2 | 0.01677 (12) | 0.02136 (15) | 0.01138 (14) | 0.000 | −0.00022 (8) | 0.000 |
K | 0.0250 (5) | 0.0191 (6) | 0.0355 (7) | 0.0009 (4) | 0.0020 (5) | 0.0037 (5) |
S1 | 0.0179 (5) | 0.0125 (6) | 0.0200 (6) | 0.0001 (4) | −0.0002 (4) | 0.0015 (5) |
S2 | 0.0137 (6) | 0.0163 (8) | 0.0125 (7) | 0.000 | −0.0007 (6) | 0.000 |
O1 | 0.0254 (17) | 0.021 (2) | 0.035 (2) | −0.0024 (15) | −0.0121 (16) | 0.0002 (19) |
O2 | 0.036 (2) | 0.024 (2) | 0.039 (3) | 0.0090 (19) | 0.0039 (18) | −0.009 (2) |
O3 | 0.0230 (17) | 0.034 (2) | 0.029 (2) | −0.0062 (15) | 0.0020 (15) | 0.0122 (19) |
O4 | 0.0320 (19) | 0.019 (2) | 0.027 (2) | −0.0062 (16) | −0.0086 (16) | −0.0024 (17) |
O5 | 0.025 (2) | 0.011 (2) | 0.011 (2) | 0.000 | −0.0010 (18) | 0.000 |
O6 | 0.015 (2) | 0.052 (4) | 0.011 (2) | 0.000 | 0.0027 (19) | 0.000 |
Hg1—O5 | 2.084 (3) | K—O2ix | 3.021 (5) |
Hg1—S1 | 2.3395 (15) | K—O2iv | 3.253 (5) |
Hg1—O6i | 2.688 (4) | K—O1ii | 3.276 (5) |
Hg1—O1ii | 2.837 (5) | K—S1ix | 3.474 (2) |
Hg1—O4iii | 2.941 (4) | K—S1ii | 3.614 (3) |
Hg1—O3 | 3.074 (4) | S1—O2 | 1.453 (4) |
Hg2—O5 | 2.049 (5) | S1—O3 | 1.455 (4) |
Hg2—S2 | 2.325 (2) | S1—O1 | 1.472 (4) |
Hg2—O6iv | 2.654 (5) | S1—Hg1xi | 3.4512 (17) |
Hg2—O4v | 2.913 (4) | S2—O6 | 1.472 (5) |
Hg2—O4iii | 2.913 (4) | S2—O4 | 1.473 (4) |
Hg2—O1vi | 2.932 (5) | S2—O4xii | 1.473 (4) |
K—O4 | 2.801 (4) | S2—Hg2iv | 3.381 (2) |
K—O3ii | 2.821 (5) | S2—Hg1xiii | 3.533 (2) |
K—O2vii | 2.824 (4) | S2—Hg1viii | 3.533 (2) |
K—O3viii | 2.845 (4) | S2—Hg2iii | 3.981 (3) |
K—O3ix | 2.852 (5) | S2—Hg1iv | 3.984 (2) |
K—O1x | 2.895 (4) | S2—Hg1xiv | 3.984 (2) |
O5—Hg1—S1 | 172.45 (14) | Hg1xiii—S2—Hg2iii | 61.00 (3) |
O5—Hg1—O6i | 75.84 (15) | Hg1viii—S2—Hg2iii | 61.00 (3) |
S1—Hg1—O6i | 97.48 (9) | O6—S2—Hg1iv | 100.8 (2) |
O5—Hg1—O1ii | 79.00 (14) | O4—S2—Hg1iv | 36.83 (17) |
S1—Hg1—O1ii | 105.18 (10) | O4xii—S2—Hg1iv | 83.02 (17) |
O6i—Hg1—O1ii | 142.89 (13) | Hg2—S2—Hg1iv | 143.76 (5) |
O5—Hg1—O4iii | 78.86 (16) | Hg2iv—S2—Hg1iv | 55.52 (3) |
S1—Hg1—O4iii | 108.41 (9) | Hg1xiii—S2—Hg1iv | 81.83 (5) |
O6i—Hg1—O4iii | 129.84 (11) | Hg1viii—S2—Hg1iv | 58.36 (4) |
O1ii—Hg1—O4iii | 69.68 (12) | Hg2iii—S2—Hg1iv | 119.24 (4) |
O5—Hg1—O3 | 146.78 (15) | O6—S2—Hg1xiv | 100.8 (2) |
S1—Hg1—O3 | 27.10 (7) | O4—S2—Hg1xiv | 83.02 (17) |
O6i—Hg1—O3 | 86.73 (12) | O4xii—S2—Hg1xiv | 36.83 (17) |
O1ii—Hg1—O3 | 100.28 (12) | Hg2—S2—Hg1xiv | 143.76 (5) |
O4iii—Hg1—O3 | 132.55 (12) | Hg2iv—S2—Hg1xiv | 55.52 (3) |
O5—Hg2—S2 | 179.14 (14) | Hg1xiii—S2—Hg1xiv | 58.36 (4) |
O5—Hg2—O6iv | 88.11 (17) | Hg1viii—S2—Hg1xiv | 81.83 (5) |
S2—Hg2—O6iv | 91.03 (12) | Hg2iii—S2—Hg1xiv | 119.24 (4) |
O5—Hg2—O4v | 80.07 (14) | Hg1iv—S2—Hg1xiv | 48.64 (3) |
S2—Hg2—O4v | 100.71 (9) | S1—O1—Hg1xi | 101.7 (2) |
O6iv—Hg2—O4v | 152.41 (9) | S1—O1—Kxv | 133.9 (2) |
O5—Hg2—O4iii | 80.07 (14) | Hg1xi—O1—Kxv | 88.27 (11) |
S2—Hg2—O4iii | 100.71 (9) | S1—O1—Hg2xi | 122.6 (2) |
O6iv—Hg2—O4iii | 152.41 (9) | Hg1xi—O1—Hg2xi | 73.99 (11) |
O4v—Hg2—O4iii | 49.26 (16) | Kxv—O1—Hg2xi | 103.45 (12) |
O5—Hg2—O1vi | 77.21 (9) | S1—O1—Hg1 | 46.07 (13) |
S2—Hg2—O1vi | 102.70 (9) | Hg1xi—O1—Hg1 | 76.51 (11) |
O6iv—Hg2—O1vi | 84.37 (7) | Kxv—O1—Hg1 | 163.48 (17) |
O4v—Hg2—O1vi | 68.79 (11) | Hg2xi—O1—Hg1 | 78.76 (10) |
O4iii—Hg2—O1vi | 116.59 (11) | S1—O1—Kxi | 90.99 (19) |
O4—K—O3ii | 102.80 (13) | Hg1xi—O1—Kxi | 167.26 (14) |
O4—K—O2vii | 135.63 (13) | Kxv—O1—Kxi | 83.41 (11) |
O3ii—K—O2vii | 78.43 (13) | Hg2xi—O1—Kxi | 98.54 (13) |
O4—K—O3viii | 80.36 (13) | Hg1—O1—Kxi | 112.65 (12) |
O3ii—K—O3viii | 126.13 (11) | S1—O2—Kxvi | 156.6 (3) |
O2vii—K—O3viii | 65.23 (13) | S1—O2—Kix | 95.4 (2) |
O4—K—O3ix | 142.54 (13) | Kxvi—O2—Kix | 89.43 (14) |
O3ii—K—O3ix | 108.64 (10) | S1—O2—Hg1 | 46.08 (15) |
O2vii—K—O3ix | 71.81 (13) | Kxvi—O2—Hg1 | 152.62 (18) |
O3viii—K—O3ix | 96.58 (11) | Kix—O2—Hg1 | 106.08 (14) |
O4—K—O1x | 70.83 (12) | S1—O2—Kiii | 123.9 (2) |
O3ii—K—O1x | 92.15 (13) | Kxvi—O2—Kiii | 76.81 (11) |
O2vii—K—O1x | 153.12 (14) | Kix—O2—Kiii | 102.76 (14) |
O3viii—K—O1x | 136.64 (14) | Hg1—O2—Kiii | 77.81 (11) |
O3ix—K—O1x | 87.91 (12) | S1—O2—Hg1xi | 74.6 (2) |
O4—K—O2ix | 142.15 (13) | Kxvi—O2—Hg1xi | 99.81 (13) |
O3ii—K—O2ix | 62.97 (12) | Kix—O2—Hg1xi | 169.99 (15) |
O2vii—K—O2ix | 78.57 (12) | Hg1—O2—Hg1xi | 67.04 (10) |
O3viii—K—O2ix | 137.08 (13) | Kiii—O2—Hg1xi | 83.25 (11) |
O3ix—K—O2ix | 48.52 (12) | S1—O3—Kxi | 111.4 (2) |
O1x—K—O2ix | 74.74 (13) | S1—O3—Ki | 146.2 (2) |
O4—K—O2iv | 85.91 (12) | Kxi—O3—Ki | 93.16 (13) |
O3ii—K—O2iv | 165.93 (12) | S1—O3—Kix | 102.7 (2) |
O2vii—K—O2iv | 103.19 (11) | Kxi—O3—Kix | 119.66 (15) |
O3viii—K—O2iv | 65.78 (12) | Ki—O3—Kix | 83.42 (11) |
O3ix—K—O2iv | 59.64 (12) | S1—O3—Hg1 | 47.08 (14) |
O1x—K—O2iv | 80.18 (13) | Kxi—O3—Hg1 | 128.60 (16) |
O2ix—K—O2iv | 103.40 (12) | Ki—O3—Hg1 | 99.47 (12) |
O4—K—O1ii | 78.00 (12) | Kix—O3—Hg1 | 111.22 (15) |
O3ii—K—O1ii | 45.94 (10) | S2—O4—K | 144.5 (2) |
O2vii—K—O1ii | 71.72 (13) | S2—O4—Hg2iv | 95.2 (2) |
O3viii—K—O1ii | 84.23 (12) | K—O4—Hg2iv | 106.36 (13) |
O3ix—K—O1ii | 139.21 (12) | S2—O4—Hg1iv | 125.7 (2) |
O1x—K—O1ii | 119.01 (14) | K—O4—Hg1iv | 88.05 (11) |
O2ix—K—O1ii | 106.27 (12) | Hg2iv—O4—Hg1iv | 72.75 (9) |
O2iv—K—O1ii | 148.02 (11) | S2—O4—Hg2 | 44.44 (13) |
O2—S1—O3 | 112.5 (3) | K—O4—Hg2 | 104.87 (13) |
O2—S1—O1 | 112.5 (3) | Hg2iv—O4—Hg2 | 94.51 (12) |
O3—S1—O1 | 111.2 (3) | Hg1iv—O4—Hg2 | 164.18 (16) |
O2—S1—Hg1 | 107.4 (2) | S2—O4—Hg1viii | 86.66 (18) |
O3—S1—Hg1 | 105.82 (17) | K—O4—Hg1viii | 95.24 (12) |
O1—S1—Hg1 | 106.98 (18) | Hg2iv—O4—Hg1viii | 137.74 (14) |
O2—S1—Hg1xi | 81.5 (2) | Hg1iv—O4—Hg1viii | 72.16 (10) |
O3—S1—Hg1xi | 163.6 (2) | Hg2—O4—Hg1viii | 114.77 (12) |
O1—S1—Hg1xi | 53.59 (19) | S2—O4—Hg1xiv | 75.96 (17) |
Hg1—S1—Hg1xi | 76.40 (5) | K—O4—Hg1xiv | 139.47 (12) |
O2—S1—Hg2xi | 136.9 (2) | Hg2iv—O4—Hg1xiv | 56.67 (7) |
O3—S1—Hg2xi | 109.2 (2) | Hg1iv—O4—Hg1xiv | 52.80 (7) |
O1—S1—Hg2xi | 38.99 (17) | Hg2—O4—Hg1xiv | 112.48 (12) |
Hg1—S1—Hg2xi | 70.31 (5) | Hg1viii—O4—Hg1xiv | 83.29 (9) |
Hg1xi—S1—Hg2xi | 55.70 (3) | S2—O4—Hg1xiii | 48.14 (15) |
O6—S2—O4 | 110.7 (2) | K—O4—Hg1xiii | 143.72 (14) |
O6—S2—O4xii | 110.7 (2) | Hg2iv—O4—Hg1xiii | 104.32 (11) |
O4—S2—O4xii | 111.0 (3) | Hg1iv—O4—Hg1xiii | 82.94 (10) |
O6—S2—Hg2 | 105.9 (2) | Hg2—O4—Hg1xiii | 91.47 (9) |
O4—S2—Hg2 | 109.22 (18) | Hg1viii—O4—Hg1xiii | 48.55 (6) |
O4xii—S2—Hg2 | 109.22 (18) | Hg1xiv—O4—Hg1xiii | 51.82 (6) |
O6—S2—Hg2iv | 153.5 (2) | Hg2—O5—Hg1xii | 114.25 (16) |
O4—S2—Hg2iv | 59.08 (17) | Hg2—O5—Hg1 | 114.25 (16) |
O4xii—S2—Hg2iv | 59.08 (17) | Hg1xii—O5—Hg1 | 103.9 (2) |
Hg2—S2—Hg2iv | 100.67 (5) | Hg2—O5—Hg1ii | 93.07 (14) |
O6—S2—Hg1xiii | 44.44 (15) | Hg1xii—O5—Hg1ii | 141.4 (2) |
O4—S2—Hg1xiii | 113.77 (18) | Hg1—O5—Hg1ii | 87.51 (9) |
O4xii—S2—Hg1xiii | 68.75 (18) | Hg2—O5—Hg1vi | 93.07 (14) |
Hg2—S2—Hg1xiii | 134.36 (5) | Hg1xii—O5—Hg1vi | 87.51 (9) |
Hg2iv—S2—Hg1xiii | 113.87 (5) | Hg1—O5—Hg1vi | 141.4 (2) |
O6—S2—Hg1viii | 44.44 (15) | Hg1ii—O5—Hg1vi | 63.19 (10) |
O4—S2—Hg1viii | 68.75 (18) | S2—O6—Hg2iii | 148.3 (3) |
O4xii—S2—Hg1viii | 113.77 (18) | S2—O6—Hg1viii | 113.0 (2) |
Hg2—S2—Hg1viii | 134.36 (5) | Hg2iii—O6—Hg1viii | 91.71 (13) |
Hg2iv—S2—Hg1viii | 113.87 (5) | S2—O6—Hg1xiii | 113.0 (2) |
Hg1xiii—S2—Hg1viii | 55.34 (4) | Hg2iii—O6—Hg1xiii | 91.71 (13) |
O6—S2—Hg2iii | 20.5 (2) | Hg1viii—O6—Hg1xiii | 75.24 (14) |
O4—S2—Hg2iii | 119.08 (17) | S2—O6—Hg2 | 46.70 (16) |
O4xii—S2—Hg2iii | 119.08 (17) | Hg2iii—O6—Hg2 | 101.55 (16) |
Hg2—S2—Hg2iii | 85.33 (4) | Hg1viii—O6—Hg2 | 140.31 (9) |
Hg2iv—S2—Hg2iii | 174.00 (5) | Hg1xiii—O6—Hg2 | 140.31 (9) |
Symmetry codes: (i) x, y, z+1; (ii) x−1/2, y, −z+3/2; (iii) x+1/2, y, −z+1/2; (iv) x−1/2, y, −z+1/2; (v) x+1/2, −y+1/2, −z+1/2; (vi) x−1/2, −y+1/2, −z+3/2; (vii) −x+1/2, −y, z−1/2; (viii) x, y, z−1; (ix) −x, −y, −z+1; (x) x−1, y, z−1; (xi) x+1/2, y, −z+3/2; (xii) x, −y+1/2, z; (xiii) x, −y+1/2, z−1; (xiv) x−1/2, −y+1/2, −z+1/2; (xv) x+1, y, z+1; (xvi) −x+1/2, −y, z+1/2. |
Experimental details
Crystal data | |
Chemical formula | K2[O(HgSO3)3] |
Mr | 936.15 |
Crystal system, space group | Orthorhombic, Pnma |
Temperature (K) | 298 |
a, b, c (Å) | 7.352 (4), 20.734 (11), 7.780 (4) |
V (Å3) | 1185.9 (11) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 40.01 |
Crystal size (mm) | 0.12 × 0.11 × 0.04 |
Data collection | |
Diffractometer | Bruke SMART APEX CCD area-detector diffractometer |
Absorption correction | Numerical (HABITUS; Herrendorf, 1997) |
Tmin, Tmax | 0.086, 0.327 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 12066, 1763, 1612 |
Rint | 0.046 |
(sin θ/λ)max (Å−1) | 0.704 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.023, 0.055, 1.06 |
No. of reflections | 1763 |
No. of parameters | 89 |
Δρmax, Δρmin (e Å−3) | ?, ? |
Computer programs: SMART (Bruker, 2003), SAINT (Bruker, 2003), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ATOMS (Dowty, 2006).
Hg1—O5 | 2.084 (3) | K—O2vii | 2.824 (4) |
Hg1—S1 | 2.3395 (15) | K—O3viii | 2.845 (4) |
Hg1—O6i | 2.688 (4) | K—O3ix | 2.852 (5) |
Hg1—O1ii | 2.837 (5) | K—O1x | 2.895 (4) |
Hg1—O4iii | 2.941 (4) | K—O2ix | 3.021 (5) |
Hg1—O3 | 3.074 (4) | K—O2iv | 3.253 (5) |
Hg2—O5 | 2.049 (5) | K—O1ii | 3.276 (5) |
Hg2—S2 | 2.325 (2) | S1—O2 | 1.453 (4) |
Hg2—O6iv | 2.654 (5) | S1—O3 | 1.455 (4) |
Hg2—O4v | 2.913 (4) | S1—O1 | 1.472 (4) |
Hg2—O4iii | 2.913 (4) | S2—O6 | 1.472 (5) |
Hg2—O1vi | 2.932 (5) | S2—O4 | 1.473 (4) |
K—O4 | 2.801 (4) | S2—O4xi | 1.473 (4) |
K—O3ii | 2.821 (5) | ||
O5—Hg1—S1 | 172.45 (14) | O6—S2—O4xi | 110.7 (2) |
O5—Hg2—S2 | 179.14 (14) | O4—S2—O4xi | 111.0 (3) |
O2—S1—O3 | 112.5 (3) | O6—S2—Hg2 | 105.9 (2) |
O2—S1—O1 | 112.5 (3) | O4—S2—Hg2 | 109.22 (18) |
O3—S1—O1 | 111.2 (3) | O4xi—S2—Hg2 | 109.22 (18) |
O2—S1—Hg1 | 107.4 (2) | Hg2—O5—Hg1xi | 114.25 (16) |
O3—S1—Hg1 | 105.82 (17) | Hg2—O5—Hg1 | 114.25 (16) |
O1—S1—Hg1 | 106.98 (18) | Hg1xi—O5—Hg1 | 103.9 (2) |
O6—S2—O4 | 110.7 (2) |
Symmetry codes: (i) x, y, z+1; (ii) x−1/2, y, −z+3/2; (iii) x+1/2, y, −z+1/2; (iv) x−1/2, y, −z+1/2; (v) x+1/2, −y+1/2, −z+1/2; (vi) x−1/2, −y+1/2, −z+3/2; (vii) −x+1/2, −y, z−1/2; (viii) x, y, z−1; (ix) −x, −y, −z+1; (x) x−1, y, z−1; (xi) x, −y+1/2, z. |
In a recent project we have studied the formation conditions and crystal structures of (NH4)[Hg(SO3)Cl] and (NH4)2[Hg(SO3)2] (Weil et al., 2007). Continuing our work on sulfite complexes of mercury, we have also investigated in some detail the systems K2SO3–HgX2 (X = Cl or Br) in aqueous solutions and the solid phases formed therein. Depending on the molar ratios of the components and on the conditions, several phases with the general formula xK[XHgSO3].yHgX2.zKX were obtained. A characteristic of all phases structurally studied so far is the segregation of the K+ cations and of the anions and HgX2 molecules into layers (Weil et al., 2008). On heating solid HgO in an aqueous K2SO3 solution, a related phase was obtained, viz. a formally basic salt of composition K2SO3·2HgSO3·HgO, or, with respect to the crystal structure determination presented here, K2[O(HgSO3)3].
The asymmetric unit of the title compound contains one K, two Hg, two S and six O sites. As in the above-mentioned xK[XHgSO3].yHgX2.zKX structures, a segregation of cations (K+) and anions {[O(HgSO3)3]2-} into layers is a characteristic feature of the structure, here with a stacking of the layers parallel to (010) (Fig. 1). The cationic and anionic layers adopt the symmetries (a:c).21:α-p1121/a and (a:c).m.21-p21ma, respectively (Shubnikov & Koptsik, 1974). The [O(HgSO3)3]2- complex anion has site symmetry m, with the mirror plane running through atoms O5/Hg2/S2/O6 (Fig. 2). The anion is related to the [O(HgCl)3]+ and [O(HgI)2(HgOH)]+ cationic complexes which are present in the structures of 2HgCl2·HgO {or, in a more detailed formula, [O(HgCl)3]Cl} (Aurivillius, 1964) and [O(HgI)2(HgOH)]ClO4 (Köhler et al., 1974, 1975). Both the anionic and the two cationic complexes contain flat nearly trigonal–pyramidal [OHg3] cores, i.e. they are all trimercurio–oxonium complexes which are representatives of metallo complexes, and thus they exhibit similar bonding parameters. In the anionic complex, the average O—Hg bond length is 2.07 Å (Table 1), compared with 2.04 and 2.05 Å, respectively, in the cationic complexes. The slight difference may be due to the strong trans-influence of the sulfite ligands and to the different charges, which is also mirrored in the different average Hg—O—Hg bond angles of 110.8° for the anionic complex and of 118.9 and 119.8° for the cationic complexes.
In the title compound, the average Hg—S bond length is 2.335 Å (Table 1), and the O—Hg—S structural fragments are slightly bent with only a minor deviation from linearity (mean O—Hg—S angle = 174.7°), due to the intermolecular donor–acceptor interactions with S—O····Hg > 2.65 Å. These interactions cause linking of the anions to the above-mentioned layers and the remote O atoms expand the coordination spheres of the Hg2+ cations to five- and six-coordination if Hg—O distances > 3.0 Å are neglected. The average Hg—S bond length is similar to the average Hg—Cl distance of 2.31 Å in [O(HgCl)3]Cl and in good agreement with the Hg—S bond lengths in the sulfitomercurates (NH4)[Hg(SO3)Cl], (NH4)2[Hg(SO3)2] (Weil et al., 2007) and Na2[Hg(SO3)2]·H2O (Nyberg & Cynkier, 1972), with average values of 2.394, 2.364 and 2.406 Å, respectively. In contrast with K2[O(HgSO3)3], in the latter structures Cl—Hg—SO3 and O3S—Hg—SO3 moieties are present. Nevertheless, in agreement with the preference of mercury for linear coordination, the Cl—Hg—S and S—Hg—S angles are close to 180 °, viz. 165.5, 174.4 and 172.8 °, respectively.
The S—O bond lengths of the two independent SO3 groups in K2[O(HgSO3)3] differ slightly (mean S—O = 1.460 and 1.473 Å) because of their different roles in the linking within and between the cationic and anionic layers. Not all of the O atoms of the SO3 groups are involved in donor–acceptor interactions within the anionic layers, and only some of the O atoms are coordinated to the K+ cation, and thus contribute to the linking of the cationic and anionic layers. The K+ cation has nine O neighbours with a [6 + 1+2] coordination and with K—O distances ranging from 2.801 (4) to 3.276 (5) Å (Table 1). The resulting coordination polyhedron may be described as a distorted tricapped trigonal prism.
Results from bond-valence sum calculations (Brown, 2002), using the parameters of Brese & O'Keeffe (1991), are in good agreement with the expected values for K, Hg and O (expected 1, 2 and 2): Hg1, Hg2 (including all distances < 3.0 Å) 1.99 and 2.10; K 1.07; O1 [coordination number (CN) = 5; 1 S, 2 Hg, 2 K] 1.94, O2 (CN = 4; 1 S, 3 K) 1.97, O3 (CN = 4; 1 S, 3 K) 2.11, O4 (CN = 4; 1 S, 1 Hg, 2 K) 1.90, O5 (CN = 3; 3 Hg) 2.29 and O6 (CN = 4; 1 S, 3 Hg) 2.04. Following this concept, the S atoms are considerably `overbonded', with valence units of 5.87 for S1 and 5.75 for S2. This behaviour is attributed to the additional metal–sulfur coordination via the lone-pair electrons of the S atoms, which leads to enhanced S—O π-bonding as a consequence (Cruickshank, 1961), and thus to shorter S—O bond lengths. So, in comparison with other sulfates(IV) of the formula type MSIVO3 (M is a divalent metal) where the S atom is not coordinated to the metal centres, the overall S—O distance is significantly shorter here (1.47 versus 1.54 Å). Nevertheless, the bonding situation in the title compound is in agreement with the HSAB (hard and soft acids and bases) concept, where the soft acid Hg2+ prefers bonding to the soft base SIV with its lone-pair electrons.