Single crystals of dipotassium titanium trisilicate hydrate were synthesized and the crystal structure was refined using data from single-crystal X-ray diffraction. The structure is a three-dimensional mixed framework and contains channels formed by six- and eight-membered rings. K+ ions and water molecules are located in the channels.
Supporting information
The synthesis of the title compound was carried out by hydrothermal reaction. KOH (10.240 g) and colloidal silica Ludox (2.531 g; HS-40, Aldrich) were added to distilled water (59.974 g). KF (0.968 g) and then TiCl3 (5.760 g) solution (15wt% TiCl3, 10wt% HCl, Aldrich) were added under continuous stirring. The TiCl3:SiO2:KF:KOH:H2O molar ratio was 1:3:3:32:600 H2O and the pH was 1.5. Excess KOH was added to increase the pH to 14.0. The solution was heated in a 23 ml Teflon-lined autoclave at 488 K for 100 h under autogeneous pressure. The colorless transparent crystals formed were filtered and washed, first with water, then with acetone and finally dried at 328 K.
The positions of the non-H atoms were refined anisotropically using the model obtained by X-ray powder diffraction (Dadachov & LeBail, 1997). Then H-atom positions were obtained from the difference Fourier map and were refined isotropically with Uiso equal to 1.5Ueq(O), and O—H and H—H distances restrained to 0.95 (2) and 1.50 (2) Å, respectively. The total number of measured reflections for determining the absolute structure was 2215, among which 913 were Friedel pairs. The Flack (1983) parameter of −0.01 (3) indicated that the crystal was not twinned.
Data collection: EXPOSE (Stoe & Cie, 1997); cell refinement: CELL (Stoe & Cie, 1997); data reduction: INTEGRATE (Stoe & Cie, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: DIAMOND (Bergerhoff, 1996).
dipotassium titanium trisilicate hydrate
top
Crystal data top
K2TiSi3O9·H2O | Dx = 2.686 Mg m−3 |
Mr = 372.39 | Mo Kα radiation, λ = 0.71073 Å |
Orthorhombic, P212121 | Cell parameters from 1183 reflections |
a = 7.1543 (7) Å | θ = 2.5–28.0° |
b = 9.9408 (11) Å | µ = 2.27 mm−1 |
c = 12.946 (1) Å | T = 293 K |
V = 920.71 (15) Å3 | Prism, colourless |
Z = 4 | 0.10 × 0.06 × 0.04 mm |
F(000) = 736 | |
Data collection top
Stoe IPDS diffractometer | 2215 independent reflections |
Radiation source: fine-focus sealed tube | 1983 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.073 |
Detector resolution: 6.0 pixels mm-1 | θmax = 28.0°, θmin = 2.6° |
Area–detector scans | h = −9→9 |
Absorption correction: numerical (X-RED; Stoe & Cie, 1997) | k = −13→13 |
Tmin = 0.850, Tmax = 0.921 | l = −15→17 |
8937 measured reflections | |
Refinement top
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.029 | H atoms treated by a mixture of independent and constrained refinement |
wR(F2) = 0.068 | w = 1/[σ2(Fo2) + (0.0376P)2] where P = (Fo2 + 2Fc2)/3 |
S = 0.99 | (Δ/σ)max < 0.001 |
2215 reflections | Δρmax = 0.39 e Å−3 |
151 parameters | Δρmin = −0.59 e Å−3 |
3 restraints | Absolute structure: Flack (1983) |
Primary atom site location: structure-invariant direct methods | Absolute structure parameter: −0.01 (3) |
Crystal data top
K2TiSi3O9·H2O | V = 920.71 (15) Å3 |
Mr = 372.39 | Z = 4 |
Orthorhombic, P212121 | Mo Kα radiation |
a = 7.1543 (7) Å | µ = 2.27 mm−1 |
b = 9.9408 (11) Å | T = 293 K |
c = 12.946 (1) Å | 0.10 × 0.06 × 0.04 mm |
Data collection top
Stoe IPDS diffractometer | 2215 independent reflections |
Absorption correction: numerical (X-RED; Stoe & Cie, 1997) | 1983 reflections with I > 2σ(I) |
Tmin = 0.850, Tmax = 0.921 | Rint = 0.073 |
8937 measured reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.029 | H atoms treated by a mixture of independent and constrained refinement |
wR(F2) = 0.068 | Δρmax = 0.39 e Å−3 |
S = 0.99 | Δρmin = −0.59 e Å−3 |
2215 reflections | Absolute structure: Flack (1983) |
151 parameters | Absolute structure parameter: −0.01 (3) |
3 restraints | |
Special details top
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. |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
Ti1 | 0.24091 (8) | 0.45398 (5) | 0.71163 (4) | 0.00424 (12) | |
K1 | 0.20469 (12) | 0.93268 (9) | 0.92120 (7) | 0.02031 (19) | |
K2 | 0.15175 (16) | 0.79399 (10) | 0.63473 (7) | 0.0260 (2) | |
Si1 | 0.26869 (12) | 0.46207 (9) | 0.45344 (6) | 0.00406 (17) | |
Si2 | 0.49308 (13) | 0.17930 (9) | 0.67332 (7) | 0.00459 (18) | |
Si3 | 0.08136 (13) | 0.14281 (9) | 0.66836 (7) | 0.00465 (17) | |
O1 | 0.4507 (3) | 0.3365 (2) | 0.69111 (19) | 0.0081 (5) | |
O2 | 0.2992 (3) | 0.0959 (2) | 0.65008 (19) | 0.0109 (5) | |
O3 | 0.0723 (3) | 0.3020 (2) | 0.68961 (17) | 0.0080 (5) | |
O4 | 0.1235 (3) | 0.3372 (2) | 0.42936 (19) | 0.0105 (5) | |
O5 | 0.0109 (3) | 0.5599 (2) | 0.73828 (18) | 0.0086 (5) | |
O6 | 0.2553 (3) | 0.4247 (2) | 0.86425 (17) | 0.0076 (4) | |
O7 | 0.4799 (3) | 0.3989 (3) | 0.44128 (18) | 0.0091 (5) | |
O8 | 0.3975 (3) | 0.6140 (2) | 0.73005 (18) | 0.0091 (5) | |
O9 | 0.2292 (4) | 0.5138 (2) | 0.56809 (17) | 0.0074 (5) | |
O10 | 0.3756 (5) | 0.1830 (3) | 0.9343 (2) | 0.0281 (7) | |
H1 | 0.342 (7) | 0.270 (3) | 0.909 (4) | 0.042* | |
H2 | 0.474 (6) | 0.153 (5) | 0.897 (4) | 0.042* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Ti1 | 0.0040 (3) | 0.0049 (2) | 0.0038 (2) | 0.0010 (2) | 0.0002 (2) | −0.0005 (2) |
K1 | 0.0211 (4) | 0.0207 (4) | 0.0191 (4) | 0.0011 (3) | −0.0085 (4) | −0.0028 (3) |
K2 | 0.0395 (6) | 0.0222 (4) | 0.0163 (4) | 0.0103 (4) | 0.0074 (4) | 0.0078 (4) |
Si1 | 0.0034 (4) | 0.0057 (4) | 0.0030 (3) | 0.0001 (4) | 0.0001 (3) | 0.0002 (3) |
Si2 | 0.0029 (4) | 0.0059 (4) | 0.0050 (4) | 0.0018 (3) | 0.0002 (3) | −0.0004 (3) |
Si3 | 0.0030 (4) | 0.0059 (4) | 0.0051 (4) | −0.0007 (3) | −0.0004 (3) | 0.0001 (3) |
O1 | 0.0077 (11) | 0.0068 (11) | 0.0097 (12) | 0.0001 (9) | 0.0010 (9) | −0.0012 (9) |
O2 | 0.0049 (11) | 0.0094 (11) | 0.0184 (13) | 0.0006 (9) | 0.0011 (9) | −0.0047 (10) |
O3 | 0.0054 (10) | 0.0092 (11) | 0.0093 (12) | −0.0024 (9) | −0.0008 (9) | 0.0004 (9) |
O4 | 0.0134 (12) | 0.0105 (11) | 0.0077 (11) | −0.0045 (10) | −0.0052 (9) | 0.0018 (9) |
O5 | 0.0083 (10) | 0.0098 (11) | 0.0078 (11) | 0.0032 (10) | −0.0001 (9) | −0.0020 (9) |
O6 | 0.0090 (11) | 0.0096 (10) | 0.0041 (9) | −0.0001 (11) | −0.0004 (9) | −0.0003 (8) |
O7 | 0.0072 (11) | 0.0140 (11) | 0.0062 (12) | 0.0049 (10) | −0.0008 (9) | −0.0001 (9) |
O8 | 0.0112 (12) | 0.0087 (11) | 0.0073 (11) | −0.0028 (9) | −0.0019 (9) | −0.0008 (9) |
O9 | 0.0094 (12) | 0.0095 (10) | 0.0034 (10) | −0.0001 (9) | 0.0006 (9) | 0.0015 (8) |
O10 | 0.043 (2) | 0.0221 (15) | 0.0195 (14) | 0.0142 (14) | 0.0137 (13) | 0.0073 (12) |
Geometric parameters (Å, º) top
Ti1—O1 | 1.920 (2) | Si1—K1i | 3.7668 (13) |
Ti1—O9 | 1.953 (2) | Si1—K2vii | 3.8333 (13) |
Ti1—O3 | 1.954 (2) | Si2—O1 | 1.609 (2) |
Ti1—O8 | 1.961 (2) | Si2—O8viii | 1.612 (2) |
Ti1—O5 | 1.984 (2) | Si2—O4ix | 1.632 (3) |
Ti1—O6 | 2.000 (2) | Si2—O2 | 1.644 (3) |
Ti1—K2 | 3.5808 (11) | Si2—K1viii | 3.5380 (13) |
Ti1—K1i | 3.6283 (11) | Si2—K1vi | 3.7275 (13) |
Ti1—K2i | 3.7918 (12) | Si2—K2viii | 3.7325 (14) |
K1—O3ii | 2.770 (3) | Si3—O5i | 1.605 (2) |
K1—O10iii | 2.778 (4) | Si3—O3 | 1.607 (2) |
K1—O5ii | 2.871 (3) | Si3—O2 | 1.644 (3) |
K1—O7iv | 2.894 (2) | Si3—O7x | 1.647 (3) |
K1—O4v | 2.953 (3) | Si3—K2i | 3.3968 (13) |
K1—O2v | 2.977 (3) | Si3—K2xi | 3.5309 (13) |
K1—O1iv | 3.017 (3) | Si3—K1vi | 3.6255 (13) |
K1—O4ii | 3.187 (3) | Si3—K1i | 3.7196 (12) |
K1—O9ii | 3.210 (3) | O1—K1viii | 3.017 (3) |
K1—Si2iv | 3.5380 (13) | O2—K1vi | 2.977 (3) |
K1—Si3v | 3.6255 (13) | O2—K2xi | 3.188 (3) |
K1—Ti1ii | 3.6283 (11) | O3—K1i | 2.770 (3) |
K2—O10vi | 2.612 (3) | O3—K2i | 2.784 (2) |
K2—O3ii | 2.784 (2) | O4—Si2x | 1.632 (2) |
K2—O8 | 2.795 (3) | O4—K1vi | 2.953 (3) |
K2—O5 | 2.868 (3) | O4—K1i | 3.187 (3) |
K2—O9 | 2.968 (2) | O5—Si3ii | 1.605 (2) |
K2—O2iii | 3.188 (3) | O5—K1i | 2.871 (3) |
K2—O6ii | 3.189 (3) | O5—K2i | 3.324 (3) |
K2—O5ii | 3.324 (3) | O6—Si1v | 1.622 (2) |
K2—Si3ii | 3.3968 (13) | O6—K2i | 3.189 (3) |
K2—Si3iii | 3.5309 (13) | O7—Si3ix | 1.647 (2) |
K2—Si2iv | 3.7325 (14) | O7—K1viii | 2.894 (2) |
Si1—O9 | 1.596 (2) | O8—Si2iv | 1.612 (2) |
Si1—O6vi | 1.622 (2) | O9—K1i | 3.210 (3) |
Si1—O7 | 1.644 (3) | O10—K2v | 2.612 (3) |
Si1—O4 | 1.649 (2) | O10—K1xi | 2.778 (4) |
| | | |
O1—Ti1—O9 | 95.00 (11) | O8—K2—Si3iii | 131.58 (6) |
O1—Ti1—O3 | 89.55 (10) | O5—K2—Si3iii | 133.55 (6) |
O9—Ti1—O3 | 94.04 (10) | O9—K2—Si3iii | 169.76 (5) |
O1—Ti1—O8 | 93.64 (11) | O2iii—K2—Si3iii | 27.72 (5) |
O9—Ti1—O8 | 83.86 (10) | O6ii—K2—Si3iii | 57.93 (5) |
O3—Ti1—O8 | 176.32 (11) | O5ii—K2—Si3iii | 26.86 (4) |
O1—Ti1—O5 | 174.42 (10) | Si3ii—K2—Si3iii | 105.78 (3) |
O9—Ti1—O5 | 88.18 (10) | O10vi—K2—Ti1 | 111.84 (7) |
O3—Ti1—O5 | 85.64 (10) | O3ii—K2—Ti1 | 84.40 (5) |
O8—Ti1—O5 | 91.26 (10) | O8—K2—Ti1 | 32.99 (5) |
O1—Ti1—O6 | 90.46 (10) | O5—K2—Ti1 | 33.58 (5) |
O9—Ti1—O6 | 170.63 (9) | O9—K2—Ti1 | 33.05 (4) |
O3—Ti1—O6 | 93.62 (9) | O2iii—K2—Ti1 | 144.35 (6) |
O8—Ti1—O6 | 88.20 (10) | O6ii—K2—Ti1 | 123.10 (5) |
O5—Ti1—O6 | 87.02 (10) | O5ii—K2—Ti1 | 132.51 (5) |
O1—Ti1—K2 | 132.43 (8) | Si3ii—K2—Ti1 | 57.40 (2) |
O9—Ti1—K2 | 55.96 (7) | Si3iii—K2—Ti1 | 156.65 (3) |
O3—Ti1—K2 | 125.41 (7) | O10vi—K2—Si2iv | 137.65 (8) |
O8—Ti1—K2 | 50.92 (8) | O3ii—K2—Si2iv | 81.77 (6) |
O5—Ti1—K2 | 53.09 (7) | O8—K2—Si2iv | 23.43 (5) |
O6—Ti1—K2 | 114.91 (7) | O5—K2—Si2iv | 71.35 (5) |
O1—Ti1—K1i | 125.87 (7) | O9—K2—Si2iv | 77.28 (5) |
O9—Ti1—K1i | 61.91 (8) | O2iii—K2—Si2iv | 91.20 (5) |
O3—Ti1—K1i | 48.97 (7) | O6ii—K2—Si2iv | 138.02 (5) |
O8—Ti1—K1i | 127.38 (8) | O5ii—K2—Si2iv | 98.74 (5) |
O5—Ti1—K1i | 52.02 (7) | Si3ii—K2—Si2iv | 72.51 (3) |
O6—Ti1—K1i | 120.32 (7) | Si3iii—K2—Si2iv | 108.36 (3) |
K2—Ti1—K1i | 76.51 (3) | Ti1—K2—Si2iv | 53.51 (2) |
O1—Ti1—K2i | 113.38 (8) | O9—Si1—O6vi | 114.81 (12) |
O9—Ti1—K2i | 126.53 (8) | O9—Si1—O7 | 112.01 (13) |
O3—Ti1—K2i | 45.17 (7) | O6vi—Si1—O7 | 107.10 (13) |
O8—Ti1—K2i | 134.42 (7) | O9—Si1—O4 | 107.89 (13) |
O5—Ti1—K2i | 61.11 (7) | O6vi—Si1—O4 | 108.75 (13) |
O6—Ti1—K2i | 57.23 (7) | O7—Si1—O4 | 105.87 (14) |
K2—Ti1—K2i | 114.19 (2) | O9—Si1—K1i | 57.68 (10) |
K1i—Ti1—K2i | 64.73 (2) | O6vi—Si1—K1i | 105.40 (9) |
O3ii—K1—O10iii | 140.06 (9) | O7—Si1—K1i | 146.94 (9) |
O3ii—K1—O5ii | 56.62 (7) | O4—Si1—K1i | 57.08 (9) |
O10iii—K1—O5ii | 83.43 (9) | O9—Si1—K2vii | 101.50 (9) |
O3ii—K1—O7iv | 145.29 (8) | O6vi—Si1—K2vii | 54.86 (9) |
O10iii—K1—O7iv | 73.93 (9) | O7—Si1—K2vii | 63.64 (9) |
O5ii—K1—O7iv | 155.85 (8) | O4—Si1—K2vii | 150.53 (10) |
O3ii—K1—O4v | 83.70 (7) | K1i—Si1—K2vii | 145.10 (3) |
O10iii—K1—O4v | 128.93 (9) | O1—Si2—O8viii | 111.80 (14) |
O5ii—K1—O4v | 130.52 (7) | O1—Si2—O4ix | 108.76 (13) |
O7iv—K1—O4v | 63.13 (7) | O8viii—Si2—O4ix | 108.30 (13) |
O3ii—K1—O2v | 117.64 (8) | O1—Si2—O2 | 110.92 (13) |
O10iii—K1—O2v | 91.67 (8) | O8viii—Si2—O2 | 110.42 (14) |
O5ii—K1—O2v | 138.85 (8) | O4ix—Si2—O2 | 106.43 (13) |
O7iv—K1—O2v | 51.96 (7) | O1—Si2—K1viii | 58.19 (9) |
O4v—K1—O2v | 83.19 (7) | O8viii—Si2—K1viii | 104.96 (10) |
O3ii—K1—O1iv | 100.74 (7) | O4ix—Si2—K1viii | 55.97 (9) |
O10iii—K1—O1iv | 87.33 (8) | O2—Si2—K1viii | 144.24 (10) |
O5ii—K1—O1iv | 103.41 (7) | O1—Si2—K1vi | 110.12 (10) |
O7iv—K1—O1iv | 67.83 (7) | O8viii—Si2—K1vi | 138.04 (10) |
O4v—K1—O1iv | 52.36 (6) | O4ix—Si2—K1vi | 58.26 (10) |
O2v—K1—O1iv | 117.19 (7) | O2—Si2—K1vi | 50.86 (9) |
O3ii—K1—O4ii | 69.36 (7) | K1viii—Si2—K1vi | 98.15 (3) |
O10iii—K1—O4ii | 123.65 (8) | O1—Si2—K2viii | 74.70 (9) |
O5ii—K1—O4ii | 99.90 (7) | O8viii—Si2—K2viii | 43.59 (9) |
O7iv—K1—O4ii | 99.58 (7) | O4ix—Si2—K2viii | 100.59 (10) |
O4v—K1—O4ii | 90.82 (5) | O2—Si2—K2viii | 148.26 (10) |
O2v—K1—O4ii | 50.24 (7) | K1viii—Si2—K2viii | 66.22 (3) |
O1iv—K1—O4ii | 143.14 (7) | K1vi—Si2—K2viii | 158.84 (3) |
O3ii—K1—O9ii | 56.53 (7) | O5i—Si3—O3 | 111.10 (13) |
O10iii—K1—O9ii | 101.42 (8) | O5i—Si3—O2 | 110.67 (14) |
O5ii—K1—O9ii | 53.19 (6) | O3—Si3—O2 | 109.99 (14) |
O7iv—K1—O9ii | 139.17 (7) | O5i—Si3—O7x | 109.77 (13) |
O4v—K1—O9ii | 129.00 (7) | O3—Si3—O7x | 112.19 (13) |
O2v—K1—O9ii | 88.40 (6) | O2—Si3—O7x | 102.85 (13) |
O1iv—K1—O9ii | 152.92 (7) | O5i—Si3—K2i | 57.31 (9) |
O4ii—K1—O9ii | 48.42 (6) | O3—Si3—K2i | 54.29 (9) |
O3ii—K1—Si2iv | 85.65 (6) | O2—Si3—K2i | 134.34 (10) |
O10iii—K1—Si2iv | 112.94 (7) | O7x—Si3—K2i | 122.79 (10) |
O5ii—K1—Si2iv | 113.16 (6) | O5i—Si3—K2xi | 69.35 (9) |
O7iv—K1—Si2iv | 69.73 (6) | O3—Si3—K2xi | 173.52 (10) |
O4v—K1—Si2iv | 27.27 (5) | O2—Si3—K2xi | 64.45 (9) |
O2v—K1—Si2iv | 106.37 (5) | O7x—Si3—K2xi | 73.10 (9) |
O1iv—K1—Si2iv | 26.94 (5) | K2i—Si3—K2xi | 126.66 (3) |
O4ii—K1—Si2iv | 116.62 (5) | O5i—Si3—K1vi | 137.06 (10) |
O9ii—K1—Si2iv | 141.70 (5) | O3—Si3—K1vi | 111.83 (9) |
O3ii—K1—Si3v | 131.45 (6) | O2—Si3—K1vi | 54.12 (9) |
O10iii—K1—Si3v | 86.89 (7) | O7x—Si3—K1vi | 51.21 (9) |
O5ii—K1—Si3v | 162.31 (6) | K2i—Si3—K1vi | 163.99 (4) |
O7iv—K1—Si3v | 26.34 (5) | K2xi—Si3—K1vi | 68.14 (3) |
O4v—K1—Si3v | 66.71 (5) | O5i—Si3—K1i | 113.96 (10) |
O2v—K1—Si3v | 26.57 (5) | O3—Si3—K1i | 43.00 (9) |
O1iv—K1—Si3v | 90.85 (5) | O2—Si3—K1i | 134.13 (10) |
O4ii—K1—Si3v | 73.36 (5) | O7x—Si3—K1i | 71.58 (9) |
O9ii—K1—Si3v | 114.97 (5) | K2i—Si3—K1i | 67.73 (3) |
Si2iv—K1—Si3v | 84.25 (3) | K2xi—Si3—K1i | 143.21 (4) |
O3ii—K1—Ti1ii | 32.15 (5) | K1vi—Si3—K1i | 96.75 (3) |
O10iii—K1—Ti1ii | 111.31 (8) | Si2—O1—Ti1 | 139.26 (14) |
O5ii—K1—Ti1ii | 33.00 (5) | Si2—O1—K1viii | 94.87 (10) |
O7iv—K1—Ti1ii | 169.57 (6) | Ti1—O1—K1viii | 120.85 (10) |
O4v—K1—Ti1ii | 115.83 (5) | Si3—O2—Si2 | 129.12 (16) |
O2v—K1—Ti1ii | 117.98 (5) | Si3—O2—K1vi | 99.30 (11) |
O1iv—K1—Ti1ii | 120.53 (5) | Si2—O2—K1vi | 103.78 (11) |
O4ii—K1—Ti1ii | 69.99 (5) | Si3—O2—K2xi | 87.83 (10) |
O9ii—K1—Ti1ii | 32.46 (4) | Si2—O2—K2xi | 139.94 (13) |
Si2iv—K1—Ti1ii | 114.50 (3) | K1vi—O2—K2xi | 81.07 (6) |
Si3v—K1—Ti1ii | 143.25 (3) | Si3—O3—Ti1 | 139.59 (15) |
O10vi—K2—O3ii | 139.98 (10) | Si3—O3—K1i | 113.70 (12) |
O10vi—K2—O8 | 122.79 (9) | Ti1—O3—K1i | 98.88 (9) |
O3ii—K2—O8 | 91.14 (7) | Si3—O3—K2i | 97.76 (11) |
O10vi—K2—O5 | 120.59 (10) | Ti1—O3—K2i | 104.97 (10) |
O3ii—K2—O5 | 55.87 (7) | K1i—O3—K2i | 91.40 (8) |
O8—K2—O5 | 59.70 (7) | Si2x—O4—Si1 | 126.14 (15) |
O10vi—K2—O9 | 78.89 (8) | Si2x—O4—K1vi | 96.76 (11) |
O3ii—K2—O9 | 111.82 (7) | Si1—O4—K1vi | 115.38 (12) |
O8—K2—O9 | 53.87 (7) | Si2x—O4—K1i | 95.92 (11) |
O5—K2—O9 | 55.96 (7) | Si1—O4—K1i | 97.18 (11) |
O10vi—K2—O2iii | 90.25 (9) | K1vi—O4—K1i | 126.80 (8) |
O3ii—K2—O2iii | 96.48 (7) | Si3ii—O5—Ti1 | 138.14 (15) |
O8—K2—O2iii | 111.53 (8) | Si3ii—O5—K2 | 94.59 (11) |
O5—K2—O2iii | 148.32 (7) | Ti1—O5—K2 | 93.33 (9) |
O9—K2—O2iii | 147.14 (8) | Si3ii—O5—K1i | 123.14 (13) |
O10vi—K2—O6ii | 84.26 (9) | Ti1—O5—K1i | 94.97 (9) |
O3ii—K2—O6ii | 57.25 (6) | K2—O5—K1i | 102.12 (8) |
O8—K2—O6ii | 146.44 (7) | Si3ii—O5—K2i | 83.79 (10) |
O5—K2—O6ii | 90.45 (7) | Ti1—O5—K2i | 87.38 (8) |
O9—K2—O6ii | 123.65 (7) | K2—O5—K2i | 178.19 (9) |
O2iii—K2—O6ii | 85.31 (6) | K1i—O5—K2i | 79.46 (6) |
O10vi—K2—O5ii | 113.30 (8) | Si1v—O6—Ti1 | 126.66 (13) |
O3ii—K2—O5ii | 51.06 (7) | Si1v—O6—K2i | 100.57 (10) |
O8—K2—O5ii | 120.72 (7) | Ti1—O6—K2i | 90.95 (8) |
O5—K2—O5ii | 106.92 (3) | Si1—O7—Si3ix | 125.72 (15) |
O9—K2—O5ii | 162.87 (7) | Si1—O7—K1viii | 127.85 (12) |
O2iii—K2—O5ii | 48.40 (6) | Si3ix—O7—K1viii | 102.45 (11) |
O6ii—K2—O5ii | 49.76 (6) | Si2iv—O8—Ti1 | 134.31 (15) |
O10vi—K2—Si3ii | 138.36 (9) | Si2iv—O8—K2 | 112.98 (12) |
O3ii—K2—Si3ii | 27.96 (5) | Ti1—O8—K2 | 96.09 (9) |
O8—K2—Si3ii | 72.21 (6) | Si1—O9—Ti1 | 141.17 (14) |
O5—K2—Si3ii | 28.10 (5) | Si1—O9—K2 | 127.29 (11) |
O9—K2—Si3ii | 83.95 (5) | Ti1—O9—K2 | 90.99 (8) |
O2iii—K2—Si3ii | 122.16 (5) | Si1—O9—K1i | 97.48 (11) |
O6ii—K2—Si3ii | 74.26 (5) | Ti1—O9—K1i | 85.63 (8) |
O5ii—K2—Si3ii | 78.97 (5) | K2—O9—K1i | 92.45 (7) |
O10vi—K2—Si3iii | 91.49 (7) | K2v—O10—K1xi | 96.08 (10) |
O3ii—K2—Si3iii | 77.83 (6) | | |
Symmetry codes: (i) −x, y−1/2, −z+3/2; (ii) −x, y+1/2, −z+3/2; (iii) x, y+1, z; (iv) −x+1, y+1/2, −z+3/2; (v) −x+1/2, −y+1, z+1/2; (vi) −x+1/2, −y+1, z−1/2; (vii) x+1/2, −y+3/2, −z+1; (viii) −x+1, y−1/2, −z+3/2; (ix) x+1/2, −y+1/2, −z+1; (x) x−1/2, −y+1/2, −z+1; (xi) x, y−1, z. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
O10—H1···O6 | 0.95 (2) | 1.76 (2) | 2.708 (4) | 174 (5) |
O10—H2···O8viii | 0.91 (2) | 1.92 (3) | 2.762 (4) | 154 (5) |
O10—H2···O9viii | 0.91 (2) | 2.57 (4) | 3.290 (4) | 136 (4) |
Symmetry code: (viii) −x+1, y−1/2, −z+3/2. |
Experimental details
Crystal data |
Chemical formula | K2TiSi3O9·H2O |
Mr | 372.39 |
Crystal system, space group | Orthorhombic, P212121 |
Temperature (K) | 293 |
a, b, c (Å) | 7.1543 (7), 9.9408 (11), 12.946 (1) |
V (Å3) | 920.71 (15) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 2.27 |
Crystal size (mm) | 0.10 × 0.06 × 0.04 |
|
Data collection |
Diffractometer | Stoe IPDS diffractometer |
Absorption correction | Numerical (X-RED; Stoe & Cie, 1997) |
Tmin, Tmax | 0.850, 0.921 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 8937, 2215, 1983 |
Rint | 0.073 |
(sin θ/λ)max (Å−1) | 0.661 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.029, 0.068, 0.99 |
No. of reflections | 2215 |
No. of parameters | 151 |
No. of restraints | 3 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.39, −0.59 |
Absolute structure | Flack (1983) |
Absolute structure parameter | −0.01 (3) |
Selected bond lengths (Å) topTi1—O1 | 1.920 (2) | Si1—O4 | 1.649 (2) |
Ti1—O9 | 1.953 (2) | Si2—O1 | 1.609 (2) |
Ti1—O3 | 1.954 (2) | Si2—O8ii | 1.612 (2) |
Ti1—O8 | 1.961 (2) | Si2—O4iii | 1.632 (3) |
Ti1—O5 | 1.984 (2) | Si2—O2 | 1.644 (3) |
Ti1—O6 | 2.000 (2) | Si3—O5iv | 1.605 (2) |
Si1—O9 | 1.596 (2) | Si3—O3 | 1.607 (2) |
Si1—O6i | 1.622 (2) | Si3—O2 | 1.644 (3) |
Si1—O7 | 1.644 (3) | Si3—O7v | 1.647 (3) |
Symmetry codes: (i) −x+1/2, −y+1, z−1/2; (ii) −x+1, y−1/2, −z+3/2; (iii) x+1/2, −y+1/2, −z+1; (iv) −x, y−1/2, −z+3/2; (v) x−1/2, −y+1/2, −z+1. |
The synthesis and structure refinement of the title compound were undertaken as part of our on-going project aimed at preparing Ti–Si mixed framework compounds. There has recently been much interest in synthesizing open-framework titanium silicates because of their zeolite-like properties and potential applications as molecular sieves, ion-exchange materials and catalysts. Despite extensive worldwide synthetic efforts, only some titanium silicates analogous to minerals and a few titanium silicates with new structures have been reported, for example, Na2TiSi5O13.xH2O (Kuznicki, 1989; Anderson et al., 1995; Wang & Jacobson, 1999), Na4Ti2Si8O22.4H2O (Roberts et al., 1996), Na3(Na,H)Ti2O2[Si2O6]2.2H2O (Dadachov et al., 1997) and Na4[Ti4O4(SiO4)3.6H2O (Dadachov & Harrison, 1997). We have also synthesized a new titanium silicate, K2TiSi3O9.H2O, and the crystal structure was determined using X-ray powder data (Dadachov & LeBail, 1997). All non-H atoms were found and their positions were refined isotropically. The structure appeared to be isostructural with the alkaline Zr–silicate umbite K2ZrSi3O9.H2O (Ilyukhin et al., 1981) and K2(Zr0.86Ti0.14)Si3O9.H2O minerals (Ilyushin, 1993). Recently, we were able to grow crystals of K2TiSi3O9.H2O in sizes suitable for single-crystal structure determination. We report here the accurate crystal structure of K2TiSi3O9.H2O.
The structure is built up from [Si3O9]n wollastonite-type chains running parallel to the a axis. These chains are connected by isolated TiO6 octahedra forming a three-dimensional framework structure. Two types of channels are found along the a axis, i.e. eight-ring channels formed by alternating SiO4 tetrahedra and TiO6 octahedra, and six-ring channels formed by alternating SiO4 tetrahedral pairs and TiO6 octahedra. Two K+ ions are located inside the eight-ring channels and the other two K+ ions inside the six-ring channels. Two water molecules are also located inside the eight-ring channels, forming hydrogen bonds with the framework O atoms; O—H···O distances are 1.76 (2) (H1···O6), 1.92 (3) (H2···O8) and 2.57 (4) Å (H2···O9).