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The framework of K2Mn(H2P2O7)2·2H2O consists of metallate layers linked by O-P-O bridges and weak hydrogen bridging bonds. Mn sites have an octahedral coordination by two bidentate [H2P2O7]2- anions and two water molecules.
Supporting information
Key indicators
- Single-crystal X-ray study
- T = 294 K
- Mean (P-O) = 0.002 Å
- R factor = 0.037
- wR factor = 0.063
- Data-to-parameter ratio = 14.8
checkCIF results
No syntax errors found
ADDSYM reports no extra symmetry
Stoichiometric amounts of Mn(CH3COO)2 and K4P2O7 were dissolved in distilled water. After a day of stirring at room temperature, the solution was allowed to stand for two weeks. Large prismatic light pink crystals deposited which were filtered off and washed with a water—ethanol solution (20:80).
Data collection: SMART (Bruker, 1999); cell refinement: SAINT (Bruker, 1999); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ATOMS (Dowty,1999); software used to prepare material for publication: SHELXL97.
Dipotasium manganese bis(dihydrogendiphosphate) dihydrate
top
Crystal data top
H8K2MnO16P4 | F(000) = 1036 |
Mr = 521.08 | Dx = 2.371 Mg m−3 |
Orthorhombic, Pnma | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ac 2n | Cell parameters from 3757 reflections |
a = 9.7613 (8) Å | θ = 2.4–30.8° |
b = 11.1627 (9) Å | µ = 2.00 mm−1 |
c = 13.3949 (11) Å | T = 294 K |
V = 1459.5 (2) Å3 | Needle, colorless |
Z = 4 | 0.23 × 0.11 × 0.08 mm |
Data collection top
Bruker SmartApex CCD area-detector diffractometer | 1890 independent reflections |
Radiation source: fine-focus sealed tube | 1332 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.079 |
ω scans | θmax = 28.3°, θmin = 2.4° |
Absorption correction: multi-scan (XPREP; Sheldrick, 1997) | h = −13→12 |
Tmin = 0.670, Tmax = 0.893 | k = −14→14 |
14628 measured reflections | l = −17→17 |
Refinement top
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.037 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.063 | All H-atom parameters refined |
S = 1.00 | w = 1/[σ2(Fo2) + (0.0136P)2] where P = (Fo2 + 2Fc2)/3 |
1890 reflections | (Δ/σ)max < 0.001 |
128 parameters | Δρmax = 0.84 e Å−3 |
0 restraints | Δρmin = −0.69 e Å−3 |
Crystal data top
H8K2MnO16P4 | V = 1459.5 (2) Å3 |
Mr = 521.08 | Z = 4 |
Orthorhombic, Pnma | Mo Kα radiation |
a = 9.7613 (8) Å | µ = 2.00 mm−1 |
b = 11.1627 (9) Å | T = 294 K |
c = 13.3949 (11) Å | 0.23 × 0.11 × 0.08 mm |
Data collection top
Bruker SmartApex CCD area-detector diffractometer | 1890 independent reflections |
Absorption correction: multi-scan (XPREP; Sheldrick, 1997) | 1332 reflections with I > 2σ(I) |
Tmin = 0.670, Tmax = 0.893 | Rint = 0.079 |
14628 measured reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.037 | 0 restraints |
wR(F2) = 0.063 | All H-atom parameters refined |
S = 1.00 | Δρmax = 0.84 e Å−3 |
1890 reflections | Δρmin = −0.69 e Å−3 |
128 parameters | |
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. |
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. |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
Mn1 | 0.33051 (7) | 0.2500 | 0.36103 (5) | 0.01938 (17) | |
O1W | 0.4837 (4) | 0.2500 | 0.4806 (3) | 0.0277 (8) | |
H1W | 0.530 (3) | 0.193 (3) | 0.487 (2) | 0.047 (13)* | |
O2W | 0.1915 (4) | 0.2500 | 0.2273 (3) | 0.0333 (9) | |
H2W | 0.149 (3) | 0.191 (3) | 0.219 (3) | 0.043 (12)* | |
P1 | 0.43974 (8) | 0.51850 (7) | 0.27879 (6) | 0.01861 (19) | |
P2 | 0.24339 (8) | 0.51768 (7) | 0.44285 (6) | 0.01899 (19) | |
O1 | 0.2142 (2) | 0.38573 (18) | 0.43567 (15) | 0.0251 (5) | |
O2 | 0.1122 (2) | 0.5935 (2) | 0.45127 (18) | 0.0241 (6) | |
H2 | 0.058 (3) | 0.582 (3) | 0.412 (2) | 0.030 (12)* | |
O3 | 0.3390 (2) | 0.55569 (19) | 0.52372 (16) | 0.0278 (5) | |
O4 | 0.3061 (2) | 0.56086 (18) | 0.33763 (15) | 0.0236 (5) | |
O5 | 0.5636 (2) | 0.5700 (2) | 0.33626 (18) | 0.0295 (6) | |
H5 | 0.595 (3) | 0.523 (3) | 0.384 (2) | 0.041 (11)* | |
O6 | 0.4296 (2) | 0.57680 (19) | 0.17940 (15) | 0.0283 (6) | |
O7 | 0.44528 (19) | 0.38401 (17) | 0.28054 (15) | 0.0224 (5) | |
K1 | 0.05769 (12) | 0.7500 | 0.59987 (8) | 0.0390 (3) | |
K2 | 0.74566 (10) | 0.7500 | 0.36729 (9) | 0.0339 (3) | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Mn1 | 0.0194 (4) | 0.0163 (3) | 0.0224 (4) | 0.000 | 0.0016 (3) | 0.000 |
O1W | 0.028 (2) | 0.022 (2) | 0.033 (2) | 0.000 | −0.0085 (16) | 0.000 |
O2W | 0.028 (2) | 0.025 (2) | 0.047 (2) | 0.000 | −0.0138 (18) | 0.000 |
P1 | 0.0188 (4) | 0.0176 (4) | 0.0194 (4) | 0.0008 (3) | 0.0014 (3) | 0.0021 (3) |
P2 | 0.0178 (4) | 0.0192 (4) | 0.0200 (4) | 0.0012 (3) | 0.0006 (4) | −0.0009 (4) |
O1 | 0.0253 (13) | 0.0208 (12) | 0.0290 (13) | 0.0002 (9) | 0.0093 (10) | −0.0034 (11) |
O2 | 0.0191 (13) | 0.0289 (14) | 0.0243 (14) | 0.0052 (10) | −0.0028 (11) | −0.0066 (11) |
O3 | 0.0264 (13) | 0.0313 (13) | 0.0259 (13) | −0.0053 (10) | −0.0077 (11) | 0.0029 (10) |
O4 | 0.0253 (12) | 0.0240 (11) | 0.0217 (12) | 0.0057 (10) | 0.0062 (9) | 0.0037 (10) |
O5 | 0.0284 (14) | 0.0263 (14) | 0.0337 (15) | −0.0065 (11) | −0.0094 (11) | 0.0064 (12) |
O6 | 0.0251 (13) | 0.0350 (14) | 0.0247 (13) | 0.0083 (10) | 0.0027 (10) | 0.0094 (11) |
O7 | 0.0234 (12) | 0.0185 (11) | 0.0251 (12) | 0.0000 (9) | 0.0045 (10) | −0.0013 (10) |
K1 | 0.0600 (8) | 0.0358 (7) | 0.0210 (6) | 0.000 | 0.0040 (6) | 0.000 |
K2 | 0.0267 (6) | 0.0216 (6) | 0.0536 (8) | 0.000 | 0.0076 (6) | 0.000 |
Geometric parameters (Å, º) top
Mn1—O1 | 2.141 (2) | O5—H5 | 0.89 (3) |
Mn1—O1i | 2.141 (2) | K1—O2 | 2.702 (2) |
Mn1—O7 | 2.158 (2) | K1—O2ii | 2.702 (2) |
Mn1—O7i | 2.158 (2) | K1—O7iii | 2.845 (2) |
Mn1—O1W | 2.192 (4) | K1—O7iv | 2.845 (2) |
Mn1—O2W | 2.247 (4) | K1—O2Wiii | 2.984 (4) |
O1W—H1W | 0.79 (3) | K1—O1v | 3.093 (2) |
O2W—H2W | 0.79 (3) | K1—O1vi | 3.093 (2) |
P1—O6 | 1.485 (2) | K1—O2Wvi | 3.358 (4) |
P1—O7 | 1.502 (2) | K2—O6vii | 2.712 (2) |
P1—O5 | 1.545 (2) | K2—O6viii | 2.712 (2) |
P1—O4 | 1.596 (2) | K2—O5 | 2.714 (2) |
P2—O3 | 1.491 (2) | K2—O5ii | 2.714 (2) |
P2—O1 | 1.503 (2) | K2—O1Wix | 3.027 (4) |
P2—O2 | 1.539 (2) | K2—O1x | 3.068 (2) |
P2—O4 | 1.610 (2) | K2—O1ix | 3.068 (2) |
O2—H2 | 0.76 (3) | | |
| | | |
O1i—Mn1—O1 | 90.09 (11) | P1—O7—K1xi | 120.78 (11) |
O1i—Mn1—O7i | 91.03 (7) | Mn1—O7—K1xi | 93.16 (7) |
O1—Mn1—O7i | 177.86 (9) | O2ii—K1—O2 | 80.60 (10) |
O1i—Mn1—O7 | 177.86 (9) | O2ii—K1—O7iv | 106.78 (7) |
O1—Mn1—O7 | 91.03 (7) | O2—K1—O7iv | 165.64 (8) |
O7i—Mn1—O7 | 87.79 (11) | O2ii—K1—O7iii | 165.64 (8) |
O1i—Mn1—O1W | 91.17 (9) | O2—K1—O7iii | 106.78 (7) |
O1—Mn1—O1W | 91.17 (9) | O7iv—K1—O7iii | 63.44 (8) |
O7i—Mn1—O1W | 90.63 (9) | O2ii—K1—O2Wiii | 105.05 (8) |
O7—Mn1—O1W | 90.63 (9) | O2—K1—O2Wiii | 105.05 (8) |
O1i—Mn1—O2W | 92.99 (9) | O7iv—K1—O2Wiii | 61.44 (7) |
O1—Mn1—O2W | 92.99 (9) | O7iii—K1—O2Wiii | 61.44 (7) |
O7i—Mn1—O2W | 85.13 (9) | O2ii—K1—O1vi | 111.87 (7) |
O7—Mn1—O2W | 85.13 (9) | O2—K1—O1vi | 74.86 (7) |
O1W—Mn1—O2W | 174.11 (15) | O7iv—K1—O1vi | 112.31 (6) |
Mn1—O1W—K2ix | 89.27 (12) | O7iii—K1—O1vi | 82.22 (6) |
Mn1—O1W—H1W | 118 (3) | O2Wiii—K1—O1vi | 142.37 (6) |
K2ix—O1W—H1W | 111 (3) | O2ii—K1—O1v | 74.86 (7) |
Mn1—O2W—K1xi | 87.74 (12) | O2—K1—O1v | 111.87 (7) |
Mn1—O2W—K1vi | 83.55 (12) | O7iv—K1—O1v | 82.22 (6) |
K1xi—O2W—K1vi | 171.29 (13) | O7iii—K1—O1v | 112.31 (6) |
Mn1—O2W—H2W | 116 (3) | O2Wiii—K1—O1v | 142.37 (6) |
K1xi—O2W—H2W | 111 (3) | O1vi—K1—O1v | 58.66 (8) |
K1vi—O2W—H2W | 73 (3) | O6vii—K2—O6viii | 90.96 (10) |
O6—P1—O7 | 117.01 (12) | O6vii—K2—O5 | 157.82 (8) |
O6—P1—O5 | 109.61 (13) | O6viii—K2—O5 | 82.56 (7) |
O7—P1—O5 | 109.65 (13) | O6vii—K2—O5ii | 82.56 (7) |
O6—P1—O4 | 104.98 (12) | O6viii—K2—O5ii | 157.82 (8) |
O7—P1—O4 | 108.53 (11) | O5—K2—O5ii | 95.49 (11) |
O5—P1—O4 | 106.47 (12) | O6vii—K2—O1Wix | 130.16 (6) |
O3—P2—O1 | 116.34 (13) | O6viii—K2—O1Wix | 130.16 (6) |
O3—P2—O2 | 108.12 (13) | O5—K2—O1Wix | 67.59 (7) |
O1—P2—O2 | 112.69 (13) | O5ii—K2—O1Wix | 67.59 (7) |
O3—P2—O4 | 108.22 (12) | O6vii—K2—O1x | 76.22 (6) |
O1—P2—O4 | 108.01 (12) | O6viii—K2—O1x | 117.77 (7) |
O2—P2—O4 | 102.46 (12) | O5—K2—O1x | 125.50 (7) |
P2—O1—Mn1 | 128.52 (12) | O5ii—K2—O1x | 81.36 (7) |
P2—O1—K2ix | 113.86 (11) | O1Wix—K2—O1x | 61.02 (7) |
Mn1—O1—K2ix | 89.12 (7) | O6vii—K2—O1ix | 117.77 (7) |
P2—O1—K1vi | 130.72 (11) | O6viii—K2—O1ix | 76.22 (6) |
Mn1—O1—K1vi | 92.09 (7) | O5—K2—O1ix | 81.36 (7) |
K2ix—O1—K1vi | 90.00 (6) | O5ii—K2—O1ix | 125.50 (7) |
P2—O2—K1 | 124.99 (13) | O1Wix—K2—O1ix | 61.02 (7) |
P2—O2—H2 | 116 (3) | O1x—K2—O1ix | 59.18 (8) |
K1—O2—H2 | 119 (3) | O6vii—K2—H5 | 164.5 (6) |
P1—O4—P2 | 130.86 (13) | O6viii—K2—H5 | 74.5 (6) |
P1—O5—K2 | 149.84 (14) | O5—K2—H5 | 17.5 (6) |
P1—O5—H5 | 114 (2) | O5ii—K2—H5 | 108.9 (6) |
K2—O5—H5 | 96 (2) | O1Wix—K2—H5 | 65.1 (6) |
P1—O6—K2xii | 124.28 (12) | O1x—K2—H5 | 115.0 (6) |
P1—O7—Mn1 | 132.99 (12) | O1ix—K2—H5 | 64.6 (7) |
Symmetry codes: (i) x, −y+1/2, z; (ii) x, −y+3/2, z; (iii) −x+1/2, −y+1, z+1/2; (iv) −x+1/2, y+1/2, z+1/2; (v) −x, y+1/2, −z+1; (vi) −x, −y+1, −z+1; (vii) x+1/2, −y+3/2, −z+1/2; (viii) x+1/2, y, −z+1/2; (ix) −x+1, −y+1, −z+1; (x) −x+1, y+1/2, −z+1; (xi) −x+1/2, −y+1, z−1/2; (xii) x−1/2, y, −z+1/2. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
O1W—H1W···O3xiii | 0.79 (3) | 2.00 (3) | 2.776 (3) | 169 (4) |
O2W—H2W···O7xiv | 0.79 (3) | 2.16 (3) | 2.833 (4) | 144 (3) |
O2—H2···O6xii | 0.76 (3) | 1.75 (3) | 2.505 (3) | 172 (4) |
O5—H5···O3ix | 0.89 (3) | 1.64 (3) | 2.528 (3) | 176 (3) |
Symmetry codes: (ix) −x+1, −y+1, −z+1; (xii) x−1/2, y, −z+1/2; (xiii) −x+1, y−1/2, −z+1; (xiv) x−1/2, −y+1/2, −z+1/2. |
Experimental details
Crystal data |
Chemical formula | H8K2MnO16P4 |
Mr | 521.08 |
Crystal system, space group | Orthorhombic, Pnma |
Temperature (K) | 294 |
a, b, c (Å) | 9.7613 (8), 11.1627 (9), 13.3949 (11) |
V (Å3) | 1459.5 (2) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 2.00 |
Crystal size (mm) | 0.23 × 0.11 × 0.08 |
|
Data collection |
Diffractometer | Bruker SmartApex CCD area-detector diffractometer |
Absorption correction | Multi-scan (XPREP; Sheldrick, 1997) |
Tmin, Tmax | 0.670, 0.893 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 14628, 1890, 1332 |
Rint | 0.079 |
(sin θ/λ)max (Å−1) | 0.667 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.037, 0.063, 1.00 |
No. of reflections | 1890 |
No. of parameters | 128 |
H-atom treatment | All H-atom parameters refined |
Δρmax, Δρmin (e Å−3) | 0.84, −0.69 |
Selected bond lengths (Å) topMn1—O1 | 2.141 (2) | P2—O4 | 1.610 (2) |
Mn1—O7 | 2.158 (2) | K1—O2 | 2.702 (2) |
Mn1—O1W | 2.192 (4) | K1—O7i | 2.845 (2) |
Mn1—O2W | 2.247 (4) | K1—O2Wi | 2.984 (4) |
P1—O6 | 1.485 (2) | K1—O1ii | 3.093 (2) |
P1—O7 | 1.502 (2) | K1—O2Wiii | 3.358 (4) |
P1—O5 | 1.545 (2) | K2—O6iv | 2.712 (2) |
P1—O4 | 1.596 (2) | K2—O5 | 2.714 (2) |
P2—O3 | 1.491 (2) | K2—O1Wv | 3.027 (4) |
P2—O1 | 1.503 (2) | K2—O1vi | 3.068 (2) |
P2—O2 | 1.539 (2) | | |
Symmetry codes: (i) −x+1/2, −y+1, z+1/2; (ii) −x, y+1/2, −z+1; (iii) −x, −y+1, −z+1; (iv) x+1/2, −y+3/2, −z+1/2; (v) −x+1, −y+1, −z+1; (vi) −x+1, y+1/2, −z+1. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
O1W—H1W···O3vii | 0.79 (3) | 2.00 (3) | 2.776 (3) | 169 (4) |
O2W—H2W···O7viii | 0.79 (3) | 2.16 (3) | 2.833 (4) | 144 (3) |
O2—H2···O6ix | 0.76 (3) | 1.75 (3) | 2.505 (3) | 172 (4) |
O5—H5···O3v | 0.89 (3) | 1.64 (3) | 2.528 (3) | 176 (3) |
Symmetry codes: (v) −x+1, −y+1, −z+1; (vii) −x+1, y−1/2, −z+1; (viii) x−1/2, −y+1/2, −z+1/2; (ix) x−1/2, y, −z+1/2. |
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Bibliographical data on acidic metal pyrophosphates and their applications have been widely discussed in previous works realised by our research group (Alaoui et al. 2002, 2003). The present work is a continuation of our investigations in the series (A,T)x(H2P2O7)y.zH2O (A = alkaline earth and T = transition metal). We report here the synthesis and crystal structure of K2Mn(H2P2O7)2·2H2O.
In the structure of the title compound, potassium polyhedra share an edge to form dimers [K2O13]. These latter are linked by Mn···O interactions as they share a face with [MnO6]. This results in a metallate layer, parallel to (010). Two such layers are linked by O—P—O bridges from [H2P2O7] moeties stacked in a parallel phosphate layer by weak bridging hydrogen bonds. Fig. 1 represents a perspective view of the structure.
Potassium possess two kind of sites in the structure with seven and eightfold coordination. Average K···O distances in [K1O8] and [K2O7] are 2.953 (2) and 2.859 (2) Å, respectively. These values can be compared to 2.959 Å measured in K2Zn(H2P2O7)2·2H2O (Alaoui et al. 2003) or 2.908 Å in K2H2P2O7 (Larbot et al., 1983).
Two bidentate [H2P2O7]2− anions and two water molecules form the sixfold coordination of the Mn2+ cation in the structure. The average Mn—O distance in the distorded octahedron is 2.173 (2) Å, a value close to that measured in MnHP2O7 (2.027 Å; Durif & Averbuch-Pouchot, 1982). [MnO6] polyhedra are isolated, with the shortest dMn—Mn of 5.716 Å. The irregularity in the manganese environments in K2Mn(H2P2O7)2·2H2O may be attributed in part to the Jahn–Teller effect. In fact, in the case of an octahedral crystal field, this phenomenon has an influence on the energy levels 3 d4.
The phosphorus (V) is coordinated by four oxygen atoms in a slightly distorted tetrahedron. Of the four oxygen apices, one is an hydroxyl group. Two tetrahedra share a corner (O4) to form the [H2P2O7]2− anion in a roughly eclipsed conformation. Average dP—O of 1.534 (2) Å is similar to that found in K2Zn(H2P2O7)2·2H2O [1.537 (2) Å; Alaoui et al. 2003] or 1.543 Å in K3H(H2P2O7)2 (Dumas, 1978). The bridging angle P—O—P of 130.86 (13)° is close to that in Ca2P2O7 (130.0°; Calvo, 1968) or 130.8 (2)° in K2Zn(H2P2O7)2·2H2O. We display in Fig. 2 the coordination polyhedra of K, Mn and P in the new structure.