Download citation
Download citation
link to html
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

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536803007189/br6094sup1.cif
Contains datablocks global, I

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S1600536803007189/br6094Isup2.hkl
Contains datablock I

Key indicators

  • Single-crystal X-ray study
  • T = 294 K
  • Mean [sigma](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








Comment top

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.

Experimental top

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).

Computing details top

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.

Figures top
[Figure 1] Fig. 1. Projection along the c axis of K2Mn(H2P2O7)2·2H2O. Polyhedra: yellow [H2P2O7], rose [MnO6]; circles: large blue K, small grey H.
[Figure 2] Fig. 2. Coordination polyhedra with numbering of atoms of K+, Mn2+ and P5+ in the title compound. Displacement ellipsoids are at the 50% probability level. [Symmetry codes: (i) 0.5 − x, 1 − y, 0.5 + z; (ii) −x, 0.5 + y, 1 − z; (iii) 0.5 + x, 1.5 − y, 0.5 − z; (iv) −x, 1 − y, 1 − z; (v) 0.5 + x, y, 0.5 − z; (vi) x, 0.5 − y, z; (vii) x, 1.5 − y, z; (viii) 0.5 − x, 0.5 + y, 0.5 + z.]
Dipotasium manganese bis(dihydrogendiphosphate) dihydrate top
Crystal data top
H8K2MnO16P4F(000) = 1036
Mr = 521.08Dx = 2.371 Mg m3
Orthorhombic, PnmaMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2nCell parameters from 3757 reflections
a = 9.7613 (8) Åθ = 2.4–30.8°
b = 11.1627 (9) ŵ = 2.00 mm1
c = 13.3949 (11) ÅT = 294 K
V = 1459.5 (2) Å3Needle, colorless
Z = 40.23 × 0.11 × 0.08 mm
Data collection top
Bruker SmartApex CCD area-detector
diffractometer
1890 independent reflections
Radiation source: fine-focus sealed tube1332 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.079
ω scansθmax = 28.3°, θmin = 2.4°
Absorption correction: multi-scan
(XPREP; Sheldrick, 1997)
h = 1312
Tmin = 0.670, Tmax = 0.893k = 1414
14628 measured reflectionsl = 1717
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.037Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.063All 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 parametersΔρmax = 0.84 e Å3
0 restraintsΔρmin = 0.69 e Å3
Crystal data top
H8K2MnO16P4V = 1459.5 (2) Å3
Mr = 521.08Z = 4
Orthorhombic, PnmaMo Kα radiation
a = 9.7613 (8) ŵ = 2.00 mm1
b = 11.1627 (9) ÅT = 294 K
c = 13.3949 (11) Å0.23 × 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 = 0.893Rint = 0.079
14628 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0370 restraints
wR(F2) = 0.063All H-atom parameters refined
S = 1.00Δρmax = 0.84 e Å3
1890 reflectionsΔρmin = 0.69 e Å3
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
xyzUiso*/Ueq
Mn10.33051 (7)0.25000.36103 (5)0.01938 (17)
O1W0.4837 (4)0.25000.4806 (3)0.0277 (8)
H1W0.530 (3)0.193 (3)0.487 (2)0.047 (13)*
O2W0.1915 (4)0.25000.2273 (3)0.0333 (9)
H2W0.149 (3)0.191 (3)0.219 (3)0.043 (12)*
P10.43974 (8)0.51850 (7)0.27879 (6)0.01861 (19)
P20.24339 (8)0.51768 (7)0.44285 (6)0.01899 (19)
O10.2142 (2)0.38573 (18)0.43567 (15)0.0251 (5)
O20.1122 (2)0.5935 (2)0.45127 (18)0.0241 (6)
H20.058 (3)0.582 (3)0.412 (2)0.030 (12)*
O30.3390 (2)0.55569 (19)0.52372 (16)0.0278 (5)
O40.3061 (2)0.56086 (18)0.33763 (15)0.0236 (5)
O50.5636 (2)0.5700 (2)0.33626 (18)0.0295 (6)
H50.595 (3)0.523 (3)0.384 (2)0.041 (11)*
O60.4296 (2)0.57680 (19)0.17940 (15)0.0283 (6)
O70.44528 (19)0.38401 (17)0.28054 (15)0.0224 (5)
K10.05769 (12)0.75000.59987 (8)0.0390 (3)
K20.74566 (10)0.75000.36729 (9)0.0339 (3)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Mn10.0194 (4)0.0163 (3)0.0224 (4)0.0000.0016 (3)0.000
O1W0.028 (2)0.022 (2)0.033 (2)0.0000.0085 (16)0.000
O2W0.028 (2)0.025 (2)0.047 (2)0.0000.0138 (18)0.000
P10.0188 (4)0.0176 (4)0.0194 (4)0.0008 (3)0.0014 (3)0.0021 (3)
P20.0178 (4)0.0192 (4)0.0200 (4)0.0012 (3)0.0006 (4)0.0009 (4)
O10.0253 (13)0.0208 (12)0.0290 (13)0.0002 (9)0.0093 (10)0.0034 (11)
O20.0191 (13)0.0289 (14)0.0243 (14)0.0052 (10)0.0028 (11)0.0066 (11)
O30.0264 (13)0.0313 (13)0.0259 (13)0.0053 (10)0.0077 (11)0.0029 (10)
O40.0253 (12)0.0240 (11)0.0217 (12)0.0057 (10)0.0062 (9)0.0037 (10)
O50.0284 (14)0.0263 (14)0.0337 (15)0.0065 (11)0.0094 (11)0.0064 (12)
O60.0251 (13)0.0350 (14)0.0247 (13)0.0083 (10)0.0027 (10)0.0094 (11)
O70.0234 (12)0.0185 (11)0.0251 (12)0.0000 (9)0.0045 (10)0.0013 (10)
K10.0600 (8)0.0358 (7)0.0210 (6)0.0000.0040 (6)0.000
K20.0267 (6)0.0216 (6)0.0536 (8)0.0000.0076 (6)0.000
Geometric parameters (Å, º) top
Mn1—O12.141 (2)O5—H50.89 (3)
Mn1—O1i2.141 (2)K1—O22.702 (2)
Mn1—O72.158 (2)K1—O2ii2.702 (2)
Mn1—O7i2.158 (2)K1—O7iii2.845 (2)
Mn1—O1W2.192 (4)K1—O7iv2.845 (2)
Mn1—O2W2.247 (4)K1—O2Wiii2.984 (4)
O1W—H1W0.79 (3)K1—O1v3.093 (2)
O2W—H2W0.79 (3)K1—O1vi3.093 (2)
P1—O61.485 (2)K1—O2Wvi3.358 (4)
P1—O71.502 (2)K2—O6vii2.712 (2)
P1—O51.545 (2)K2—O6viii2.712 (2)
P1—O41.596 (2)K2—O52.714 (2)
P2—O31.491 (2)K2—O5ii2.714 (2)
P2—O11.503 (2)K2—O1Wix3.027 (4)
P2—O21.539 (2)K2—O1x3.068 (2)
P2—O41.610 (2)K2—O1ix3.068 (2)
O2—H20.76 (3)
O1i—Mn1—O190.09 (11)P1—O7—K1xi120.78 (11)
O1i—Mn1—O7i91.03 (7)Mn1—O7—K1xi93.16 (7)
O1—Mn1—O7i177.86 (9)O2ii—K1—O280.60 (10)
O1i—Mn1—O7177.86 (9)O2ii—K1—O7iv106.78 (7)
O1—Mn1—O791.03 (7)O2—K1—O7iv165.64 (8)
O7i—Mn1—O787.79 (11)O2ii—K1—O7iii165.64 (8)
O1i—Mn1—O1W91.17 (9)O2—K1—O7iii106.78 (7)
O1—Mn1—O1W91.17 (9)O7iv—K1—O7iii63.44 (8)
O7i—Mn1—O1W90.63 (9)O2ii—K1—O2Wiii105.05 (8)
O7—Mn1—O1W90.63 (9)O2—K1—O2Wiii105.05 (8)
O1i—Mn1—O2W92.99 (9)O7iv—K1—O2Wiii61.44 (7)
O1—Mn1—O2W92.99 (9)O7iii—K1—O2Wiii61.44 (7)
O7i—Mn1—O2W85.13 (9)O2ii—K1—O1vi111.87 (7)
O7—Mn1—O2W85.13 (9)O2—K1—O1vi74.86 (7)
O1W—Mn1—O2W174.11 (15)O7iv—K1—O1vi112.31 (6)
Mn1—O1W—K2ix89.27 (12)O7iii—K1—O1vi82.22 (6)
Mn1—O1W—H1W118 (3)O2Wiii—K1—O1vi142.37 (6)
K2ix—O1W—H1W111 (3)O2ii—K1—O1v74.86 (7)
Mn1—O2W—K1xi87.74 (12)O2—K1—O1v111.87 (7)
Mn1—O2W—K1vi83.55 (12)O7iv—K1—O1v82.22 (6)
K1xi—O2W—K1vi171.29 (13)O7iii—K1—O1v112.31 (6)
Mn1—O2W—H2W116 (3)O2Wiii—K1—O1v142.37 (6)
K1xi—O2W—H2W111 (3)O1vi—K1—O1v58.66 (8)
K1vi—O2W—H2W73 (3)O6vii—K2—O6viii90.96 (10)
O6—P1—O7117.01 (12)O6vii—K2—O5157.82 (8)
O6—P1—O5109.61 (13)O6viii—K2—O582.56 (7)
O7—P1—O5109.65 (13)O6vii—K2—O5ii82.56 (7)
O6—P1—O4104.98 (12)O6viii—K2—O5ii157.82 (8)
O7—P1—O4108.53 (11)O5—K2—O5ii95.49 (11)
O5—P1—O4106.47 (12)O6vii—K2—O1Wix130.16 (6)
O3—P2—O1116.34 (13)O6viii—K2—O1Wix130.16 (6)
O3—P2—O2108.12 (13)O5—K2—O1Wix67.59 (7)
O1—P2—O2112.69 (13)O5ii—K2—O1Wix67.59 (7)
O3—P2—O4108.22 (12)O6vii—K2—O1x76.22 (6)
O1—P2—O4108.01 (12)O6viii—K2—O1x117.77 (7)
O2—P2—O4102.46 (12)O5—K2—O1x125.50 (7)
P2—O1—Mn1128.52 (12)O5ii—K2—O1x81.36 (7)
P2—O1—K2ix113.86 (11)O1Wix—K2—O1x61.02 (7)
Mn1—O1—K2ix89.12 (7)O6vii—K2—O1ix117.77 (7)
P2—O1—K1vi130.72 (11)O6viii—K2—O1ix76.22 (6)
Mn1—O1—K1vi92.09 (7)O5—K2—O1ix81.36 (7)
K2ix—O1—K1vi90.00 (6)O5ii—K2—O1ix125.50 (7)
P2—O2—K1124.99 (13)O1Wix—K2—O1ix61.02 (7)
P2—O2—H2116 (3)O1x—K2—O1ix59.18 (8)
K1—O2—H2119 (3)O6vii—K2—H5164.5 (6)
P1—O4—P2130.86 (13)O6viii—K2—H574.5 (6)
P1—O5—K2149.84 (14)O5—K2—H517.5 (6)
P1—O5—H5114 (2)O5ii—K2—H5108.9 (6)
K2—O5—H596 (2)O1Wix—K2—H565.1 (6)
P1—O6—K2xii124.28 (12)O1x—K2—H5115.0 (6)
P1—O7—Mn1132.99 (12)O1ix—K2—H564.6 (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, z1/2; (xii) x1/2, y, z+1/2.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O1W—H1W···O3xiii0.79 (3)2.00 (3)2.776 (3)169 (4)
O2W—H2W···O7xiv0.79 (3)2.16 (3)2.833 (4)144 (3)
O2—H2···O6xii0.76 (3)1.75 (3)2.505 (3)172 (4)
O5—H5···O3ix0.89 (3)1.64 (3)2.528 (3)176 (3)
Symmetry codes: (ix) x+1, y+1, z+1; (xii) x1/2, y, z+1/2; (xiii) x+1, y1/2, z+1; (xiv) x1/2, y+1/2, z+1/2.

Experimental details

Crystal data
Chemical formulaH8K2MnO16P4
Mr521.08
Crystal system, space groupOrthorhombic, Pnma
Temperature (K)294
a, b, c (Å)9.7613 (8), 11.1627 (9), 13.3949 (11)
V3)1459.5 (2)
Z4
Radiation typeMo Kα
µ (mm1)2.00
Crystal size (mm)0.23 × 0.11 × 0.08
Data collection
DiffractometerBruker SmartApex CCD area-detector
diffractometer
Absorption correctionMulti-scan
(XPREP; Sheldrick, 1997)
Tmin, Tmax0.670, 0.893
No. of measured, independent and
observed [I > 2σ(I)] reflections
14628, 1890, 1332
Rint0.079
(sin θ/λ)max1)0.667
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.037, 0.063, 1.00
No. of reflections1890
No. of parameters128
H-atom treatmentAll H-atom parameters refined
Δρmax, Δρmin (e Å3)0.84, 0.69

Computer programs: SMART (Bruker, 1999), SAINT (Bruker, 1999), SAINT, SHELXS97 (Sheldrick, 1990), SHELXL97 (Sheldrick, 1997), ATOMS (Dowty,1999), SHELXL97.

Selected bond lengths (Å) top
Mn1—O12.141 (2)P2—O41.610 (2)
Mn1—O72.158 (2)K1—O22.702 (2)
Mn1—O1W2.192 (4)K1—O7i2.845 (2)
Mn1—O2W2.247 (4)K1—O2Wi2.984 (4)
P1—O61.485 (2)K1—O1ii3.093 (2)
P1—O71.502 (2)K1—O2Wiii3.358 (4)
P1—O51.545 (2)K2—O6iv2.712 (2)
P1—O41.596 (2)K2—O52.714 (2)
P2—O31.491 (2)K2—O1Wv3.027 (4)
P2—O11.503 (2)K2—O1vi3.068 (2)
P2—O21.539 (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···AD—HH···AD···AD—H···A
O1W—H1W···O3vii0.79 (3)2.00 (3)2.776 (3)169 (4)
O2W—H2W···O7viii0.79 (3)2.16 (3)2.833 (4)144 (3)
O2—H2···O6ix0.76 (3)1.75 (3)2.505 (3)172 (4)
O5—H5···O3v0.89 (3)1.64 (3)2.528 (3)176 (3)
Symmetry codes: (v) x+1, y+1, z+1; (vii) x+1, y1/2, z+1; (viii) x1/2, y+1/2, z+1/2; (ix) x1/2, y, z+1/2.
 

Follow Acta Cryst. E
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds