inorganic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

Journal logoCRYSTALLOGRAPHIC
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ISSN: 2056-9890
Volume 67| Part 6| June 2011| Pages i37-i38

The triclinic form of dipotassium cobalt(II) bis­­(di­hydrogendiphosphate) dihydrate

aLaboratory of Mineral Solid and Analytical Chemistry (LCSMA), Department of Chemistry, Faculty of Sciences, University Mohamed I, PO Box 717, 60000 Oujda, Morocco, and bInstitute of Physics of the ASCR, v.v.i., Na Slovance 2, 182 21 Praha 8, Czech Republic
*Correspondence e-mail: b.elbali@fso.ump.ma

(Received 13 April 2011; accepted 29 April 2011; online 20 May 2011)

In the title compound, K2Co(H2P2O7)2·2H2O, the octa­hedrally coordinated Co2+ ion lies on an inversion centre. Two bidentate dihydrogendiphosphate anions form the equatorial plane of the [CoO6] octa­hedron which is completed by two water mol­ecules in axial positions. This results in isolated {Co(H2O)2[H2P2O7]2}4− entities linked into a three-dimensional network through K—O bonds and O—H⋯O hydrogen-bonding inter­actions involving the dihydrogendiphosphate anions and water mol­ecules. The dihydrogendiphosphate anion, (H2P2O7)2−, is bent and shows an almost eclipsed conformation.

Related literature

The triclinic title compound is isotypic with K2Ni(H2P2O7)2·2H2O (Tahiri et al., 2004[Tahiri, A. A., Messouri, I., Lachkar, M., Zavalij, P. Y., Glaum, R., El Bali, B. & Rachid, O. (2004). Acta Cryst. E60, i3-i5.]) and K2Zn(H2P2O7)2·2H2O (Tahiri et al., 2003[Tahiri, A. A., Ouarsal, R., Lachkar, M., Zavalij, P. Y. & El Bali, B. (2003). Acta Cryst. E59, i50-i52.]). For ortho­rhom­bic forms of crystals of this formula type, see: Tahiri et al. (2002[Tahiri, A. A., Ouarsal, R., Lachkar, M., El Bali, B. & Bolte, M. (2002). Acta Cryst. E58, i91-i92.]); Essehli et al. (2005[Essehli, R., El Bali, B., Alaoui Tahiri, A., Lachkar, M., Manoun, B., Dušek, M. & Fejfarova, K. (2005). Acta Cryst. C61, i120-i124.]).

Experimental

Crystal data
  • K2Co(H2P2O7)2·2H2O

  • Mr = 525.1

  • Triclinic, [P \overline 1]

  • a = 6.8737 (14) Å

  • b = 7.3565 (11) Å

  • c = 7.6141 (14) Å

  • α = 80.740 (14)°

  • β = 72.397 (17)°

  • γ = 83.484 (14)°

  • V = 361.35 (12) Å3

  • Z = 1

  • Mo Kα radiation

  • μ = 2.29 mm−1

  • T = 292 K

  • 0.16 × 0.11 × 0.03 mm

Data collection
  • Oxford Diffraction Xcalibur diffractometer with a Sapphire 2 CCD detector

  • Absorption correction: analytical based on the crystal shape (CrysAlis RED; Oxford Diffraction, 2004[Oxford Diffraction (2004). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Abingdon, England.]) Tmin = 0.648, Tmax = 0.838

  • 4546 measured reflections

  • 1489 independent reflections

  • 1013 reflections with I > 3σ(I)

  • Rint = 0.054

Refinement
  • R[F2 > 2σ(F2)] = 0.038

  • wR(F2) = 0.090

  • S = 1.17

  • 1489 reflections

  • 118 parameters

  • Only H-atom coordinates refined

  • Δρmax = 0.47 e Å−3

  • Δρmin = −0.45 e Å−3

Table 1
Selected geometric parameters (Å, °)

K1—O2i 2.785 (3)
K1—O4ii 2.884 (3)
K1—O5 2.979 (3)
K1—O6iii 2.771 (4)
K1—O7iv 2.919 (3)
K1—O8i 2.972 (4)
Co1—O2 2.101 (3)
Co1—O5 2.085 (3)
Co1—O8 2.094 (3)
P1—O1 1.602 (3)
P1—O2 1.495 (3)
P1—O3 1.496 (3)
P1—O4 1.556 (3)
P2—O1 1.602 (3)
P2—O5 1.493 (3)
P2—O6 1.546 (3)
P2—O7 1.499 (3)
P1—O1—P2 130.90 (19)
Symmetry codes: (i) -x+1, -y+1, -z+1; (ii) -x+1, -y, -z+1; (iii) x, y, z+1; (iv) -x+2, -y, -z+1.

Table 2
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
O4—H1⋯O7ii 0.81 (5) 1.75 (5) 2.545 (5) 169 (5)
O6—H2⋯O3v 0.72 (6) 1.82 (6) 2.522 (5) 168 (5)
O8—H3⋯O3vi 0.71 (5) 2.03 (5) 2.745 (4) 178 (6)
O8—H4⋯O7vii 0.79 (5) 2.01 (6) 2.798 (5) 175 (5)
Symmetry codes: (ii) -x+1, -y, -z+1; (v) x+1, y, z; (vi) -x+1, -y+1, -z; (vii) x, y+1, z.

Data collection: CrysAlis CCD (Oxford Diffraction, 2004[Oxford Diffraction (2004). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Abingdon, England.]); cell refinement: CrysAlis RED (Oxford Diffraction, 2004[Oxford Diffraction (2004). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Abingdon, England.]); data reduction: CrysAlis RED; program(s) used to solve structure: SIR2002 (Burla et al., 2003[Burla, M. C., Camalli, M., Carrozzini, B., Cascarano, G. L., Giacovazzo, C., Polidori, G. & Spagna, R. (2003). J. Appl. Cryst. 36, 1103.]); program(s) used to refine structure: JANA2006 (Petříček et al., 2006[Petříček, V., Dušek, M. & Palatinus, L. (2006). JANA2006. Institute of Physics, Czech Academy of Sciences, Prague, Czech Republic.]); molecular graphics: DIAMOND (Brandenburg, 1999[Brandenburg, K. (1999). DIAMOND. Crystal Impact GbR, Bonn, Germany.]); software used to prepare material for publication: JANA2006.

Supporting information


Comment top

The triclinic form of K2Co(H2P2O7)2.2H2O is isotypic with K2Ni(H2P2O7)2.2H2O (Tahiri et al., 2004) and K2Zn(H2P2O7)2.2H2O (Tahiri et al., 2003). All these K2M(H2P2O7)2.2H2O dihydrogendiphosphates crystallise also in an orthorhombic form, see: Tahiri et al. (2002) for M = Co; Essehli et al. (2005) for M = Ni and Zn.

The crystal structure of the title compound can be described in terms of centrosymmetric {Co(H2O)2[H2P2O7]2}4- units (Fig. 1) that are linked through K—O bonds and an intricate network of O—H···O hydrogen bonds into a three-dimensional network (Fig. 2). The slightly distorted coordination octahedron around Co2+ is composed of four O atoms from two bidendate [H2P2O7]2- groups in equatorial positions and two O atoms from water molecules in axial positions. The average Co—O bond length of 2.093 (8) Å is in the same range as 2.047 Å for the orthorhombic form (Tahiri et al., 2002). The dihydrogendiphosphate anion is bent and shows an almost eclipsed conformation, with an bridging angle P1—O1—P2 of 130.90 (19) °. P—O bond lengths and O—P—O angles values are of similar values as in known dihydrogendiphosphates. The K+ cation is coordinated by six O atoms in form of a very distorted octahedron, with K—O distances ranging from 2.771 (4) to 2.979 (3) Å. Such values are likewise found in isotypic or isoformular dihydrogendiphosphates.

Related literature top

The triclinic title compound is isotypic with K2Ni(H2P2O7)2.2H2O (Tahiri et al., 2004) and K2Zn(H2P2O7)2.2H2O (Tahiri et al., 2003). For orthorhombic forms of crystals of this formula type, see: Tahiri et al. (2002); Essehli et al. (2005).

Experimental top

To prepare the present crystals we used the same procedure as described in detail in (Tahiri et al., 2002). Solutions of CoCl2.4H2O (10 ml, 10 mmol) and K4P2O7 (10 ml, 20 mmol) were mixed in a beaker. The mixture was stirred for six hours and then allowed to stand for two weeks at room temperature. At the end of this period, large prismatic pink crystals have deposited, which were filtered-off and washed with a water-ethanol solution (20:80).

Refinement top

All hydrogen atoms were found in difference Fourier maps and their coordinates were refined independently. The isotropic atomic displacement parameters of hydrogen atoms were treated with 1.2×Ueq of the respective parent O atom.

Computing details top

Data collection: CrysAlis CCD (Oxford Diffraction, 2004); cell refinement: CrysAlis RED (Oxford Diffraction, 2004); data reduction: CrysAlis RED (Oxford Diffraction, 2004); program(s) used to solve structure: SIR2002 (Burla et al., 2003); program(s) used to refine structure: JANA2006 (Petříček et al., 2006); molecular graphics: DIAMOND (Brandenburg, 1999); software used to prepare material for publication: JANA2006 (Petříček et al., 2006).

Figures top
[Figure 1] Fig. 1. : The main coordination polyhedra in the title compound, shown as an ellipsoid plot with anisotropic displacement parameters drawn at the 50% probability level. [Symmetry codes: (i) 1 - x, 1 - y, 1 - z; (ii) 1 - x, -y, 1 - z; (iii) x, y, 1 + z; (iv) 2 - x, -y, 1 - z].
[Figure 2] Fig. 2. : Projection of the structure along the b-axis. H-bonds are displayed as dashed lines.
dipotassium cobalt(II) bis(dihydrogendiphosphate) dihydrate top
Crystal data top
K2Co(H2P2O7)2·2H2OZ = 1
Mr = 525.1F(000) = 261
Triclinic, P1Dx = 2.412 Mg m3
Hall symbol: -P 1Mo Kα radiation, λ = 0.71069 Å
a = 6.8737 (14) ÅCell parameters from 4546 reflections
b = 7.3565 (11) Åθ = 3.1–26.6°
c = 7.6141 (14) ŵ = 2.29 mm1
α = 80.740 (14)°T = 292 K
β = 72.397 (17)°Prism, pink
γ = 83.484 (14)°0.16 × 0.11 × 0.03 mm
V = 361.35 (12) Å3
Data collection top
Oxford Diffraction Xcalibur
diffractometer with a Sapphire 2 CCD detector
1489 independent reflections
Radiation source: Mo X-ray tube1013 reflections with I > 3σ(I)
Graphite monochromatorRint = 0.054
Detector resolution: 8.3438 pixels mm-1θmax = 26.6°, θmin = 3.1°
Rotation method data acquisition using ω scansh = 88
Absorption correction: analytical
based on the crystal shape (CrysAlis RED; Oxford Diffraction, 2004)
k = 99
Tmin = 0.648, Tmax = 0.838l = 99
4546 measured reflections
Refinement top
Refinement on F24 constraints
R[F2 > 2σ(F2)] = 0.038Only H-atom coordinates refined
wR(F2) = 0.090Weighting scheme based on measured s.u.'s w = 1/[σ2(I) + 0.0016I2]
S = 1.17(Δ/σ)max = 0.044
1489 reflectionsΔρmax = 0.47 e Å3
118 parametersΔρmin = 0.45 e Å3
0 restraints
Crystal data top
K2Co(H2P2O7)2·2H2Oγ = 83.484 (14)°
Mr = 525.1V = 361.35 (12) Å3
Triclinic, P1Z = 1
a = 6.8737 (14) ÅMo Kα radiation
b = 7.3565 (11) ŵ = 2.29 mm1
c = 7.6141 (14) ÅT = 292 K
α = 80.740 (14)°0.16 × 0.11 × 0.03 mm
β = 72.397 (17)°
Data collection top
Oxford Diffraction Xcalibur
diffractometer with a Sapphire 2 CCD detector
1489 independent reflections
Absorption correction: analytical
based on the crystal shape (CrysAlis RED; Oxford Diffraction, 2004)
1013 reflections with I > 3σ(I)
Tmin = 0.648, Tmax = 0.838Rint = 0.054
4546 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0380 restraints
wR(F2) = 0.090Only H-atom coordinates refined
S = 1.17Δρmax = 0.47 e Å3
1489 reflectionsΔρmin = 0.45 e Å3
118 parameters
Special details top

Refinement. The hydrogen atoms were localized from the difference Fourier map. Their coordinates were refined independently. The isotropic temperature parameters of hydrogen atoms were calculated as 1.2*Ueq of the parent atom.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
K10.89288 (17)0.26574 (14)0.70307 (15)0.0365 (4)
Co10.50.50.50.0172 (3)
P10.32488 (16)0.27153 (14)0.24623 (14)0.0181 (4)
P20.75153 (16)0.18965 (14)0.24070 (14)0.0177 (4)
O10.5649 (4)0.2309 (4)0.1518 (4)0.0242 (11)
O20.2951 (4)0.3930 (4)0.3932 (4)0.0213 (10)
O30.2401 (4)0.3486 (4)0.0882 (4)0.0241 (10)
O40.2372 (5)0.0812 (4)0.3353 (4)0.0263 (11)
H10.252 (7)0.045 (6)0.437 (6)0.0316*
O50.7435 (4)0.3267 (4)0.3681 (4)0.0231 (10)
O60.9309 (4)0.2143 (4)0.0601 (4)0.0258 (11)
H21.011 (7)0.252 (7)0.083 (7)0.0309*
O70.7467 (5)0.0072 (4)0.3310 (4)0.0283 (11)
O80.5496 (5)0.7064 (4)0.2702 (4)0.0274 (12)
H30.602 (8)0.692 (7)0.176 (7)0.0329*
H40.606 (7)0.790 (7)0.280 (7)0.0329*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
K10.0433 (6)0.0353 (6)0.0362 (6)0.0096 (5)0.0215 (5)0.0093 (5)
Co10.0201 (4)0.0177 (4)0.0175 (4)0.0005 (3)0.0093 (3)0.0069 (3)
P10.0183 (5)0.0215 (6)0.0184 (5)0.0008 (4)0.0095 (4)0.0062 (4)
P20.0193 (5)0.0204 (6)0.0166 (5)0.0009 (4)0.0084 (4)0.0068 (4)
O10.0183 (15)0.0363 (18)0.0229 (15)0.0048 (12)0.0110 (12)0.0128 (13)
O20.0212 (15)0.0236 (15)0.0238 (15)0.0009 (12)0.0095 (12)0.0110 (12)
O30.0222 (16)0.0337 (17)0.0198 (15)0.0011 (13)0.0130 (13)0.0008 (13)
O40.0359 (18)0.0235 (16)0.0238 (17)0.0081 (13)0.0143 (15)0.0005 (13)
O50.0225 (16)0.0294 (16)0.0225 (15)0.0037 (13)0.0099 (13)0.0156 (13)
O60.0215 (17)0.0403 (19)0.0180 (15)0.0081 (14)0.0039 (13)0.0105 (14)
O70.0388 (18)0.0224 (16)0.0269 (17)0.0040 (14)0.0137 (14)0.0024 (13)
O80.039 (2)0.0253 (18)0.0188 (16)0.0079 (15)0.0065 (15)0.0063 (14)
Geometric parameters (Å, º) top
K1—O2i2.785 (3)Co1—O8i2.094 (3)
K1—O4ii2.884 (3)P1—O11.602 (3)
K1—O52.979 (3)P1—O21.495 (3)
K1—O6iii2.771 (4)P1—O31.496 (3)
K1—O7iv2.919 (3)P1—O41.556 (3)
K1—O8i2.972 (4)P2—O11.602 (3)
Co1—O22.101 (3)P2—O51.493 (3)
Co1—O2i2.101 (3)P2—O61.546 (3)
Co1—O52.085 (3)P2—O71.499 (3)
Co1—O5i2.085 (3)O4—H10.81 (5)
Co1—O82.094 (3)O6—H20.72 (6)
O2i—K1—O4ii123.43 (10)O5i—Co1—O5180
O2i—K1—O560.33 (9)O5i—Co1—O886.81 (11)
O2i—K1—O6iii113.92 (10)O5i—Co1—O8i93.19 (11)
O2i—K1—O7iv151.28 (8)O8i—Co1—O8180
O2i—K1—O8i60.69 (9)O1—P1—O2109.27 (18)
O4ii—K1—O572.55 (9)O1—P1—O3105.02 (15)
O4ii—K1—O6iii104.16 (10)O1—P1—O4106.45 (15)
O4ii—K1—O7iv74.58 (9)O2—P1—O3116.17 (17)
O4ii—K1—O8i68.68 (9)O2—P1—O4110.05 (16)
O5—K1—O6iii166.01 (9)O3—P1—O4109.36 (19)
O5—K1—O7iv113.42 (9)O1—P2—O5110.97 (16)
O5—K1—O8i57.71 (8)O1—P2—O698.96 (17)
O6iii—K1—O7iv77.87 (9)O1—P2—O7107.47 (18)
O6iii—K1—O8i108.32 (9)O5—P2—O6112.65 (18)
O7iv—K1—O8i143.17 (10)O5—P2—O7114.33 (17)
O2—Co1—O2i180O6—P2—O7111.27 (17)
O2—Co1—O592.27 (11)P1—O1—P2130.90 (19)
O2—Co1—O5i87.73 (11)K1i—O2—Co195.37 (10)
O2—Co1—O887.94 (13)K1i—O2—P1110.42 (15)
O2—Co1—O8i92.06 (13)Co1—O2—P1132.80 (16)
O2i—Co1—O2180K1ii—O4—P1150.05 (19)
O2i—Co1—O587.73 (11)P1—O4—H1114 (4)
O2i—Co1—O5i92.27 (11)K1—O5—Co190.21 (10)
O2i—Co1—O892.06 (13)K1—O5—P2127.17 (15)
O2i—Co1—O8i87.94 (13)Co1—O5—P2130.12 (19)
O5—Co1—O5i180K1v—O6—P2125.12 (18)
O5—Co1—O893.19 (11)P2—O6—H2107 (4)
O5—Co1—O8i86.81 (11)H3—O8—H4101 (5)
Symmetry codes: (i) x+1, y+1, z+1; (ii) x+1, y, z+1; (iii) x, y, z+1; (iv) x+2, y, z+1; (v) x, y, z1.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O4—H1···O7ii0.81 (5)1.75 (5)2.545 (5)169 (5)
O6—H2···O3vi0.72 (6)1.82 (6)2.522 (5)168 (5)
O8—H3···O3vii0.71 (5)2.03 (5)2.745 (4)178 (6)
O8—H4···O7viii0.79 (5)2.01 (6)2.798 (5)175 (5)
Symmetry codes: (ii) x+1, y, z+1; (vi) x+1, y, z; (vii) x+1, y+1, z; (viii) x, y+1, z.

Experimental details

Crystal data
Chemical formulaK2Co(H2P2O7)2·2H2O
Mr525.1
Crystal system, space groupTriclinic, P1
Temperature (K)292
a, b, c (Å)6.8737 (14), 7.3565 (11), 7.6141 (14)
α, β, γ (°)80.740 (14), 72.397 (17), 83.484 (14)
V3)361.35 (12)
Z1
Radiation typeMo Kα
µ (mm1)2.29
Crystal size (mm)0.16 × 0.11 × 0.03
Data collection
DiffractometerOxford Diffraction Xcalibur
diffractometer with a Sapphire 2 CCD detector
Absorption correctionAnalytical
based on the crystal shape (CrysAlis RED; Oxford Diffraction, 2004)
Tmin, Tmax0.648, 0.838
No. of measured, independent and
observed [I > 3σ(I)] reflections
4546, 1489, 1013
Rint0.054
(sin θ/λ)max1)0.629
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.038, 0.090, 1.17
No. of reflections1489
No. of parameters118
H-atom treatmentOnly H-atom coordinates refined
Δρmax, Δρmin (e Å3)0.47, 0.45

Computer programs: CrysAlis CCD (Oxford Diffraction, 2004), CrysAlis RED (Oxford Diffraction, 2004), SIR2002 (Burla et al., 2003), JANA2006 (Petříček et al., 2006), DIAMOND (Brandenburg, 1999).

Selected geometric parameters (Å, º) top
K1—O2i2.785 (3)P1—O11.602 (3)
K1—O4ii2.884 (3)P1—O21.495 (3)
K1—O52.979 (3)P1—O31.496 (3)
K1—O6iii2.771 (4)P1—O41.556 (3)
K1—O7iv2.919 (3)P2—O11.602 (3)
K1—O8i2.972 (4)P2—O51.493 (3)
Co1—O22.101 (3)P2—O61.546 (3)
Co1—O52.085 (3)P2—O71.499 (3)
Co1—O82.094 (3)
P1—O1—P2130.90 (19)
Symmetry codes: (i) x+1, y+1, z+1; (ii) x+1, y, z+1; (iii) x, y, z+1; (iv) x+2, y, z+1.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O4—H1···O7ii0.81 (5)1.75 (5)2.545 (5)169 (5)
O6—H2···O3v0.72 (6)1.82 (6)2.522 (5)168 (5)
O8—H3···O3vi0.71 (5)2.03 (5)2.745 (4)178 (6)
O8—H4···O7vii0.79 (5)2.01 (6)2.798 (5)175 (5)
Symmetry codes: (ii) x+1, y, z+1; (v) x+1, y, z; (vi) x+1, y+1, z; (vii) x, y+1, z.
 

Acknowledgements

We acknowledge support by the Grant Agency of the Czech Republic, grant No. P204/11/0809.

References

First citationBrandenburg, K. (1999). DIAMOND. Crystal Impact GbR, Bonn, Germany.  Google Scholar
First citationBurla, M. C., Camalli, M., Carrozzini, B., Cascarano, G. L., Giacovazzo, C., Polidori, G. & Spagna, R. (2003). J. Appl. Cryst. 36, 1103.  CrossRef IUCr Journals Google Scholar
First citationEssehli, R., El Bali, B., Alaoui Tahiri, A., Lachkar, M., Manoun, B., Dušek, M. & Fejfarova, K. (2005). Acta Cryst. C61, i120–i124.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationOxford Diffraction (2004). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Abingdon, England.  Google Scholar
First citationPetříček, V., Dušek, M. & Palatinus, L. (2006). JANA2006. Institute of Physics, Czech Academy of Sciences, Prague, Czech Republic.  Google Scholar
First citationTahiri, A. A., Messouri, I., Lachkar, M., Zavalij, P. Y., Glaum, R., El Bali, B. & Rachid, O. (2004). Acta Cryst. E60, i3–i5.  Web of Science CrossRef IUCr Journals Google Scholar
First citationTahiri, A. A., Ouarsal, R., Lachkar, M., El Bali, B. & Bolte, M. (2002). Acta Cryst. E58, i91–i92.  Web of Science CrossRef IUCr Journals Google Scholar
First citationTahiri, A. A., Ouarsal, R., Lachkar, M., Zavalij, P. Y. & El Bali, B. (2003). Acta Cryst. E59, i50–i52.  Web of Science CrossRef IUCr Journals Google Scholar

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ISSN: 2056-9890
Volume 67| Part 6| June 2011| Pages i37-i38
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