Acta Cryst. (2008). E64, i69-i70 [ doi:10.1107/S1600536808028365 ]
Single crystals of Co3(PO4)2·H2O, tricobalt(II) bis[orthophosphate(V)] monohydrate, were obtained under hydrothermal conditions. The compound is the second polymorph of this composition and is isotypic with its zinc analogue, Zn3(PO4)2·H2O. Three independent Co2+ cations are bridged by two independent orthophosphate anions. Two of the metal cations exhibit a distorted tetrahedral coordination while the third exhibits a considerably distorted [5 + 1] octahedral coordination environment with one very long Co-O distance of 2.416 (3) Å. The former cations are bonded to four different phosphate anions, and the latter cation is bonded to four anions (one of which is bidentate) and one water molecule, leading to a framework structure. Additional hydrogen bonds of the type O-H
O stabilize this arrangement.
Conditions of the hydrothermal single crystal growth of the hydrous cobalt(II) orthophosphates Co3(PO4)2.H2O and Co3(PO4)2.4 H2O were described in detail in a preceding communication (Lee et al., 2008).
Water H atoms were located in difference Fourier maps and were refined with Uiso(H) values fixed at 1.5Ueq of the parent O atoms. O—H bond length restraints of 0.89 (1) Å were also employed. The highest peak and the deepest hole in the final Fourier map are located 1.74 Å from O1 and 0.20 Å from P1, respectively.
Data collection: SMART (Siemens, 1995); cell refinement: SAINT (Siemens, 1995); data reduction: SAINT and XPREP (Siemens, 1995); program(s) used to solve structure: SIR97 (Altomare et al., 1999); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997), WebLab ViewerPro (Molecular Simulations, 2000) and POV-Ray (Cason, 2002).; software used to prepare material for publication: enCIFer (Allen et al., 2004).
![[Figure 1]](./wm2194fig1thm.gif)
| Fig. 1. The asymmetric unit of compound (I), drawn with displacement parameters at the 50% probability level. H atoms are given as spheres of arbitrary radius. |
![[Figure 2]](./wm2194fig2thm.gif)
| Fig. 2. A schematic representation of a section of the three-dimensional network of (I) in a projection along [010]. Hydrogen atoms are omitted for clarity. |
| Co3(PO4)2·H2O | F(000) = 740 |
| Mr = 384.75 | Dx = 3.629 Mg m−3 |
| Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
| Hall symbol: -P 2ybc | Cell parameters from 4684 reflections |
| a = 8.7038 (15) Å | θ = 2.5–28.4° |
| b = 4.8667 (9) Å | µ = 7.47 mm−1 |
| c = 16.705 (3) Å | T = 150 K |
| β = 95.670 (3)° | Plate, purple |
| V = 704.1 (2) Å3 | 0.46 × 0.14 × 0.08 mm |
| Z = 4 |
| Siemens SMART 1000 CCD diffractometer | 1697 independent reflections |
| Radiation source: sealed tube | 1603 reflections with I > 2σ(I) |
| graphite | Rint = 0.026 |
| ω scans | θmax = 28.4°, θmin = 2.4° |
| Absorption correction: multi-scan (SADABS; Sheldrick, 1999) | h = −11→11 |
| Tmin = 0.247, Tmax = 0.554 | k = −6→6 |
| 6569 measured reflections | l = −21→21 |
| 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)] = 0.033 | Hydrogen site location: difference Fourier map |
| wR(F2) = 0.095 | H atoms treated by a mixture of independent and constrained refinement |
| S = 1.07 | w = 1/[σ2(Fo2) + (0.0597P)2 + 3.2629P] where P = (Fo2 + 2Fc2)/3 |
| 1697 reflections | (Δ/σ)max < 0.001 |
| 133 parameters | Δρmax = 0.74 e Å−3 |
| 2 restraints | Δρmin = −1.39 e Å−3 |
| Co3(PO4)2·H2O | V = 704.1 (2) Å3 |
| Mr = 384.75 | Z = 4 |
| Monoclinic, P21/c | Mo Kα radiation |
| a = 8.7038 (15) Å | µ = 7.47 mm−1 |
| b = 4.8667 (9) Å | T = 150 K |
| c = 16.705 (3) Å | 0.46 × 0.14 × 0.08 mm |
| β = 95.670 (3)° |
| Siemens SMART 1000 CCD diffractometer | 1697 independent reflections |
| Absorption correction: multi-scan (SADABS; Sheldrick, 1999) | 1603 reflections with I > 2σ(I) |
| Tmin = 0.247, Tmax = 0.554 | Rint = 0.026 |
| 6569 measured reflections | θmax = 28.4° |
| R[F2 > 2σ(F2)] = 0.033 | H atoms treated by a mixture of independent and constrained refinement |
| wR(F2) = 0.095 | Δρmax = 0.74 e Å−3 |
| S = 1.07 | Δρmin = −1.39 e Å−3 |
| 1697 reflections | Absolute structure: ? |
| 133 parameters | Flack parameter: ? |
| 2 restraints | Rogers parameter: ? |
Experimental. The crystal was coated in Exxon Paratone N hydrocarbon oil and mounted on a thin mohair fibre attached to a copper pin. Upon mounting on the diffractometer, the crystal was quenched to 150(K) under a cold nitrogen gas stream supplied by an Oxford Cryosystems Cryostream. |
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 | ||
| Co1 | 0.32855 (5) | 0.20270 (9) | 0.94291 (3) | 0.00253 (14) | |
| Co2 | 0.56640 (5) | −0.20252 (9) | 0.84576 (3) | 0.00303 (15) | |
| Co3 | 0.92910 (6) | 0.49852 (10) | 0.82254 (3) | 0.00814 (16) | |
| P1 | 0.68190 (11) | 0.29320 (19) | 0.94510 (6) | 0.0086 (2) | |
| P2 | 0.23599 (11) | −0.51187 (19) | 0.78087 (6) | 0.0087 (2) | |
| O1 | 0.5357 (3) | 0.1481 (6) | 0.90286 (17) | 0.0114 (5) | |
| O2 | 0.3621 (3) | 0.3976 (6) | 1.04804 (16) | 0.0106 (5) | |
| O3 | 0.1907 (3) | 0.3427 (6) | 0.85760 (17) | 0.0119 (5) | |
| O4 | 0.2836 (3) | −0.1747 (6) | 0.96996 (17) | 0.0121 (6) | |
| O5 | 0.7445 (3) | −0.2368 (6) | 0.78428 (17) | 0.0116 (5) | |
| O6 | 0.8153 (3) | 0.2545 (6) | 0.89463 (17) | 0.0120 (5) | |
| O7 | 0.9749 (4) | 0.7679 (6) | 0.91711 (18) | 0.0137 (6) | |
| O8 | 0.9060 (3) | 0.1703 (6) | 0.74391 (17) | 0.0108 (5) | |
| O9 | 0.3852 (3) | −0.3512 (6) | 0.79103 (18) | 0.0148 (6) | |
| H1 | 1.0769 (18) | 0.797 (12) | 0.929 (3) | 0.022* | |
| H2 | 0.933 (6) | 0.936 (5) | 0.909 (3) | 0.022* |
| U11 | U22 | U33 | U12 | U13 | U23 | |
| Co1 | 0.0013 (2) | 0.0038 (2) | 0.0025 (2) | 0.00007 (15) | −0.00013 (17) | 0.00053 (15) |
| Co2 | 0.0006 (2) | 0.0045 (3) | 0.0040 (2) | −0.00041 (15) | 0.00015 (17) | −0.00098 (15) |
| Co3 | 0.0077 (3) | 0.0083 (3) | 0.0088 (3) | −0.00123 (17) | 0.00306 (19) | −0.00064 (17) |
| P1 | 0.0070 (5) | 0.0090 (5) | 0.0098 (5) | −0.0004 (3) | 0.0014 (3) | −0.0002 (3) |
| P2 | 0.0067 (5) | 0.0103 (4) | 0.0091 (4) | 0.0003 (3) | 0.0008 (3) | 0.0001 (3) |
| O1 | 0.0101 (13) | 0.0112 (12) | 0.0129 (13) | −0.0009 (10) | 0.0004 (10) | −0.0005 (10) |
| O2 | 0.0114 (13) | 0.0106 (13) | 0.0099 (13) | 0.0026 (10) | 0.0011 (10) | −0.0003 (10) |
| O3 | 0.0121 (13) | 0.0133 (13) | 0.0102 (13) | −0.0003 (11) | 0.0007 (11) | 0.0014 (10) |
| O4 | 0.0135 (14) | 0.0116 (13) | 0.0110 (13) | −0.0005 (10) | −0.0004 (11) | 0.0009 (10) |
| O5 | 0.0108 (14) | 0.0131 (12) | 0.0114 (13) | 0.0007 (10) | 0.0041 (10) | 0.0008 (10) |
| O6 | 0.0106 (14) | 0.0132 (12) | 0.0127 (13) | −0.0009 (11) | 0.0035 (11) | 0.0007 (10) |
| O7 | 0.0110 (14) | 0.0132 (13) | 0.0164 (14) | 0.0012 (11) | −0.0014 (11) | −0.0015 (11) |
| O8 | 0.0075 (13) | 0.0122 (13) | 0.0131 (13) | −0.0006 (10) | 0.0026 (10) | −0.0022 (10) |
| O9 | 0.0109 (14) | 0.0163 (13) | 0.0171 (14) | −0.0033 (11) | 0.0012 (11) | −0.0011 (11) |
| Co1—O3 | 1.897 (3) | Co3—O3iv | 2.416 (3) |
| Co1—O4 | 1.941 (3) | Co3—P2v | 2.8266 (12) |
| Co1—O2 | 1.992 (3) | P1—O6 | 1.513 (3) |
| Co1—O1 | 2.002 (3) | P1—O4i | 1.534 (3) |
| Co2—O9 | 1.887 (3) | P1—O2vi | 1.560 (3) |
| Co2—O5 | 1.949 (3) | P1—O1 | 1.561 (3) |
| Co2—O1 | 1.986 (3) | P2—O9 | 1.511 (3) |
| Co2—O2i | 2.054 (3) | P2—O8vii | 1.544 (3) |
| Co3—O6 | 2.019 (3) | P2—O3viii | 1.549 (3) |
| Co3—O7 | 2.061 (3) | P2—O5vii | 1.565 (3) |
| Co3—O8 | 2.065 (3) | P2—Co3ix | 2.8266 (12) |
| Co3—O8ii | 2.075 (3) | O7—H1 | 0.903 (10) |
| Co3—O5iii | 2.108 (3) | O7—H2 | 0.90 (3) |
| O3—Co1—O4 | 112.81 (13) | O4i—P1—O2vi | 108.77 (15) |
| O3—Co1—O2 | 121.22 (12) | O6—P1—O1 | 109.15 (16) |
| O4—Co1—O2 | 105.11 (12) | O4i—P1—O1 | 108.94 (16) |
| O3—Co1—O1 | 108.70 (12) | O2vi—P1—O1 | 105.94 (16) |
| O4—Co1—O1 | 99.28 (12) | O9—P2—O8vii | 112.91 (17) |
| O2—Co1—O1 | 107.42 (12) | O9—P2—O3viii | 115.46 (17) |
| O9—Co2—O5 | 112.44 (13) | O8vii—P2—O3viii | 102.81 (16) |
| O9—Co2—O1 | 114.62 (13) | O9—P2—O5vii | 106.80 (16) |
| O5—Co2—O1 | 118.58 (12) | O8vii—P2—O5vii | 110.75 (16) |
| O9—Co2—O2i | 114.12 (12) | O3viii—P2—O5vii | 108.04 (16) |
| O5—Co2—O2i | 103.10 (12) | O9—P2—Co3ix | 141.79 (13) |
| O1—Co2—O2i | 91.48 (11) | O8vii—P2—Co3ix | 45.96 (10) |
| O6—Co3—O7 | 89.20 (12) | O3viii—P2—Co3ix | 58.69 (11) |
| O6—Co3—O8 | 84.37 (11) | O5vii—P2—Co3ix | 110.73 (12) |
| O7—Co3—O8 | 168.15 (12) | P1—O1—Co2 | 117.61 (16) |
| O6—Co3—O8ii | 164.15 (12) | P1—O1—Co1 | 120.63 (16) |
| O7—Co3—O8ii | 93.56 (12) | Co2—O1—Co1 | 116.29 (14) |
| O8—Co3—O8ii | 90.02 (7) | P1vi—O2—Co1 | 120.56 (16) |
| O6—Co3—O5iii | 97.82 (11) | P1vi—O2—Co2i | 115.98 (15) |
| O7—Co3—O5iii | 85.85 (12) | Co1—O2—Co2i | 123.17 (15) |
| O8—Co3—O5iii | 104.85 (11) | P2iii—O3—Co1 | 126.29 (18) |
| O8ii—Co3—O5iii | 97.95 (11) | P1i—O4—Co1 | 123.07 (17) |
| O6—Co3—O3iv | 100.18 (11) | P2x—O5—Co2 | 116.94 (17) |
| O7—Co3—O3iv | 84.70 (11) | P2x—O5—Co3viii | 120.43 (16) |
| O8—Co3—O3iv | 86.65 (10) | Co2—O5—Co3viii | 120.96 (14) |
| O8ii—Co3—O3iv | 64.61 (10) | P1—O6—Co3 | 135.08 (18) |
| O5iii—Co3—O3iv | 159.51 (11) | Co3—O7—H1 | 113 (4) |
| O6—Co3—P2v | 131.88 (9) | Co3—O7—H2 | 115 (4) |
| O7—Co3—P2v | 94.83 (9) | H1—O7—H2 | 105 (5) |
| O8—Co3—P2v | 82.21 (8) | P2x—O8—Co3 | 129.77 (16) |
| O8ii—Co3—P2v | 32.34 (8) | P2x—O8—Co3xi | 101.70 (14) |
| O5iii—Co3—P2v | 130.28 (8) | Co3—O8—Co3xi | 128.53 (14) |
| O6—P1—O4i | 112.20 (17) | P2—O9—Co2 | 157.0 (2) |
| O6—P1—O2vi | 111.63 (16) | ||
| O6—P1—O1—Co2 | 36.4 (2) | O1—Co2—O5—P2x | −54.5 (2) |
| O4i—P1—O1—Co2 | −86.41 (19) | O2i—Co2—O5—P2x | −153.51 (18) |
| O2vi—P1—O1—Co2 | 156.73 (16) | O9—Co2—O5—Co3viii | −111.58 (17) |
| O6—P1—O1—Co1 | −170.63 (17) | O1—Co2—O5—Co3viii | 110.83 (17) |
| O4i—P1—O1—Co1 | 66.5 (2) | O2i—Co2—O5—Co3viii | 11.79 (18) |
| O2vi—P1—O1—Co1 | −50.3 (2) | O4i—P1—O6—Co3 | −132.6 (2) |
| O9—Co2—O1—P1 | −176.28 (16) | O2vi—P1—O6—Co3 | −10.2 (3) |
| O5—Co2—O1—P1 | −39.6 (2) | O1—P1—O6—Co3 | 106.6 (3) |
| O2i—Co2—O1—P1 | 66.23 (18) | O7—Co3—O6—P1 | 55.9 (3) |
| O9—Co2—O1—Co1 | 29.6 (2) | O8—Co3—O6—P1 | −134.0 (3) |
| O5—Co2—O1—Co1 | 166.29 (13) | O8ii—Co3—O6—P1 | 156.2 (3) |
| O2i—Co2—O1—Co1 | −87.91 (15) | O5iii—Co3—O6—P1 | −29.8 (3) |
| O3—Co1—O1—P1 | 122.72 (19) | P2v—Co3—O6—P1 | 151.72 (19) |
| O4—Co1—O1—P1 | −119.25 (19) | O6—Co3—O8—P2x | 44.9 (2) |
| O2—Co1—O1—P1 | −10.1 (2) | O7—Co3—O8—P2x | 102.3 (6) |
| O3—Co1—O1—Co2 | −83.97 (17) | O8ii—Co3—O8—P2x | −150.0 (2) |
| O4—Co1—O1—Co2 | 34.06 (16) | O5iii—Co3—O8—P2x | −51.7 (2) |
| O2—Co1—O1—Co2 | 143.21 (14) | P2v—Co3—O8—P2x | 178.6 (2) |
| O3—Co1—O2—P1vi | −18.9 (2) | O6—Co3—O8—Co3xi | −134.86 (19) |
| O4—Co1—O2—P1vi | −148.23 (18) | O7—Co3—O8—Co3xi | −77.4 (6) |
| O1—Co1—O2—P1vi | 106.71 (19) | O8ii—Co3—O8—Co3xi | 30.29 (16) |
| O3—Co1—O2—Co2i | 154.62 (15) | O5iii—Co3—O8—Co3xi | 128.52 (17) |
| O4—Co1—O2—Co2i | 25.34 (19) | P2v—Co3—O8—Co3xi | −1.19 (16) |
| O1—Co1—O2—Co2i | −79.72 (18) | O8vii—P2—O9—Co2 | 116.3 (5) |
| O4—Co1—O3—P2iii | −129.2 (2) | O3viii—P2—O9—Co2 | −1.5 (6) |
| O2—Co1—O3—P2iii | 105.0 (2) | O5vii—P2—O9—Co2 | −121.7 (5) |
| O1—Co1—O3—P2iii | −20.1 (2) | Co3ix—P2—O9—Co2 | 69.4 (6) |
| O3—Co1—O4—P1i | −150.21 (19) | O5—Co2—O9—P2 | 137.1 (5) |
| O2—Co1—O4—P1i | −16.1 (2) | O1—Co2—O9—P2 | −83.5 (6) |
| O1—Co1—O4—P1i | 94.9 (2) | O2i—Co2—O9—P2 | 20.1 (6) |
| O9—Co2—O5—P2x | 83.1 (2) |
| Symmetry codes: (i) −x+1, −y, −z+2; (ii) −x+2, y+1/2, −z+3/2; (iii) x, y+1, z; (iv) x+1, y, z; (v) x+1, y+1, z; (vi) −x+1, −y+1, −z+2; (vii) −x+1, y−1/2, −z+3/2; (viii) x, y−1, z; (ix) x−1, y−1, z; (x) −x+1, y+1/2, −z+3/2; (xi) −x+2, y−1/2, −z+3/2. |
| D—H···A | D—H | H···A | D···A | D—H···A |
| O7—H2···O6iii | 0.90 (3) | 1.86 (4) | 2.753 (4) | 170 (5) |
| O7—H1···O4v | 0.90 (1) | 1.86 (2) | 2.758 (4) | 171 (5) |
| Symmetry codes: (iii) x, y+1, z; (v) x+1, y+1, z. |
| Co1—O3 | 1.897 (3) | Co3—O8ii | 2.075 (3) |
| Co1—O4 | 1.941 (3) | Co3—O5iii | 2.108 (3) |
| Co1—O2 | 1.992 (3) | Co3—O3iv | 2.416 (3) |
| Co1—O1 | 2.002 (3) | P1—O6 | 1.513 (3) |
| Co2—O9 | 1.887 (3) | P1—O4i | 1.534 (3) |
| Co2—O5 | 1.949 (3) | P1—O2v | 1.560 (3) |
| Co2—O1 | 1.986 (3) | P1—O1 | 1.561 (3) |
| Co2—O2i | 2.054 (3) | P2—O9 | 1.511 (3) |
| Co3—O6 | 2.019 (3) | P2—O8vi | 1.544 (3) |
| Co3—O7 | 2.061 (3) | P2—O3vii | 1.549 (3) |
| Co3—O8 | 2.065 (3) | P2—O5vi | 1.565 (3) |
| Symmetry codes: (i) −x+1, −y, −z+2; (ii) −x+2, y+1/2, −z+3/2; (iii) x, y+1, z; (iv) x+1, y, z; (v) −x+1, −y+1, −z+2; (vi) −x+1, y−1/2, −z+3/2; (vii) x, y−1, z. |
| D—H···A | D—H | H···A | D···A | D—H···A |
| O7—H2···O6iii | 0.90 (3) | 1.86 (4) | 2.753 (4) | 170 (5) |
| O7—H1···O4viii | 0.90 (1) | 1.86 (2) | 2.758 (4) | 171 (5) |
| Symmetry codes: (iii) x, y+1, z; (viii) x+1, y+1, z. |
We gratefully acknowledge the Brain Korea 21 programme and the Australian Research Council for support.
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Synthesis and structural investigations of transition-metal phosphates under various conditions, including high temperature and high pressure, have been investigated for many years (Murugavel et al., 2008). This is not only because of the multifarious structural chemistry, but also due to many potential applications. For a listing of reviews on these materials, see Lee et al. (2008). We are currently investigating the synthesis of a variety of similar functional materials through templation effects under hydrothermal conditions. The title compound, Co3(PO4)2.H2O, (I), and the related compound Co3(PO4)2.4H2O (Lee et al., 2008) were synthesized as a part of these studies.
In the past, many different cobalt(II) orthophosphates have been described, ranging from the anhydrous form Co3(PO4)2 to its corresponding octahydrate (Mellor, 1935). In 1976 Anderson et al. reported a first polymorph of Co3(PO4)2.H2O formed under high pressure conditions. The second polymorph of Co3(PO4)2.H2O presented here has a different unit cell and a considerably different cell volume (638.3 (Anderson et al., 1976) versus 704.1 Å3 (this study)) and exhibits also a different assembly of the structural building units. The second polymorph (I) is isotypic with its Zn analogue Zn3(PO4)2.H2O (Riou et al., 1986).
The structure of (I) contains three different Co2+ centres bridged by orthophosphate anions (Fig 1). The coordination spheres of Co1 and Co2 are distorted tetrahedral while that of Co3 is distorted octahedral, with one considerably longer Co—O bond of 2.416 (3) Å (Table 1). Co1 and Co2 are bonded to the O atoms of four phosphate ligands, whereas Co3 is bonded to five O atoms of four phosphate ligands (one bidentate) and the sixth coordination site is occupied by a water molecule. This assembly leads to the formation of a three-dimensional framework (Fig. 2), which is stabilized by additional O—H···O hydrogen bonds (Table 2).