Dipotassium diaqua­bis(methyl­enedi­phospho­nato-κ2O,O′)cobaltate(II)

Visser, H.G.; Venter, J.A.; Van der Merwe, K.A.

doi:10.1107/S160053680905106X

metal-organic compounds

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ISSN: 2056-9890

Volume 66| Part 2| February 2010| Page m159

https://doi.org/10.1107/S160053680905106X

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Dipotassium diaquabis(methylenediphosphonato-κ²O,O′)cobaltate(II)

H.G. Visser,^a ^* J.A. Venter ^a and K.A. Van der Merwe ^a

^aDepartment of Chemistry, University of the Free State, PO Box 339, Bloemfontein 9300, South Africa
^*Correspondence e-mail: visserhg.sci@ufs.ac.za

(Received 12 November 2009; accepted 26 November 2009; online 16 January 2010)

In the title complex, K₂[Co(CH₄O₆P₂)₂(H₂O)₂], the asymmetric unit contains two K⁺ cations and two half-anions in which the Co atoms lie on inversion centers. The Co^II ions assume an octahedral CoO₆ coordination geometry. In the crystal, a three-dimensional network is formed through O—H⋯O hydrogen-bond interactions as well as intermolecular interactions between the K⁺ cations and neighbouring O atoms.

Related literature

For related structures, see: DeLaMatter et al. (1973 ); Jurisson et al. (1983 ); Barthelet et al. (2002 ); Stahl et al. (2006 ); Van der Merwe et al. (2009 ).

Experimental

Crystal data

K₂[Co(CH₄O₆P₂)₂(H₂O)₂]
M_r = 521.13
Triclinic, $[P \overline 1]$
a = 6.4523 (3) Å
b = 8.7056 (3) Å
c = 13.1930 (5) Å
α = 91.334 (2)°
β = 93.304 (2)°
γ = 93.333 (2)°
V = 738.32 (5) Å³
Z = 2
Mo Kα radiation
μ = 2.23 mm⁻¹
T = 100 K
0.28 × 0.17 × 0.17 mm

Data collection

Bruker X8 APEXII 4K Kappa CCD diffractometer
Absorption correction: multi-scan SADABS (Bruker, 2004 ) T_min = 0.635, T_max = 0.690
13474 measured reflections
3645 independent reflections
3194 reflections with I > 2σ(I)
R_int = 0.036

Refinement

R[F² > 2σ(F²)] = 0.040
wR(F²) = 0.1096
S = 1.23
3645 reflections
235parameters
14 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 1.04 e Å⁻³
Δρ_min = −0.61 e Å⁻³

Table 1
Selected bond lengths (Å)

O1—Co1	2.052 (3)
O2—Co1	2.132 (2)
O3—Co1	2.127 (3)
O8—Co2	2.081 (3)
O9—Co2	2.117 (2)
O10—Co2	2.064 (3)

Table 2
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O3—H3A⋯O14ⁱ	0.85 (2)	1.83 (2)	2.680 (4)	175 (4)
O3—H3B⋯O6ⁱⁱ	0.86 (2)	1.89 (2)	2.737 (4)	172 (4)
O4—H4⋯O9ⁱⁱⁱ	0.84 (2)	1.81 (2)	2.632 (4)	166 (5)
O7—H7⋯O6^iv	0.85 (2)	1.72 (2)	2.570 (4)	177 (5)
O8—H8A⋯O5^v	0.85 (2)	1.84 (2)	2.678 (4)	170 (4)
O8—H8B⋯O11^vi	0.85 (2)	1.84 (2)	2.687 (4)	176 (5)
O12—H12⋯O11^vii	0.85 (1)	1.72 (1)	2.561 (4)	175 (5)
O13—H13⋯O2ⁱ	0.84 (2)	1.78 (2)	2.616 (4)	174 (5)
Symmetry codes: (i) -x+1, -y+1, -z; (ii) x-1, y, z; (iii) x, y+1, z; (iv) -x+2, -y+2, -z; (v) x, y-1, z; (vi) -x+2, -y, -z+1; (vii) -x+2, -y+1, -z+1.

Data collection: APEX2 (Bruker, 2005 ); cell refinement: SAINT-Plus (Bruker, 2004); data reduction: SAINT-Plus and XPREP (Bruker, 2004); program(s) used to solve structure: SIR97 (Altomare et al., 1999 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ); molecular graphics: DIAMOND (Brandenburg & Putz, 2005 ); software used to prepare material for publication: WinGX (Farrugia, 1999 ).

Supporting information

Crystal structure: contains datablocks global, I. DOI: https://doi.org/10.1107/S160053680905106X/ds2013sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S160053680905106X/ds2013Isup2.hkl

checkCIF report

Comment top

We reported a similar structure recently with the only differences being the cation and the +2 oxidation state of the cobalt ion (Van der Merwe et al.<i/>, 2009).

The Co^III ion in the title complex, K[Co(C₂H₄O₆P)₂(H₂O)₂], is in a slightly distorted octahedral environment with O–Co–O bond angles varying from 83.75 (10) to 96.25 (10)°. All the bonding distance and angles fall within the normal range observed for complexes of this nature. The P-O distances are significantly different for P═O and P-OH type bonds and vary from 1.501 (3) to 1.580 (3) Å. This could possibly be an indication that the assignment of positional disorders for the respective Co^II complex previously was correct since these difference were not so prominent in the previous structure.

A three-dimensional network is provided by numerous hydrogen bonds and other weak interactions between the potassium ions and the oxygen atoms of the anionic species.

Related literature top

For related structures, see: DeLaMatter et al. (1973); Jurisson et al., 1983; Barthelet et al. (2002); Stahl et al. (2006); Van der Merwe et al. (2009).

Experimental top

CoCl₂.6H₂O (0,1696 g, 71 mmol) was dissolved in water (7 cm³) and heated to 70°C. Potassium bicarbonate was added to raise the pH to 5,5 after which methylene disphosphonate (0,25 g, 142 mmol), dissolved in water (5 cm³) was added dropwise. The final pH of the solution was adjusted to 1.50 to obtain the Co^II salt as described previously (Van der Merwe et al.<i/> 2009). Crystals of the Co^III salt, suitable for X-ray diffraction, was obtained from redissolving and adding H₂O₂ to the solution.

Structure description top

We reported a similar structure recently with the only differences being the cation and the +2 oxidation state of the cobalt ion (Van der Merwe et al.<i/>, 2009).

A three-dimensional network is provided by numerous hydrogen bonds and other weak interactions between the potassium ions and the oxygen atoms of the anionic species.

For related structures, see: DeLaMatter et al. (1973); Jurisson et al., 1983; Barthelet et al. (2002); Stahl et al. (2006); Van der Merwe et al. (2009).

Computing details top

Data collection: APEX2 (Bruker, 2005); cell refinement: SAINT-Plus (Bruker, 2004); data reduction: SAINT-Plus and XPREP (Bruker, 2004); program(s) used to solve structure: SIR97 (Altomare et al., 1999); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg & Putz, 2005); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures top

Fig. 1. View of (I) (50% probability displacement ellipsoids). The potassium cations and hydrogen atoms have been omitted for clarity.

Dipotassium diaquabis(methylenediphosphonato-κ²O,O')cobaltate(II) top

Crystal data top

K₂[Co(CH₄O₆P₂)₂(H₂O)₂]	Z = 2
M_r = 521.13	F(000) = 522
Triclinic, P1	D_x = 2.344 Mg m⁻³
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 6.4523 (3) Å	Cell parameters from 5231 reflections
b = 8.7056 (3) Å	θ = 2.1–28.3°
c = 13.1930 (5) Å	µ = 2.23 mm⁻¹
α = 91.334 (2)°	T = 100 K
β = 93.304 (2)°	Cuboid, pink
γ = 93.333 (2)°	0.28 × 0.17 × 0.17 mm
V = 738.32 (5) Å³

Data collection top

Bruker X8 APEXII 4K Kappa CCD diffractometer	3645 independent reflections
Radiation source: sealed tube	3194 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.036
phi and ω scans	θ_max = 28.4°, θ_min = 3.1°
Absorption correction: multi-scan SADABS (Bruker, 2004)	h = −8→8
T_min = 0.635, T_max = 0.690	k = −11→9
13474 measured reflections	l = −16→17

Refinement top

Refinement on F²	14 restraints
Least-squares matrix: full	H atoms treated by a mixture of independent and constrained refinement
R[F² > 2σ(F²)] = 0.040	w = 1/[σ²(F_o²) + (0.0164P)² + 3.9058P] where P = (F_o² + 2F_c²)/3
wR(F²) = 0.096	(Δ/σ)_max < 0.001
S = 1.18	Δρ_max = 0.95 e Å⁻³
3645 reflections	Δρ_min = −0.55 e Å⁻³
235 parameters

Crystal data top

K₂[Co(CH₄O₆P₂)₂(H₂O)₂]	γ = 93.333 (2)°
M_r = 521.13	V = 738.32 (5) Å³
Triclinic, P1	Z = 2
a = 6.4523 (3) Å	Mo Kα radiation
b = 8.7056 (3) Å	µ = 2.23 mm⁻¹
c = 13.1930 (5) Å	T = 100 K
α = 91.334 (2)°	0.28 × 0.17 × 0.17 mm
β = 93.304 (2)°

Data collection top

Bruker X8 APEXII 4K Kappa CCD diffractometer	3645 independent reflections
Absorption correction: multi-scan SADABS (Bruker, 2004)	3194 reflections with I > 2σ(I)
T_min = 0.635, T_max = 0.690	R_int = 0.036
13474 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.040	14 restraints
wR(F²) = 0.096	H atoms treated by a mixture of independent and constrained refinement
S = 1.18	Δρ_max = 0.95 e Å⁻³
3645 reflections	Δρ_min = −0.55 e Å⁻³
235 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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
C2	0.6164 (6)	0.3660 (4)	0.4121 (3)	0.0083 (7)
H2A	0.6647	0.4636	0.3852	0.01*
H2B	0.4955	0.3844	0.4501	0.01*
O2	0.7149 (4)	0.6643 (3)	−0.06002 (19)	0.0084 (5)
O1	0.4857 (4)	0.6095 (3)	0.1386 (2)	0.0100 (5)
O4	0.3898 (4)	0.8338 (3)	0.2356 (2)	0.0093 (5)
O5	0.7656 (4)	0.7614 (3)	0.2543 (2)	0.0116 (5)
O6	1.0177 (4)	0.7998 (3)	0.0450 (2)	0.0088 (5)
O8	0.6907 (4)	−0.1647 (3)	0.4464 (2)	0.0137 (6)
O9	0.4598 (4)	0.0840 (3)	0.35124 (19)	0.0087 (5)
O10	0.7627 (4)	0.1422 (3)	0.5352 (2)	0.0109 (5)
O11	1.0208 (4)	0.3123 (3)	0.4451 (2)	0.0091 (5)
O12	0.8299 (4)	0.4173 (3)	0.59244 (19)	0.0097 (5)
O13	0.3411 (4)	0.3121 (3)	0.2569 (2)	0.0094 (5)
O14	0.7069 (4)	0.2216 (3)	0.2347 (2)	0.0105 (5)
P1	0.80660 (14)	0.81239 (10)	−0.00988 (7)	0.00684 (18)
P2	0.57617 (14)	0.76121 (11)	0.18262 (7)	0.00712 (18)
P3	0.53703 (14)	0.23561 (10)	0.30689 (7)	0.00681 (18)
P4	0.81776 (14)	0.30133 (11)	0.49860 (7)	0.00724 (18)
K1	0.08042 (13)	0.57684 (9)	0.19914 (6)	0.01125 (17)
K2	0.02621 (13)	0.04058 (10)	0.31295 (7)	0.01350 (18)
Co1	0.5	0.5	0	0.00676 (15)
Co2	0.5	0	0.5	0.00634 (15)
O7	0.8190 (4)	0.9319 (3)	−0.0975 (2)	0.0092 (5)
O3	0.2452 (4)	0.6119 (3)	−0.0684 (2)	0.0112 (5)
C1	0.6299 (6)	0.8839 (4)	0.0776 (3)	0.0079 (7)
H1A	0.4994	0.9006	0.0404	0.01*
H1B	0.6864	0.9831	0.1048	0.01*
H8B	0.778 (6)	−0.215 (5)	0.482 (3)	0.02*
H8A	0.699 (7)	−0.185 (5)	0.3838 (14)	0.02*
H7	0.877 (7)	1.020 (3)	−0.081 (4)	0.02*
H4	0.433 (8)	0.911 (4)	0.271 (3)	0.02*
H13	0.332 (8)	0.318 (6)	0.1935 (15)	0.02*
H3B	0.175 (7)	0.665 (5)	−0.029 (3)	0.02*
H3A	0.266 (8)	0.661 (5)	−0.122 (2)	0.02*
H12	0.872 (7)	0.5089 (18)	0.581 (2)	0.02*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
C2	0.0098 (17)	0.0062 (16)	0.0087 (16)	−0.0003 (13)	−0.0010 (13)	0.0003 (13)
O2	0.0098 (12)	0.0077 (12)	0.0073 (12)	−0.0033 (10)	0.0005 (10)	0.0002 (9)
O1	0.0146 (13)	0.0065 (12)	0.0089 (12)	−0.0016 (10)	0.0035 (10)	0.0000 (10)
O4	0.0087 (12)	0.0097 (13)	0.0092 (12)	0.0009 (10)	−0.0002 (10)	−0.0023 (10)
O5	0.0108 (13)	0.0146 (13)	0.0095 (13)	0.0031 (10)	−0.0004 (10)	−0.0010 (10)
O6	0.0082 (12)	0.0078 (12)	0.0102 (12)	−0.0004 (9)	−0.0006 (10)	−0.0002 (10)
O8	0.0150 (14)	0.0183 (14)	0.0087 (13)	0.0097 (11)	−0.0005 (11)	−0.0010 (11)
O9	0.0138 (13)	0.0062 (12)	0.0060 (12)	−0.0009 (10)	0.0005 (10)	0.0016 (9)
O10	0.0088 (12)	0.0092 (12)	0.0146 (13)	−0.0013 (10)	−0.0011 (10)	0.0065 (10)
O11	0.0084 (12)	0.0096 (12)	0.0092 (12)	−0.0005 (10)	0.0020 (10)	0.0003 (10)
O12	0.0139 (13)	0.0077 (12)	0.0072 (12)	−0.0016 (10)	0.0002 (10)	−0.0008 (10)
O13	0.0109 (13)	0.0116 (13)	0.0060 (12)	0.0023 (10)	−0.0004 (10)	0.0006 (10)
O14	0.0118 (13)	0.0127 (13)	0.0075 (12)	0.0023 (10)	0.0023 (10)	0.0021 (10)
P1	0.0077 (4)	0.0062 (4)	0.0067 (4)	0.0000 (3)	0.0006 (3)	0.0005 (3)
P2	0.0080 (4)	0.0076 (4)	0.0059 (4)	0.0014 (3)	0.0010 (3)	−0.0004 (3)
P3	0.0086 (4)	0.0063 (4)	0.0057 (4)	0.0013 (3)	0.0005 (3)	0.0006 (3)
P4	0.0083 (4)	0.0063 (4)	0.0069 (4)	−0.0006 (3)	−0.0010 (3)	0.0008 (3)
K1	0.0112 (4)	0.0122 (4)	0.0107 (4)	0.0026 (3)	0.0011 (3)	0.0015 (3)
K2	0.0109 (4)	0.0126 (4)	0.0167 (4)	0.0017 (3)	−0.0022 (3)	−0.0013 (3)
Co1	0.0083 (3)	0.0060 (3)	0.0061 (3)	0.0004 (2)	0.0010 (2)	−0.0001 (2)
Co2	0.0072 (3)	0.0061 (3)	0.0058 (3)	0.0001 (2)	0.0008 (2)	0.0007 (2)
O7	0.0137 (13)	0.0055 (12)	0.0081 (12)	−0.0021 (10)	0.0003 (10)	0.0016 (10)
O3	0.0123 (13)	0.0130 (13)	0.0091 (13)	0.0030 (10)	0.0036 (10)	0.0028 (10)
C1	0.0104 (17)	0.0061 (16)	0.0077 (16)	0.0015 (13)	0.0016 (13)	0.0017 (13)

Geometric parameters (Å, º) top

C2—P4	1.803 (4)	O13—K1	3.018 (3)
C2—P3	1.804 (4)	O13—K2	3.156 (3)
C2—H2A	0.97	O13—H13	0.837 (19)
C2—H2B	0.97	O14—P3	1.502 (3)
O2—P1	1.509 (3)	O14—K2ⁱⁱ	2.829 (3)
O1—Co1	2.052 (3)	P1—O7	1.575 (3)
O2—Co1	2.132 (2)	P1—C1	1.795 (4)
O3—Co1	2.127 (3)	P2—C1	1.806 (4)
O1—P2	1.503 (3)	K1—O12^v	2.776 (3)
O1—K1	2.779 (3)	K1—O5^vi	2.780 (3)
O4—P2	1.581 (3)	K1—O6^vi	2.871 (3)
O4—K1	2.922 (3)	K1—O3^vii	3.023 (3)
O4—K2ⁱ	3.235 (3)	K1—O2^viii	3.153 (3)
O4—H4	0.84 (2)	K2—O14^vi	2.829 (3)
O5—P2	1.501 (3)	K2—O11^vi	2.909 (3)
O5—K1ⁱⁱ	2.780 (3)	K2—O10^iv	2.913 (3)
O5—K2ⁱⁱⁱ	2.936 (3)	K2—O5^ix	2.936 (3)
O6—P1	1.516 (3)	K2—O7^viii	3.076 (3)
O6—K1ⁱⁱ	2.871 (3)	K2—O4^x	3.235 (3)
O8—Co2	2.081 (3)	K2—O8^vi	3.334 (3)
O8—K2ⁱⁱ	3.334 (3)	Co1—O1^viii	2.052 (3)
O8—H8B	0.854 (19)	Co1—O3	2.126 (3)
O8—H8A	0.845 (19)	Co1—O3^viii	2.126 (3)
O9—P3	1.525 (3)	Co1—O2^viii	2.132 (2)
O9—Co2	2.117 (2)	Co2—O10^iv	2.064 (3)
O9—K2	2.816 (3)	Co2—O8^iv	2.081 (3)
O10—P4	1.508 (3)	Co2—O9^iv	2.117 (2)
O10—Co2	2.064 (3)	O7—K2^viii	3.076 (3)
O10—K2^iv	2.913 (3)	O7—H7	0.849 (19)
O11—P4	1.523 (3)	O3—K1^vii	3.023 (3)
O11—K2ⁱⁱ	2.909 (3)	O3—H3B	0.855 (19)
O12—P4	1.575 (3)	O3—H3A	0.851 (19)
O12—K1^v	2.776 (3)	C1—H1A	0.97
O12—H12	0.848 (12)	C1—H1B	0.97
O13—P3	1.581 (3)

P4—C2—P3	115.32 (19)	P2^vi—K1—H13	153.4 (10)
P4—C2—H2A	108.4	Co1—K1—H13	54.0 (7)
P3—C2—H2A	108.4	K2ⁱ—K1—H13	146.4 (9)
P4—C2—H2B	108.4	O9—K2—O14^vi	135.52 (8)
P3—C2—H2B	108.4	O9—K2—O11^vi	83.20 (8)
H2A—C2—H2B	107.5	O9—K2—O10^iv	60.10 (7)
P1—O2—Co1	127.62 (15)	O9—K2—O5^ix	130.52 (8)
P2—O1—Co1	133.27 (16)	O9—K2—O7^viii	77.74 (7)
P2—O1—K1	106.53 (13)	O5^ix—K2—O7^viii	91.81 (8)
Co1—O1—K1	108.92 (11)	O9—K2—O13	49.14 (7)
P2—O4—K1	98.19 (12)	O14^vi—K2—O13	86.68 (8)
P2—O4—H4	110 (4)	O11^vi—K2—O13	66.26 (7)
K1—O4—H4	148 (4)	O10^iv—K2—O13	107.66 (7)
K2ⁱ—O4—H4	66 (4)	O5^ix—K2—O13	150.33 (8)
Co2—O8—H8B	127 (3)	O7^viii—K2—O13	58.52 (7)
K2ⁱⁱ—O8—H8B	99 (3)	O9—K2—O4^x	50.98 (7)
Co2—O8—H8A	123 (3)	O13—K2—O4^x	82.11 (7)
K2ⁱⁱ—O8—H8A	60 (4)	O9—K2—O8^vi	127.53 (8)
H8B—O8—H8A	110 (3)	O13—K2—O8^vi	159.31 (8)
P3—O9—Co2	130.58 (16)	O9—K2—P3	23.35 (5)
P3—O9—K2	109.60 (13)	O14^vi—K2—P3	112.35 (6)
Co2—O9—K2	101.82 (10)	O11^vi—K2—P3	73.94 (6)
P4—O10—Co2	129.21 (16)	O10^iv—K2—P3	82.69 (6)
P4—O12—H12	115.7 (19)	O5^ix—K2—P3	145.87 (6)
K1^v—O12—H12	98 (2)	O7^viii—K2—P3	66.54 (5)
P3—O13—K1	155.08 (15)	O13—K2—P3	25.79 (5)
P3—O13—K2	93.90 (12)	O4^x—K2—P3	64.15 (5)
K1—O13—K2	106.16 (8)	O8^vi—K2—P3	147.32 (6)
P3—O13—H13	118 (4)	O9—K2—P4^vi	103.51 (6)
K1—O13—H13	71 (4)	O13—K2—P4^vi	88.53 (5)
K2—O13—H13	107 (4)	P3—K2—P4^vi	97.09 (3)
O2—P1—O6	114.49 (15)	O9—K2—P3^vi	143.95 (6)
O2—P1—O7	105.55 (15)	P3—K2—P3^vi	124.45 (3)
O6—P1—O7	111.05 (15)	O1^viii—Co1—O1	180.00 (7)
O2—P1—C1	109.75 (16)	O1^viii—Co1—O3	85.70 (11)
O6—P1—C1	109.14 (16)	O1—Co1—O3	94.30 (11)
O7—P1—C1	106.53 (15)	O1—Co1—O3^viii	85.70 (11)
O5—P2—O1	118.26 (16)	O3—Co1—O3^viii	180
O5—P2—O4	111.00 (15)	O1^viii—Co1—O2	83.75 (10)
O1—P2—O4	104.54 (15)	O1—Co1—O2	96.25 (10)
O5—P2—C1	109.50 (17)	O3—Co1—O2	90.87 (10)
O1—P2—C1	107.35 (16)	O3^viii—Co1—O2	89.13 (10)
O4—P2—C1	105.35 (15)	O1—Co1—O2^viii	83.75 (10)
O5—P2—K1	130.08 (11)	O3—Co1—O2^viii	89.13 (10)
O1—P2—K1	49.28 (11)	O2—Co1—O2^viii	180
O4—P2—K1	55.38 (10)	O1^viii—Co1—K1	138.32 (8)
C1—P2—K1	120.38 (13)	O1—Co1—K1	41.68 (8)
O14—P3—O9	114.63 (15)	O3—Co1—K1	69.01 (7)
O14—P3—O13	112.37 (15)	O3^viii—Co1—K1	110.99 (7)
O9—P3—O13	107.36 (15)	O2—Co1—K1	127.38 (7)
O14—P3—C2	111.63 (17)	O2^viii—Co1—K1	52.62 (7)
O9—P3—C2	107.33 (16)	O1—Co1—K1^viii	138.32 (8)
O13—P3—C2	102.70 (15)	O3—Co1—K1^viii	110.99 (7)
O14—P3—K2	131.70 (12)	O2—Co1—K1^viii	52.62 (7)
O9—P3—K2	47.05 (10)	K1—Co1—K1^viii	180
O13—P3—K2	60.31 (10)	O10^iv—Co2—O10	180
C2—P3—K2	116.55 (12)	O10^iv—Co2—O8	91.42 (11)
O10—P4—O11	113.25 (15)	O10—Co2—O8	88.58 (11)
O10—P4—O12	108.39 (15)	O10—Co2—O8^iv	91.42 (11)
O11—P4—O12	110.21 (15)	O8—Co2—O8^iv	180.00 (14)
O10—P4—C2	111.43 (16)	O10^iv—Co2—O9	86.68 (10)
O11—P4—C2	107.68 (16)	O10—Co2—O9	93.32 (10)
O12—P4—C2	105.61 (16)	O8—Co2—O9	89.71 (10)
O1—K1—O4	50.58 (7)	O8^iv—Co2—O9	90.29 (10)
O5^vi—K1—O4	90.83 (8)	O10—Co2—O9^iv	86.68 (10)
O6^vi—K1—O4	71.15 (8)	O8—Co2—O9^iv	90.29 (10)
O12^v—K1—O13	69.91 (8)	O9—Co2—O9^iv	180.0000 (10)
O1—K1—O13	66.27 (8)	O10^iv—Co2—K2	48.07 (7)
O5^vi—K1—O13	146.12 (8)	O10—Co2—K2	131.93 (7)
O6^vi—K1—O13	142.50 (8)	O8—Co2—K2	110.65 (8)
O4—K1—O13	99.99 (8)	O8^iv—Co2—K2	69.35 (8)
O1—K1—P2	24.20 (6)	O9—Co2—K2	45.66 (7)
O5^vi—K1—P2	116.53 (7)	O9^iv—Co2—K2	134.34 (7)
O6^vi—K1—P2	76.27 (6)	O10—Co2—K2^iv	48.07 (7)
O4—K1—P2	26.43 (5)	O8—Co2—K2^iv	69.35 (8)
O13—K1—P2	81.17 (6)	O9—Co2—K2^iv	134.34 (7)
O1—K1—Co1	29.41 (6)	K2—Co2—K2^iv	180.00 (2)
O5^vi—K1—Co1	146.14 (6)	P1—O7—K2^viii	139.92 (14)
O6^vi—K1—Co1	74.83 (5)	P1—O7—H7	116 (3)
O4—K1—Co1	76.27 (5)	K2^viii—O7—H7	90 (3)
O13—K1—Co1	67.68 (5)	Co1—O3—K1^vii	118.88 (11)
O3^vii—K1—Co1	90.27 (5)	Co1—O3—H3B	117 (3)
O2^viii—K1—Co1	32.50 (5)	K1^vii—O3—H3B	104 (3)
P2—K1—Co1	51.534 (19)	Co1—O3—H3A	118 (3)
O1—K1—H13	59.5 (10)	K1^vii—O3—H3A	85 (3)
O5^vi—K1—H13	159.3 (8)	H3B—O3—H3A	110 (3)
O6^vi—K1—H13	127.9 (5)	P1—C1—P2	115.47 (19)
O4—K1—H13	102.4 (10)	P1—C1—H1A	108.4
O13—K1—H13	16.1 (4)	P2—C1—H1A	108.4
O3^vii—K1—H13	87.6 (9)	P1—C1—H1B	108.4
O2^viii—K1—H13	34.1 (4)	P2—C1—H1B	108.4
P2—K1—H13	79.2 (10)	H1A—C1—H1B	107.5

Symmetry codes: (i) x, y+1, z; (ii) x+1, y, z; (iii) x+1, y+1, z; (iv) −x+1, −y, −z+1; (v) −x+1, −y+1, −z+1; (vi) x−1, y, z; (vii) −x, −y+1, −z; (viii) −x+1, −y+1, −z; (ix) x−1, y−1, z; (x) x, y−1, z.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O3—H3A···O14^viii	0.85 (2)	1.83 (2)	2.680 (4)	175 (4)
O3—H3B···O6^vi	0.86 (2)	1.89 (2)	2.737 (4)	172 (4)
O4—H4···O9ⁱ	0.84 (2)	1.81 (2)	2.632 (4)	166 (5)
O7—H7···O6^xi	0.85 (2)	1.72 (2)	2.570 (4)	177 (5)
O8—H8A···O5^x	0.85 (2)	1.84 (2)	2.678 (4)	170 (4)
O8—H8B···O11^xii	0.85 (2)	1.84 (2)	2.687 (4)	176 (5)
O12—H12···O11^xiii	0.85 (1)	1.72 (1)	2.561 (4)	175 (5)
O13—H13···O2^viii	0.84 (2)	1.78 (2)	2.616 (4)	174 (5)

Symmetry codes: (i) x, y+1, z; (vi) x−1, y, z; (viii) −x+1, −y+1, −z; (x) x, y−1, z; (xi) −x+2, −y+2, −z; (xii) −x+2, −y, −z+1; (xiii) −x+2, −y+1, −z+1.

Experimental details

Crystal data
Chemical formula	K₂[Co(CH₄O₆P₂)₂(H₂O)₂]
M_r	521.13
Crystal system, space group	Triclinic, P1
Temperature (K)	100
a, b, c (Å)	6.4523 (3), 8.7056 (3), 13.1930 (5)
α, β, γ (°)	91.334 (2), 93.304 (2), 93.333 (2)
V (Å³)	738.32 (5)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	2.23
Crystal size (mm)	0.28 × 0.17 × 0.17

Data collection
Diffractometer	Bruker X8 APEXII 4K Kappa CCD
Absorption correction	Multi-scan SADABS (Bruker, 2004)
T_min, T_max	0.635, 0.690
No. of measured, independent and observed [I > 2σ(I)] reflections	13474, 3645, 3194
R_int	0.036
(sin θ/λ)_max (Å⁻¹)	0.668

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.040, 0.096, 1.18
No. of reflections	3645
No. of parameters	235
No. of restraints	14
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.95, −0.55

Computer programs: APEX2 (Bruker, 2005), SAINT-Plus (Bruker, 2004), SAINT-Plus and XPREP (Bruker, 2004), SIR97 (Altomare et al., 1999), SHELXL97 (Sheldrick, 2008), DIAMOND (Brandenburg & Putz, 2005), WinGX (Farrugia, 1999).

Selected bond lengths (Å) top

O1—Co1	2.052 (3)	O8—Co2	2.081 (3)
O2—Co1	2.132 (2)	O9—Co2	2.117 (2)
O3—Co1	2.127 (3)	O10—Co2	2.064 (3)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O3—H3A···O14ⁱ	0.851 (19)	1.83 (2)	2.680 (4)	175 (4)
O3—H3B···O6ⁱⁱ	0.855 (19)	1.89 (2)	2.737 (4)	172 (4)
O4—H4···O9ⁱⁱⁱ	0.84 (2)	1.81 (2)	2.632 (4)	166 (5)
O7—H7···O6^iv	0.849 (19)	1.72 (2)	2.570 (4)	177 (5)
O8—H8A···O5^v	0.845 (19)	1.84 (2)	2.678 (4)	170 (4)
O8—H8B···O11^vi	0.854 (19)	1.84 (2)	2.687 (4)	176 (5)
O12—H12···O11^vii	0.848 (12)	1.716 (13)	2.561 (4)	175 (5)
O13—H13···O2ⁱ	0.837 (19)	1.78 (2)	2.616 (4)	174 (5)

Symmetry codes: (i) −x+1, −y+1, −z; (ii) x−1, y, z; (iii) x, y+1, z; (iv) −x+2, −y+2, −z; (v) x, y−1, z; (vi) −x+2, −y, −z+1; (vii) −x+2, −y+1, −z+1.

Acknowledgements

The research fund of the University of the Free State is gratefully acknowledged.

References

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