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Pyridinium di­aqua­bis­­(methyl­enedi­phospho­nato-κ2O,O′)chromate(III) tetra­hydrate

aDepartment of Chemistry, University of the Free State, PO Box 339, Bloemfontein 9330, South Africa
*Correspondence e-mail: kinavdmerwe@gmail.com

(Received 14 July 2010; accepted 20 July 2010; online 24 July 2010)

In the title complex, (C5H6N)[Cr(CH4O6P2)2(H2O)2]·4H2O, the CrIII atom, lying on an inversion centre, is coordinated by two bidentate methyl­ene diphospho­nate ligands and two water molecules in a distorted octa­hedral coordination geometry. The pyridinium cation is located on an inversion centre, with an N atom and a C atom sharing a position each at a half occupancy. A three-dimensional network is constructed by O—H⋯O, N—H⋯O and C—H⋯O hydrogen bonds between the pyridin­ium cation, complex anion and uncoordinated water mol­ecules.

Related literature

For general background to metal-organic frameworks with diphospho­nic acids, see: Barthelet et al. (2002[Barthelet, K., Riou, D. & Férey, G. (2002). Acta Cryst. C58, m264-m265.]). For related structures, see: Byun et al. (2006[Byun, J. C., Yoon, C. H., Mun, D. H., Kim, K. J. & Park, Y. C. (2006). Bull. Korean Chem. Soc. 27, 687-693.]); Suh et al. (1997[Suh, J.-S., Park, S.-J., Lee, K.-W., Suh, I.-H., Lee, J.-H., Song, J.-H. & Oh, M.-R. (1997). Acta Cryst. C53, 432-434.]); Van der Merwe et al. (2009[Van der Merwe, K. A., Visser, H. G. & Venter, J. A. (2009). Acta Cryst. E65, m1394.]); Visser et al. (2010[Visser, H. G., Venter, J. A. & Van der Merwe, K. A. (2010). Acta Cryst. E66, m159.]).

[Scheme 1]

Experimental

Crystal data
  • (C5H6N)[Cr(CH4O6P2)2(H2O)2]·4H2O

  • Mr = 588.17

  • Triclinic, [P \overline 1]

  • a = 7.206 (5) Å

  • b = 7.485 (5) Å

  • c = 10.984 (5) Å

  • α = 107.085 (5)°

  • β = 106.128 (5)°

  • γ = 94.496 (5)°

  • V = 535.7 (6) Å3

  • Z = 1

  • Mo Kα radiation

  • μ = 0.92 mm−1

  • T = 100 K

  • 0.22 × 0.16 × 0.08 mm

Data collection
  • Bruker APEXII CCD diffractometer

  • Absorption correction: multi-scan (SADABS; (Bruker, 2001[Bruker (2001). SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.843, Tmax = 0.931

  • 8784 measured reflections

  • 2632 independent reflections

  • 2483 reflections with I > 2σ(I)

  • Rint = 0.020

Refinement
  • R[F2 > 2σ(F2)] = 0.024

  • wR(F2) = 0.070

  • S = 1.05

  • 2632 reflections

  • 179 parameters

  • 16 restraints

  • H atoms treated by a mixture of independent and constrained refinement

  • Δρmax = 0.47 e Å−3

  • Δρmin = −0.62 e Å−3

Table 1
Selected bond lengths (Å)

Cr1—O1 1.991 (4)
Cr1—O2 1.956 (4)
Cr1—O7 1.964 (4)

Table 2
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
C1—H4⋯O6i 0.97 2.49 3.346 (7) 147
C4—H4A⋯O9ii 0.93 2.16 2.93 (7) 140
N1—H1⋯O9ii 0.86 2.32 3.03 (5) 141
O1—H1A⋯O6i 0.80 (6) 1.83 (6) 2.634 (6) 176 (9)
O1—H1B⋯O4iii 0.83 (6) 1.87 (6) 2.704 (6) 177 (9)
O3—H3⋯O8iv 0.82 1.83 2.629 (6) 163
O5—H6⋯O4ii 0.83 (5) 1.80 (5) 2.619 (6) 175 (10)
O8—H7⋯O6v 0.83 (6) 1.86 (6) 2.687 (6) 171 (9)
O8—H8⋯O9 0.85 (7) 1.94 (8) 2.748 (7) 158 (11)
O9—H9A⋯O4 0.83 (6) 2.00 (6) 2.833 (6) 179 (10)
O9—H10⋯O8vi 0.84 (7) 1.99 (7) 2.820 (7) 174 (13)
Symmetry codes: (i) -x+1, -y+2, -z+1; (ii) -x, -y+1, -z+1; (iii) x+1, y, z; (iv) -x+1, -y+2, -z+2; (v) x, y, z+1; (vi) -x, -y+2, -z+2.

Data collection: APEX2 (Bruker, 2007[Bruker (2007). APEX2 and SAINT-Plus. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT-Plus (Bruker, 2007[Bruker (2007). APEX2 and SAINT-Plus. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXTL; molecular graphics: DIAMOND (Brandenburg, 1999[Brandenburg, K. (1999). DIAMOND. Crystal Impact GbR, Bonn, Germany.]); software used to prepare material for publication: SHELXTL.

Supporting information


Comment top

The title compound forms part of an ongoing study in our group involving methylene diphosphonate and its coordination to various metal cores. (Van der Merwe et al., 2009; Visser et al., 2010). Diphosphonic acids are useful for the synthesis of metal-organic frameworks exhibiting microporous properties (Barthelet et al., 2002).

The CrIII ion in the title complex is in a distorted octahedral environment (Fig. 1), with Cr—O bond distances ranging from 1.956 (4) to 1.991 (4) Å (Table 1). All the bond distances and angles are well within the normal range (Byun et al., 2006; Suh et al., 1997). The pyridinium cation is located on an inversion centre and an N atom and a C atom share a position at a half occupancy for each atom. A three-dimensional network is provided by numerous hydrogen bonds between the pyridinium cation, complex anion and uncoordinated water molecules (Table 2).

Related literature top

For general background to metal-organic frameworks with diphosphonic acids, see: Barthelet et al. (2002). For related structures, see: Byun et al. (2006); Suh et al. (1997); Van der Merwe et al. (2009); Visser et al. (2010).

Experimental top

CrCl3.6H2O (0.092 g, 0.347 mmol) was dissolved in water (40 ml) and ammonium hydroxide was gradually added dropwise in order to precipitate Cr(III) hydroxide. Methylene diphosphonate (0.347 g, 2 mmol) was added to the Cr(OH)3 and water (40 ml). The reaction solution was heated on an oil bath for 5 h at 100°C, after which pyridine (10 ml) was added to the solution. Boiling H2O (30 ml) was added and the solution was centrifuged. Green crystals of the title compound crystallized from the filtrate after several days.

Refinement top

C-bound H atoms were positioned geometrically and refined as riding atoms, with C—H = 0.97 Å and Uiso(H) = 1.2Ueq(C). The H atoms attached to hydroxy groups and water molecules were located on a difference Fourier map and refined isotropically except H3, which was refined as riding, with O3—H3 = 0.82 Å and Uiso(H3) = 1.5Ueq(O3). A 50% positional disorder was assigned to N1 and C4, which share a position of the pyridine ring, as this provided the best fit of the data. Short C—C bond interactions, probably due to this disorder, are observed for the pyridinium cation.

Structure description top

The title compound forms part of an ongoing study in our group involving methylene diphosphonate and its coordination to various metal cores. (Van der Merwe et al., 2009; Visser et al., 2010). Diphosphonic acids are useful for the synthesis of metal-organic frameworks exhibiting microporous properties (Barthelet et al., 2002).

The CrIII ion in the title complex is in a distorted octahedral environment (Fig. 1), with Cr—O bond distances ranging from 1.956 (4) to 1.991 (4) Å (Table 1). All the bond distances and angles are well within the normal range (Byun et al., 2006; Suh et al., 1997). The pyridinium cation is located on an inversion centre and an N atom and a C atom share a position at a half occupancy for each atom. A three-dimensional network is provided by numerous hydrogen bonds between the pyridinium cation, complex anion and uncoordinated water molecules (Table 2).

For general background to metal-organic frameworks with diphosphonic acids, see: Barthelet et al. (2002). For related structures, see: Byun et al. (2006); Suh et al. (1997); Van der Merwe et al. (2009); Visser et al. (2010).

Computing details top

Data collection: APEX2 (Bruker, 2007); cell refinement: SAINT-Plus (Bruker, 2007); data reduction: SAINT-Plus (Bruker, 2007); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 1999); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. Molecular structure of the title compound. Displacement ellipsoids are drawn at the 50% probability level. [Symmetry code: (i) 1-x, 1-y, 1-z.]
Pyridinium diaquabis(methylenediphosphonato-κ2O,O')chromate(III) tetrahydrate top
Crystal data top
(C5H6N)[Cr(CH4O6P2)2(H2O)2]·4H2OZ = 1
Mr = 588.17F(000) = 303
Triclinic, P1Dx = 1.823 Mg m3
Hall symbol: -P 1Mo Kα radiation, λ = 0.71073 Å
a = 7.206 (5) ÅCell parameters from 6300 reflections
b = 7.485 (5) Åθ = 0.8–0.9°
c = 10.984 (5) ŵ = 0.92 mm1
α = 107.085 (5)°T = 100 K
β = 106.128 (5)°Cuboid, green
γ = 94.496 (5)°0.22 × 0.16 × 0.08 mm
V = 535.7 (6) Å3
Data collection top
Bruker APEXII CCD
diffractometer
2483 reflections with I > 2σ(I)
φ and ω scansRint = 0.020
Absorption correction: multi-scan
(SADABS; (Bruker, 2001)
θmax = 28.3°, θmin = 4.1°
Tmin = 0.843, Tmax = 0.931h = 99
8784 measured reflectionsk = 96
2632 independent reflectionsl = 1414
Refinement top
Refinement on F216 restraints
Least-squares matrix: fullH atoms treated by a mixture of independent and constrained refinement
R[F2 > 2σ(F2)] = 0.024 w = 1/[σ2(Fo2) + (0.0342P)2 + 0.4874P]
where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.070(Δ/σ)max < 0.001
S = 1.05Δρmax = 0.47 e Å3
2632 reflectionsΔρmin = 0.62 e Å3
179 parameters
Crystal data top
(C5H6N)[Cr(CH4O6P2)2(H2O)2]·4H2Oγ = 94.496 (5)°
Mr = 588.17V = 535.7 (6) Å3
Triclinic, P1Z = 1
a = 7.206 (5) ÅMo Kα radiation
b = 7.485 (5) ŵ = 0.92 mm1
c = 10.984 (5) ÅT = 100 K
α = 107.085 (5)°0.22 × 0.16 × 0.08 mm
β = 106.128 (5)°
Data collection top
Bruker APEXII CCD
diffractometer
2632 independent reflections
Absorption correction: multi-scan
(SADABS; (Bruker, 2001)
2483 reflections with I > 2σ(I)
Tmin = 0.843, Tmax = 0.931Rint = 0.020
8784 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.02416 restraints
wR(F2) = 0.070H atoms treated by a mixture of independent and constrained refinement
S = 1.05Δρmax = 0.47 e Å3
2632 reflectionsΔρmin = 0.62 e Å3
179 parameters
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/UeqOcc. (<1)
Cr10.50000.50000.50000.0082 (3)
P20.2173 (2)0.79359 (19)0.41325 (14)0.0086 (4)
P10.29362 (19)0.7622 (2)0.69142 (14)0.0085 (4)
O20.4491 (6)0.6457 (6)0.6635 (4)0.0110 (8)
O50.0069 (6)0.7069 (6)0.3539 (4)0.0128 (8)
O30.3700 (6)0.8943 (6)0.8418 (4)0.0134 (8)
H30.47740.95690.85700.020*
O70.3373 (6)0.6353 (6)0.3947 (4)0.0113 (8)
O90.0373 (8)0.7358 (7)0.8942 (5)0.0235 (10)
O10.7325 (6)0.6953 (6)0.5401 (4)0.0121 (8)
C10.2683 (8)0.9145 (8)0.5903 (6)0.0108 (10)
H40.38851.00630.62260.013*
H50.16330.98410.60270.013*
O40.0957 (6)0.6494 (6)0.6673 (4)0.0118 (8)
O80.2601 (7)0.9720 (7)1.1133 (5)0.0198 (10)
N10.381 (7)0.479 (8)0.070 (5)0.028 (12)0.50
H10.30250.46910.11450.034*0.50
C40.381 (8)0.466 (10)0.078 (5)0.024 (10)0.50
H4A0.30510.44050.12940.029*0.50
C30.5612 (13)0.5896 (11)0.1367 (8)0.0312 (17)
H3A0.60250.64540.22950.037*
C20.3206 (12)0.3837 (11)0.0627 (8)0.0322 (17)
H20.20080.30140.10340.039*
O60.2543 (6)0.9385 (6)0.3492 (4)0.0133 (8)
H80.193 (16)0.882 (13)1.042 (9)0.06 (3)*
H70.262 (14)0.950 (13)1.184 (7)0.03 (2)*
H1B0.844 (10)0.677 (12)0.577 (8)0.03 (2)*
H1A0.731 (13)0.806 (9)0.573 (8)0.025*
H60.032 (11)0.597 (8)0.352 (9)0.03 (3)*
H9A0.002 (13)0.710 (13)0.828 (8)0.03 (2)*
H100.110 (17)0.817 (16)0.888 (14)0.07 (4)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cr10.0067 (6)0.0081 (6)0.0107 (6)0.0020 (4)0.0035 (4)0.0035 (5)
P20.0072 (6)0.0076 (7)0.0120 (7)0.0015 (5)0.0031 (5)0.0042 (5)
P10.0068 (6)0.0084 (7)0.0103 (7)0.0011 (5)0.0032 (5)0.0025 (5)
O20.0103 (18)0.0121 (19)0.0119 (19)0.0050 (15)0.0043 (15)0.0042 (15)
O50.0077 (18)0.011 (2)0.019 (2)0.0004 (15)0.0019 (15)0.0053 (16)
O30.0110 (18)0.013 (2)0.0126 (19)0.0004 (15)0.0036 (15)0.0006 (16)
O70.0103 (18)0.0116 (19)0.0136 (19)0.0046 (15)0.0047 (15)0.0048 (15)
O90.029 (3)0.024 (3)0.021 (2)0.004 (2)0.014 (2)0.007 (2)
O10.0082 (18)0.0088 (19)0.019 (2)0.0013 (15)0.0034 (16)0.0043 (16)
C10.010 (2)0.008 (2)0.013 (3)0.0014 (19)0.003 (2)0.003 (2)
O40.0085 (18)0.0114 (19)0.0153 (19)0.0000 (14)0.0039 (15)0.0043 (15)
O80.018 (2)0.026 (2)0.013 (2)0.0028 (18)0.0032 (17)0.0052 (19)
N10.04 (2)0.028 (18)0.033 (19)0.019 (13)0.019 (16)0.023 (13)
C40.026 (18)0.019 (15)0.018 (15)0.001 (12)0.008 (12)0.008 (13)
C30.042 (5)0.020 (3)0.021 (3)0.007 (3)0.004 (3)0.006 (3)
C20.033 (4)0.023 (4)0.029 (4)0.000 (3)0.008 (3)0.009 (3)
O60.0148 (19)0.0108 (19)0.016 (2)0.0016 (15)0.0053 (16)0.0073 (16)
Geometric parameters (Å, º) top
Cr1—O11.991 (4)O1—H1B0.83 (6)
Cr1—O21.956 (4)O1—H1A0.80 (6)
Cr1—O71.964 (4)C1—H40.9700
P2—O61.499 (4)C1—H50.9700
P2—O71.519 (4)O8—H80.85 (7)
P2—O51.568 (4)O8—H70.83 (6)
P2—C11.804 (6)N1—C21.34 (5)
P1—O41.512 (4)N1—C31.36 (4)
P1—O41.512 (4)N1—H10.8600
P1—O21.515 (4)C4—C31.40 (5)
P1—O31.568 (4)C4—C21.41 (5)
P1—C11.797 (6)C4—H4A0.9300
O5—H60.83 (5)C3—C2i1.371 (13)
O3—H30.8200C3—H3A0.9300
O9—H9A0.83 (6)C2—C3i1.371 (13)
O9—H100.84 (7)C2—H20.9300
O2ii—Cr1—O2180.00 (15)P2—O5—H6114 (5)
O2ii—Cr1—O788.35 (17)P1—O3—H3109.5
O2—Cr1—O791.65 (17)P2—O7—Cr1140.0 (3)
O2ii—Cr1—O7ii91.65 (17)H9A—O9—H10108 (10)
O2—Cr1—O7ii88.35 (17)Cr1—O1—H1B119 (6)
O7—Cr1—O7ii180.0 (2)Cr1—O1—H1A120 (6)
O2ii—Cr1—O1ii90.51 (17)H1B—O1—H1A107 (9)
O2—Cr1—O1ii89.49 (17)P1—C1—P2114.8 (3)
O7—Cr1—O1ii90.81 (18)P1—C1—H4108.6
O7ii—Cr1—O1ii89.19 (18)P2—C1—H4108.6
O2ii—Cr1—O189.49 (17)P1—C1—H5108.6
O2—Cr1—O190.51 (17)P2—C1—H5108.6
O7—Cr1—O189.19 (18)H4—C1—H5107.5
O7ii—Cr1—O190.81 (18)H8—O8—H7114 (10)
O1ii—Cr1—O1180.0 (3)C2—N1—C3123 (4)
O6—P2—O7114.8 (2)C2—N1—H1118.3
O6—P2—O5107.8 (2)C3—N1—H1118.3
O7—P2—O5109.7 (2)C3—C4—C2116 (5)
O6—P2—C1108.2 (3)C3—C4—H4A122.1
O7—P2—C1109.0 (2)C2—C4—H4A122.1
O5—P2—C1107.1 (2)N1—C3—C2i118 (2)
O4—P1—O2115.5 (2)C2i—C3—C4122 (3)
O4—P1—O2115.5 (2)N1—C3—H3A121.1
O4—P1—O3107.9 (2)C2i—C3—H3A121.1
O4—P1—O3107.9 (2)C4—C3—H3A116.7
O2—P1—O3108.6 (2)N1—C2—C3i119 (2)
O4—P1—C1110.1 (2)C3i—C2—C4122 (2)
O4—P1—C1110.1 (2)N1—C2—H2120.7
O2—P1—C1107.6 (2)C3i—C2—H2120.7
O3—P1—C1106.9 (3)C4—C2—H2117.1
P1—O2—Cr1134.1 (2)
Symmetry codes: (i) x+1, y+1, z; (ii) x+1, y+1, z+1.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C1—H4···O6iii0.972.493.346 (7)147
C4—H4A···O9iv0.932.162.93 (7)140
N1—H1···O9iv0.862.323.03 (5)141
O1—H1A···O6iii0.80 (6)1.83 (6)2.634 (6)176 (9)
O1—H1B···O4v0.83 (6)1.87 (6)2.704 (6)177 (9)
O3—H3···O8vi0.821.832.629 (6)163
O5—H6···O4iv0.83 (5)1.80 (5)2.619 (6)175 (10)
O8—H7···O6vii0.83 (6)1.86 (6)2.687 (6)171 (9)
O8—H8···O90.85 (7)1.94 (8)2.748 (7)158 (11)
O9—H9A···O40.83 (6)2.00 (6)2.833 (6)179 (10)
O9—H10···O8viii0.84 (7)1.99 (7)2.820 (7)174 (13)
Symmetry codes: (iii) x+1, y+2, z+1; (iv) x, y+1, z+1; (v) x+1, y, z; (vi) x+1, y+2, z+2; (vii) x, y, z+1; (viii) x, y+2, z+2.

Experimental details

Crystal data
Chemical formula(C5H6N)[Cr(CH4O6P2)2(H2O)2]·4H2O
Mr588.17
Crystal system, space groupTriclinic, P1
Temperature (K)100
a, b, c (Å)7.206 (5), 7.485 (5), 10.984 (5)
α, β, γ (°)107.085 (5), 106.128 (5), 94.496 (5)
V3)535.7 (6)
Z1
Radiation typeMo Kα
µ (mm1)0.92
Crystal size (mm)0.22 × 0.16 × 0.08
Data collection
DiffractometerBruker APEXII CCD
Absorption correctionMulti-scan
(SADABS; (Bruker, 2001)
Tmin, Tmax0.843, 0.931
No. of measured, independent and
observed [I > 2σ(I)] reflections
8784, 2632, 2483
Rint0.020
(sin θ/λ)max1)0.666
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.024, 0.070, 1.05
No. of reflections2632
No. of parameters179
No. of restraints16
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.47, 0.62

Computer programs: APEX2 (Bruker, 2007), SAINT-Plus (Bruker, 2007), SHELXTL (Sheldrick, 2008), DIAMOND (Brandenburg, 1999).

Selected bond lengths (Å) top
Cr1—O11.991 (4)Cr1—O71.964 (4)
Cr1—O21.956 (4)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C1—H4···O6i0.972.493.346 (7)147
C4—H4A···O9ii0.932.162.93 (7)140
N1—H1···O9ii0.862.323.03 (5)141
O1—H1A···O6i0.80 (6)1.83 (6)2.634 (6)176 (9)
O1—H1B···O4iii0.83 (6)1.87 (6)2.704 (6)177 (9)
O3—H3···O8iv0.821.832.629 (6)163
O5—H6···O4ii0.83 (5)1.80 (5)2.619 (6)175 (10)
O8—H7···O6v0.83 (6)1.86 (6)2.687 (6)171 (9)
O8—H8···O90.85 (7)1.94 (8)2.748 (7)158 (11)
O9—H9A···O40.83 (6)2.00 (6)2.833 (6)179 (10)
O9—H10···O8vi0.84 (7)1.99 (7)2.820 (7)174 (13)
Symmetry codes: (i) x+1, y+2, z+1; (ii) x, y+1, z+1; (iii) x+1, y, z; (iv) x+1, y+2, z+2; (v) x, y, z+1; (vi) x, y+2, z+2.
 

Acknowledgements

The University of the Free State and Professor A. Roodt are gratefully acknowledged for financial support.

References

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