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

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Polymeric potassium triformatocobalt(II)

aInstitut für Anorganische Chemie, Christian-Albrechts-Universität Kiel, Max-Eyth-Strasse 2, 24118 Kiel, Germany, and bDepartement of Chemistry, Texas A&M University, College Station, Texas 77843, USA
*Correspondence e-mail: swoehlert@ac.uni-kiel.de

(Received 18 February 2011; accepted 7 March 2011; online 12 March 2011)

In the crystal structure of the title compound, poly[tri-μ-formato-cobalt(II)potassium], [CoK(CHO2)3]n the Co2+ cations are coordinated by six O-bonded formate anions in an octa­hedral coordination mode and the K+ cations are eightfold coordinated by seven O-bonded formate anions within irregular polyhedra. The Co2+ cations are connected by bridging formate anions into a three-dimensional coordination network in which the K+ cations are embedded. The asymmetric unit consits of one Co2+ cation located on a center of inversion, one K+ cation located on a twofold axis and two crystallographically independent formato anions, of which one is located on a twofold axis and the other occupies a general position.

Related literature

For background to this work see: Boeckmann et al. (2010)[Boeckmann, J., Wriedt, M. & Näther, C. (2010). Eur. J. Inorg. Chem. pp. 1820-1828.]; Wriedt & Näther (2010[Wriedt, M. & Näther, C. (2010). Z. Anorg. Allg. Chem. 636, 569-575.]); Wriedt et al. (2009)[Wriedt, M., Sellmer, S. & Näther, C. (2009). Inorg. Chem. 48, 6896-6903.]. For structures of bimetallic compounds based on potassium formate, see: Antsyshkina et al. (1983[Antsyshkina, A. S., Porai-Koshits, M. A., Ostrikova, V. N. & Sadikov, G. G. (1983). Koord. Khim. 9, 855-864.]); Leontiev et al. (1988[Leontiev, A. Yu., Arion, M. D., Razdobreev, I. M., Kiosse, G. A., Yablokov, Yu. V., Malinovskii, T. I. & Popvich, G. A. (1988). Dokl. Akad. Nauk SSSR, 300, 1129-1140.]). For a description of the Cambridge Structural Database, see: Allen (2002[Allen, F. H. (2002). Acta Cryst. B58, 380-388.]).

[Scheme 1]

Experimental

Crystal data
  • [CoK(CHO2)3]

  • Mr = 233.08

  • Monoclinic, C 2/c

  • a = 10.7244 (8) Å

  • b = 8.9653 (6) Å

  • c = 6.8742 (5) Å

  • β = 95.539 (6)°

  • V = 657.85 (8) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 3.22 mm−1

  • T = 293 K

  • 0.16 × 0.09 × 0.06 mm

Data collection
  • Stoe IPDS-2 diffractometer

  • Absorption correction: numerical (X-SHAPE and X-RED32; Stoe & Cie, 2008)[Stoe & Cie (2008). X-AREA, X-RED32 and X-SHAPE. Stoe & Cie, Darmstadt, Germany.] Tmin = 0.711, Tmax = 0.817

  • 6120 measured reflections

  • 892 independent reflections

  • 853 reflections with I > 2σ(I)

  • Rint = 0.031

Refinement
  • R[F2 > 2σ(F2)] = 0.020

  • wR(F2) = 0.046

  • S = 1.15

  • 892 reflections

  • 54 parameters

  • H-atom parameters constrained

  • Δρmax = 0.25 e Å−3

  • Δρmin = −0.57 e Å−3

Table 1
Selected bond lengths (Å)

K1—O1 2.7371 (10)
K1—O2i 2.8193 (10)
K1—O11i 2.8507 (11)
Co1—O1 2.0943 (10)
Co1—O2ii 2.1015 (10)
Co1—O11iii 2.1026 (9)
Symmetry codes: (i) [x-{\script{1\over 2}}, y-{\script{1\over 2}}, z]; (ii) [x, -y+1, z-{\script{1\over 2}}]; (iii) [-x+{\script{1\over 2}}, -y+{\script{1\over 2}}, -z].

Data collection: X-AREA (Stoe & Cie, 2008)[Stoe & Cie (2008). X-AREA, X-RED32 and X-SHAPE. Stoe & Cie, Darmstadt, Germany.]; cell refinement: X-AREA[Stoe & Cie (2008). X-AREA, X-RED32 and X-SHAPE. Stoe & Cie, Darmstadt, Germany.]; data reduction: X-AREA[Stoe & Cie (2008). X-AREA, X-RED32 and X-SHAPE. Stoe & Cie, Darmstadt, Germany.]; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: XP in SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]) and DIAMOND (Brandenburg, 1999[Brandenburg, K. (1999). DIAMOND. Crystal Impact GbR, Bonn, Germany.]); software used to prepare material for publication: XCIF in SHELXTL.

Supporting information


Comment top

In our current investigation on the synthesis, structures and properties of new coordination polymers based on paramagnetic transition metal, small-sized anions and N-donor ligands, we have shown that thermal decomposition reactions are an elegante route for the discovery and preparation of new ligand-deficient coordination polymers (Boeckmann et al., 2010; Wriedt & Näther, 2010; Wriedt et al., 2009). Within this project we tried to prepare new ligand-rich precursor compounds based on cobalt formate and pyrazine as coligand. However, reaction of cobalt(II) chloride, potassium formate and pyrazine in acteonitrile unexpectedly resulted in single crystals of the title compound.

In the crystal structure of the title compound, each cobalt(II) cation is coordinated by six bridging formato anions with Co—OCHO distances between 2.0943 (10) Å and 2.1026 (9) Å. The CoO6 octahedron is slightly distorted with angles ranging from 82.66 (4) ° to 97.34 (4) ° and 180° (Fig. 1 and Tab. 1). The K+ cations are coordinated by eight oxygen atoms belonging to seven formato anions within irregular polyhedra. The K—O distances ranges from 2.7371 (10) Å to 2.8507 (11) Å and the O—K—O angles are between 59.81 (3) ° and 147.11 (3) °. The cobalt cations are connected via µ-1,3 bridging formato anions into a three dimensional coordination network (Fig. 2). Within this networks cavities are formed in which the K+ cations are embedded (Fig 3). The shortest Co···Co distances amount to 5.6487 (3) Å and the shortest K···K distances are 3.9067 (4) Å).

According to a search in the CCDC database (ConQuest Ver.1.12.2010) (Allen, 2002) mixed cobalt and potassium formates are unkown but bimetallic compounds based on potassium formate are known with different metals (Antsyshkina et al., 1983 and Leontiev et al., 1988.

Related literature top

For background to this work see: Boeckmann et al. (2010); Wriedt & Näther (2010); Wriedt et al. (2009). For structures of bimetallic compounds based on potassium formate, see: Antsyshkina et al. (1983); Leontiev et al. (1988). For a description of the Cambridge Structural Database, see: Allen (2002).

Experimental top

Potassium formate (KCHOO) and pyrazine were obtained from Alfa Aesar and cobalt(II) chloride was obtained from Acros Organics. All chemicals were used without further purification. 0.25 mmol (32.5 mg) CoCl2, 0.5 mmol (42.1 mg) KCHOO and 0.5 mmol (40 mg) pyrazine were reacted with 1 ml acetonitrile in a closed test-tube at 120°C for three days. On cooling block-shaped single crystals of the title compound were obtained in a mixture with an unknown phase. It must be noted, that the reaction under similar conditions without pyrazine does not lead to the formation of the title compound.

Refinement top

The H atoms were positioned with idealized geometry and were refined isotropic with Uiso(H) = 1.2Ueq(C) and C—H distances of 0.93 Å using a riding model.

Computing details top

Data collection: X-AREA (Stoe & Cie, 2008); cell refinement: X-AREA (Stoe & Cie, 2008); data reduction: X-AREA (Stoe & Cie, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XP in SHELXTL (Sheldrick, 2008) and DIAMOND (Brandenburg, 1999); software used to prepare material for publication: XCIF in SHELXTL (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. : Crystal structure of the title compound with labelling and displacement ellipsoids drawn at the 50 % probability level. Symmetry codes: i = -x+1/2, y-1/2, -z+1/2; ii = -x+1/2, -y+1/2, -z; iii = +x, -y+1, +z-1/2; iv = -x+1, +y, -z+1/2; v = +x-1/2, -y+1/2, +z-1/2.
[Figure 2] Fig. 2. Crystal structure of the title compound with view along the crystallographic b axis. The K+ cations are omitted for clarity.
[Figure 3] Fig. 3. Crystal structure of the title compound with view along the crystallographic c axis.
Poly[tri-µ-formato-cobalt(II)potassium] top
Crystal data top
[CoK(CHO2)3]F(000) = 460
Mr = 233.08Dx = 2.353 Mg m3
Monoclinic, C2/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2ycCell parameters from 6120 reflections
a = 10.7244 (8) Åθ = 3.0–29.2°
b = 8.9653 (6) ŵ = 3.22 mm1
c = 6.8742 (5) ÅT = 293 K
β = 95.539 (6)°Block, light blue
V = 657.85 (8) Å30.16 × 0.09 × 0.06 mm
Z = 4
Data collection top
Stoe IPDS-2
diffractometer
892 independent reflections
Radiation source: fine-focus sealed tube853 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.031
ω scansθmax = 29.2°, θmin = 3.0°
Absorption correction: numerical
(X-SHAPE and X-RED32; Stoe & Cie, 2008)
h = 1414
Tmin = 0.711, Tmax = 0.817k = 1212
6120 measured reflectionsl = 99
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.020H-atom parameters constrained
wR(F2) = 0.046 w = 1/[σ2(Fo2) + (0.0276P)2 + 0.1263P]
where P = (Fo2 + 2Fc2)/3
S = 1.15(Δ/σ)max < 0.001
892 reflectionsΔρmax = 0.25 e Å3
54 parametersΔρmin = 0.57 e Å3
0 restraintsExtinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.0126 (12)
Crystal data top
[CoK(CHO2)3]V = 657.85 (8) Å3
Mr = 233.08Z = 4
Monoclinic, C2/cMo Kα radiation
a = 10.7244 (8) ŵ = 3.22 mm1
b = 8.9653 (6) ÅT = 293 K
c = 6.8742 (5) Å0.16 × 0.09 × 0.06 mm
β = 95.539 (6)°
Data collection top
Stoe IPDS-2
diffractometer
892 independent reflections
Absorption correction: numerical
(X-SHAPE and X-RED32; Stoe & Cie, 2008)
853 reflections with I > 2σ(I)
Tmin = 0.711, Tmax = 0.817Rint = 0.031
6120 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0200 restraints
wR(F2) = 0.046H-atom parameters constrained
S = 1.15Δρmax = 0.25 e Å3
892 reflectionsΔρmin = 0.57 e Å3
54 parameters
Special details top

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 > 2sigma(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
K10.00000.10357 (5)0.25000.02582 (12)
Co10.25000.25000.00000.01561 (10)
O10.16793 (10)0.33291 (11)0.24238 (15)0.0274 (2)
O20.25445 (9)0.54804 (11)0.34563 (15)0.0271 (2)
C10.18397 (13)0.44031 (15)0.3568 (2)0.0244 (3)
H10.13710.43920.46380.029*
O110.43048 (9)0.31029 (12)0.12114 (14)0.0260 (2)
C110.50000.2478 (2)0.25000.0271 (4)
H110.50000.14410.25000.033*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
K10.0278 (2)0.01932 (19)0.0318 (2)0.0000.01004 (16)0.000
Co10.01611 (14)0.01374 (14)0.01648 (14)0.00041 (8)0.00102 (8)0.00122 (8)
O10.0332 (5)0.0223 (5)0.0277 (5)0.0087 (4)0.0091 (4)0.0093 (4)
O20.0300 (5)0.0204 (4)0.0318 (5)0.0063 (4)0.0076 (4)0.0089 (4)
C10.0312 (6)0.0213 (6)0.0215 (6)0.0042 (5)0.0069 (5)0.0037 (5)
O110.0215 (4)0.0303 (5)0.0245 (5)0.0036 (4)0.0063 (4)0.0033 (4)
C110.0270 (9)0.0217 (9)0.0310 (10)0.0000.0057 (8)0.000
Geometric parameters (Å, º) top
K1—O12.7371 (10)Co1—O11iv2.1026 (9)
K1—O2i2.8193 (10)O1—C11.2448 (17)
K1—O11ii2.8335 (10)O2—C11.2335 (17)
K1—O11i2.8507 (11)C1—H10.9300
K1—C11i3.189 (2)O11—C111.2356 (13)
Co1—O12.0943 (10)C11—H110.9300
Co1—O2iii2.1015 (10)
O1—K1—O1v82.62 (5)O1—Co1—O11iv87.99 (4)
O1—K1—O2i140.19 (3)O1iv—Co1—O11iv92.01 (4)
O1v—K1—O2i59.81 (3)O2iii—Co1—O11iv94.96 (4)
O2i—K1—O2vi159.66 (4)O2vi—Co1—O11iv85.04 (4)
O1—K1—O11ii92.48 (3)O11iv—Co1—O11180.00 (6)
O1v—K1—O11ii63.08 (3)C1—O1—Co1137.25 (9)
O2i—K1—O11ii60.35 (3)C1—O1—K1128.31 (9)
O2vi—K1—O11ii126.22 (3)Co1—O1—K194.38 (3)
O11ii—K1—O11iv148.37 (5)C1—O2—Co1vii126.81 (9)
O1—K1—O11i147.11 (3)C1—O2—K1viii138.13 (9)
O1v—K1—O11i123.09 (3)Co1vii—O2—K1viii91.88 (3)
O2i—K1—O11i71.79 (3)O2—C1—O1127.90 (13)
O2vi—K1—O11i89.25 (3)O2—C1—H1116.0
O11ii—K1—O11i116.58 (3)O1—C1—H1116.0
O11iv—K1—O11i93.17 (3)C11—O11—Co1129.50 (9)
O11i—K1—O11vi45.45 (4)C11—O11—K1iv125.17 (6)
O1—K1—C11i138.69 (2)Co1—O11—K1iv91.47 (3)
O2i—K1—C11i79.83 (2)C11—O11—K1viii94.23 (9)
O11ii—K1—C11i105.81 (2)Co1—O11—K1viii124.29 (4)
O11i—K1—C11i22.727 (19)K1iv—O11—K1viii86.83 (3)
O1—Co1—O1iv180.0O11ix—C11—O11126.09 (18)
O1—Co1—O2iii97.34 (4)O11ix—C11—K1viii63.04 (9)
O1iv—Co1—O2iii82.66 (4)O11—C11—H11117.0
O2iii—Co1—O2vi180.00 (3)K1viii—C11—H11180.0
Symmetry codes: (i) x1/2, y1/2, z; (ii) x1/2, y+1/2, z+1/2; (iii) x, y+1, z1/2; (iv) x+1/2, y+1/2, z; (v) x, y, z+1/2; (vi) x+1/2, y1/2, z+1/2; (vii) x+1/2, y+1/2, z+1/2; (viii) x+1/2, y+1/2, z; (ix) x+1, y, z+1/2.

Experimental details

Crystal data
Chemical formula[CoK(CHO2)3]
Mr233.08
Crystal system, space groupMonoclinic, C2/c
Temperature (K)293
a, b, c (Å)10.7244 (8), 8.9653 (6), 6.8742 (5)
β (°) 95.539 (6)
V3)657.85 (8)
Z4
Radiation typeMo Kα
µ (mm1)3.22
Crystal size (mm)0.16 × 0.09 × 0.06
Data collection
DiffractometerStoe IPDS2
diffractometer
Absorption correctionNumerical
(X-SHAPE and X-RED32; Stoe & Cie, 2008)
Tmin, Tmax0.711, 0.817
No. of measured, independent and
observed [I > 2σ(I)] reflections
6120, 892, 853
Rint0.031
(sin θ/λ)max1)0.686
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.020, 0.046, 1.15
No. of reflections892
No. of parameters54
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.25, 0.57

Computer programs: X-AREA (Stoe & Cie, 2008), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), XP in SHELXTL (Sheldrick, 2008) and DIAMOND (Brandenburg, 1999), XCIF in SHELXTL (Sheldrick, 2008).

Selected bond lengths (Å) top
K1—O12.7371 (10)Co1—O12.0943 (10)
K1—O2i2.8193 (10)Co1—O2ii2.1015 (10)
K1—O11i2.8507 (11)Co1—O11iii2.1026 (9)
Symmetry codes: (i) x1/2, y1/2, z; (ii) x, y+1, z1/2; (iii) x+1/2, y+1/2, z.
 

Acknowledgements

We gratefully acknowledge financial support by the DFG (project number NA 720/3-1) and the State of Schleswig-Holstein. We thank Professor Dr Bensch for access to his experimental facility.

References

First citationAllen, F. H. (2002). Acta Cryst. B58, 380–388.  Web of Science CrossRef CAS IUCr Journals
First citationAntsyshkina, A. S., Porai-Koshits, M. A., Ostrikova, V. N. & Sadikov, G. G. (1983). Koord. Khim. 9, 855–864.  CAS
First citationBoeckmann, J., Wriedt, M. & Näther, C. (2010). Eur. J. Inorg. Chem. pp. 1820–1828.  Web of Science CSD CrossRef
First citationBrandenburg, K. (1999). DIAMOND. Crystal Impact GbR, Bonn, Germany.
First citationLeontiev, A. Yu., Arion, M. D., Razdobreev, I. M., Kiosse, G. A., Yablokov, Yu. V., Malinovskii, T. I. & Popvich, G. A. (1988). Dokl. Akad. Nauk SSSR, 300, 1129–1140.
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals
First citationStoe & Cie (2008). X-AREA, X-RED32 and X-SHAPE. Stoe & Cie, Darmstadt, Germany.
First citationWriedt, M. & Näther, C. (2010). Z. Anorg. Allg. Chem. 636, 569–575.  CSD CrossRef CAS
First citationWriedt, M., Sellmer, S. & Näther, C. (2009). Inorg. Chem. 48, 6896–6903.  Web of Science CSD CrossRef CAS PubMed

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