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Redetermination of nickel(II) formate dihydrate

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aInstitute for Chemical Technologies and Analytics, Division of Structural Chemistry, TU Wien, Getreidemarkt 9/164-SC, A-1060 Vienna, Austria
*Correspondence e-mail: matthias.weil@tuwien.ac.at

Edited by W. T. A. Harrison, University of Aberdeen, Scotland (Received 8 March 2018; accepted 13 March 2018; online 23 March 2018)

In comparison with the previous structure determination of poly[di­aquadi-μ-formato-nickel(II)], [Ni(HCOO)2(H2O)2]n, based on Weissenberg film data [Krogmann & Mattes (1963[Krogmann, K. & Mattes, R. (1963). Z. Kristallogr. 118, 291-302.]). Z. Kristallogr. 118, 291–302], the current redetermination from modern CCD data revealed the positions of the H atoms, thus making a detailed description of the hydrogen-bonding pattern possible. Both Ni2+ cations in the crystal structure are located on inversion centres and are octa­hedrally coordinated. One Ni2+ cation is bound to six O atoms of six formate anions whereas the other Ni2+ cation is bound to four O atoms of water mol­ecules and to two formate O atoms. In this way, the formate anions bridge the two types of Ni2+ cations into a three-dimensional framework. O—H⋯O hydrogen bonds of medium strength between water mol­ecules and formate O atoms consolidate the packing.

3D view (loading...)
[Scheme 3D1]
Chemical scheme
[Scheme 1]

Structure description

Recycling of tungsten carbide from WC–Ni hard metals or composites thereof can be achieved by debinding WC–Ni with formic acid to selectively dissolve nickel. Nickel formate then can either be crystallized as the dihydrate from the obtained solution, or formic acid can be regenerated through cation exchange with sulfuric acid. In the latter case, nickel can be precipitated as Ni(OH)2 from the inter­mediate nickel sulfate solution by adding caustic soda (Weissensteiner, 2012[Weissensteiner, C. (2012). Diploma thesis, TU Wien, Austria.]). In the course of these studies it became apparent that a redetermination of the crystal structure of nickel formate dihydrate, Ni(HCOO)2·2H2O, (Krogmann & Mattes, 1963[Krogmann, K. & Mattes, R. (1963). Z. Kristallogr. 118, 291-302.]) was desirable in terms of higher precision and accuracy and for an unambiguous assignment of the hydrogen-bonding scheme. Although a profile refinement using the Rietveld method has been performed on this material, leading to precise room-temperature lattice parameters (Kellerman et al., 2016[Kellerman, D. G., Barykina, Yu. A., Zheleznikov, K. A., Tyutyunnik, A. P. & Krasilnikov, V. N. (2016). Phys. Status Solidi B, 253, 2209-2216.]), improved structural data are still missing.

The crystal structure of Ni(HCOO)2·2H2O comprises two Ni2+ cations on inversion centres, one on Wyckoff position 2b (Ni1), one on 2a (Ni2), and two formate anions and two water mol­ecules in general positions. The Ni2+ cations are stacked in rows parallel to [101]. Both cations have a distorted octa­hedral coordination environment by oxygen atoms, but with different types of ligands. Ni1 is bound to six O atoms of six formate anions (O1–O3 and symmetry-related counterparts), whereas Ni2 is bound to four O atoms of two pairs of water mol­ecules (O5, O6 and symmetry-related counterparts) and two formate anions (O4 and its symmetry-related counterpart). Relevant bond lengths and a comparison with the previous determination are collated in Table 1[link]. In general, bond lengths and angles are similar to related divalent first-row transition metal formates (Viertelhaus et al., 2005[Viertelhaus, M., Adler, P., Clérac, R., Anson, C. E. & Powell, A. (2005). Eur. J. Inorg. Chem. pp. 692-703.]).

Table 1
Comparison of bond lengths (Å) in the current and the previous refinement of Ni(HCOO)2·2H2O(a,b)

  current refinement previous refinementa
Ni1—O1i 2.0302 (6) 2.026 (8)
Ni1—O2 2.0503 (6) 2.061 (8)
Ni1—O3 2.0942 (6) 2.097 (8)
Ni2—O5 2.0256 (7) 2.042 (8)
Ni2—O6 2.0663 (6) 2.059 (8)
Ni2—O4 2.1006 (7) 2.090 (8)
O1—C1 1.2593 (10) 1.256 (8)
O2—C1 1.2546 (10) 1.222 (8)
O3—C2ii 1.2618 (10) 1.278 (8)
O4—C2 1.2607 (10) 1.247 (8)
Symmetry codes: (i) −x + 1, y − [{1\over 2}], −z + [{1\over 2}]; (ii) x, −y + [{3\over 2}], z + [{1\over 2}]. Notes: (a) Krogmann & Mattes (1963[Krogmann, K. & Mattes, R. (1963). Z. Kristallogr. 118, 291-302.]); lattice parameters a = 8.60 (1), b = 7.06 (1), c = 9.21 (2) Å, β = 96.50 (10)° from single-crystal data at room temperature; (b) lattice parameters a = 8.5951 (1), b = 7.0688 (5), c = 9.2152 (2) Å, β = 97.41 (1)° from Rietveld profile refinement at room temperature (Kellerman et al., 2016[Kellerman, D. G., Barykina, Yu. A., Zheleznikov, K. A., Tyutyunnik, A. P. & Krasilnikov, V. N. (2016). Phys. Status Solidi B, 253, 2209-2216.]).

Each of the two formate anions bridges two Ni2+ cations, thus creating a three-dimensional framework. O—H⋯O hydrogen bonds of medium strength and with nearly linear O—H⋯O angles between water mol­ecules as donor groups and each of the formate carboxyl­ate O atoms as acceptor groups help to consolidate this arrangement (Fig. 1[link], Table 2[link]). In comparison with the previous determination, the H-atom positions are unambiguous and were clearly discernible from difference maps.

Table 2
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
O6—H5⋯O3i 0.787 (18) 1.985 (18) 2.7312 (9) 158.1 (16)
O5—H3⋯O2 0.89 (2) 1.87 (2) 2.7522 (9) 171.2 (19)
O5—H4⋯O4i 0.832 (18) 1.898 (18) 2.7271 (10) 174.1 (17)
O6—H6⋯O1ii 0.837 (18) 1.926 (18) 2.7610 (9) 175.5 (16)
Symmetry codes: (i) [-x, y+{\script{1\over 2}}, -z+{\script{1\over 2}}]; (ii) -x, -y+2, -z.
[Figure 1]
Figure 1
The crystal structure of Ni(HCOO)2·2H2O in a projection along [[\overline{1}]00]. Displacement ellipsoids are drawn at the 97% probability level. Ni atoms are green, C atoms grey, formate O atoms red, water O atoms yellow. H atoms are shown as white spheres of arbitrary radius; O—H⋯O hydrogen bonding is indicated by thin blue lines.

Synthesis and crystallization

Crystals of the title compound were harvested from a saturated aqueous solution of nickel formate (Königswarter & Ebell, Chemische Fabrik GmbH, Germany) that was stored in a closed glass bottle for several months.

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 3[link]. Starting coordinates for refinement were taken from the previous determination (Krogmann & Mattes, 1963[Krogmann, K. & Mattes, R. (1963). Z. Kristallogr. 118, 291-302.]).

Table 3
Experimental details

Crystal data
Chemical formula [Ni(HCOO)2(H2O)2]
Mr 184.78
Crystal system, space group Monoclinic, P21/c
Temperature (K) 100
a, b, c (Å) 8.5806 (4), 7.0202 (3), 9.2257 (4)
β (°) 97.551 (1)
V3) 550.91 (4)
Z 4
Radiation type Mo Kα
μ (mm−1) 3.48
Crystal size (mm) 0.12 × 0.10 × 0.02
 
Data collection
Diffractometer Bruker APEXII CCD
Absorption correction Multi-scan (SADABS; Bruker, 2015[Bruker (2015). APEX3, SAINT and SADABS. Bruker AXS Inc. Madison, Wisconsin, USA.])
Tmin, Tmax 0.667, 0.748
No. of measured, independent and observed [I > 2σ(I)] reflections 44072, 3433, 2591
Rint 0.036
(sin θ/λ)max−1) 0.907
 
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.021, 0.049, 1.04
No. of reflections 3433
No. of parameters 101
H-atom treatment H atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å−3) 0.52, −0.55
Computer programs: APEX3 and SAINT (Bruker, 2015[Bruker (2015). APEX3, SAINT and SADABS. Bruker AXS Inc. Madison, Wisconsin, USA.]), SHELXL2016 (Sheldrick, 2015[Sheldrick, G. M. (2015). Acta Cryst. C71, 3-8.]), ATOMS (Dowty, 2006[Dowty, E. (2006). ATOMS. Shape Software, Kingsport, Tennessee, USA.]) and publCIF (Westrip, 2010[Westrip, S. P. (2010). J. Appl. Cryst. 43, 920-925.]). Coordinates from previous determination.

Structural data


Computing details top

Data collection: APEX3 (Bruker, 2015); cell refinement: SAINT (Bruker, 2015); data reduction: SAINT (Bruker, 2015); program(s) used to solve structure: coordinates from previous determination; program(s) used to refine structure: SHELXL2016 (Sheldrick, 2015); molecular graphics: ATOMS (Dowty, 2006); software used to prepare material for publication: publCIF (Westrip, 2010).

Poly[diaquadi-µ-formato-nickel(II)] top
Crystal data top
[Ni(CHO2)2(H2O)2]F(000) = 376
Mr = 184.78Dx = 2.228 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
a = 8.5806 (4) ÅCell parameters from 9891 reflections
b = 7.0202 (3) Åθ = 2.4–39.9°
c = 9.2257 (4) ŵ = 3.48 mm1
β = 97.551 (1)°T = 100 K
V = 550.91 (4) Å3Plate, green
Z = 40.12 × 0.10 × 0.02 mm
Data collection top
Bruker APEXII CCD
diffractometer
2591 reflections with I > 2σ(I)
ω– and φ–scansRint = 0.036
Absorption correction: multi-scan
(SADABS; Bruker, 2015)
θmax = 40.1°, θmin = 2.4°
Tmin = 0.667, Tmax = 0.748h = 1515
44072 measured reflectionsk = 1212
3433 independent reflectionsl = 1616
Refinement top
Refinement on F20 restraints
Least-squares matrix: fullHydrogen site location: mixed
R[F2 > 2σ(F2)] = 0.021H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.049 w = 1/[σ2(Fo2) + (0.0181P)2 + 0.2503P]
where P = (Fo2 + 2Fc2)/3
S = 1.04(Δ/σ)max = 0.001
3433 reflectionsΔρmax = 0.52 e Å3
101 parametersΔρmin = 0.55 e Å3
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. H atoms bound to O atoms were located from a difference map and were refined freely.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
Ni10.5000001.0000000.5000000.00423 (3)
Ni20.0000001.0000000.0000000.00564 (3)
O10.40966 (7)1.27481 (9)0.09909 (7)0.00780 (10)
O20.40368 (7)1.10493 (9)0.30080 (7)0.00783 (10)
O30.29319 (7)0.84112 (9)0.49822 (7)0.00847 (10)
O40.06317 (8)0.72530 (10)0.07671 (8)0.01179 (11)
O50.08832 (8)1.11264 (12)0.19580 (8)0.01638 (14)
O60.21606 (8)0.97254 (10)0.07381 (7)0.00910 (10)
C10.46712 (10)1.22417 (12)0.22586 (9)0.00844 (12)
H10.5639881.2793650.2670770.010*
C20.17660 (10)0.61599 (12)0.06198 (10)0.00963 (13)
H20.1741050.4915370.1020540.012*
H50.2593 (18)1.071 (3)0.0623 (17)0.023 (4)*
H30.188 (2)1.098 (3)0.2325 (18)0.039 (5)*
H40.036 (2)1.148 (3)0.2609 (19)0.033 (5)*
H60.278 (2)0.898 (3)0.0248 (18)0.031 (4)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Ni10.00443 (5)0.00435 (5)0.00395 (5)0.00014 (4)0.00061 (4)0.00003 (4)
Ni20.00466 (5)0.00628 (6)0.00601 (6)0.00038 (4)0.00083 (4)0.00025 (5)
O10.0087 (2)0.0080 (2)0.0065 (2)0.00071 (19)0.00013 (18)0.00185 (18)
O20.0081 (2)0.0087 (2)0.0066 (2)0.00015 (19)0.00077 (18)0.00260 (19)
O30.0065 (2)0.0094 (2)0.0098 (2)0.00125 (19)0.00243 (18)0.00016 (19)
O40.0090 (2)0.0106 (3)0.0168 (3)0.0033 (2)0.0056 (2)0.0040 (2)
O50.0071 (2)0.0307 (4)0.0112 (3)0.0001 (3)0.0010 (2)0.0095 (3)
O60.0071 (2)0.0090 (3)0.0113 (3)0.00036 (19)0.00169 (19)0.00004 (19)
C10.0084 (3)0.0081 (3)0.0084 (3)0.0013 (2)0.0006 (2)0.0017 (2)
C20.0082 (3)0.0089 (3)0.0120 (3)0.0016 (2)0.0023 (2)0.0013 (3)
Geometric parameters (Å, º) top
Ni1—O1i2.0302 (6)Ni2—O4iv2.1007 (7)
Ni1—O1ii2.0302 (6)O1—C11.2593 (10)
Ni1—O22.0503 (6)O2—C11.2546 (10)
Ni1—O2iii2.0504 (6)O3—C2v1.2618 (10)
Ni1—O3iii2.0942 (6)O4—C21.2607 (10)
Ni1—O32.0942 (6)O5—H30.89 (2)
Ni2—O5iv2.0255 (7)O5—H40.832 (18)
Ni2—O52.0256 (7)O6—H50.787 (18)
Ni2—O62.0663 (6)O6—H60.837 (18)
Ni2—O6iv2.0664 (6)C1—H10.9500
Ni2—O42.1006 (7)C2—H20.9500
O1i—Ni1—O1ii180.00 (3)O6—Ni2—O490.36 (3)
O1i—Ni1—O289.49 (2)O6iv—Ni2—O489.64 (3)
O1ii—Ni1—O290.51 (2)O5iv—Ni2—O4iv90.47 (3)
O1i—Ni1—O2iii90.51 (2)O5—Ni2—O4iv89.53 (3)
O1ii—Ni1—O2iii89.49 (2)O6—Ni2—O4iv89.64 (3)
O2—Ni1—O2iii180.00 (4)O6iv—Ni2—O4iv90.36 (3)
O1i—Ni1—O3iii87.42 (2)O4—Ni2—O4iv180.0
O1ii—Ni1—O3iii92.58 (2)C1—O1—Ni1vi120.79 (5)
O2—Ni1—O3iii93.27 (2)C1—O2—Ni1125.50 (6)
O2iii—Ni1—O3iii86.73 (2)C2v—O3—Ni1126.31 (6)
O1i—Ni1—O392.58 (2)C2—O4—Ni2133.73 (6)
O1ii—Ni1—O387.42 (2)Ni2—O5—H3121.7 (12)
O2—Ni1—O386.73 (2)Ni2—O5—H4126.1 (12)
O2iii—Ni1—O393.27 (2)H3—O5—H4110.0 (16)
O3iii—Ni1—O3180.0Ni2—O6—H5107.5 (12)
O5iv—Ni2—O5180.00 (2)Ni2—O6—H6114.6 (11)
O5iv—Ni2—O690.62 (3)H5—O6—H6103.0 (16)
O5—Ni2—O689.38 (3)O2—C1—O1123.70 (8)
O5iv—Ni2—O6iv89.38 (3)O2—C1—H1118.1
O5—Ni2—O6iv90.62 (3)O1—C1—H1118.1
O6—Ni2—O6iv180.0O4—C2—O3vii125.14 (8)
O5iv—Ni2—O489.53 (3)O4—C2—H2117.4
O5—Ni2—O490.47 (3)O3vii—C2—H2117.4
Symmetry codes: (i) x, y+5/2, z+1/2; (ii) x+1, y1/2, z+1/2; (iii) x+1, y+2, z+1; (iv) x, y+2, z; (v) x, y+3/2, z+1/2; (vi) x+1, y+1/2, z+1/2; (vii) x, y+3/2, z1/2.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O6—H5···O3viii0.787 (18)1.985 (18)2.7312 (9)158.1 (16)
O5—H3···O20.89 (2)1.87 (2)2.7522 (9)171.2 (19)
O5—H4···O4viii0.832 (18)1.898 (18)2.7271 (10)174.1 (17)
O6—H6···O1iv0.837 (18)1.926 (18)2.7610 (9)175.5 (16)
Symmetry codes: (iv) x, y+2, z; (viii) x, y+1/2, z+1/2.
Comparison of bond lengths (Å) in the current and the previous refinement of Ni(HCOO)2·2H2O(a,b ) top
current refinementprevious refinementa
Ni1—O1i2.0302 (6)2.026 (8)
Ni1—O22.0503 (6)2.061 (8)
Ni1—O32.0942 (6)2.097 (8)
Ni2—O52.0256 (7)2.042 (8)
Ni2—O62.0663 (6)2.059 (8)
Ni2—O42.1006 (7)2.090 (8)
O1—C11.2593 (10)1.256 (8)
O2—C11.2546 (10)1.222 (8)
O3—C2ii1.2618 (10)1.278 (8)
O4—C21.2607 (10)1.247 (8)
Symmetry codes: (i) -x + 1, y - 1/2, -z + 1/2; (ii) x, -y + 3/2, z + 1/2. Notes: (a) Krogmann & Mattes (1963); lattice parameters a = 8.60 (1), b = 7.06 (1), c = 9.21 (2) Å, β = 96.50 (10)° from single-crystal data at room temperature; (b) lattice parameters a = 8.5951 (1), b = 7.0688 (5), c = 9.2152 (2) Å, β = 97.41 (1)° from Rietveld profile refinement at room temperature (Kellerman et al., 2016).
 

Acknowledgements

Dr Christian Weissensteiner kindly supplied the crystals used for this redetermination.

Funding information

The X-ray centre of TU Wien is acknowledged for financial support and for providing access to the single-crystal X-ray diffractometer.

References

First citationBruker (2015). APEX3, SAINT and SADABS. Bruker AXS Inc. Madison, Wisconsin, USA.  Google Scholar
First citationDowty, E. (2006). ATOMS. Shape Software, Kingsport, Tennessee, USA.  Google Scholar
First citationKellerman, D. G., Barykina, Yu. A., Zheleznikov, K. A., Tyutyunnik, A. P. & Krasilnikov, V. N. (2016). Phys. Status Solidi B, 253, 2209–2216.  CrossRef CAS Google Scholar
First citationKrogmann, K. & Mattes, R. (1963). Z. Kristallogr. 118, 291–302.  CrossRef CAS Google Scholar
First citationSheldrick, G. M. (2015). Acta Cryst. C71, 3–8.  Web of Science CrossRef IUCr Journals Google Scholar
First citationViertelhaus, M., Adler, P., Clérac, R., Anson, C. E. & Powell, A. (2005). Eur. J. Inorg. Chem. pp. 692–703.  CSD CrossRef Google Scholar
First citationWeissensteiner, C. (2012). Diploma thesis, TU Wien, Austria.  Google Scholar
First citationWestrip, S. P. (2010). J. Appl. Cryst. 43, 920–925.  Web of Science CrossRef CAS IUCr Journals Google Scholar

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