Crystal structure of tetra­aqua­bis­(thio­cyanato-κN)nickel(II)–2,5-di­methyl­pyrazine (1/4)

Stefan Suckert; Mario Wriedt; Inke Jess; Christian Näther

doi:10.1107/S2056989014026991

. 2015 Jan 3;71(Pt 2):m18. doi: 10.1107/S2056989014026991

Crystal structure of tetraaquabis(thiocyanato-κN)nickel(II)–2,5-dimethylpyrazine (1/4)

Stefan Suckert ^a,^*, Mario Wriedt ^b, Inke Jess ^a, Christian Näther ^a

PMCID: PMC4384548 PMID: 25878833

Abstract

In the crystal structure of the title compound, [Ni(NCS)₂(H₂O)₄]·4C₆H₈N₂, the Ni^II cations are coordinated by four water ligands and two trans-coordinated terminally N-bonded thiocyanate anions in a slightly distorted octahedral geometry. The asymmetric unit consists of a Ni²⁺ cation located on a centre of inversion, two water molecules and one thiocyanate ligand, as well as two uncoordinated 2,5-dimethylpyrazine ligands in general positions. In the crystal, discrete complex molecules are linked into a three-dimensional network by O—H⋯N hydrogen bonding between the water H atoms and the 2,5-dimethylpyrazine N atoms.

Keywords: crystal structure; thiocyanat; nickel(II) complex; 2,5-dimethylpyrazine; hydrogen bonding

Related literature

For background information on the design and preparation of coordination polymers, see Näther et al. (2013 ▸). For a different structure with thiocyanates and 2,5-dimethylpyrazine, see: Otieno et al. (2003 ▸).

Experimental

Crystal data

[Ni(NCS)₂(H₂O)₄]·4C₆H₈N₂
M _r = 679.51
Orthorhombic,
a = 13.0731 (6) Å
b = 14.7989 (8) Å
c = 17.3092 (11) Å
V = 3348.8 (3) Å³
Z = 4
Mo Kα radiation
μ = 0.75 mm⁻¹
T = 170 K
0.12 × 0.10 × 0.08 mm

Data collection

Stoe IPDS-1 diffractometer
Absorption correction: numerical (X-SHAPE and X-RED32; Stoe & Cie, 2008 ▸) T _min = 0.912, T _max = 0.938
21266 measured reflections
4041 independent reflections
3146 reflections with I > 2σ(I)
R _int = 0.035

Refinement

R[F ² > 2σ(F ²)] = 0.036
wR(F ²) = 0.100
S = 1.02
4041 reflections
201 parameters
H-atom parameters constrained
Δρ_max = 0.35 e Å⁻³
Δρ_min = −0.40 e Å⁻³

Data collection: X-AREA (Stoe & Cie, 2008 ▸); cell refinement: X-AREA; data reduction: X-AREA; 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: publCIF (Westrip, 2010 ▸).

Supplementary Material

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S2056989014026991/pk2540sup1.cif

e-71-00m18-sup1.cif^{(24.6KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S2056989014026991/pk2540Isup2.hkl

e-71-00m18-Isup2.hkl^{(198.2KB, hkl)}

Click here for additional data file.^{(359.1KB, tif)}

. DOI: 10.1107/S2056989014026991/pk2540fig1.tif

Part of the crystal structure of the title compound with labelling and displacement ellipsoids drawn at the 50% probability level. Symmetry code: i = x+1,-y+1,-z+1.

Click here for additional data file.^{(1.7MB, tif)}

a . DOI: 10.1107/S2056989014026991/pk2540fig2.tif

Crystal structure of the title compound with view along the crystallographic a axis. Hydrogen bonding is shown as dashed lines and for clarity only the O-H H atoms are shown.

CCDC reference: 1038309

Additional supporting information: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (, ).

DHA	DH	HA	D A	DHA
O1H1O1N12	0.84	1.99	2.8284(18)	174
O1H2O1N11ⁱ	0.84	2.06	2.8963(18)	173
O2H1O2N2ⁱⁱ	0.84	2.00	2.8286(19)	169
O2H2O2N1ⁱⁱⁱ	0.84	2.03	2.8665(19)	176

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) .

Acknowledgments

We gratefully acknowledge financial support by the DFG (project No. NA 720/5-1) and the State of Schleswig–Holstein. We thank Professor Dr Wolfgang Bensch for access to his experimental facilities.

supplementary crystallographic information

S1. Synthesis and crystallization

NiSO₄.6 H₂O and 2,5-dimethylpyrazine were purchased from Merck and Ba(NCS)₂.3 H₂O was purchased from Alfa Aesar. Ni(NCS)₂ was synthesized by stirring 17.5 g (56.91 mmol) Ba(NCS)₂.3 H₂O and 15.00 g (57.03 mmol) NiSO₄.6 H₂O in 500 ml H₂O at RT for two hours. The white residue of BaSO₄ was filtered of and the solvent removed with a rotary evaporator. The homogeneity of the product was investigated by X-ray powder diffraction and elemental analysis. The title compound was prepared by the reaction of (0.15 mmol) 27.8 mg Ni(NCS)₂ and (0.9 mmol) 97.5 µl 2,5-dimethylpyrazine at RT. After a few days blue block shaped crystals of the title compound were obtained.

S2. Refinement

The C—H H atoms were positioned with idealized geometry (methyl H atoms allowed to rotate but not to tip) and were refined using a riding model with C—H = 0.95 Å for aromatic and C—H = 0.98 Å for methyl. Water hydrogen atoms were found in difference-electron density maps and fixed (SHELXL command AFIX 3). U_iso(H) values were set to either 1.2U_eq or 1.5U_eq (-CH₃, H₂O) of the attached parent atom.