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In the structure of the title compound, [Co(SCN)2(C5H6N2)2(H2O)2], the cobalt cation is surrounded by two water mol­ecules, two thio­cyanate anions and two 2-methyl­pyrazine ligands in a slightly distorted octahedron. The cobalt cation is located on a centre of inversion and all other atoms are located in general positions. For the 2-methyl­pyrazine ligand, only the N atom which is not adjacent to the methyl group is involved in cobalt coordination. The complexes are connected via O—H...N and O—H...S hydrogen bonding, forming sheets parallel to (010).

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536801021444/bt6098sup1.cif
Contains datablocks I, global

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S1600536801021444/bt6098Isup2.hkl
Contains datablock I

CCDC reference: 180522

Key indicators

  • Single-crystal X-ray study
  • T = 293 K
  • Mean [sigma](C-C) = 0.003 Å
  • R factor = 0.030
  • wR factor = 0.079
  • Data-to-parameter ratio = 22.8

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry








Comment top

We have worked on the preparation, structural characterization and properties of new coordination polymers based on transition metal cations, aromatic amine ligands and pseudo halide anions. As ligands we used aromatic amines, which contain two N atoms in 1,4 position like 2-methylpyrazine, which can act as bridging ligands via µ-N,N'coordination forming typical coordination polymers like in catena-[bis(µ-2-methylpyrazine-N,N')bis(µ2-cyano-C,N)dicopper(I)], catena-[bis(µ-cyano-C,N)(µ-2-methylpyrazine-N,N')dicopper(I)] and catena-[bis(µ-2-methylpyrazine-N,N)bis(µ-thiocyanato-N,S)dicopper(I)] (Teichert & Sheldrick, 1999) or in poly[bis(µ-2-methylpyrazine)bis(cyanato)copper(II)] (Otieno et al., 1993). With 2-methylpyrazine as ligand only a few structures are known in the Cambridge Structural Database (Version 1.2 of 2001; Allen & Kennard, 1993), but none contain cobalt as the transition metal.

In the structure of the title compound, (I), the cobalt cation is located on a centre of inversion and all other atoms are located in general positions. The cobalt cation is sixfold coordinated by two O atoms of two water molecules, two N atoms of two 2-methylpyrazine ligands and two N atoms of the thiocyanato ligands. Bond lengths and angles are in the usual range compared with those of structures retrieved from the Cambridge Structural Database (Version 1.20 of 2001; Allen & Kennard, 1993) and the coordination polyhedron around the cobalt cation can be described as an slightly distorted octahedron. As expected, the Co—N bond lengths to the negatively charged thiocyanate anions are significantly shorter than those to the neutral ligands.

The 2-methylpyrazine molecules do not act as bridging ligands and only the N atom which is not neighboured to the methyl group is involved in cobalt coordination. This cannot be only regarded to sterically repulsion between the H atoms of the methyl group and the cobalt cation which would appear in the hexacoordinated complex, because in poly[bis(µ-2-methylpyrazine)bis(cyanato)copper(II)] (Otieno et al., 1993), in which the transition is also hexacoordinated and of approximately comparable size the N atom which is the neighbour of the methyl group of the 2-methylpyrazine ligand is involved in the transition metal coordination. It is highly likely that in the title compound this is due to hydrogen bonding because the N atom neighbouring the methyl group acts as an acceptor for a H atom of a water molecule of a symmetry-related complex. The geometry of this interaction indicates strong hydrogen bonding. Altogether two O—H···N hydrogen bonds between neighbouring complexes are formed which are located around a centre of inversion, forming chains in the direction of the crystallographic a axis. The chains are connected by additionally short contacts between the S atoms of the thiocyanate anions and the H atoms of the water molecules which are indicating for O—H···S hydrogen bonding. Two of such contacts occur between neighboured complexes located around centres of inversion. The O—H···N and O—H···S hydrogen bonding leads to sheets parallel to (010).

Experimental top

The title compound was prepared by the reaction of 119.95 mg (0.5 mmol) CoIICl2·6H2O, 97.51 mg (1 mmol) KSCN and 0.094 ml (1 mmol) 2-methylpyrazine (ACROS) in 5 ml water at room temperature in a glass container. After three weeks, the residue was filtered off and washed with ethanol and diethyl ether. The precipitate is not phase pure and consists of yellow crystals of the title compound and a small amount of a microcrystalline powder, which could not be identified using X-ray powder diffraction.

Refinement top

The positions of all H atoms were located from difference map. The C—H H atoms were positioned with idealized geometry and refined using a riding model. The positions of the methyl H atoms were idealized, then refined as rigid groups allowed to rotate but not tip. The H atoms of the water molecules were identified from difference syntheses, refined as rigid groups with idealized O—H bond lengths of 0.82 Å. Their isotropic displacement parameters were refined. All other H atoms were refined using fixed isotropic displacement parameters [Uiso(H) = 1.2UeqC(methylene) = 1.5UeqC(methyl)].

Computing details top

Data collection: DIF4 (Stoe & Cie, 1992); cell refinement: DIF4; data reduction: REDU4 (Stoe & Cie, 1992); program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: XP in SHELXTL (Bruker AXS, 1998); software used to prepare material for publication: CIFTAB in SHELXTL.

Figures top
[Figure 1] Fig. 1. The crystal structure of the title compound with view of the cobalt coordination with labelling [displacement ellipsoids drawn at the 50% probability level; symmetry code: (i) -x, -y, -z + 1].
[Figure 2] Fig. 2. The crystal structure viewed on (010) showing the hydrogen-bonding pattern (hydrogen bonding is shown as dotted lines).
Di-aqua-bis(thiocyanato-N)(bis(2-methylpyrazine-N)cobalt(II) top
Crystal data top
[Co(SCN)2(C5H6N2)2(H2O)2]Z = 1
Mr = 399.36F(000) = 205
Triclinic, P1Dx = 1.534 Mg m3
a = 6.910 (2) ÅMo Kα radiation, λ = 0.71073 Å
b = 8.085 (2) ÅCell parameters from 92 reflections
c = 9.234 (2) Åθ = 11–17.5°
α = 107.85 (1)°µ = 1.25 mm1
β = 111.93 (1)°T = 293 K
γ = 99.42 (1)°Block, yellow-orange
V = 432.32 (19) Å30.12 × 0.08 × 0.06 mm
Data collection top
Stoe AED-II four-circle
diffractometer
1972 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.033
Graphite monochromatorθmax = 30.0°, θmin = 2.6°
ωθ scansh = 90
Absorption correction: numerical
(X-SHAPE; Stoe & Cie, 1998)
k = 1111
Tmin = 0.796, Tmax = 0.876l = 1212
2790 measured reflections4 standard reflections every 120 min
2513 independent reflections intensity decay: none
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)] = 0.030H-atom parameters constrained
wR(F2) = 0.079 w = 1/[σ2(Fo2) + (0.0379P)2 + 0.0709P]
where P = (Fo2 + 2Fc2)/3
S = 1.06(Δ/σ)max < 0.001
2513 reflectionsΔρmax = 0.31 e Å3
110 parametersΔρmin = 0.35 e Å3
0 restraintsExtinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.013 (3)
Crystal data top
[Co(SCN)2(C5H6N2)2(H2O)2]γ = 99.42 (1)°
Mr = 399.36V = 432.32 (19) Å3
Triclinic, P1Z = 1
a = 6.910 (2) ÅMo Kα radiation
b = 8.085 (2) ŵ = 1.25 mm1
c = 9.234 (2) ÅT = 293 K
α = 107.85 (1)°0.12 × 0.08 × 0.06 mm
β = 111.93 (1)°
Data collection top
Stoe AED-II four-circle
diffractometer
1972 reflections with I > 2σ(I)
Absorption correction: numerical
(X-SHAPE; Stoe & Cie, 1998)
Rint = 0.033
Tmin = 0.796, Tmax = 0.8764 standard reflections every 120 min
2790 measured reflections intensity decay: none
2513 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0300 restraints
wR(F2) = 0.079H-atom parameters constrained
S = 1.06Δρmax = 0.31 e Å3
2513 reflectionsΔρmin = 0.35 e Å3
110 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.

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 > σ(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
Co10.00000.00000.50000.03017 (11)
N10.1593 (2)0.26766 (19)0.52115 (18)0.0324 (3)
C10.3077 (3)0.3998 (2)0.6713 (2)0.0346 (3)
H10.35120.37310.76740.042*
C20.3993 (3)0.5756 (2)0.6892 (2)0.0332 (3)
N20.3358 (2)0.62013 (19)0.55386 (19)0.0351 (3)
C30.1890 (3)0.4866 (2)0.4029 (2)0.0348 (3)
H30.14350.51330.30670.042*
C40.1035 (3)0.3112 (2)0.3855 (2)0.0336 (3)
H40.00550.22180.27800.040*
C50.5687 (3)0.7200 (3)0.8584 (3)0.0470 (5)
H5A0.68160.78870.84340.070*
H5B0.63230.66320.93370.070*
H5C0.50080.80080.90640.070*
S10.21696 (8)0.26214 (8)0.06723 (7)0.05225 (15)
C60.1073 (3)0.1841 (2)0.1918 (2)0.0348 (3)
N30.0293 (3)0.1296 (2)0.2804 (2)0.0440 (4)
O10.3034 (2)0.02333 (18)0.64223 (19)0.0482 (4)
H1O10.41980.05590.71510.066 (8)*
H2O10.33080.11820.60620.063 (8)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Co10.02759 (17)0.02892 (17)0.03004 (17)0.00760 (12)0.00976 (13)0.01161 (12)
N10.0287 (6)0.0327 (7)0.0345 (7)0.0088 (5)0.0123 (6)0.0147 (6)
C10.0308 (8)0.0383 (8)0.0321 (8)0.0105 (7)0.0097 (6)0.0165 (7)
C20.0254 (7)0.0348 (8)0.0362 (8)0.0101 (6)0.0128 (7)0.0112 (7)
N20.0331 (7)0.0332 (7)0.0412 (8)0.0109 (6)0.0177 (6)0.0163 (6)
C30.0338 (8)0.0394 (9)0.0349 (8)0.0134 (7)0.0151 (7)0.0193 (7)
C40.0297 (8)0.0356 (8)0.0308 (8)0.0085 (6)0.0103 (6)0.0123 (6)
C50.0407 (10)0.0440 (10)0.0374 (9)0.0033 (8)0.0103 (8)0.0072 (8)
S10.0378 (3)0.0635 (3)0.0389 (3)0.0075 (2)0.0170 (2)0.0046 (2)
C60.0313 (8)0.0337 (8)0.0314 (8)0.0045 (6)0.0091 (7)0.0122 (7)
N30.0457 (9)0.0431 (8)0.0412 (8)0.0108 (7)0.0208 (7)0.0146 (7)
O10.0311 (7)0.0337 (7)0.0566 (9)0.0096 (5)0.0017 (6)0.0121 (6)
Geometric parameters (Å, º) top
Co1—N3i2.0798 (17)N2—C31.342 (2)
Co1—N32.0798 (17)C3—C41.379 (2)
Co1—O12.0930 (14)C3—H30.9300
Co1—O1i2.0930 (14)C4—H40.9300
Co1—N12.1756 (15)C5—H5A0.9600
Co1—N1i2.1756 (15)C5—H5B0.9600
N1—C11.337 (2)C5—H5C0.9600
N1—C41.340 (2)S1—C61.6307 (19)
C1—C21.390 (2)C6—N31.157 (2)
C1—H10.9300O1—H1O10.8200
C2—N21.343 (2)O1—H2O10.8200
C2—C51.497 (2)
N3i—Co1—N3180.0N2—C2—C1120.26 (15)
N3i—Co1—O191.55 (7)N2—C2—C5118.31 (17)
N3—Co1—O188.45 (7)C1—C2—C5121.43 (16)
N3i—Co1—O1i88.45 (7)C3—N2—C2117.07 (15)
N3—Co1—O1i91.55 (7)N2—C3—C4122.21 (15)
O1—Co1—O1i180.0N2—C3—H3118.9
N3i—Co1—N188.77 (6)C4—C3—H3118.9
N3—Co1—N191.23 (6)N1—C4—C3121.05 (15)
O1—Co1—N191.33 (6)N1—C4—H4119.5
O1i—Co1—N188.67 (6)C3—C4—H4119.5
N3i—Co1—N1i91.23 (6)C2—C5—H5A109.5
N3—Co1—N1i88.77 (6)C2—C5—H5B109.5
O1—Co1—N1i88.67 (6)H5A—C5—H5B109.5
O1i—Co1—N1i91.33 (6)C2—C5—H5C109.5
N1—Co1—N1i180.0H5A—C5—H5C109.5
C1—N1—C4116.78 (15)H5B—C5—H5C109.5
C1—N1—Co1121.70 (11)N3—C6—S1179.59 (17)
C4—N1—Co1121.41 (11)C6—N3—Co1160.59 (16)
N1—C1—C2122.54 (15)Co1—O1—H1O1130.4
N1—C1—H1118.7Co1—O1—H2O1118.9
C2—C1—H1118.7H1O1—O1—H2O1107.8
Symmetry code: (i) x, y, z+1.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O1—H1O1···S1ii0.822.433.2508 (17)173
O1—H2O1···N2iii0.822.032.816 (2)160
Symmetry codes: (ii) x+1, y, z+1; (iii) x, y1, z.

Experimental details

Crystal data
Chemical formula[Co(SCN)2(C5H6N2)2(H2O)2]
Mr399.36
Crystal system, space groupTriclinic, P1
Temperature (K)293
a, b, c (Å)6.910 (2), 8.085 (2), 9.234 (2)
α, β, γ (°)107.85 (1), 111.93 (1), 99.42 (1)
V3)432.32 (19)
Z1
Radiation typeMo Kα
µ (mm1)1.25
Crystal size (mm)0.12 × 0.08 × 0.06
Data collection
DiffractometerStoe AED-II four-circle
diffractometer
Absorption correctionNumerical
(X-SHAPE; Stoe & Cie, 1998)
Tmin, Tmax0.796, 0.876
No. of measured, independent and
observed [I > 2σ(I)] reflections
2790, 2513, 1972
Rint0.033
(sin θ/λ)max1)0.704
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.030, 0.079, 1.06
No. of reflections2513
No. of parameters110
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.31, 0.35

Computer programs: DIF4 (Stoe & Cie, 1992), DIF4, REDU4 (Stoe & Cie, 1992), SHELXS97 (Sheldrick, 1990), SHELXL97 (Sheldrick, 1997), XP in SHELXTL (Bruker AXS, 1998), CIFTAB in SHELXTL.

Selected geometric parameters (Å, º) top
Co1—N32.0798 (17)Co1—N12.1756 (15)
Co1—O12.0930 (14)
N3i—Co1—N3180.0O1—Co1—N191.33 (6)
N3i—Co1—O191.55 (7)O1i—Co1—N188.67 (6)
N3—Co1—O188.45 (7)N1—Co1—N1i180.0
O1—Co1—O1i180.0C1—N1—Co1121.70 (11)
N3i—Co1—N188.77 (6)C4—N1—Co1121.41 (11)
N3—Co1—N191.23 (6)
Symmetry code: (i) x, y, z+1.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O1—H1O1···S1ii0.822.433.2508 (17)173.3
O1—H2O1···N2iii0.822.032.816 (2)160.4
Symmetry codes: (ii) x+1, y, z+1; (iii) x, y1, z.
 

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