Poly[bis­(cyanato-κN)bis­(μ-pyrazine-κ2N:N′)cobalt(II)]

Wriedt, M.; Jess, I.; Näther, C.

doi:10.1107/S1600536809005686

metal-organic compounds

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ISSN: 2056-9890

Volume 65| Part 4| April 2009| Page m431

doi:10.1107/S1600536809005686

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Poly[bis(cyanato-κN)bis(μ-pyrazine-κ²N:N′)cobalt(II)]

Mario Wriedt,^a Inke Jess ^a and Christian Näther ^a ^*

^aInstitut für Anorganische Chemie, Christian-Albrechts-Universität Kiel, Max-Eyth-Strasse 2, D-24118 Kiel, Germany
^*Correspondence e-mail: mwriedt@ac.uni-kiel.de

(Received 16 February 2009; accepted 17 February 2009; online 25 March 2009)

In the crystal structure of the title compound, [Co(NCO)₂(C₄H₄N₂)₂]_n, the Co(II) cation is coordinated by four N-bonded pyrazine ligands and two N-bonded cyanate anions in a slightly distorted octahedral geometry. The crystal structure consists of μ-N:N′ pyrazine-bridged cobalt cyanate chains; these are further linked by additional μ-N:N′-bridging pyrazine ligands into layers, which are stacked perpendicular to the crystallographic a axis. The C and O atoms in both crystallographic independent cyanate anions are disordered in two orientations and were refined using a split model with site occupation factor ratios of 0.75/0.25 and 0.7/0.3.

Related literature

For related pyrazine structures, see: Lloret et al. (1999 ); Real et al. (1991 ); Lu et al. (1997 ); Wriedt et al. (2009 ). For general background, see: Näther & Greve (2003 ); Näther et al. (2003 ); Wriedt et al. (2008 , 2009); Näther et al. (2007 ); Näther & Jess (2004 ).

Experimental

Crystal data

[Co(NCO)₂(C₄H₄N₂)₂]
M_r = 303.15
Monoclinic, C 2/c
a = 25.5712 (17) Å
b = 10.1230 (8) Å
c = 10.1863 (7) Å
β = 104.763 (8)°
V = 2549.8 (3) Å³
Z = 8
Mo Kα radiation
μ = 1.35 mm⁻¹
T = 170 K
0.24 × 0.14 × 0.07 mm

Data collection

Stoe IPDS-1 diffractometer
Absorption correction: numerical (X-SHAPE and X-RED32; Stoe & Cie, 2008 ) T_min = 0.789, T_max = 0.903
11369 measured reflections
2684 independent reflections
2058 reflections with I > 2σ(I)
R_int = 0.039

Refinement

R[F² > 2σ(F²)] = 0.051
wR(F²) = 0.139
S = 1.04
2684 reflections
198 parameters
H-atom parameters constrained
Δρ_max = 0.71 e Å⁻³
Δρ_min = −1.17 e Å⁻³

Table 1
Selected geometric parameters (Å, °)

Co1—N21	2.039 (3)
Co1—N31	2.059 (3)
Co1—N11	2.191 (3)
Co1—N2ⁱ	2.193 (3)
Co1—N12ⁱⁱ	2.197 (3)
Co1—N1	2.200 (3)
Symmetry codes: (i) $[x, -y+1, z-{\script{1\over 2}}]$ ; (ii) $[x, -y+2, z+{\script{1\over 2}}]$ .

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); software used to prepare material for publication: XCIF in SHELXTL.

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809005686/bt2872sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536809005686/bt2872Isup2.hkl

checkCIF report

Comment top

In our investigations we have recently demonstrated that new ligand deficient coordination polymers with interestic magnetic properties can be prepared by thermal decomposition of suitable ligand rich precursor compounds (Näther & Greve, 2003; Wriedt et al., 2009). In order to prepare additional ligand rich precursor compounds we have reacted cobalt(II) nitrate hexahydrate and potassium cyanate with pyrazine in a methanol water mixture. In this reaction single crystals of the title compound were obtained in an inhomogenous mixture containing additional unknown phases.

In the crystal structure of the 1:2 title compound [Co(OCN)₂(pyrazine)₂]_n the cobalt(II) cations are coordinated by four pyrazine ligands and two thiocyanate anions within slightly distorted octahedra (Fig. 1). The cobalt cations are µ-1,4-(N,N) bridged by the pyrazine ligands forming layers, which are stacked perpendicular to the crystallographic a-axis (Fig. 2). The cyanate anions do not act as bridging ligands and are only terminal N-bonded to the metal center. A similar structural motif is observed in the structures of the 1:2 thiocyanate compounds of composition [M(SCN)₂(pyrazine)₂]_n (M = Mn, Fe, Co, Ni) reported recently (Lloret et al., 1999; Real et al., 1991; Lu et al.., 1997; Wriedt et al., 2009). The Co—NCO distances amount to 2.039 (3) and 2.059 (3) Å and are significantly shorter as the Co—N_pyrazine distances, which range from 2.191 (3) to 2.200 (3) Å. The angles around the cobalt cations range between 89.23 (12) and 179.58 (12)° (Tab. 1). The shortest intra- and interchain Co···Co distances amount to 7.1721 (4) and 8.2170 (5) Å, respectively.

Related literature top

For related pyrazine structures, see: Lloret et al. (1999); Real et al. (1991); Lu et al. (1997); Wriedt et al. (2009). For general background, see: Näther & Greve (2003); Näther et al. (2003); Wriedt et al. (2008, 2009); Näther et al. (2007); Näther & Jeß (2004).

Experimental top

Co(NO₃)₂.6H₂O, pyrazine and methanol were obtained from Alfa Aesar as well as KOCN was obtained from Fluka. 0.5 mmol (145.5 mg) Co(NO₃)₂.6H₂O, 1 mmol (81.1 mg) KOCN, 0.5 mmol (40.1 mg) pyrazine, 0.5 mL methanol and 0.5 mL water were transfered in a closed test-tube. The mixture was heated at 120 °C for three days. After cooling yellow block-shaped single crystals of the title compound were obtained in a heterogenous mixture.

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); software used to prepare material for publication: XCIF in SHELXTL (Sheldrick, 2008).

Figures top

	Fig. 1. Crystal structure of the title compound with labelling and displacement ellipsoids drawn at the 50% probability level. The disorder of the cyanate anions is not show for clarity. [Symmetry codes: (i) x, -y+1, z-1/2; (ii) x, -y+2, z+1/2.]
	Fig. 2. Crystal structure of the title compound with view along the a-axis.

Poly[bis(cyanato-κN)bis(µ-pyrazine-κ²N:N')cobalt(II)] top

Crystal data top

[Co(NCO)₂(C₄H₄N₂)₂]	F(000) = 1224
M_r = 303.15	D_x = 1.579 Mg m⁻³
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 8000 reflections
a = 25.5712 (17) Å	θ = 14.1–25.9°
b = 10.1230 (8) Å	µ = 1.35 mm⁻¹
c = 10.1863 (7) Å	T = 170 K
β = 104.763 (8)°	Block, yellow
V = 2549.8 (3) Å³	0.24 × 0.14 × 0.07 mm
Z = 8

Data collection top

Stoe IPDS-1 diffractometer	2684 independent reflections
Radiation source: fine-focus sealed tube	2058 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.039
ϕ scans	θ_max = 27.1°, θ_min = 2.9°
Absorption correction: numerical (X-SHAPE and X-RED32; Stoe & Cie, 2008)	h = −32→32
T_min = 0.789, T_max = 0.903	k = −12→12
11369 measured reflections	l = −13→13

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.051	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.139	H-atom parameters constrained
S = 1.04	w = 1/[σ²(F_o²) + (0.0575P)² + 18.631P] where P = (F_o² + 2F_c²)/3
2684 reflections	(Δ/σ)_max = 0.001
198 parameters	Δρ_max = 0.71 e Å⁻³
0 restraints	Δρ_min = −1.17 e Å⁻³

Crystal data top

[Co(NCO)₂(C₄H₄N₂)₂]	V = 2549.8 (3) Å³
M_r = 303.15	Z = 8
Monoclinic, C2/c	Mo Kα radiation
a = 25.5712 (17) Å	µ = 1.35 mm⁻¹
b = 10.1230 (8) Å	T = 170 K
c = 10.1863 (7) Å	0.24 × 0.14 × 0.07 mm
β = 104.763 (8)°

Data collection top

Stoe IPDS-1 diffractometer	2684 independent reflections
Absorption correction: numerical (X-SHAPE and X-RED32; Stoe & Cie, 2008)	2058 reflections with I > 2σ(I)
T_min = 0.789, T_max = 0.903	R_int = 0.039
11369 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.051	0 restraints
wR(F²) = 0.139	H-atom parameters constrained
S = 1.04	w = 1/[σ²(F_o²) + (0.0575P)² + 18.631P] where P = (F_o² + 2F_c²)/3
2684 reflections	Δρ_max = 0.71 e Å⁻³
198 parameters	Δρ_min = −1.17 e Å⁻³

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

	x	y	z	U_iso*/U_eq	Occ. (<1)
Co1	0.629290 (19)	0.75059 (4)	0.63502 (4)	0.01326 (17)
N1	0.62838 (13)	0.5943 (3)	0.7846 (3)	0.0162 (6)
C1	0.66193 (17)	0.5983 (3)	0.9072 (4)	0.0224 (8)
H1	0.6868	0.6695	0.9297	0.027*
C2	0.66194 (17)	0.5014 (4)	1.0044 (3)	0.0224 (8)
H2	0.6864	0.5088	1.0916	0.027*
N2	0.62829 (13)	0.3981 (3)	0.9778 (3)	0.0171 (6)
C3	0.59444 (17)	0.3935 (4)	0.8537 (3)	0.0230 (8)
H3	0.5700	0.3215	0.8305	0.028*
C4	0.59412 (17)	0.4920 (4)	0.7578 (4)	0.0225 (8)
H4	0.5690	0.4864	0.6714	0.027*
N11	0.63140 (13)	0.9093 (3)	0.4902 (3)	0.0163 (6)
C11	0.67047 (17)	0.9151 (4)	0.4247 (4)	0.0228 (8)
H11	0.6992	0.8528	0.4461	0.027*
C12	0.67008 (17)	1.0102 (3)	0.3260 (4)	0.0222 (8)
H12	0.6984	1.0110	0.2810	0.027*
N12	0.63094 (13)	1.1005 (3)	0.2930 (3)	0.0167 (6)
C13	0.59214 (17)	1.0958 (4)	0.3588 (4)	0.0259 (9)
H13	0.5637	1.1590	0.3381	0.031*
C14	0.59239 (18)	1.0000 (4)	0.4575 (4)	0.0259 (9)
H14	0.5641	0.9993	0.5025	0.031*
N21	0.54684 (14)	0.7557 (3)	0.5817 (3)	0.0238 (7)
C21	0.5047 (3)	0.7083 (8)	0.5445 (8)	0.0347 (16)	0.75
O21	0.4602 (3)	0.6596 (9)	0.5110 (10)	0.109 (4)	0.75
O21'	0.4627 (6)	0.7506 (17)	0.4184 (18)	0.052 (4)	0.25
C21'	0.5054 (9)	0.7583 (16)	0.498 (2)	0.023 (4)	0.25
N31	0.71251 (14)	0.7443 (3)	0.6873 (3)	0.0218 (7)
C31	0.7539 (3)	0.7288 (7)	0.7698 (8)	0.0250 (15)	0.70
O31	0.7962 (3)	0.7135 (8)	0.8513 (7)	0.074 (3)	0.70
C31'	0.7530 (9)	0.7621 (19)	0.734 (2)	0.030 (6)*	0.30
O31'	0.8018 (11)	0.771 (2)	0.789 (3)	0.098 (8)*	0.30

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Co1	0.0272 (3)	0.0060 (2)	0.0076 (2)	−0.00033 (18)	0.00627 (18)	0.00004 (16)
N1	0.0307 (18)	0.0095 (13)	0.0085 (13)	−0.0035 (11)	0.0050 (13)	0.0015 (10)
C1	0.037 (2)	0.0124 (16)	0.0150 (16)	−0.0096 (15)	0.0022 (16)	0.0021 (13)
C2	0.037 (2)	0.0160 (17)	0.0103 (15)	−0.0053 (15)	−0.0003 (16)	0.0024 (13)
N2	0.0319 (18)	0.0090 (13)	0.0093 (13)	−0.0019 (11)	0.0033 (13)	0.0010 (10)
C3	0.039 (2)	0.0161 (17)	0.0119 (16)	−0.0099 (15)	0.0021 (16)	0.0006 (13)
C4	0.036 (2)	0.0161 (17)	0.0110 (15)	−0.0066 (15)	−0.0009 (16)	0.0028 (13)
N11	0.0312 (18)	0.0083 (13)	0.0119 (13)	0.0028 (11)	0.0100 (13)	0.0027 (10)
C11	0.036 (2)	0.0137 (17)	0.0241 (18)	0.0075 (15)	0.0172 (17)	0.0096 (14)
C12	0.036 (2)	0.0147 (16)	0.0220 (17)	0.0080 (15)	0.0182 (17)	0.0087 (14)
N12	0.0331 (18)	0.0079 (13)	0.0129 (14)	0.0033 (11)	0.0126 (14)	0.0015 (10)
C13	0.041 (2)	0.0177 (18)	0.0257 (19)	0.0137 (16)	0.0198 (19)	0.0117 (15)
C14	0.039 (2)	0.0179 (18)	0.0278 (19)	0.0093 (16)	0.0216 (18)	0.0111 (15)
N21	0.0311 (18)	0.0192 (16)	0.0204 (15)	−0.0023 (14)	0.0056 (16)	−0.0001 (12)
C21	0.034 (4)	0.032 (4)	0.040 (4)	0.000 (3)	0.014 (3)	−0.027 (3)
O21	0.041 (4)	0.137 (8)	0.152 (8)	−0.033 (4)	0.031 (5)	−0.114 (7)
O21'	0.027 (7)	0.061 (11)	0.055 (9)	0.012 (7)	−0.016 (8)	−0.038 (8)
C21'	0.040 (12)	0.004 (8)	0.023 (9)	0.001 (7)	0.003 (9)	0.004 (6)
N31	0.0318 (18)	0.0171 (16)	0.0183 (15)	0.0012 (13)	0.0099 (15)	−0.0002 (12)
C31	0.038 (4)	0.018 (3)	0.016 (3)	0.007 (3)	0.001 (3)	−0.010 (3)
O31	0.052 (4)	0.089 (5)	0.055 (4)	0.036 (4)	−0.031 (4)	−0.053 (4)

Geometric parameters (Å, º) top

Co1—N21	2.039 (3)	N11—C11	1.337 (5)
Co1—N31	2.059 (3)	C11—C12	1.390 (5)
Co1—N11	2.191 (3)	C11—H11	0.9500
Co1—N2ⁱ	2.193 (3)	C12—N12	1.333 (5)
Co1—N12ⁱⁱ	2.197 (3)	C12—H12	0.9500
Co1—N1	2.200 (3)	N12—C13	1.332 (5)
N1—C1	1.324 (5)	N12—Co1^iv	2.197 (3)
N1—C4	1.339 (5)	C13—C14	1.397 (5)
C1—C2	1.394 (5)	C13—H13	0.9500
C1—H1	0.9500	C14—H14	0.9500
C2—N2	1.337 (5)	N21—C21	1.151 (8)
C2—H2	0.9500	N21—C21'	1.18 (2)
N2—C3	1.338 (5)	C21—O21	1.206 (9)
N2—Co1ⁱⁱⁱ	2.193 (3)	O21'—C21'	1.19 (3)
C3—C4	1.395 (5)	N31—C31'	1.04 (2)
C3—H3	0.9500	N31—C31	1.182 (8)
C4—H4	0.9500	C31—O31	1.195 (9)
N11—C14	1.334 (5)	C31'—O31'	1.24 (4)

N21—Co1—N31	179.45 (13)	N1—C4—H4	119.2
N21—Co1—N11	90.19 (12)	C3—C4—H4	119.2
N31—Co1—N11	89.76 (12)	C14—N11—C11	116.8 (3)
N21—Co1—N2ⁱ	90.23 (12)	C14—N11—Co1	121.8 (2)
N31—Co1—N2ⁱ	89.23 (12)	C11—N11—Co1	121.2 (2)
N11—Co1—N2ⁱ	90.53 (11)	N11—C11—C12	121.5 (3)
N21—Co1—N12ⁱⁱ	90.19 (12)	N11—C11—H11	119.2
N31—Co1—N12ⁱⁱ	90.35 (12)	C12—C11—H11	119.2
N11—Co1—N12ⁱⁱ	89.45 (10)	N12—C12—C11	121.6 (3)
N2ⁱ—Co1—N12ⁱⁱ	179.58 (12)	N12—C12—H12	119.2
N21—Co1—N1	90.57 (12)	C11—C12—H12	119.2
N31—Co1—N1	89.49 (12)	C13—N12—C12	117.1 (3)
N11—Co1—N1	178.55 (11)	C13—N12—Co1^iv	121.0 (2)
N2ⁱ—Co1—N1	90.70 (10)	C12—N12—Co1^iv	121.9 (2)
N12ⁱⁱ—Co1—N1	89.32 (10)	N12—C13—C14	121.3 (3)
C1—N1—C4	116.7 (3)	N12—C13—H13	119.3
C1—N1—Co1	120.9 (2)	C14—C13—H13	119.3
C4—N1—Co1	122.5 (2)	N11—C14—C13	121.6 (3)
N1—C1—C2	122.1 (3)	N11—C14—H14	119.2
N1—C1—H1	118.9	C13—C14—H14	119.2
C2—C1—H1	118.9	C21—N21—C21'	34.7 (8)
N2—C2—C1	121.5 (3)	C21—N21—Co1	153.4 (5)
N2—C2—H2	119.3	C21'—N21—Co1	150.6 (11)
C1—C2—H2	119.3	N21—C21—O21	177.2 (8)
C2—N2—C3	116.5 (3)	N21—C21'—O21'	174 (2)
C2—N2—Co1ⁱⁱⁱ	120.1 (2)	C31'—N31—C31	24.8 (10)
C3—N2—Co1ⁱⁱⁱ	123.4 (2)	C31'—N31—Co1	163.3 (12)
N2—C3—C4	121.6 (3)	C31—N31—Co1	150.1 (5)
N2—C3—H3	119.2	N31—C31—O31	178.7 (10)
C4—C3—H3	119.2	N31—C31'—O31'	174 (2)
N1—C4—C3	121.6 (3)

Symmetry codes: (i) x, −y+1, z−1/2; (ii) x, −y+2, z+1/2; (iii) x, −y+1, z+1/2; (iv) x, −y+2, z−1/2.

Experimental details

Crystal data
Chemical formula	[Co(NCO)₂(C₄H₄N₂)₂]
M_r	303.15
Crystal system, space group	Monoclinic, C2/c
Temperature (K)	170
a, b, c (Å)	25.5712 (17), 10.1230 (8), 10.1863 (7)
β (°)	104.763 (8)
V (Å³)	2549.8 (3)
Z	8
Radiation type	Mo Kα
µ (mm⁻¹)	1.35
Crystal size (mm)	0.24 × 0.14 × 0.07

Data collection
Diffractometer	Stoe IPDS1 diffractometer
Absorption correction	Numerical (X-SHAPE and X-RED32; Stoe & Cie, 2008)
T_min, T_max	0.789, 0.903
No. of measured, independent and observed [I > 2σ(I)] reflections	11369, 2684, 2058
R_int	0.039
(sin θ/λ)_max (Å⁻¹)	0.641

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.051, 0.139, 1.04
No. of reflections	2684
No. of parameters	198
H-atom treatment	H-atom parameters constrained
	w = 1/[σ²(F_o²) + (0.0575P)² + 18.631P] where P = (F_o² + 2F_c²)/3
Δρ_max, Δρ_min (e Å⁻³)	0.71, −1.17

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

Selected geometric parameters (Å, º) top

Co1—N21	2.039 (3)	Co1—N2ⁱ	2.193 (3)
Co1—N31	2.059 (3)	Co1—N12ⁱⁱ	2.197 (3)
Co1—N11	2.191 (3)	Co1—N1	2.200 (3)

N21—Co1—N31	179.45 (13)	N11—Co1—N12ⁱⁱ	89.45 (10)
N21—Co1—N11	90.19 (12)	N2ⁱ—Co1—N12ⁱⁱ	179.58 (12)
N31—Co1—N11	89.76 (12)	N21—Co1—N1	90.57 (12)
N21—Co1—N2ⁱ	90.23 (12)	N31—Co1—N1	89.49 (12)
N31—Co1—N2ⁱ	89.23 (12)	N11—Co1—N1	178.55 (11)
N11—Co1—N2ⁱ	90.53 (11)	N2ⁱ—Co1—N1	90.70 (10)
N21—Co1—N12ⁱⁱ	90.19 (12)	N12ⁱⁱ—Co1—N1	89.32 (10)
N31—Co1—N12ⁱⁱ	90.35 (12)

Symmetry codes: (i) x, −y+1, z−1/2; (ii) x, −y+2, z+1/2.

Acknowledgements

MW thanks the Stiftung Stipendien-Fonds des Verbandes der Chemischen Industrie and the Studienstiftung des deutschen Volkes for a PhD scholarship. We gratefully acknowledge financial support by the State of Schleswig-Holstein and we thank Professor Dr Wolfgang Bensch for the opportunity to use his experimental facility.

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