catena-Poly[[bis­­(4-methyl­pyridine-κN)cobalt(II)]-di-μ-dicyanamido-κ²N¹:N⁵]

Cobalt(II) nitrate hexa­hydrate and sodium dicyanamide self-assembled in dimethyl­formamide (DMF) and 4-methyl­pyridine solutions to form the title compound, [Co(C₂N₃)₂(C₆H₇N)₂]_n. The Co²⁺ ion lies on an inversion center and adopts an octa­hedral coordination geometry in which four N atoms from four different dicyanamide ligands lie in the equatorial plane and two 4-methyl­pyridine N atoms occupy the axial positions. The Co^II atoms are connected by two bridging dicyanamide ligands, resulting in a chain parallel to the c axis. The chains are connected into a three-dimensional network by C—H⋯N hydrogen bonds.

Related literature

The design and syntheses of metal-organic compounds has attracted great attention not only as a result of their intriguing architectures and topologies (Eddaoudi et al., 2001), but also because of their potential applications (Banerjee et al., 2008).

Experimental

Crystal data

• [Co(C₂N₃)₂(C₆H₇N)₂]

• M_r = 377.28

• Monoclinic, P 2₁ /c

• a = 9.3686 (19) Å

• b = 13.080 (3) Å

• c = 7.3048 (15) Å

• β = 106.86 (3)°

• V = 856.7 (3) ų

• Z = 2

• Mo Kα radiation

• μ = 1.02 mm⁻¹

• T = 150 K

• 0.21 × 0.17 × 0.15 mm

Data collection

• Rigaku Saturn724+ diffractometer

• Absorption correction: multi-scan (CrystalClear; Rigaku, 2008) T_min = 0.815, T_max = 1.000

• 4994 measured reflections

• 1549 independent reflections

• 1419 reflections with I > 2σ(I)

• R_int = 0.016

Refinement

• R[F² > 2σ(F²)] = 0.031

• wR(F²) = 0.085

• S = 1.07

• 1549 reflections

• 115 parameters

• H-atom parameters constrained

• Δρ_max = 0.94 e Å⁻³

• Δρ_min = −0.26 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C4—H4A⋯N3^i	0.93	2.57	3.487 (3)	168
Symmetry code: (i) -x+1, -y, -z+1.

Data collection: CrystalClear (Rigaku, 2008); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Supporting information

S1. Comment

The design and syntheses of metal-organic compounds have attracted great attention in recent years because of not only their intriguing architectures and topologies (Eddaoudi et al., 2001) but also their potential applications (Banerjee et al., 2008). The title compound {Co[N(CN)₂]₂(NC₆H₇)₂}_n is constructed by the flexible dicyanamide bridging ligands through diffusion reaction.

As illustrated in Fig. 1, Co²⁺ ion lies on an inversion center and adopts an octahedral coordination geometry, where four N atoms from four different dicyanamide ligands lie in the equatorial plane and two 4-methylpyridine N atoms occupy the axial positions. The Co atoms are connected by two dicyanamide ligands, resulting in a neutral chain along the c-axis. In the crystal, the chains are linked by C—H···N hydrogen bonds (Table 1) into a three-dimensional network.

Related literature

The design and syntheses of metal-organic compounds has attracted great attention not only as a result of their intriguing architectures and topologies (Eddaoudi et al., 2001) but also because of their potential applications (Banerjee et al., 2008).

S2. Experimental

Co(NO₃)₂?6H₂O (116.6 mg, 0.4 mmol) was added into 1 ml dmf with thorough stir for 5 minutes. After filtration, the purple filtrate was carefully laid on the surface with the solution of NaN(CN)₂ (89.1 mg, 1 mmol) in 1 ml dmf, 1 ml 4-methylpyridine and 5 ml i-PrOH. Pink block crystals were obtained after two weeks.

S3. Refinement

H atoms were positioned geometrically and refined with riding model, with U_iso = 1.5U_eq and 1.2U_eq for methyl and pyridyl H atoms, respectively. The C—H bonds are 0.96 Å in methyl and 0.93 Å in pyridyl.

Computing details

Data collection: CrystalClear (Rigaku, 2008); cell refinement: CrystalClear (Rigaku, 2008); data reduction: CrystalClear (Rigaku, 2008); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures

Fig. 1. Portion of the polymeric chain of the title compound, with 30% probability displacement ellipsoids. All H atoms have been omitted. Symmetry code: (i) 2-x, -y, 1-z.

catena-Poly[[bis(4-methylpyridine-κN)cobalt(II)]- di-µ-dicyanamido-κ²N¹:N⁵]

Crystal data

[Co(C2N3)2(C6H7N)2]	F(000) = 386
Mr = 377.28	Dx = 1.463 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 3521 reflections
a = 9.3686 (19) Å	θ = 3.1–28.7°
b = 13.080 (3) Å	µ = 1.02 mm^−1
c = 7.3048 (15) Å	T = 150 K
β = 106.86 (3)°	Block, pink
V = 856.7 (3) Å^3	0.21 × 0.17 × 0.15 mm
Z = 2

Data collection

Rigaku Saturn724+ diffractometer	1549 independent reflections
Radiation source: fine-focus sealed tube	1419 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.016
ω scans	θmax = 25.4°, θmin = 3.3°
Absorption correction: multi-scan (CrystalClear; Rigaku, 2008)	h = −10→11
Tmin = 0.815, Tmax = 1.000	k = −12→15
4994 measured reflections	l = −8→8

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.031	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.085	H-atom parameters constrained
S = 1.07	w = 1/[σ^2(Fo^2) + (0.0483P)^2 + 0.6117P] where P = (Fo^2 + 2Fc^2)/3
1549 reflections	(Δ/σ)max < 0.001
115 parameters	Δρmax = 0.94 e Å^−3
0 restraints	Δρmin = −0.26 e Å^−3

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
Co1	1.0000	0.0000	0.5000	0.01854 (16)
N1	0.86523 (19)	−0.07208 (14)	0.6510 (3)	0.0262 (4)
N2	0.87457 (19)	−0.07142 (14)	1.2428 (2)	0.0249 (4)
N3	0.76592 (19)	−0.12944 (15)	0.9113 (2)	0.0275 (4)
N4	0.85008 (18)	0.12713 (13)	0.4394 (2)	0.0213 (4)
C1	0.8228 (2)	−0.09665 (15)	0.7775 (3)	0.0203 (4)
C2	0.8276 (2)	−0.09642 (15)	1.0853 (3)	0.0194 (4)
C3	0.7023 (2)	0.11338 (17)	0.3732 (3)	0.0274 (5)
H3B	0.6656	0.0469	0.3562	0.033*
C4	0.6022 (2)	0.19299 (18)	0.3293 (3)	0.0315 (5)
H4A	0.5006	0.1796	0.2828	0.038*
C5	0.6525 (2)	0.29340 (17)	0.3544 (3)	0.0287 (5)
C6	0.5461 (3)	0.3821 (2)	0.3074 (4)	0.0420 (6)
H6A	0.4458	0.3570	0.2615	0.063*
H6B	0.5682	0.4235	0.2105	0.063*
H6C	0.5566	0.4225	0.4203	0.063*
C7	0.8053 (2)	0.30713 (17)	0.4229 (3)	0.0301 (5)
H7A	0.8448	0.3728	0.4420	0.036*
C8	0.8989 (2)	0.22389 (16)	0.4628 (3)	0.0261 (5)
H8A	1.0010	0.2353	0.5083	0.031*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Co1	0.0207 (2)	0.0195 (2)	0.0153 (2)	−0.00038 (14)	0.00501 (16)	−0.00061 (14)
N1	0.0278 (9)	0.0278 (10)	0.0236 (9)	−0.0027 (7)	0.0086 (8)	0.0009 (8)
N2	0.0263 (9)	0.0267 (9)	0.0206 (10)	−0.0019 (7)	0.0053 (7)	−0.0036 (7)
N3	0.0242 (9)	0.0401 (11)	0.0181 (9)	−0.0131 (8)	0.0059 (7)	−0.0038 (8)
N4	0.0218 (8)	0.0219 (9)	0.0198 (9)	−0.0009 (7)	0.0053 (7)	−0.0008 (7)
C1	0.0169 (9)	0.0205 (10)	0.0201 (10)	−0.0007 (7)	0.0001 (8)	−0.0034 (8)
C2	0.0167 (9)	0.0191 (9)	0.0227 (11)	−0.0006 (7)	0.0064 (8)	0.0021 (8)
C3	0.0241 (10)	0.0258 (11)	0.0309 (12)	−0.0044 (8)	0.0056 (9)	−0.0032 (9)
C4	0.0193 (10)	0.0349 (12)	0.0386 (13)	−0.0010 (9)	0.0055 (9)	−0.0012 (10)
C5	0.0285 (11)	0.0283 (12)	0.0285 (11)	0.0055 (9)	0.0072 (9)	0.0017 (9)
C6	0.0370 (13)	0.0372 (14)	0.0511 (16)	0.0127 (11)	0.0118 (12)	0.0034 (12)
C7	0.0309 (11)	0.0213 (11)	0.0382 (13)	−0.0014 (9)	0.0102 (10)	−0.0010 (9)
C8	0.0217 (10)	0.0250 (11)	0.0306 (12)	−0.0024 (8)	0.0062 (9)	−0.0005 (9)

Geometric parameters (Å, º)

Co1—N2^i	2.1219 (18)	C3—C4	1.376 (3)
Co1—N2^ii	2.1219 (18)	C3—H3B	0.9300
Co1—N1^iii	2.1229 (18)	C4—C5	1.389 (3)
Co1—N1	2.1229 (18)	C4—H4A	0.9300
Co1—N4	2.1385 (17)	C5—C7	1.384 (3)
Co1—N4^iii	2.1385 (17)	C5—C6	1.503 (3)
N1—C1	1.152 (3)	C6—H6A	0.9600
N2—C2	1.153 (3)	C6—H6B	0.9600
N2—Co1^iv	2.1219 (18)	C6—H6C	0.9600
N3—C2	1.308 (3)	C7—C8	1.375 (3)
N3—C1	1.314 (3)	C7—H7A	0.9300
N4—C8	1.340 (3)	C8—H8A	0.9300
N4—C3	1.340 (3)
N2^i—Co1—N2^ii	180.00 (7)	N2—C2—N3	175.1 (2)
N2^i—Co1—N1^iii	89.76 (7)	N4—C3—C4	123.1 (2)
N2^ii—Co1—N1^iii	90.24 (7)	N4—C3—H3B	118.5
N2^i—Co1—N1	90.24 (7)	C4—C3—H3B	118.5
N2^ii—Co1—N1	89.76 (7)	C3—C4—C5	120.2 (2)
N1^iii—Co1—N1	180.00 (9)	C3—C4—H4A	119.9
N2^i—Co1—N4	89.84 (7)	C5—C4—H4A	119.9
N2^ii—Co1—N4	90.16 (7)	C7—C5—C4	116.5 (2)
N1^iii—Co1—N4	90.06 (7)	C7—C5—C6	122.0 (2)
N1—Co1—N4	89.94 (7)	C4—C5—C6	121.5 (2)
N2^i—Co1—N4^iii	90.16 (7)	C5—C6—H6A	109.5
N2^ii—Co1—N4^iii	89.84 (7)	C5—C6—H6B	109.5
N1^iii—Co1—N4^iii	89.94 (7)	H6A—C6—H6B	109.5
N1—Co1—N4^iii	90.06 (7)	C5—C6—H6C	109.5
N4—Co1—N4^iii	180.0	H6A—C6—H6C	109.5
C1—N1—Co1	159.33 (16)	H6B—C6—H6C	109.5
C2—N2—Co1^iv	163.96 (16)	C8—C7—C5	120.2 (2)
C2—N3—C1	117.09 (17)	C8—C7—H7A	119.9
C8—N4—C3	116.84 (18)	C5—C7—H7A	119.9
C8—N4—Co1	121.94 (13)	N4—C8—C7	123.2 (2)
C3—N4—Co1	121.22 (14)	N4—C8—H8A	118.4
N1—C1—N3	175.1 (2)	C7—C8—H8A	118.4

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C4—H4A···N3^v	0.93	2.57	3.487 (3)	168

Symmetry code: (v) −x+1, −y, −z+1.