Crystal structure of bis-(azido-κN)bis[2,5-bis(pyridin-2-yl)-1,3,4-thia-diazole-κ(2) N (2),N (3)]cobalt(II).

In the mononuclear title complex, [Co(N3)2(C12H8N4S)2], the cobalt(II) atom is located on an inversion centre and displays an axially weakly compressed octa-hedral coordination geometry. The equatorial positions are occupied by the N atoms of two 2,5-bis-(pyridin-2-yl)-1,3,4-thia-diazole ligands, whereas the axial positions are occupied by N atoms of the azide anions. The thia-diazole and pyridine rings linked to the metal are almost coplanar, with a maximum deviation from the mean plane of 0.0273 (16) Å. The cohesion of the crystal is ensured by weak C-H⋯N hydrogen bonds and by π-π inter-actions between pyridine rings [inter-centroid distance = 3.6356 (11) Å], forming a layered arrangement parallel to (001). The structure of the title compound is isotypic with that of the analogous nickel(II) complex [Laachir et al. (2013 ▶). Acta Cryst. E69, m351-m352].

Chemical context

In recent years, the use of the ligand 2,5-bis­(pyridin-2-yl)-1,3,4-thia­diazole has been studied for the synthesis of numerous complexes with transition-metal salts. An inter­esting feature of the n class="Chemical">metal–ligand chemistry of these compounds is that the resulting complexes can be mononuclear (Bentiss et al., 2011a ▸; 2012 ▸; Kaase et al., 2014 ▸) or binuclear (Bentiss et al., 2004 ▸; Laachir et al., 2013 ▸). Another preparation method involves the use of the organic ligand and pseudohalide ions, especially the azide ion which is known to exhibit different coordination modes (Nath & Baruah, 2012 ▸; Ray et al., 2011 ▸).

Structural commentary

The structure of the title compound (Fig. 1 ▸) is isotypic with its nickel(II) analogue (Laachir et al., 2015 ▸) and similar to that of the homologous compound, [Co(C12n class="Species">H8N4S)2(H2O)2]·2BF4, in which the water mol­ecules are substituted by azide ions which at the same time neutralize the positive charge of Co2+ (Bentiss et al., 2011b ▸). The main difference between the two structures lies in the values of the dihedral angle between the two pyridine rings: this is 18.72 (6)° in the hydrated mol­ecule, whereas it is 3.03 (2)° in the title mol­ecule, (I). The dihedral angles formed by the thia­diazole ring and the pyridine rings N1/C1–C4 and N2/C8–C11 in (I) are 2.87 (9) and 1.1 (2)°, respectively. The cobalt cation, which is located on an inversion centre, shows an axially weakly compressed octa­hedral coordination geometry with the equatorial plane provided by four nitro­gen atoms belonging to the pyridine and thia­diazole rings of two organic ligands [Co1—N3 = 2.1301 (14) and Co1—N4 = 2.1535 (14) Å] and the axial positions occupied by two nitro­gen atoms from azide anions [Co1—N5 = 2.1132 (17) Å].

Figure 1

The mol­ecular structure of the title compound with displacement ellipsoids drawn at the 50% probability level. H atoms are represented as spheres of arbitrary radius. [Symmetry code: (i) −x, −y, −z.]

Supra­molecular features

In the crystal, the mol­ecules are linked by π–π inter­actions between pyridine rings [inter­centroid distance = 3.6356 (11) Å] and by weak C—H⋯N n class="Chemical">hydrogen bonds (Table 1 ▸), forming a layered arrangement parallel to (001) (Fig. 2 ▸). The layers are connected by further C—H⋯N hydrogen bonds into a three-dimensional network.

Table 1

Hydrogen-bond geometry (, )

DHA	DH	HA	D A	DHA
C2H2N6i	0.93	2.59	3.432(3)	151
C11H11N7ii	0.93	2.60	3.528(3)	173
C10H10N1iii	0.93	2.63	3.438(2)	146

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

Figure 2

Partial crystal packing of the title compound, showing inter­molecular π–π inter­actions between pyridine rings (dashed green lines) and inter­molecular C—H⋯N hydrogen bonds (dashed blue lines).

Synthesis and crystallization

The ligand 2,5-bis­(pyridin-2-yl)-1,3,4-thia­diazole (noted L) was synthesized as described previously by Lebrini et al. (2005 ▸). The complex [CoL 2(N3)2] was synthesized in bulk qu­antity by dropwise addition with constant stirring at room temperature of an aqueous solution of n class="Chemical">NaN3 (0.4 mmol, 26 mg) to an ethanol/water solution (1:1 v/v) of L (0.1 mmol, 24 mg) and CoCl2·6H2O (0.1 mmol, 24 mg). The red-coloured solid precipitated was filtered and washed with cold ethanol. Single crystals of the title compound suitable for X-ray data collection were obtained by slow inter­diffusion of a solution of CoCl2·6H2O and L in aceto­nitrile into NaN3 dissolved in water. Red block-shaped single crystals appeared after one month. The crystals were washed with water and dried under vacuum (yield 60%). Analysis calculated for C24H16N14CoS2: C, 46.23; H, 2.59; N, 31.45 S, 10.28. Found: C, 46.42; H, 2.63; N, 31.35; S, 10.51.

CAUTION! Azide compounds are potentially explosive. Only a small amount of material should be prepared and handled with care.

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2 ▸. H atoms were located in a difference Fourier map and treated as riding, with C—H = 0.93 Å, and with U iso(H) = 1.2 U eq(C). Two outliers (002 and 24) were omitted in the last cycles of refinement.

Table 2

Experimental details

Crystal data
Chemical formula	[Co(N3)2(C12H8N4S)2]
M r	623.56
Crystal system, space group	Monoclinic, P21/c
Temperature (K)	296
a, b, c ()	7.8004(3), 8.2439(3), 20.3222(8)
()	92.910(2)
V (3)	1305.15(9)
Z	2
Radiation type	Mo K
(mm1)	0.86
Crystal size (mm)	0.39 0.31 0.18
Data collection
Diffractometer	Bruker APEXII CCD
Absorption correction	Multi-scan (SADABS; Bruker, 2009 ▸)
T min, T max	0.640, 0.747
No. of measured, independent and observed [I > 2(I)] reflections	27415, 3667, 2884
R int	0.043
(sin /)max (1)	0.694
Refinement
R[F 2 > 2(F 2)], wR(F 2), S	0.035, 0.088, 1.03
No. of reflections	3667
No. of parameters	187
H-atom treatment	H-atom parameters constrained
max, min (e 3)	0.70, 0.26

Computer programs: APEX2 and SAINT (Bruker, 2009 ▸), SHELXS97 and SHELXL97 (Sheldrick, 2008 ▸), ORTEP-3 for Windows and WinGX (Farrugia, 2012 ▸).

Crystal structure: contains datablock(s) I. DOI: 10.1107/S2056989015006544/rz5153sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S2056989015006544/rz5153Isup2.hkl

CCDC reference: 1057234

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

[Co(N3)2(C12H8N4S)2]	F(000) = 634
Mr = 623.56	Dx = 1.587 Mg m−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 3667 reflections
a = 7.8004 (3) Å	θ = 2.6–29.6°
b = 8.2439 (3) Å	µ = 0.86 mm−1
c = 20.3222 (8) Å	T = 296 K
β = 92.910 (2)°	Block, red
V = 1305.15 (9) Å3	0.39 × 0.31 × 0.18 mm
Z = 2

Bruker APEXII CCD diffractometer	3667 independent reflections
Radiation source: fine-focus sealed tube	2884 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.043
φ and ω scans	θmax = 29.6°, θmin = 2.6°
Absorption correction: multi-scan (SADABS; Bruker, 2009)	h = −8→10
Tmin = 0.640, Tmax = 0.747	k = −11→11
27415 measured reflections	l = −28→28

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)] = 0.035	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.088	H-atom parameters constrained
S = 1.03	w = 1/[σ2(Fo2) + (0.0381P)2 + 0.5683P] where P = (Fo2 + 2Fc2)/3
3667 reflections	(Δ/σ)max < 0.001
187 parameters	Δρmax = 0.70 e Å−3
0 restraints	Δρmin = −0.26 e Å−3

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.

	x	y	z	Uiso*/Ueq
C1	0.7907 (3)	0.4986 (3)	0.07266 (12)	0.0486 (5)
H1	0.8731	0.5035	0.0412	0.058*
C2	0.8166 (3)	0.5770 (3)	0.13200 (13)	0.0540 (6)
H2	0.9169	0.6353	0.1416	0.065*
C3	0.6910 (3)	0.5672 (3)	0.17662 (13)	0.0568 (6)
H3	0.7097	0.6203	0.2167	0.068*
N1	0.5445 (2)	0.4873 (2)	0.16646 (9)	0.0448 (4)
C5	0.5212 (2)	0.4114 (2)	0.10851 (9)	0.0316 (4)
C6	0.3585 (2)	0.3225 (2)	0.10077 (8)	0.0298 (4)
C7	0.0891 (2)	0.1991 (2)	0.11550 (8)	0.0285 (3)
C8	−0.0761 (2)	0.1314 (2)	0.13257 (8)	0.0276 (3)
C9	−0.1510 (2)	0.1627 (2)	0.19143 (8)	0.0338 (4)
H9	−0.0963	0.2283	0.2233	0.041*
C10	−0.3087 (2)	0.0943 (2)	0.20186 (9)	0.0369 (4)
H10	−0.3623	0.1133	0.2410	0.044*
C11	−0.3856 (2)	−0.0022 (2)	0.15379 (10)	0.0382 (4)
H11	−0.4920	−0.0493	0.1599	0.046*
C12	−0.3022 (2)	−0.0285 (2)	0.09601 (9)	0.0348 (4)
H12	−0.3547	−0.0941	0.0637	0.042*
C4	0.6406 (2)	0.4123 (2)	0.06039 (10)	0.0383 (4)
H4	0.6204	0.3565	0.0210	0.046*
N2	0.30958 (18)	0.23430 (19)	0.05046 (7)	0.0314 (3)
N3	0.15296 (18)	0.16405 (19)	0.05884 (7)	0.0307 (3)
N4	−0.14945 (18)	0.03680 (18)	0.08497 (7)	0.0285 (3)
N5	0.1294 (2)	−0.1959 (2)	0.04761 (8)	0.0425 (4)
N6	0.1687 (2)	−0.1872 (2)	0.10472 (8)	0.0394 (4)
N7	0.2046 (3)	−0.1805 (3)	0.16093 (9)	0.0650 (6)
S1	0.21579 (6)	0.32700 (6)	0.16328 (2)	0.03604 (12)
Co1	0.0000	0.0000	0.0000	0.02677 (10)

	U11	U22	U33	U12	U13	U23
C1	0.0316 (10)	0.0552 (13)	0.0600 (14)	−0.0009 (10)	0.0134 (9)	0.0183 (11)
C2	0.0366 (11)	0.0422 (12)	0.0829 (17)	−0.0157 (10)	0.0016 (11)	0.0003 (12)
C3	0.0475 (13)	0.0543 (14)	0.0687 (15)	−0.0162 (11)	0.0041 (11)	−0.0261 (12)
N1	0.0358 (9)	0.0484 (10)	0.0508 (10)	−0.0103 (8)	0.0086 (8)	−0.0184 (8)
C5	0.0270 (8)	0.0304 (9)	0.0371 (9)	−0.0022 (7)	0.0009 (7)	0.0008 (7)
C6	0.0269 (8)	0.0349 (9)	0.0278 (8)	−0.0020 (7)	0.0028 (7)	0.0002 (7)
C7	0.0292 (8)	0.0349 (9)	0.0213 (7)	−0.0025 (7)	0.0004 (6)	−0.0024 (6)
C8	0.0277 (8)	0.0330 (9)	0.0223 (7)	−0.0009 (7)	0.0028 (6)	0.0013 (6)
C9	0.0368 (9)	0.0432 (10)	0.0216 (8)	−0.0008 (8)	0.0040 (7)	−0.0026 (7)
C10	0.0371 (9)	0.0468 (11)	0.0280 (9)	0.0032 (9)	0.0118 (7)	0.0033 (8)
C11	0.0308 (9)	0.0445 (11)	0.0403 (10)	−0.0032 (8)	0.0112 (8)	0.0055 (8)
C12	0.0310 (9)	0.0393 (10)	0.0342 (9)	−0.0060 (8)	0.0042 (7)	−0.0026 (7)
C4	0.0353 (9)	0.0443 (11)	0.0355 (10)	0.0012 (8)	0.0029 (8)	0.0038 (8)
N2	0.0284 (7)	0.0407 (8)	0.0252 (7)	−0.0078 (6)	0.0032 (6)	−0.0028 (6)
N3	0.0281 (7)	0.0411 (8)	0.0229 (7)	−0.0064 (6)	0.0028 (6)	−0.0027 (6)
N4	0.0283 (7)	0.0340 (7)	0.0235 (7)	−0.0032 (6)	0.0034 (6)	−0.0012 (6)
N5	0.0489 (10)	0.0472 (10)	0.0316 (8)	0.0043 (8)	0.0037 (7)	0.0004 (7)
N6	0.0301 (8)	0.0476 (10)	0.0404 (9)	−0.0064 (7)	0.0010 (7)	0.0125 (7)
N7	0.0610 (13)	0.0935 (17)	0.0391 (10)	−0.0169 (12)	−0.0125 (9)	0.0198 (10)
S1	0.0322 (2)	0.0481 (3)	0.0282 (2)	−0.0092 (2)	0.00487 (17)	−0.01202 (19)
Co1	0.02599 (16)	0.03633 (19)	0.01818 (15)	−0.00561 (14)	0.00290 (11)	−0.00329 (13)

C1—C2	1.374 (3)	C9—H9	0.9300
C1—C4	1.382 (3)	C10—C11	1.374 (3)
C1—H1	0.9300	C10—H10	0.9300
C2—C3	1.371 (3)	C11—C12	1.388 (3)
C2—H2	0.9300	C11—H11	0.9300
C3—N1	1.326 (3)	C12—N4	1.337 (2)
C3—H3	0.9300	C12—H12	0.9300
N1—C5	1.338 (2)	C4—H4	0.9300
C5—C4	1.384 (3)	N2—N3	1.3704 (19)
C5—C6	1.467 (2)	N3—Co1	2.1301 (14)
C6—N2	1.297 (2)	N4—Co1	2.1535 (14)
C6—S1	1.7317 (16)	N5—N6	1.187 (2)
C7—N3	1.310 (2)	N5—Co1	2.1132 (17)
C7—C8	1.462 (2)	N6—N7	1.164 (2)
C7—S1	1.7128 (17)	Co1—N5i	2.1132 (17)
C8—N4	1.347 (2)	Co1—N3i	2.1301 (14)
C8—C9	1.382 (2)	Co1—N4i	2.1535 (14)
C9—C10	1.380 (3)
C2—C1—C4	119.10 (19)	N4—C12—C11	122.64 (17)
C2—C1—H1	120.5	N4—C12—H12	118.7
C4—C1—H1	120.5	C11—C12—H12	118.7
C3—C2—C1	118.31 (19)	C1—C4—C5	118.00 (19)
C3—C2—H2	120.8	C1—C4—H4	121.0
C1—C2—H2	120.8	C5—C4—H4	121.0
N1—C3—C2	124.4 (2)	C6—N2—N3	111.59 (13)
N1—C3—H3	117.8	C7—N3—N2	113.40 (14)
C2—C3—H3	117.8	C7—N3—Co1	113.97 (11)
C3—N1—C5	116.54 (18)	N2—N3—Co1	132.53 (10)
N1—C5—C4	123.60 (17)	C12—N4—C8	117.54 (15)
N1—C5—C6	113.95 (15)	C12—N4—Co1	126.96 (12)
C4—C5—C6	122.44 (17)	C8—N4—Co1	115.44 (11)
N2—C6—C5	125.69 (15)	N6—N5—Co1	119.66 (14)
N2—C6—S1	114.57 (12)	N7—N6—N5	178.7 (2)
C5—C6—S1	119.72 (13)	C7—S1—C6	86.85 (8)
N3—C7—C8	120.22 (15)	N5—Co1—N5i	180.0
N3—C7—S1	113.57 (13)	N5—Co1—N3i	90.73 (6)
C8—C7—S1	126.20 (12)	N5i—Co1—N3i	89.27 (6)
N4—C8—C9	123.13 (16)	N5—Co1—N3	89.27 (6)
N4—C8—C7	113.46 (14)	N5i—Co1—N3	90.73 (6)
C9—C8—C7	123.40 (16)	N3i—Co1—N3	180.0
C10—C9—C8	118.44 (17)	N5—Co1—N4	90.35 (6)
C10—C9—H9	120.8	N5i—Co1—N4	89.65 (6)
C8—C9—H9	120.8	N3i—Co1—N4	103.24 (5)
C11—C10—C9	119.22 (16)	N3—Co1—N4	76.76 (5)
C11—C10—H10	120.4	N5—Co1—N4i	89.65 (6)
C9—C10—H10	120.4	N5i—Co1—N4i	90.34 (6)
C10—C11—C12	119.01 (17)	N3i—Co1—N4i	76.76 (5)
C10—C11—H11	120.5	N3—Co1—N4i	103.24 (5)
C12—C11—H11	120.5	N4—Co1—N4i	180.0

D—H···A	D—H	H···A	D···A	D—H···A
C2—H2···N6ii	0.93	2.59	3.432 (3)	151
C11—H11···N7iii	0.93	2.60	3.528 (3)	173
C10—H10···N1iv	0.93	2.63	3.438 (2)	146