Crystal structure of a looped-chain CoII coordination polymer: catena-poly[[bis-(nitrato-κO)cobalt(II)]bis-[μ-bis-(pyridin-3-ylmeth-yl)sulfane-κ2N:N']].

The asymmetric unit of the title compound, [Co(NO3)2(C12H12N2S)2] n , contains a bis-(pyridin-3-ylmeth-yl)sulfane (L) ligand, an NO3- anion and half a CoII cation, which lies on an inversion centre. The CoII cation is six-coordinated, being bound to four pyridine N atoms from four symmetry-related L ligands. The remaining coordination sites are occupied by two O atoms from two symmetry-related nitrate anions in a monodentate manner. Thus, the CoII centre adopts a distorted octa-hedral geometry. Two symmetry-related L ligands are connected by two symmetry-related CoII cations, forming a 20-membered cyclic dimer, in which the CoII atoms are separated by 10.2922 (7) Å. The cyclic dimers are connected to each other by sharing CoII atoms, giving rise to the formation of an infinite looped chain propagating along the [101] direction. Inter-molecular C-H⋯π (H⋯ring centroid = 2.89 Å) inter-actions between one pair of corresponding L ligands and C-H⋯O hydrogen bonds between the L ligands and the nitrate anions occur in the looped chain. In the crystal, adjacent looped chains are connected by inter-molecular π-π stacking inter-actions [centroid-to-centroid distance = 3.8859 (14) Å] and C-H⋯π hydrogen bonds (H⋯ring centroid = 2.65 Å), leading to the formation of layers parallel to (101). These layers are further connected through C-H⋯O hydrogen bonds between the layers, resulting in the formation of a three-dimensional supra-molecular architecture.

Chemical context

Over the last two decades, numerous one-dimensional coord­ination polymers have been developed, not only because of their fascinating architectures but also their potential applications as functional materials (Furukawa et al., 2014 ▸; Silva et al., 2015 ▸). In this area of research, dipyridyl-type mol­ecules as organic building blocks have been widely used to construct diverse one-dimensional self-assembled coordination polymers with intriguing structural topologies (Leong & Vittal, 2011 ▸; Wang et al., 2012 ▸). Our group has also developed several one-dimensional coordination polymers with fascinating topologies such as zigzag (Lee et al., 2013 ▸; Moon et al., 2016 ▸), helical (Moon et al., 2014 ▸, 2015 ▸), double helical (Lee et al., 2015 ▸), looped chain (Ju et al., 2014 ▸) and ribbon-type double-stranded (Moon et al., 2017 ▸; Park et al., 2010 ▸) structures using dipyridyl-type ligands. In an extension of our research, the title compound was prepared by the reaction of cobalt(II) nitrate with bis­(pyridin-3-ylmeth­yl)sulfane (L) as a flexible dipyridyl-type ligand, synthesized using a literature procedure (Park et al., 2010 ▸; Lee et al., 2012 ▸). Herein, we report the crystal structure of the title compound, which adopts a one-dimensional looped-chain structure.

Structural commentary

As illustrated in Fig. 1 ▸, the asymmetric unit of the title compound consists of one CoII cation located on an inversion centre, one (pyridin-3-ylmeth­yl)sulfane ligand, L, and one NO3 − anion. The CoII cation is coordinated by four pyridine N atoms from four symmetry-related L ligands. In addition, the CoII cation binds to two O atoms of two symmetry-related monodentate nitrate anions, forming a distorted octa­hedral CoN4O2 coordination. Selected bond lengths and angles around the Co1 atom are listed in Table 1 ▸. The N1- and N2-pyridine rings coordinated to the CoII centre are tilted by 70.75 (7)° with respect to each other (Fig. 1 ▸).

Figure 1

View of the cyclic dimer structure of the title compound, showing the geometry around CoII centre and the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level. Inter­molecular C—H⋯π and C—H⋯O hydrogen bonds are represented by yellow and black dashed lines, respectively [symmetry codes: (i) x + 1, y, z + 1; (ii) −x + 1, −y + 1, −z + 1; (iii) −x, −y + 1, −z; (iv) x − 1, y, z − 1].

Table 1

Selected geometric parameters (Å, °)

Co1—O1	2.1414 (16)	Co1—N2i	2.1907 (18)
Co1—N1	2.1571 (17)
O1ii—Co1—O1	180.0	N1—Co1—N2i	92.32 (6)
O1—Co1—N1	85.34 (7)	O1—Co1—N2iii	88.21 (7)
O1—Co1—N1ii	94.66 (7)	N1—Co1—N2iii	87.68 (6)
N1—Co1—N1ii	180.0	N2i—Co1—N2iii	180.0
O1—Co1—N2i	91.79 (7)

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

Two symmetry-related L ligands bridge two CoII atoms, resulting in the formation of a 20-membered cyclic dimer with a Co⋯Co separation of 10.2922 (7) Å. The cyclic dimers are connected by sharing CoII atoms, leading to the formation of an infinite looped chain propagating along the [101] direction. An inter­molecular C7—H7B⋯ Cg2i inter­actions [H⋯π = 2.89 Å; Table 2 ▸; yellow dashed lines in Fig. 1 ▸; Cg2 is the centroid of atoms N2/C8–C12; symmetry code: (i) −x, −y + 1, −z] between one pair of corresponding L ligands and several C—H⋯O hydrogen bonds between the L ligands and the NO3 − anions (Table 2 ▸; black dashed lines in Fig. 1 ▸) contribute to the stabilization of the looped chain.

Table 2

Hydrogen-bond geometry (Å, °)

Cg2 is the centroid of the N2/C8–C12 ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C1—H1⋯O3iv	0.93	2.60	3.466 (3)	155
C5—H5⋯O2ii	0.93	2.30	3.171 (3)	157
C9—H9⋯O2ii	0.93	2.54	3.373 (3)	149
C11—H11⋯O1iii	0.93	2.43	3.032 (3)	122
C12—H12⋯O1v	0.93	2.53	3.134 (3)	123
C12—H12⋯O2v	0.93	2.59	3.219 (3)	125
C6—H6A⋯Cg2vi	0.97	2.65	3.546 (3)	154
C7—H7B⋯Cg2iii	0.97	2.89	3.565 (3)	127

Symmetry codes: (ii) ; (iii) ; (iv) ; (v) ; (vi) .

Supra­molecular features

Adjacent looped chains in the structure are connected by inter­molecular π–π stacking inter­actions between the N1-pyridine rings [Cg1⋯Cg1ii = 3.8859 (14) Å; yellow dashed lines in Fig. 2 ▸; Cg1 is the centroid of atoms N1/C1–C5; symmetry code: (ii) −x + 1, −y + 2, −z + 1] together with inter­molecular C6—H6A⋯Cg2iii hydrogen bonds [H⋯π = 2.65 Å; Table 2 ▸; black dashed lines in Fig. 2 ▸; symmetry code: (iii) −x, −y + 2, −z], generating layers parallel to (101). Neighboring layers are packed by C1—H1⋯O3iv hydrogen bonds [H⋯O = 2.60 Å; Table 2 ▸; yellow dashed lines in Fig. 3 ▸; symmetry code: (iv) −x + 2, −y + 1, −z + 1] between pyridine H atoms and nitro­gen O atoms, resulting in the formation of a three-dimensional supra­molecular architecture.

Figure 2

The supra­molecular layer formed by inter­molecular π–π stacking inter­actions (yellow dashed lines) and C—H⋯π hydrogen bonds (black dashed lines) between the looped chains. H atoms not involved in inter­molecular inter­actions have been omitted for clarity.

Figure 3

The three-dimensional supra­molecular network formed via inter­molecular C—H⋯O hydrogen bonds (yellow dashed lines) between the layers. H atoms not involved in inter­molecular inter­actions have been omitted for clarity.

Synthesis and crystallization

The L ligand was synthesized according to a literature method (Park et al., 2010 ▸; Lee et al., 2012 ▸). Crystals of the title compound were grown by slow evaporation of a methanol/H2O (2:1) solution of the L ligand with Co(NO3)2·6H2O in a 2:1 molar ratio.

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 3 ▸. All H atoms were positioned geometrically and refined as riding: C—H = 0.93 Å for Csp 2—H and 0.97 Å for methyl­ene C—H with U iso(H) = 1.2U eq(C).

Table 3

Experimental details

Crystal data
Chemical formula	[Co(NO3)2(C12H12N2S)2]
M r	615.54
Crystal system, space group	Triclinic, P
Temperature (K)	298
a, b, c (Å)	8.1620 (7), 8.8158 (8), 9.5078 (8)
α, β, γ (°)	98.531 (2), 109.218 (2), 92.062 (2)
V (Å3)	636.22 (10)
Z	1
Radiation type	Mo Kα
μ (mm−1)	0.89
Crystal size (mm)	0.45 × 0.30 × 0.15
Data collection
Diffractometer	Bruker APEXII CCD area detector
Absorption correction	Multi-scan (SADABS; Bruker, 2014 ▸)
T min, T max	0.634, 0.896
No. of measured, independent and observed [I > 2σ(I)] reflections	3659, 2456, 2082
R int	0.040
(sin θ/λ)max (Å−1)	0.617
Refinement
R[F 2 > 2σ(F 2)], wR(F 2), S	0.033, 0.088, 1.04
No. of reflections	2456
No. of parameters	178
H-atom treatment	H-atom parameters constrained
Δρmax, Δρmin (e Å−3)	0.33, −0.37

Computer programs: APEX2 and SAINT (Bruker, 2014 ▸), SHELXS97 and SHELXTL (Sheldrick, 2008 ▸), SHELXL2014/7 (Sheldrick, 2015 ▸), DIAMOND (Brandenburg, 2010 ▸) and publCIF (Westrip, 2010 ▸).

Crystal structure: contains datablock(s) I, New_Global_Publ_Block. DOI: 10.1107/S2056989017014980/hg5499sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S2056989017014980/hg5499Isup2.hkl

CCDC reference: 1580230

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

[Co(NO3)2(C12H12N2S)2]	Z = 1
Mr = 615.54	F(000) = 317
Triclinic, P1	Dx = 1.607 Mg m−3
a = 8.1620 (7) Å	Mo Kα radiation, λ = 0.71073 Å
b = 8.8158 (8) Å	Cell parameters from 3659 reflections
c = 9.5078 (8) Å	θ = 2.3–26.0°
α = 98.531 (2)°	µ = 0.89 mm−1
β = 109.218 (2)°	T = 298 K
γ = 92.062 (2)°	Plate, violet
V = 636.22 (10) Å3	0.45 × 0.30 × 0.15 mm

Bruker APEXII CCD area detector diffractometer	2082 reflections with I > 2σ(I)
φ and ω scans	Rint = 0.040
Absorption correction: multi-scan (SADABS; Bruker, 2014)	θmax = 26.0°, θmin = 2.3°
Tmin = 0.634, Tmax = 0.896	h = −7→10
3659 measured reflections	k = −10→10
2456 independent reflections	l = −11→7

Refinement on F2	0 restraints
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.033	H-atom parameters constrained
wR(F2) = 0.088	w = 1/[σ2(Fo2) + (0.0488P)2 + 0.1617P] where P = (Fo2 + 2Fc2)/3
S = 1.04	(Δ/σ)max < 0.001
2456 reflections	Δρmax = 0.33 e Å−3
178 parameters	Δρmin = −0.37 e Å−3

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

	x	y	z	Uiso*/Ueq
Co1	0.5000	0.5000	0.5000	0.02620 (13)
S1	0.20509 (7)	0.89446 (7)	−0.01804 (7)	0.03834 (17)
N1	0.5427 (2)	0.7131 (2)	0.42595 (19)	0.0294 (4)
N2	−0.3498 (2)	0.5946 (2)	−0.2639 (2)	0.0294 (4)
N3	0.8472 (2)	0.3452 (2)	0.4702 (2)	0.0353 (4)
O1	0.7307 (2)	0.4382 (2)	0.4536 (2)	0.0459 (4)
O2	0.9392 (2)	0.3314 (3)	0.5987 (2)	0.0623 (6)
O3	0.8698 (3)	0.2729 (2)	0.3594 (2)	0.0600 (5)
C1	0.7012 (3)	0.7803 (3)	0.4459 (3)	0.0359 (5)
H1	0.7992	0.7378	0.5020	0.043*
C2	0.7239 (3)	0.9093 (3)	0.3867 (3)	0.0419 (6)
H2	0.8356	0.9533	0.4041	0.050*
C3	0.5807 (3)	0.9731 (3)	0.3014 (3)	0.0377 (5)
H3	0.5945	1.0595	0.2595	0.045*
C4	0.4158 (3)	0.9065 (2)	0.2792 (2)	0.0293 (4)
C5	0.4044 (3)	0.7788 (2)	0.3446 (2)	0.0288 (4)
H5	0.2939	0.7352	0.3316	0.035*
C6	0.2546 (3)	0.9672 (3)	0.1822 (3)	0.0345 (5)
H6A	0.2707	1.0788	0.1994	0.041*
H6B	0.1566	0.9379	0.2119	0.041*
C7	0.1232 (3)	0.6961 (3)	−0.0308 (3)	0.0345 (5)
H7A	0.1544	0.6312	−0.1080	0.041*
H7B	0.1802	0.6624	0.0648	0.041*
C8	−0.0710 (3)	0.6735 (2)	−0.0675 (2)	0.0298 (5)
C9	−0.1533 (3)	0.7008 (3)	0.0387 (3)	0.0390 (5)
H9	−0.0889	0.7344	0.1402	0.047*
C10	−0.3334 (3)	0.6773 (3)	−0.0089 (3)	0.0425 (6)
H10	−0.3915	0.6973	0.0603	0.051*
C11	−0.4259 (3)	0.6242 (3)	−0.1590 (3)	0.0369 (5)
H11	−0.5466	0.6082	−0.1889	0.044*
C12	−0.1752 (3)	0.6202 (2)	−0.2167 (2)	0.0292 (4)
H12	−0.1205	0.6011	−0.2885	0.035*

	U11	U22	U33	U12	U13	U23
Co1	0.0226 (2)	0.0291 (2)	0.0237 (2)	0.00094 (15)	0.00236 (16)	0.00769 (16)
S1	0.0360 (3)	0.0407 (3)	0.0324 (3)	−0.0055 (2)	0.0012 (2)	0.0141 (2)
N1	0.0260 (9)	0.0313 (9)	0.0286 (9)	0.0012 (7)	0.0049 (7)	0.0082 (7)
N2	0.0280 (9)	0.0285 (9)	0.0279 (9)	−0.0005 (7)	0.0039 (7)	0.0067 (7)
N3	0.0288 (10)	0.0424 (11)	0.0357 (11)	−0.0022 (8)	0.0122 (8)	0.0074 (9)
O1	0.0323 (9)	0.0589 (11)	0.0496 (10)	0.0161 (8)	0.0135 (8)	0.0168 (9)
O2	0.0407 (10)	0.1040 (17)	0.0441 (11)	0.0230 (11)	0.0094 (9)	0.0258 (11)
O3	0.0686 (13)	0.0642 (13)	0.0510 (12)	0.0086 (10)	0.0314 (10)	−0.0046 (10)
C1	0.0243 (11)	0.0422 (13)	0.0367 (12)	0.0025 (9)	0.0023 (9)	0.0114 (10)
C2	0.0292 (12)	0.0469 (14)	0.0478 (14)	−0.0051 (10)	0.0093 (11)	0.0133 (11)
C3	0.0368 (12)	0.0334 (12)	0.0398 (13)	−0.0066 (9)	0.0077 (10)	0.0113 (10)
C4	0.0308 (11)	0.0282 (10)	0.0247 (10)	0.0002 (8)	0.0044 (9)	0.0040 (8)
C5	0.0238 (10)	0.0331 (11)	0.0274 (10)	−0.0003 (8)	0.0056 (8)	0.0067 (9)
C6	0.0337 (12)	0.0285 (11)	0.0370 (12)	0.0035 (9)	0.0042 (10)	0.0100 (9)
C7	0.0305 (11)	0.0330 (11)	0.0311 (11)	0.0001 (9)	−0.0008 (9)	0.0047 (9)
C8	0.0315 (11)	0.0254 (10)	0.0276 (11)	−0.0008 (8)	0.0027 (9)	0.0071 (8)
C9	0.0440 (13)	0.0419 (13)	0.0249 (11)	−0.0050 (10)	0.0051 (10)	0.0037 (9)
C10	0.0441 (14)	0.0520 (15)	0.0334 (12)	−0.0032 (11)	0.0181 (11)	0.0039 (11)
C11	0.0321 (12)	0.0444 (13)	0.0347 (12)	−0.0005 (10)	0.0117 (10)	0.0083 (10)
C12	0.0294 (11)	0.0279 (10)	0.0282 (11)	0.0004 (8)	0.0072 (9)	0.0052 (8)

Co1—O1i	2.1414 (16)	C2—H2	0.9300
Co1—O1	2.1414 (16)	C3—C4	1.386 (3)
Co1—N1	2.1571 (17)	C3—H3	0.9300
Co1—N1i	2.1571 (17)	C4—C5	1.378 (3)
Co1—N2ii	2.1907 (18)	C4—C6	1.505 (3)
Co1—N2iii	2.1907 (18)	C5—H5	0.9300
S1—C6	1.820 (2)	C6—H6A	0.9700
S1—C7	1.822 (2)	C6—H6B	0.9700
N1—C1	1.346 (3)	C7—C8	1.505 (3)
N1—C5	1.346 (3)	C7—H7A	0.9700
N2—C11	1.338 (3)	C7—H7B	0.9700
N2—C12	1.345 (3)	C8—C9	1.384 (3)
N2—Co1iv	2.1907 (17)	C8—C12	1.392 (3)
N3—O3	1.219 (3)	C9—C10	1.386 (3)
N3—O2	1.232 (3)	C9—H9	0.9300
N3—O1	1.264 (2)	C10—C11	1.376 (3)
C1—C2	1.374 (3)	C10—H10	0.9300
C1—H1	0.9300	C11—H11	0.9300
C2—C3	1.378 (3)	C12—H12	0.9300
O1i—Co1—O1	180.0	C4—C3—H3	120.5
O1i—Co1—N1	94.66 (7)	C5—C4—C3	117.63 (19)
O1—Co1—N1	85.34 (7)	C5—C4—C6	120.95 (19)
O1i—Co1—N1i	85.34 (7)	C3—C4—C6	121.38 (19)
O1—Co1—N1i	94.66 (7)	N1—C5—C4	124.37 (19)
N1—Co1—N1i	180.0	N1—C5—H5	117.8
O1i—Co1—N2ii	88.21 (7)	C4—C5—H5	117.8
O1—Co1—N2ii	91.79 (7)	C4—C6—S1	112.23 (16)
N1—Co1—N2ii	92.32 (6)	C4—C6—H6A	109.2
N1i—Co1—N2ii	87.68 (6)	S1—C6—H6A	109.2
O1i—Co1—N2iii	91.79 (7)	C4—C6—H6B	109.2
O1—Co1—N2iii	88.21 (7)	S1—C6—H6B	109.2
N1—Co1—N2iii	87.68 (6)	H6A—C6—H6B	107.9
N1i—Co1—N2iii	92.32 (6)	C8—C7—S1	113.88 (15)
N2ii—Co1—N2iii	180.0	C8—C7—H7A	108.8
C6—S1—C7	101.13 (11)	S1—C7—H7A	108.8
C1—N1—C5	116.71 (18)	C8—C7—H7B	108.8
C1—N1—Co1	123.98 (14)	S1—C7—H7B	108.8
C5—N1—Co1	119.10 (13)	H7A—C7—H7B	107.7
C11—N2—C12	116.94 (19)	C9—C8—C12	117.5 (2)
C11—N2—Co1iv	121.87 (15)	C9—C8—C7	124.0 (2)
C12—N2—Co1iv	121.15 (14)	C12—C8—C7	118.5 (2)
O3—N3—O2	120.9 (2)	C8—C9—C10	118.8 (2)
O3—N3—O1	119.8 (2)	C8—C9—H9	120.6
O2—N3—O1	119.3 (2)	C10—C9—H9	120.6
N3—O1—Co1	145.89 (15)	C11—C10—C9	119.7 (2)
N1—C1—C2	122.6 (2)	C11—C10—H10	120.2
N1—C1—H1	118.7	C9—C10—H10	120.2
C2—C1—H1	118.7	N2—C11—C10	122.9 (2)
C1—C2—C3	119.8 (2)	N2—C11—H11	118.6
C1—C2—H2	120.1	C10—C11—H11	118.6
C3—C2—H2	120.1	N2—C12—C8	124.2 (2)
C2—C3—C4	118.9 (2)	N2—C12—H12	117.9
C2—C3—H3	120.5	C8—C12—H12	117.9
O3—N3—O1—Co1	122.6 (3)	C7—S1—C6—C4	73.67 (17)
O2—N3—O1—Co1	−59.0 (4)	C6—S1—C7—C8	91.15 (17)
C5—N1—C1—C2	−0.2 (3)	S1—C7—C8—C9	−82.8 (2)
Co1—N1—C1—C2	174.55 (18)	S1—C7—C8—C12	98.0 (2)
N1—C1—C2—C3	−0.9 (4)	C12—C8—C9—C10	−1.4 (3)
C1—C2—C3—C4	1.0 (4)	C7—C8—C9—C10	179.4 (2)
C2—C3—C4—C5	0.1 (3)	C8—C9—C10—C11	1.5 (4)
C2—C3—C4—C6	−177.6 (2)	C12—N2—C11—C10	−0.5 (3)
C1—N1—C5—C4	1.4 (3)	Co1iv—N2—C11—C10	177.10 (18)
Co1—N1—C5—C4	−173.66 (16)	C9—C10—C11—N2	−0.6 (4)
C3—C4—C5—N1	−1.3 (3)	C11—N2—C12—C8	0.6 (3)
C6—C4—C5—N1	176.39 (19)	Co1iv—N2—C12—C8	−177.01 (15)
C5—C4—C6—S1	−95.4 (2)	C9—C8—C12—N2	0.4 (3)
C3—C4—C6—S1	82.2 (2)	C7—C8—C12—N2	179.61 (19)

D—H···A	D—H	H···A	D···A	D—H···A
C1—H1···O3v	0.93	2.60	3.466 (3)	155
C5—H5···O2i	0.93	2.30	3.171 (3)	157
C9—H9···O2i	0.93	2.54	3.373 (3)	149
C11—H11···O1iii	0.93	2.43	3.032 (3)	122
C12—H12···O1iv	0.93	2.53	3.134 (3)	123
C12—H12···O2iv	0.93	2.59	3.219 (3)	125
C6—H6A···Cg2vi	0.97	2.65	3.546 (3)	154
C7—H7B···Cg2iii	0.97	2.89	3.565 (3)	127