catena-Poly[(di­chloridozinc)-μ-bis­­(pyridin-3-yl)methanone-κ²N:N′]

In the title polymer, [ZnCl₂(C₁₁H₈N₂O)]_n, the Zn^II atom lies on a twofold rotation axis and has a distorted tetra­hedral ZnCl₂N₂ geometry involving two chloride donors and two N-atom donors from μ₂-bridging bis­(pyridin-3-yl)methanone ligands, which also have twofold symmetry. A zigzag chain structure is formed, extending along (001). Each chain is surrounded by three others which are inter­connected through weak C=O⋯π_pyrid­yl [O⋯centroid = 2.999 (3) Å] and π_pyrid­yl–π_pyrid­yl inter­actions [minimum ring centroid separation = 4.014 (2) Å], giving a three-dimensional framework.

Related literature

For background to the coordination chemistry of pyridyl­ketone derivatives, see: Huang et al. (2003); Wan et al. (2008). For transition metal complexes of bis­(3-pyrid­yl)ketone, see: Chen et al. (2005, 2009); Chen & Mak (2005).

Experimental

Crystal data

• [ZnCl₂(C₁₁H₈N₂O)]

• M_r = 320.46

• Monoclinic, C 2/c

• a = 9.9266 (7) Å

• b = 15.5724 (10) Å

• c = 7.8963 (6) Å

• β = 93.878 (4)°

• V = 1217.82 (15) ų

• Z = 4

• Mo Kα radiation

• μ = 2.44 mm⁻¹

• T = 296 K

• 0.40 × 0.32 × 0.22 mm

Data collection

• Bruker APEXII CCD area-detector diffractometer

• Absorption correction: multi-scan (SADABS; Bruker, 2007) T_min = 0.913, T_max = 1.000

• 3481 measured reflections

• 1076 independent reflections

• 1041 reflections with I > 2σ(I)

• R_int = 0.013

Refinement

• R[F² > 2σ(F²)] = 0.020

• wR(F²) = 0.055

• S = 1.11

• 1076 reflections

• 79 parameters

• H-atom parameters constrained

• Δρ_max = 0.19 e Å⁻³

• Δρ_min = −0.32 e Å⁻³

Data collection: APEX2 (Bruker, 2007); cell refinement: APEX2 and SAINT (Bruker, 2007); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009).

Supporting information

S1. Comment

The carbonyl (C═O) group in pyridyl ketone derivatives produces versatile angular building blocks for use as ligands for the generation of various coordination supramolecular architectures (Huang et al., 2003). With two pendant pyridyl rings and the rotatable C—C σ bonds, bis(3-pyridyl)methanone functions as an excellent µ₂-bridging linker to assemble various transition metal salts into diverse coordination motifs, such as one-dimensional helical and zigzag chains (Chen & Mak, 2005), two-dimensional nets (Chen et al., 2005), as well as honeycomb-like three-dimensional frameworks (Chen et al., 2009).

Reported here is the structure of a new complex of bis(3-pyridyl)methanone with ZnCl₂, the title compound [ZnCl₂(C₅NH₄)₂]_n. In this complex, the Zn²⁺ lies on a crystallographic twofold rotation axis and adopts a distorted tetrahedral stereochemistry [N1—Zn1—N1ⁱ = 96.94 (8)°; Cl1—Zn1—Cl1ⁱ = 122.25 (3)°: symmetry code (i) -x+1, -y, -z+1], with two chloride donors and two N donors from separate µ²-bridging bis(3-pyridyl)methanone ligands, in which the C═O group also lies on a twofold rotation axis (Fig. 1). This results in a zigzag chain structure extending along (001) (Fig. 2). Each helix is surrounded by three others which are interconnected through weak C6═O1···π_pyridyl interactions [O1···Cg1ⁱⁱⁱ 2.999 (3) Å] [symmetry code (iii) x+3/2, y+1/2, z+1) and weak π_pyridyl···π_pyridyl interactions [ring centroid separation Cg1···Cg1^iv = 4.014 (2) Å] [symmetry code (iv) -x+3/2, y+1/2, -z+3/2] to form a three-dimensional framework (Fig. 3). For the C═O···π_pyridyl contact, the O atom is embraced by two symmetry related pyridyl rings, similar to that found in [Cu(L)₂(BF₄)₂] (Wan et al., 2008) (C═O···centroid = 2.9–3.1 Å) [L = 2,6-pyridinediyl(bis(3-pyridinyl)methanone)].

Related literature

For background to the coordination chemistry of pyridylketone derivatives, see: Huang et al. (2003); Wan et al. (2008). For transition metal complexes of bis(3-pyridyl)ketone, see: Chen et al. (2005, 2009); Chen & Mak (2005).

S2. Experimental

The bis(3-pyridinyl)methanone ligand was obtained using the literature reaction procedure (Chen et al., 2005). Reaction of this compound (19.1 mg, 0.1 mmol) with ZnCl₂ (14.0 mg, 0.1 mmol) in methanol gave a colorless solution which after filtration, was allowed to stand in air for two weeks, gave colourless block-like crystals (yield 20.8 mg; 65%).

S3. Refinement

All H atoms were located in the difference electron density maps but were placed in idealized positions and allowed to ride on the carrier atoms, with C—H = 0.93 Å and with U_iso(H) = 1.2U_eq(C).

Computing details

Data collection: APEX2 (Bruker, 2007); cell refinement: APEX2 and SAINT (Bruker, 2007); data reduction: SAINT (Bruker, 2007); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).

Figures

	Fig. 1. The title complex showing the atom-numbering scheme, with displacement ellipsoids shown at the 30% probability level. Hydrogen atoms are shown as spheres of arbitrary radius. Symmetry codes: (i) -x+1, -y, -z+1; (ii) -x+1, -y, -z.
	Fig. 2. The helical chain structure of the title compound, extending along the c axial direction. All H atoms are omitted.
	Fig. 3. The packing structure of the title compound as viewed down the c axis of the unit cell.

catena-Poly[(dichloridozinc)-µ-bis(pyridin-3-yl)methanone- κ²N:N']

Crystal data

[ZnCl2(C11H8N2O)]	F(000) = 640
Mr = 320.46	Dx = 1.748 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 254 reflections
a = 9.9266 (7) Å	θ = 2.6–25.0°
b = 15.5724 (10) Å	µ = 2.44 mm^−1
c = 7.8963 (6) Å	T = 296 K
β = 93.878 (4)°	Block, colorless
V = 1217.82 (15) Å^3	0.40 × 0.32 × 0.22 mm
Z = 4

Data collection

Bruker APEXII CCD area-detector diffractometer	1076 independent reflections
Radiation source: fine-focus sealed tube	1041 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.013
ω scans	θmax = 25.0°, θmin = 2.6°
Absorption correction: multi-scan (SADABS; Bruker, 2007)	h = −11→11
Tmin = 0.913, Tmax = 1.000	k = −16→18
3481 measured reflections	l = −9→9

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)] = 0.020	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.055	H-atom parameters constrained
S = 1.11	w = 1/[σ^2(Fo^2) + (0.0332P)^2 + 0.7286P] P = (Fo^2 + 2Fc^2)/3
1076 reflections	(Δ/σ)max < 0.001
79 parameters	Δρmax = 0.19 e Å^−3
0 restraints	Δρmin = −0.32 e Å^−3

Special details

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.

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 > 2sigma(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
Zn1	0.5000	0.296457 (17)	0.7500	0.03157 (13)
Cl1	0.35267 (5)	0.36506 (3)	0.57611 (6)	0.04896 (16)
N1	0.59607 (15)	0.20836 (9)	0.60337 (18)	0.0307 (3)
C2	0.77431 (19)	0.10656 (14)	0.5838 (3)	0.0444 (5)
H2A	0.8584	0.0862	0.6246	0.053*
C1	0.71626 (19)	0.17586 (13)	0.6597 (2)	0.0380 (4)
H1A	0.7621	0.2011	0.7535	0.046*
C3	0.7061 (2)	0.06820 (13)	0.4475 (2)	0.0411 (5)
H3A	0.7422	0.0203	0.3966	0.049*
C4	0.58196 (18)	0.10157 (11)	0.3857 (2)	0.0311 (4)
C5	0.53146 (17)	0.17218 (11)	0.4663 (2)	0.0299 (4)
H5A	0.4497	0.1955	0.4242	0.036*
C6	0.5000	0.05441 (16)	0.2500	0.0340 (5)
O1	0.5000	−0.02376 (12)	0.2500	0.0499 (5)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Zn1	0.0417 (2)	0.02859 (19)	0.02354 (17)	0.000	−0.00413 (12)	0.000
Cl1	0.0606 (3)	0.0468 (3)	0.0376 (3)	0.0161 (2)	−0.0108 (2)	0.0043 (2)
N1	0.0368 (8)	0.0304 (8)	0.0245 (7)	−0.0003 (6)	−0.0006 (6)	0.0026 (5)
C2	0.0372 (10)	0.0514 (12)	0.0442 (11)	0.0107 (9)	0.0001 (8)	0.0125 (9)
C1	0.0397 (10)	0.0429 (10)	0.0307 (9)	−0.0023 (8)	−0.0033 (8)	0.0076 (8)
C3	0.0505 (11)	0.0366 (10)	0.0373 (10)	0.0142 (8)	0.0112 (8)	0.0071 (8)
C4	0.0428 (10)	0.0275 (9)	0.0236 (8)	0.0026 (7)	0.0057 (7)	0.0056 (6)
C5	0.0349 (9)	0.0288 (9)	0.0257 (8)	0.0025 (7)	0.0001 (7)	0.0037 (7)
C6	0.0494 (14)	0.0271 (13)	0.0268 (12)	0.000	0.0121 (10)	0.000
O1	0.0798 (15)	0.0254 (10)	0.0452 (11)	0.000	0.0094 (10)	0.000

Geometric parameters (Å, º)

Zn1—N1^i	2.0692 (15)	C1—H1A	0.9300
Zn1—N1	2.0692 (15)	C3—C4	1.395 (3)
Zn1—Cl1^i	2.2123 (5)	C3—H3A	0.9300
Zn1—Cl1	2.2123 (5)	C4—C5	1.382 (2)
N1—C5	1.344 (2)	C4—C6	1.494 (2)
N1—C1	1.344 (2)	C5—H5A	0.9300
C2—C3	1.369 (3)	C6—O1	1.217 (3)
C2—C1	1.379 (3)	C6—C4^ii	1.494 (2)
C2—H2A	0.9300
N1^i—Zn1—N1	96.94 (8)	C2—C1—H1A	118.7
N1^i—Zn1—Cl1^i	106.45 (4)	C2—C3—C4	119.40 (18)
N1—Zn1—Cl1^i	110.92 (4)	C2—C3—H3A	120.3
N1^i—Zn1—Cl1	110.92 (4)	C4—C3—H3A	120.3
N1—Zn1—Cl1	106.45 (4)	C5—C4—C3	118.33 (17)
Cl1^i—Zn1—Cl1	122.25 (3)	C5—C4—C6	121.66 (15)
C5—N1—C1	118.25 (15)	C3—C4—C6	119.56 (16)
C5—N1—Zn1	121.04 (12)	N1—C5—C4	122.45 (16)
C1—N1—Zn1	119.81 (12)	N1—C5—H5A	118.8
C3—C2—C1	118.92 (17)	C4—C5—H5A	118.8
C3—C2—H2A	120.5	O1—C6—C4	119.45 (10)
C1—C2—H2A	120.5	O1—C6—C4^ii	119.45 (10)
N1—C1—C2	122.60 (17)	C4—C6—C4^ii	121.1 (2)
N1—C1—H1A	118.7
N1^i—Zn1—N1—C5	83.07 (13)	C2—C3—C4—C5	−0.7 (3)
Cl1^i—Zn1—N1—C5	−166.32 (11)	C2—C3—C4—C6	−173.16 (16)
Cl1—Zn1—N1—C5	−31.20 (13)	C1—N1—C5—C4	2.2 (2)
N1^i—Zn1—N1—C1	−85.85 (13)	Zn1—N1—C5—C4	−166.90 (12)
Cl1^i—Zn1—N1—C1	24.76 (14)	C3—C4—C5—N1	−1.4 (2)
Cl1—Zn1—N1—C1	159.88 (12)	C6—C4—C5—N1	170.88 (15)
C5—N1—C1—C2	−0.9 (3)	C5—C4—C6—O1	−136.51 (12)
Zn1—N1—C1—C2	168.33 (14)	C3—C4—C6—O1	35.68 (17)
C3—C2—C1—N1	−1.2 (3)	C5—C4—C6—C4^ii	43.49 (12)
C1—C2—C3—C4	1.9 (3)	C3—C4—C6—C4^ii	−144.32 (17)

Symmetry codes: (i) −x+1, y, −z+3/2; (ii) −x+1, y, −z+1/2.