catena-Poly­[[di­chlorozinc(II)]-μ-1,3-di-4-pyridyl­propane-κ²N:N′]

The title compound, [ZnCl₂(bpp)]_n (where bpp is 1,3-di-4-pyridyl­propane, C₁₃H₁₄N₂), has been prepared by the hydro­thermal reaction of ZnCl₂ and bpp at 433 K. The Zn, Cl and central propyl C atom lie on the mirrors of the P2₁/m space group. The molecular structure shows a weave-like polymeric chain. Each Zn atom is coordinated by two N atoms and two Cl atoms in a distorted tetrahedral geometry, with the Zn—N distance being 2.055 (5) Å and the Zn—Cl distances being 2.239 (3) and 2.247 (2) Å.

S1. Comment

A large amount of investigation has involved linear pyridyl-donor ligands, including pyrazine (Real et al., 1991; Kitagawa et al., 1992; Carlucci et al., 1995), 4,4'-bipyridine (bipy; Blake et al., 1997; Yaghi & Li, 1996; Tong et al., 1998) and longer bridges (Fujita et al., 1995; Withersby et al., 1997). The commercially available compound bpp is a bipyridine-type ligand with a flexible CH₂CH₂CH₂– spacer, and a number of metal-bpp coordination polymers have been reported (Pan et al., 2001; Fu et al., 2001; Carlucci et al., 2002). However, to our knowledge, only a few structures of Zn-bpp coordination polymers have been reported (Plater et al., 2000). Here, we report a new zinc(II) polymeric compound, [Zn(bpp)Cl₂]_n, (I), with a weave-like polymeric chain structure, obtained via hydrothermal synthesis. \sch

In the title compound, (I), each Zn atom is coordinated by two N atoms from two bpp ligands and two Cl atoms to form a distorted tetrahedral geometry, with the Zn—N distance being 2.055 (5) Å and the Zn—Cl distances being 2.239 (3) and 2.247 (2) Å. As the result of this coordination, the molecular structure shows a weave-like polymeric chain, as shown in Fig.1. The chains have a repeat length (`wavelength') of 12.937 Å, which is approximately one half of the value of 24.6 Å in [Ag(bpp)](CF₃SO₃)·EtOH and 23.98 Å in [Ag(bpp)](NO₃) (Batten et al., 1999). This result is due to the different coordination mode [N1—Zn—N1' = 111.7 (3), N1—Zn1—Cl1 = 104.5 (1), N1—Zn1—Cl2 = 105.1 (1) and Cl1—Zn1—Cl2 = 126.0 (1)°] of the two-coordinate Ag⁺ ions (N—Ag—N = 180°) in [Ag(bpp)](NO₃). In addition, this molecule-polymer transition is linked to the capacity of the bidentate ligand (bpp) to span two metal centres (Zn). The pyridine rings in the same bpp ligand are not coplanar] dihedral angle of two planes 66.66 (18)°].

S2. Experimental

A mixture of ZnCl₂ (0.259 g, 1.9 mmol), bpp (0.255 g, 1.3 mmol), CH₃CH₂OH (3 ml) and H₂O (13 ml) was sealed in a 25 ml Teflon-lined stainless-steel reactor, heated to 443 K for 60 h, and then slowly cooled to room temperature. Block-shaped colourless crystals of (I), suitable for X-ray analysis, were obtained by filtration (yield 41.8%). Analysis calculated for C₁₃H₁₄Cl₂N₂Zn (%): C 46.67, H 4.22, N 8.37; found: C 46.46, H 3.84, N 8.35. IR spectroscopic analysis (KBr disc, ν, cm⁻¹): 1620 (s), 1433 (s), 1221 (m), 1072 (m), 1032 (s), 823 (s), 621 (m), 519 (s).

S3. Refinement

All H atoms were located theoretically and refined as riding atoms, with C—H distances in the range 0.93–0.97 Å and with U_iso(H) = 1.2U_eq(C). Is added text OK?

Computing details

Data collection: SMART (Siemens, 1996); cell refinement: SMART and SAINT (Siemens, 1996); data reduction: XPREP in SHELXTL (Siemens, 1996); program(s) used to solve structure: SHELXTL (Siemens, 1996); program(s) used to refine structure: SHELXTL (Siemens, 1996); molecular graphics: SHELXTL (Bruker, 2001); software used to prepare material for publication: SHELXTL (Bruker, 2001).

Figures

Fig. 1. A view of the repeat unit of (I). Displacement ellipsoids are plotted at the 30% probability level and H atoms are shown as small spheres of arbitrary radii.

catena-Poly[[dichloro-zinc(II)]-µ-1,3-di-4-pyridylpropane-κ²N:N']

Crystal data

[ZnCl2(C13H14N2)]	F(000) = 340
Mr = 334.53	Dx = 1.563 Mg m^−3
Monoclinic, P21/m	Mo Kα radiation, λ = 0.71073 Å
a = 5.2254 (4) Å	Cell parameters from 1292 reflections
b = 12.9371 (9) Å	θ = 1.9–25.0°
c = 10.5425 (6) Å	µ = 2.09 mm^−1
β = 94.247 (3)°	T = 293 K
V = 710.73 (8) Å^3	Block, colourless
Z = 2	0.80 × 0.26 × 0.20 mm

Data collection

CCD area detector diffractometer	1311 independent reflections
Radiation source: fine-focus sealed tube	1091 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.034
ϕ and ω scans	θmax = 25.0°, θmin = 1.9°
Absorption correction: empirical (using intensity measurements) (SADABS; Sheldrick, 1996)	h = −5→6
Tmin = 0.486, Tmax = 0.659	k = −15→15
2313 measured reflections	l = −12→4

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)] = 0.060	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.153	H-atom parameters constrained
S = 1.08	w = 1/[σ^2(Fo^2) + (0.0526P)^2 + 3.0106P] where P = (Fo^2 + 2Fc^2)/3
1311 reflections	(Δ/σ)max < 0.001
88 parameters	Δρmax = 0.64 e Å^−3
0 restraints	Δρmin = −0.48 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
Zn1	0.4591 (2)	0.2500	0.72070 (9)	0.0464 (4)
N1	0.2451 (9)	0.3815 (4)	0.7407 (5)	0.0450 (12)
C1	0.2886 (12)	0.4433 (5)	0.8416 (6)	0.0514 (15)
H1A	0.4219	0.4268	0.9016	0.062*
C2	0.1447 (12)	0.5299 (5)	0.8605 (6)	0.0525 (15)
H2A	0.1829	0.5711	0.9316	0.063*
C3	−0.0574 (11)	0.5563 (4)	0.7739 (6)	0.0474 (14)
C4	−0.1016 (12)	0.4919 (5)	0.6701 (6)	0.0539 (16)
H4A	−0.2352	0.5058	0.6093	0.065*
C5	0.0522 (12)	0.4074 (5)	0.6573 (6)	0.0544 (16)
H5A	0.0199	0.3657	0.5861	0.065*
C6	−0.2131 (12)	0.6524 (4)	0.7918 (6)	0.0513 (15)
H6A	−0.2641	0.6544	0.8784	0.062*
H6B	−0.3677	0.6499	0.7350	0.062*
C7	−0.0646 (17)	0.7500	0.7657 (9)	0.048 (2)
H7A	−0.0234	0.7500	0.6775	0.057*
H7B	0.0956	0.7500	0.8184	0.057*
Cl1	0.7497 (5)	0.2500	0.8888 (2)	0.0557 (6)
Cl2	0.5460 (5)	0.2500	0.5159 (2)	0.0631 (7)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Zn1	0.0583 (7)	0.0359 (5)	0.0446 (6)	0.000	0.0010 (4)	0.000
N1	0.050 (3)	0.035 (3)	0.049 (3)	−0.007 (2)	0.002 (2)	0.003 (2)
C1	0.056 (4)	0.043 (3)	0.053 (4)	0.005 (3)	−0.008 (3)	−0.001 (3)
C2	0.062 (4)	0.043 (3)	0.051 (4)	−0.008 (3)	−0.002 (3)	−0.010 (3)
C3	0.051 (3)	0.032 (3)	0.060 (4)	−0.008 (3)	0.011 (3)	0.007 (3)
C4	0.059 (4)	0.046 (4)	0.054 (4)	0.002 (3)	−0.009 (3)	0.003 (3)
C5	0.065 (4)	0.047 (4)	0.050 (4)	−0.004 (3)	−0.003 (3)	−0.005 (3)
C6	0.050 (3)	0.035 (3)	0.069 (4)	0.000 (3)	0.005 (3)	0.006 (3)
C7	0.046 (5)	0.041 (5)	0.055 (5)	0.000	0.000 (4)	0.000
Cl1	0.0640 (14)	0.0469 (12)	0.0547 (13)	0.000	−0.0064 (11)	0.000
Cl2	0.0680 (15)	0.0736 (16)	0.0469 (13)	0.000	−0.0003 (11)	0.000

Geometric parameters (Å, º)

Zn1—N1^i	2.055 (5)	C3—C6	1.505 (8)
Zn1—N1	2.055 (5)	C4—C5	1.369 (9)
Zn1—Cl2	2.239 (3)	C4—H4A	0.9300
Zn1—Cl1	2.247 (2)	C5—H5A	0.9300
N1—C5	1.330 (8)	C6—C7	1.518 (7)
N1—C1	1.337 (8)	C6—H6A	0.9700
C1—C2	1.373 (9)	C6—H6B	0.9700
C1—H1A	0.9300	C7—C6^ii	1.518 (7)
C2—C3	1.386 (9)	C7—H7A	0.9700
C2—H2A	0.9300	C7—H7B	0.9700
C3—C4	1.381 (9)
N1^i—Zn1—N1	111.7 (3)	C5—C4—C3	119.7 (6)
N1^i—Zn1—Cl2	104.45 (14)	C5—C4—H4A	120.2
N1—Zn1—Cl2	104.45 (14)	C3—C4—H4A	120.2
N1^i—Zn1—Cl1	105.09 (14)	N1—C5—C4	123.9 (6)
N1—Zn1—Cl1	105.09 (14)	N1—C5—H5A	118.0
Cl2—Zn1—Cl1	125.95 (10)	C4—C5—H5A	118.0
C5—N1—C1	116.8 (5)	C3—C6—C7	112.1 (5)
C5—N1—Zn1	122.2 (4)	C3—C6—H6A	109.2
C1—N1—Zn1	121.0 (4)	C7—C6—H6A	109.2
N1—C1—C2	122.8 (6)	C3—C6—H6B	109.2
N1—C1—H1A	118.6	C7—C6—H6B	109.2
C2—C1—H1A	118.6	H6A—C6—H6B	107.9
C1—C2—C3	120.3 (6)	C6—C7—C6^ii	112.6 (7)
C1—C2—H2A	119.8	C6—C7—H7A	109.1
C3—C2—H2A	119.8	C6^ii—C7—H7A	109.1
C4—C3—C2	116.6 (6)	C6—C7—H7B	109.1
C4—C3—C6	122.5 (6)	C6^ii—C7—H7B	109.1
C2—C3—C6	120.9 (6)	H7A—C7—H7B	107.8

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