catena-Poly[[(4,4′-dimethyl-2,2′-bipyridine-κ² N,N′)cadmium]-di-μ-bromido]

Abstract

In the crystal of the title polymeric compound, [CdBr₂(C₁₂H₁₂N₂)]_n, the Cd^II cation is located on a twofold rotation axis and is six-coordinated in a distorted octa­hedral geometry formed by two N atoms from the 4,4′-dimethyl-2,2′-bipyridine ligand and by four bridging Br⁻ anions. The bridging function of the Br⁻ anions leads to a polymeric chain running along the c axis. Weak C—H⋯π inter­actions observed between adjacent chains are effective in the stabilization of the three-dimensional packing.

Related literature  

For related structures, see: Ahmadi et al. (2008 ▶); Alizadeh et al. (2010 ▶); Amani et al. (2009 ▶); Bellusci et al. (2008 ▶); Han et al. (2006 ▶); Hojjat Kashani et al. (2008 ▶); Kalateh et al. (2008 ▶, 2010 ▶); Shirvan & Haydari Dezfuli (2012 ▶); Sofetis et al. (2006 ▶); Willett et al. (2001 ▶); Yousefi et al. (2008 ▶); Zhang (2007 ▶).

Experimental  

Crystal data  

• [CdBr₂(C₁₂H₁₂N₂)]

• M _r = 456.45

• Monoclinic,

• a = 17.979 (4) Å

• b = 10.5319 (18) Å

• c = 7.4496 (16) Å

• β = 108.403 (17)°

• V = 1338.5 (5) ų

• Z = 4

• Mo Kα radiation

• μ = 7.58 mm⁻¹

• T = 298 K

• 0.25 × 0.21 × 0.20 mm

Data collection  

• Bruker APEXII CCD area-detector diffractometer

• Absorption correction: multi-scan (SADABS; Bruker, 2001 ▶) T _min = 0.188, T _max = 0.246

• 3392 measured reflections

• 1313 independent reflections

• 909 reflections with I > 2σ(I)

• R _int = 0.095

Refinement  

• R[F ² > 2σ(F ²)] = 0.079

• wR(F ²) = 0.155

• S = 1.24

• 1313 reflections

• 78 parameters

• H-atom parameters constrained

• Δρ_max = 1.20 e Å⁻³

• Δρ_min = −0.88 e Å⁻³

Data collection: APEX2 (Bruker, 2007 ▶); cell refinement: SAINT (Bruker, 2007 ▶); data reduction: SAINT; 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.

Supplementary Material

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Selected bond lengths (Å).

Cd1—N1	2.357 (10)
Cd1—Br1	2.6852 (17)
Cd1—Br1i	2.8789 (16)

Symmetry code: (i) .

Table 2. Hydrogen-bond geometry (Å, °).

Cg is the centroid of the N1-pyridine ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C4—H4B⋯Cg ii	0.96	2.84	3.575 (16)	135

Symmetry code: (ii) .

supplementary crystallographic information

Comment

Recently, we reported the synthes and crystal structure of [CdBr₂(4,4'-dmbpy)(DMSO)], (Shirvan & Haydari Dezfuli, 2012) [where 4,4'-dmbpy is 4,4'-dimethyl-2,2'-bipyridine and DMSO is dimethyl sulfoxide]. 4,4'-Dimethyl-2,2'-bipyridine is a good bidentate ligand, and numerous complexes with 4,4'-dmbipy have been prepared, such as that of mercury (Kalateh et al., 2008; Yousefi et al., 2008), indium (Ahmadi et al., 2008), iron (Amani et al., 2009), platin (Hojjat Kashani et al., 2008), silver (Bellusci et al., 2008), gallium (Sofetis et al., 2006), copper (Willett et al., 2001), cadmium (Kalateh et al., 2010) and zinc (Alizadeh et al., 2010). Here, we report the synthesis and structure of the title compound.

The asymmetric unit of the title compound, (Fig. 1), contains half-molecule; a twofold rotation axis passes through the Cd atom. The Cd^II cation is six-coordinated in a distorted octahedral geometry formed by two N atoms from the 4,4'-dimethyl-2,2'-bipyridine ligand and four bridging Br^- anions. The bridging function of the Br^- anions leads to a polymeric chain running along the b axis. The Cd—N and Cd—Br bond lengths and angles (Table 1) are within normal range [Cd(phen)(µ-Br)₂]_n, (Zhang, 2007) and [Cd(bipy)(µ-Br)₂]_n, (Han et al., 2006) [where phen is 1,10-phenanthroline and bipy is 2,2'-bipyridine].

Experimental

For the preparation of the title compound, a solution of 4,4'-dimethyl-2,2'-bipyridine (0.25 g, 1.33 mmol) in methanol (10 ml) was added to a solution of CdBr₂.4H₂O, (0.46 g, 1.33 mmol) in methanol (5 ml) at room temperature. The suitable crystals for X-ray diffraction experiment were obtained by methanol diffusion to a colorless solution in dimethylformamide. Suitable crystals were isolated after one week (yield; 0.45 g, 74.1%).

Refinement

H atoms were positioned geometrically with C—H = 0.93–0.96 Å and constrained to ride on their parent atoms, U_iso(H) = 1.2U_eq(C).

Figures

Fig. 1.

The molecular structure of the title molecule, with the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level.

Crystal data

[CdBr2(C12H12N2)]	F(000) = 864
Mr = 456.45	Dx = 2.265 Mg m−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 3392 reflections
a = 17.979 (4) Å	θ = 2.3–26.0°
b = 10.5319 (18) Å	µ = 7.58 mm−1
c = 7.4496 (16) Å	T = 298 K
β = 108.403 (17)°	Prism, colorless
V = 1338.5 (5) Å3	0.25 × 0.21 × 0.20 mm
Z = 4

Data collection

Bruker APEXII CCD area-detector diffractometer	1313 independent reflections
Radiation source: fine-focus sealed tube	909 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.095
ω scans	θmax = 26.0°, θmin = 2.3°
Absorption correction: multi-scan (SADABS; Bruker, 2001)	h = −22→22
Tmin = 0.188, Tmax = 0.246	k = −12→12
3392 measured reflections	l = −7→9

Refinement

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)] = 0.079	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.155	H-atom parameters constrained
S = 1.24	w = 1/[σ2(Fo2) + (0.0098P)2 + 54.7076P] where P = (Fo2 + 2Fc2)/3
1313 reflections	(Δ/σ)max = 0.022
78 parameters	Δρmax = 1.20 e Å−3
0 restraints	Δρmin = −0.88 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
Cd1	0.0000	0.92501 (14)	0.2500	0.0312 (4)
Br1	0.09337 (9)	1.08683 (16)	0.4997 (2)	0.0439 (5)
N1	−0.0688 (6)	0.7414 (11)	0.1090 (15)	0.030 (3)
C6	−0.0397 (7)	0.6266 (12)	0.1779 (18)	0.023 (3)
C5	−0.0804 (7)	0.5157 (13)	0.111 (2)	0.030 (3)
H5	−0.0585	0.4376	0.1574	0.036*
C1	−0.1384 (8)	0.7427 (15)	−0.025 (2)	0.042 (4)
H1	−0.1579	0.8209	−0.0767	0.050*
C3	−0.1535 (8)	0.5209 (14)	−0.025 (2)	0.031 (3)
C4	−0.2002 (8)	0.4012 (14)	−0.094 (2)	0.040 (4)
H4A	−0.2098	0.3586	0.0101	0.048*
H4B	−0.1712	0.3462	−0.1505	0.048*
H4C	−0.2493	0.4229	−0.1869	0.048*
C2	−0.1825 (8)	0.6396 (14)	−0.091 (2)	0.036 (3)
H2	−0.2318	0.6478	−0.1806	0.043*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
Cd1	0.0363 (8)	0.0203 (7)	0.0304 (9)	0.000	0.0011 (6)	0.000
Br1	0.0434 (10)	0.0394 (9)	0.0520 (12)	−0.0169 (7)	0.0195 (8)	−0.0153 (8)
N1	0.032 (6)	0.027 (5)	0.022 (6)	−0.009 (5)	−0.005 (4)	−0.006 (5)
C6	0.018 (6)	0.024 (6)	0.030 (7)	0.002 (5)	0.009 (5)	0.002 (6)
C5	0.019 (6)	0.031 (7)	0.045 (9)	0.002 (5)	0.015 (6)	−0.002 (6)
C1	0.034 (8)	0.030 (7)	0.046 (9)	0.003 (6)	−0.008 (7)	0.010 (7)
C3	0.027 (7)	0.042 (8)	0.023 (7)	0.001 (6)	0.005 (5)	−0.010 (6)
C4	0.037 (8)	0.044 (9)	0.035 (8)	−0.012 (7)	0.006 (6)	−0.003 (7)
C2	0.026 (7)	0.042 (8)	0.031 (8)	0.002 (6)	−0.005 (6)	0.004 (7)

Geometric parameters (Å, º)

Cd1—N1i	2.357 (10)	C5—C3	1.383 (18)
Cd1—N1	2.357 (10)	C5—H5	0.9300
Cd1—Br1i	2.6852 (17)	C1—C2	1.34 (2)
Cd1—Br1	2.6852 (17)	C1—H1	0.9300
Cd1—Br1ii	2.8789 (16)	C3—C2	1.39 (2)
Cd1—Br1iii	2.8790 (16)	C3—C4	1.513 (19)
Br1—Cd1iii	2.8789 (16)	C4—H4A	0.9600
N1—C1	1.331 (16)	C4—H4B	0.9600
N1—C6	1.353 (17)	C4—H4C	0.9600
C6—C5	1.384 (18)	C2—H2	0.9300
C6—C6i	1.49 (2)
N1i—Cd1—N1	69.7 (5)	N1—C6—C6i	116.2 (7)
N1i—Cd1—Br1i	162.8 (3)	C5—C6—C6i	122.4 (7)
N1—Cd1—Br1i	95.0 (3)	C3—C5—C6	120.1 (13)
N1i—Cd1—Br1	95.0 (3)	C3—C5—H5	119.9
N1—Cd1—Br1	162.8 (3)	C6—C5—H5	119.9
Br1i—Cd1—Br1	101.21 (9)	N1—C1—C2	125.0 (14)
N1i—Cd1—Br1ii	85.5 (3)	N1—C1—H1	117.5
N1—Cd1—Br1ii	90.4 (3)	C2—C1—H1	117.5
Br1i—Cd1—Br1ii	86.77 (5)	C5—C3—C2	117.4 (13)
Br1—Cd1—Br1ii	96.39 (5)	C5—C3—C4	121.0 (13)
N1i—Cd1—Br1iii	90.4 (3)	C2—C3—C4	121.6 (12)
N1—Cd1—Br1iii	85.5 (3)	C3—C4—H4A	109.5
Br1i—Cd1—Br1iii	96.39 (5)	C3—C4—H4B	109.5
Br1—Cd1—Br1iii	86.77 (5)	H4A—C4—H4B	109.5
Br1ii—Cd1—Br1iii	175.03 (9)	C3—C4—H4C	109.5
Cd1—Br1—Cd1iii	93.23 (5)	H4A—C4—H4C	109.5
C1—N1—C6	116.9 (12)	H4B—C4—H4C	109.5
C1—N1—Cd1	124.3 (10)	C1—C2—C3	119.1 (12)
C6—N1—Cd1	118.6 (8)	C1—C2—H2	120.4
N1—C6—C5	121.3 (11)	C3—C2—H2	120.4
N1i—Cd1—Br1—Cd1iii	−90.1 (3)	Br1iii—Cd1—N1—C6	−89.3 (10)
N1—Cd1—Br1—Cd1iii	−63.5 (10)	C1—N1—C6—C5	0 (2)
Br1i—Cd1—Br1—Cd1iii	95.88 (5)	Cd1—N1—C6—C5	175.0 (10)
Br1ii—Cd1—Br1—Cd1iii	−176.16 (7)	C1—N1—C6—C6i	177.6 (15)
Br1iii—Cd1—Br1—Cd1iii	0.0	Cd1—N1—C6—C6i	−7.7 (19)
N1i—Cd1—N1—C1	177.1 (15)	N1—C6—C5—C3	−2 (2)
Br1i—Cd1—N1—C1	−11.0 (12)	C6i—C6—C5—C3	−179.3 (14)
Br1—Cd1—N1—C1	148.7 (10)	C6—N1—C1—C2	2 (2)
Br1ii—Cd1—N1—C1	−97.8 (12)	Cd1—N1—C1—C2	−171.9 (13)
Br1iii—Cd1—N1—C1	85.0 (12)	C6—C5—C3—C2	1 (2)
N1i—Cd1—N1—C6	2.9 (7)	C6—C5—C3—C4	−177.8 (13)
Br1i—Cd1—N1—C6	174.7 (9)	N1—C1—C2—C3	−3 (3)
Br1—Cd1—N1—C6	−25.6 (17)	C5—C3—C2—C1	1 (2)
Br1ii—Cd1—N1—C6	87.9 (10)	C4—C3—C2—C1	−179.7 (15)

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

Hydrogen-bond geometry (Å, º)

Cg is the centroid of the N1-pyridine ring.

D—H···A	D—H	H···A	D···A	D—H···A
C4—H4B···Cgiv	0.96	2.84	3.575 (16)	135

Symmetry code: (iv) x, −y+1, z−1/2.