catena-Poly[[(5,5′-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. The Cd^II cation is six-coordinated in a distorted octa­hedral geometry formed by two N atoms from the 5,5′-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 c axis.

Related literature  

For related structures, see: Ahmadi et al. (2008 ▶, 2010 ▶); Albada et al. (2004 ▶); Amani et al. (2007 ▶, 2009 ▶); Han et al. (2006 ▶); Kalateh et al. (2010 ▶); Karaca et al. (2009 ▶); Khalighi et al. (2008 ▶); Maheshwari et al. (2007 ▶); Tadayon Pour et al. (2008 ▶); Zhang (2007 ▶).

Experimental  

Crystal data  

• [CdBr₂(C₁₂H₁₂N₂)]

• M _r = 456.45

• Monoclinic,

• a = 19.637 (5) Å

• b = 9.6563 (15) Å

• c = 7.485 (2) Å

• β = 104.76 (2)°

• V = 1372.4 (6) ų

• Z = 4

• Mo Kα radiation

• μ = 7.39 mm⁻¹

• T = 298 K

• 0.12 × 0.11 × 0.09 mm

Data collection  

• Bruker APEXII CCD area-detector diffractometer

• Absorption correction: multi-scan (SADABS; Bruker, 2001 ▶) T _min = 0.435, T _max = 0.548

• 5378 measured reflections

• 1346 independent reflections

• 1015 reflections with I > 2σ(I)

• R _int = 0.110

Refinement  

• R[F ² > 2σ(F ²)] = 0.041

• wR(F ²) = 0.091

• S = 1.03

• 1346 reflections

• 78 parameters

• H-atom parameters constrained

• Δρ_max = 0.85 e Å⁻³

• Δρ_min = −0.70 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	2.352 (4)
Cd1—Br1	2.6676 (8)
Cd1—Br1i	2.9351 (10)

Symmetry code: (i) .

supplementary crystallographic information

Comment

5,5'-Dimethyl-2,2'-bipyridine (5,5'-dmbipy), is a good bidentate ligand, and numerous complexes with 5,5'-dmbipy have been prepared, such as that of zinc (Khalighi et al., 2008), indium (Kalateh et al., 2010), iron (Amani et al., 2007), platin (Amani et al., 2009; Maheshwari et al., 2007), copper (Albada et al., 2004), gold (Karaca et al., 2009), cadmium (Ahmadi et al., 2008,2010) and mercury (Tadayon Pour et al., 2008). Here, we report the synthesis and structure of the title compound.

The asymmetric unit of the title compound, (Fig. 1), contains one half-molecule; a twofold rotation axis passes through the Cd atom. The Cd^II atom is six-coordinated in a distorted octahedral configuration by two N atoms from 5,5'-dimethyl-2,2'-bipyridine and four bridging Br atoms. The bridging function of the bromide atoms leads to a one-dimensional chain structure. The Cd—Br and Cd—N 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 5,5'-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 (10 ml) at room temperature. The suitable crystals for X-ray diffraction experiment were obtained by methanol diffusion to a colorless solution in DMSO. Suitable crystals were isolated after one week (yield; 0.45 g, 74.1%).

Refinement

H atoms were positioned geometrically with C—H = 0.93 Å and constrained to ride on their parent atoms, with 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 30% probability level [Symmetry codes: (a) 1 - x,y,1/2 - z].

Crystal data

[CdBr2(C12H12N2)]	F(000) = 864
Mr = 456.45	Dx = 2.209 Mg m−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
a = 19.637 (5) Å	Cell parameters from 5378 reflections
b = 9.6563 (15) Å	θ = 2.2–26.0°
c = 7.485 (2) Å	µ = 7.39 mm−1
β = 104.76 (2)°	T = 298 K
V = 1372.4 (6) Å3	Prism, colorless
Z = 4	0.12 × 0.11 × 0.09 mm

Data collection

Bruker APEXII CCD area-detector diffractometer	1346 independent reflections
Radiation source: fine-focus sealed tube	1015 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.110
ω scans	θmax = 26.0°, θmin = 2.2°
Absorption correction: multi-scan (SADABS; Bruker, 2001)	h = −22→24
Tmin = 0.435, Tmax = 0.548	k = −10→11
5378 measured reflections	l = −9→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)] = 0.041	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.091	H-atom parameters constrained
S = 1.03	w = 1/[σ2(Fo2) + (0.0403P)2] where P = (Fo2 + 2Fc2)/3
1346 reflections	(Δ/σ)max = 0.004
78 parameters	Δρmax = 0.85 e Å−3
0 restraints	Δρmin = −0.70 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
C1	0.3751 (3)	0.2708 (6)	−0.0036 (8)	0.0498 (15)
H1	0.3565	0.1843	−0.0435	0.060*
C2	0.3367 (3)	0.3894 (7)	−0.0747 (9)	0.0549 (16)
C3	0.2663 (4)	0.3740 (9)	−0.2097 (11)	0.085 (3)
H3A	0.2355	0.3221	−0.1537	0.102*
H3B	0.2718	0.3261	−0.3175	0.102*
H3C	0.2465	0.4639	−0.2444	0.102*
C4	0.3660 (3)	0.5147 (7)	−0.0143 (9)	0.0600 (18)
H4	0.3423	0.5960	−0.0591	0.072*
C5	0.4299 (3)	0.5211 (6)	0.1118 (8)	0.0506 (15)
H5	0.4494	0.6067	0.1527	0.061*
C6	0.4659 (3)	0.4006 (5)	0.1792 (8)	0.0421 (13)
N1	0.4378 (2)	0.2774 (5)	0.1198 (6)	0.0412 (11)
Cd1	0.5000	0.07821 (6)	0.2500	0.0476 (2)
Br1	0.41572 (3)	−0.09792 (6)	0.02140 (9)	0.0507 (2)

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
C1	0.041 (3)	0.047 (3)	0.054 (4)	−0.004 (3)	−0.001 (3)	0.008 (3)
C2	0.041 (3)	0.066 (4)	0.055 (4)	0.003 (3)	0.008 (3)	0.020 (3)
C3	0.048 (4)	0.109 (6)	0.086 (6)	0.006 (4)	−0.005 (4)	0.034 (5)
C4	0.055 (4)	0.061 (4)	0.069 (4)	0.026 (3)	0.026 (3)	0.029 (4)
C5	0.062 (4)	0.040 (3)	0.056 (4)	0.012 (3)	0.027 (3)	0.007 (3)
C6	0.044 (3)	0.036 (3)	0.049 (3)	0.003 (2)	0.017 (3)	0.007 (2)
N1	0.033 (2)	0.038 (2)	0.049 (3)	0.0021 (18)	0.003 (2)	0.006 (2)
Cd1	0.0456 (4)	0.0318 (3)	0.0530 (4)	0.000	−0.0102 (3)	0.000
Br1	0.0474 (4)	0.0423 (3)	0.0550 (4)	−0.0094 (2)	−0.0006 (3)	−0.0064 (2)

Geometric parameters (Å, º)

C1—N1	1.339 (6)	C5—C6	1.388 (8)
C1—C2	1.400 (8)	C5—H5	0.9300
C1—H1	0.9300	C6—N1	1.339 (7)
C2—C4	1.366 (10)	C6—C6i	1.481 (11)
C2—C3	1.497 (9)	Cd1—N1	2.352 (4)
C3—H3A	0.9600	Cd1—N1i	2.352 (4)
C3—H3B	0.9600	Cd1—Br1	2.6676 (8)
C3—H3C	0.9600	Cd1—Br1i	2.6676 (8)
C4—C5	1.366 (9)	Cd1—Br1ii	2.9351 (10)
C4—H4	0.9300	Cd1—Br1iii	2.9352 (10)
N1—C1—C2	122.3 (6)	C5—C6—C6i	123.0 (4)
N1—C1—H1	118.8	C6—N1—C1	120.0 (5)
C2—C1—H1	118.8	C6—N1—Cd1	117.6 (3)
C4—C2—C1	117.3 (5)	C1—N1—Cd1	122.4 (4)
C4—C2—C3	123.3 (6)	N1—Cd1—N1i	70.3 (2)
C1—C2—C3	119.4 (6)	N1—Cd1—Br1	94.81 (10)
C2—C3—H3A	109.5	N1i—Cd1—Br1	163.48 (11)
C2—C3—H3B	109.5	N1—Cd1—Br1i	163.48 (11)
H3A—C3—H3B	109.5	N1i—Cd1—Br1i	94.81 (10)
C2—C3—H3C	109.5	Br1—Cd1—Br1i	100.78 (4)
H3A—C3—H3C	109.5	N1—Cd1—Br1ii	84.78 (12)
H3B—C3—H3C	109.5	N1i—Cd1—Br1ii	89.13 (12)
C5—C4—C2	120.2 (6)	Br1—Cd1—Br1ii	96.79 (3)
C5—C4—H4	119.9	Br1i—Cd1—Br1ii	87.96 (3)
C2—C4—H4	119.9	N1—Cd1—Br1iii	89.13 (12)
C4—C5—C6	120.4 (6)	N1i—Cd1—Br1iii	84.78 (12)
C4—C5—H5	119.8	Br1—Cd1—Br1iii	87.96 (2)
C6—C5—H5	119.8	Br1i—Cd1—Br1iii	96.79 (3)
N1—C6—C5	119.7 (5)	Br1ii—Cd1—Br1iii	172.56 (3)
N1—C6—C6i	117.3 (3)	Cd1—Br1—Cd1iii	92.04 (3)
N1—C1—C2—C4	0.5 (10)	C1—N1—Cd1—N1i	−177.4 (6)
N1—C1—C2—C3	−178.9 (6)	C6—N1—Cd1—Br1	−172.9 (4)
C1—C2—C4—C5	−0.6 (10)	C1—N1—Cd1—Br1	10.0 (5)
C3—C2—C4—C5	178.8 (6)	C6—N1—Cd1—Br1i	26.4 (8)
C2—C4—C5—C6	0.2 (10)	C1—N1—Cd1—Br1i	−150.8 (4)
C4—C5—C6—N1	0.2 (10)	C6—N1—Cd1—Br1ii	90.7 (4)
C4—C5—C6—C6i	−177.8 (7)	C1—N1—Cd1—Br1ii	−86.4 (4)
C5—C6—N1—C1	−0.3 (9)	C6—N1—Cd1—Br1iii	−85.0 (4)
C6i—C6—N1—C1	177.8 (6)	C1—N1—Cd1—Br1iii	97.8 (4)
C5—C6—N1—Cd1	−177.5 (4)	N1—Cd1—Br1—Cd1iii	88.96 (12)
C6i—C6—N1—Cd1	0.5 (9)	N1i—Cd1—Br1—Cd1iii	63.9 (4)
C2—C1—N1—C6	−0.1 (9)	Br1i—Cd1—Br1—Cd1iii	−96.53 (2)
C2—C1—N1—Cd1	177.0 (5)	Br1ii—Cd1—Br1—Cd1iii	174.26 (2)
C6—N1—Cd1—N1i	−0.2 (3)	Br1iii—Cd1—Br1—Cd1iii	0.0

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