Poly[tetra-μ-cyanido-di­pyridine­cadmium(II)zinc(II)]

In the title coordination polymer, [CdZn(CN)₄(C₅H₅N)₂]_n, the Zn^II atom (site symmetry 222) adopts a distorted ZnC₄ tetra­hedral geometry, being coordinated by four crystallographically equivalent cyanide ions. The cyanide ion bridges to a Cd^II centre via its N atom. The Cd atom (site symmetry 2/m) coordination is a distorted CdN₆ octa­hedron, arising from four cyanide N atoms and two pyridine N atoms. The complete pyridine mol­ecule is generated by m symmetry, with the N atom and one C atom lying on the reflecting plane. In the crystal, the bridging cyanide ions result in a three-dimensional network.

Related literature

For background to cyanide-containing coordination networks, see: Vasylyev & Neumann (2006).

Experimental

Crystal data

• [CdZn(CN)₄(C₅H₅N)₂]

• M_r = 440.05

• Orthorhombic, C c c m

• a = 9.514 (4) Å

• b = 13.935 (6) Å

• c = 13.965 (6) Å

• V = 1851.5 (14) ų

• Z = 4

• Mo Kα radiation

• μ = 2.45 mm⁻¹

• T = 296 K

• 0.44 × 0.28 × 0.22 mm

Data collection

• Bruker APEXII CCD diffractometer

• Absorption correction: multi-scan (SADABS; Bruker, 2001) T_min = 0.412, T_max = 0.615

• 4068 measured reflections

• 827 independent reflections

• 711 reflections with I > 2σ(I)

• R_int = 0.051

Refinement

• R[F² > 2σ(F²)] = 0.050

• wR(F²) = 0.136

• S = 1.00

• 827 reflections

• 57 parameters

• H-atom parameters not refined

• Δρ_max = 2.77 e Å⁻³

• Δρ_min = −1.34 e Å⁻³

Table 1
Selected bond lengths (Å)

Cd—N3	2.345 (4)
Cd—N1	2.354 (5)
Zn1—C4	2.037 (4)

Data collection: APEX2 (Bruker, 2004); cell refinement: SAINT-Plus (Bruker, 2001); data reduction: SAINT-Plus; 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.

Supporting information

S1. Comment

It has always been the interest of many chemists to design and synthesize novel metal cyano compounds which possess broad applications in host–guest chemistry, catalysis, photochemistry and electrical conductivity etc (Vasylyev & Neumann, 2006). Herein, we report a new crystal structure.

In the asymmetric unit of complex I, there exhibit one cyano ios, half pyridine, one Cd(II), and one Zn^II, figure 1. The Zn^II ion surrounded by four cyano^-1 ligands is tetra-coordinated by four C atoms, with tetrahedral coordination sphere. The bond distances of Zn—C is 2.037 (4) /%A in the normal range compared to the reported complexes containing the Zn—C—N—Cd atoms (Vasylyev & Neumann, 2006). The cadmium(II) is hexacoordianted by six N atoms from four cyano ions and two pyridine, located in the center of the coordinated octahedral geometry. It is worthy noting that the complex exhibits three-dimensional structure via the bridge of cyano ions, figure 2.

Related literature

For background to cyanide-containing coordination networks, see: Vasylyev & Neumann (2006).

S2. Experimental

The starting materials of sodium cyanide (0.049 g, 1 mmol) and ZnSO₄.7H₂O (0.07 g, 0.25 mmol), and CdSO₄ (0.05 g, 0.25 mmol) were refluxed in the mixture solution (CH₃OH: pyridine = 10:1) until all solid was dissolved. The solution was cooled to room temperature and filtered. Colourless blocks of (I) were obtained by allowing slow evaporation.

S3. Refinement

All hydrogen atoms bound to carbon were refined using a riding model with distance C—H = 0.93 Å, U_iso = 1.2U_eq (C) for aromatic atoms.

Computing details

Data collection: APEX2 (Bruker, 2004); cell refinement: SAINT-Plus (Bruker, 2001); data reduction: SAINT-Plus (Bruker, 2001; 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).

Figures

	Fig. 1. A view of (I) with the unique atom-labelling scheme. Displacement ellipsoids are drawn at the 30% probability level.
	Fig. 2. A view of (I) supramolecular strcuture.

Poly[tetra-µ-cyanido-dipyridinecadmium(II)zinc(II)]

Crystal data

[CdZn(CN)4(C5H5N)2]	F(000) = 856
Mr = 440.05	Dx = 1.579 Mg m^−3
Orthorhombic, Cccm	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2 2c	Cell parameters from 2697 reflections
a = 9.514 (4) Å	θ = 2.6–27.9°
b = 13.935 (6) Å	µ = 2.45 mm^−1
c = 13.965 (6) Å	T = 296 K
V = 1851.5 (14) Å^3	Block, colourless
Z = 4	0.44 × 0.28 × 0.22 mm

Data collection

Bruker APEXII CCD diffractometer	827 independent reflections
Radiation source: fine-focus sealed tube	711 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.051
φ and ω scans	θmax = 25.0°, θmin = 2.9°
Absorption correction: multi-scan (SADABS; Bruker, 2001)	h = −11→11
Tmin = 0.412, Tmax = 0.615	k = −16→8
4068 measured reflections	l = −16→15

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)] = 0.050	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.136	H-atom parameters not refined
S = 1.00	w = 1/[σ^2(Fo^2) + (0.115P)^2] where P = (Fo^2 + 2Fc^2)/3
827 reflections	(Δ/σ)max = 0.001
57 parameters	Δρmax = 2.77 e Å^−3
0 restraints	Δρmin = −1.34 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
Cd	1.2500	0.2500	0.5000	0.04119 (16)
Zn1	1.0000	0.5000	0.2500	0.0357 (2)
C4	1.1171 (4)	0.4109 (3)	0.3337 (3)	0.0495 (9)
N3	1.1750 (4)	0.3577 (3)	0.3815 (3)	0.0643 (10)
N1	1.0252 (5)	0.1795 (4)	0.5000	0.0592 (13)
C1	0.9588 (8)	0.1595 (5)	0.4210 (4)	0.104 (2)
H1A	1.0043	0.1715	0.3633	0.125*
C2	0.7615 (11)	0.1001 (9)	0.5000	0.131 (4)
H2A	0.6741	0.0703	0.5000	0.157*
C3	0.8239 (8)	0.1213 (6)	0.4180 (6)	0.132 (3)
H3A	0.7787	0.1109	0.3598	0.158*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cd	0.0414 (3)	0.0350 (3)	0.0472 (3)	0.0062 (2)	0.000	0.000
Zn1	0.0399 (4)	0.0276 (4)	0.0396 (4)	0.000	0.000	0.000
C4	0.051 (2)	0.0422 (18)	0.0553 (18)	−0.0008 (18)	−0.0004 (16)	0.0053 (16)
N3	0.069 (3)	0.055 (2)	0.069 (2)	0.010 (2)	−0.0084 (17)	0.0112 (17)
N1	0.050 (3)	0.052 (3)	0.076 (3)	−0.010 (2)	0.000	0.000
C1	0.101 (4)	0.124 (5)	0.087 (4)	−0.045 (4)	−0.003 (3)	−0.020 (3)
C2	0.086 (6)	0.105 (7)	0.201 (12)	−0.048 (5)	0.000	0.000
C3	0.115 (5)	0.147 (7)	0.133 (6)	−0.083 (5)	−0.026 (4)	−0.003 (5)

Geometric parameters (Å, º)

Cd—N3^i	2.345 (4)	C4—N3	1.140 (5)
Cd—N3^ii	2.345 (4)	N1—C1	1.301 (6)
Cd—N3^iii	2.345 (4)	N1—C1^iii	1.301 (6)
Cd—N3	2.345 (4)	C1—C3	1.390 (10)
Cd—N1	2.354 (5)	C1—H1A	0.9300
Cd—N1^ii	2.354 (5)	C2—C3^iii	1.324 (9)
Zn1—C4^iv	2.037 (4)	C2—C3	1.324 (9)
Zn1—C4	2.037 (4)	C2—H2A	0.9300
Zn1—C4^v	2.037 (4)	C3—H3A	0.9300
Zn1—C4^vi	2.037 (4)
N3^i—Cd—N3^ii	89.74 (19)	C4^iv—Zn1—C4^vi	113.7 (2)
N3^i—Cd—N3^iii	180.0	C4—Zn1—C4^vi	109.9 (2)
N3^ii—Cd—N3^iii	90.26 (19)	C4^v—Zn1—C4^vi	104.9 (2)
N3^i—Cd—N3	90.26 (18)	N3—C4—Zn1	175.6 (4)
N3^ii—Cd—N3	180.0	C4—N3—Cd	167.6 (3)
N3^iii—Cd—N3	89.74 (19)	C1—N1—C1^iii	116.0 (7)
N3^i—Cd—N1	90.54 (14)	C1—N1—Cd	122.0 (3)
N3^ii—Cd—N1	90.54 (14)	C1^iii—N1—Cd	122.0 (3)
N3^iii—Cd—N1	89.46 (14)	N1—C1—C3	123.8 (6)
N3—Cd—N1	89.46 (14)	N1—C1—H1A	118.1
N3^i—Cd—N1^ii	89.46 (14)	C3—C1—H1A	118.1
N3^ii—Cd—N1^ii	89.46 (14)	C3^iii—C2—C3	119.9 (10)
N3^iii—Cd—N1^ii	90.54 (14)	C3^iii—C2—H2A	120.1
N3—Cd—N1^ii	90.54 (14)	C3—C2—H2A	120.1
N1—Cd—N1^ii	180.0	C2—C3—C1	118.2 (7)
C4^iv—Zn1—C4	104.9 (2)	C2—C3—H3A	120.9
C4^iv—Zn1—C4^v	109.9 (2)	C1—C3—H3A	120.9
C4—Zn1—C4^v	113.7 (2)

Symmetry codes: (i) −x+5/2, −y+1/2, z; (ii) −x+5/2, −y+1/2, −z+1; (iii) x, y, −z+1; (iv) −x+2, y, −z+1/2; (v) x, −y+1, −z+1/2; (vi) −x+2, −y+1, z.