catena-Poly[di-μ_1,1-azido-(1,10-phenanthroline)cadmium(II)]

The asymmetric unit of the title Cd^II compound, [Cd(N₃)₂(C₁₂H₈N₂)]_n, contains a Cd^II atom, located on a twofold axis passing through the middle of the phenanthroline mol­ecule, one azide ion and half of a 1,10-phenanthroline mol­ecule. The Cd^II atom exhibits a distorted octa­hedral coordin­ation including one chelating 1,10-phenanthroline ligand and four azide ligands. The crystal structure features chains along the c direction in which azide groups doubly bridge two adjacent Cd^II atoms in an end-on (EO) mode. Inter­chain π–π stacking inter­actions, with centroid–centroid separations of 3.408 (2) Å between the central aromatic rings of 1,10-phenanthroline mol­ecules, lead to a supra­molecular sheet parallel to the bc plane.

Related literature

For the structures of related metal-azido compounds, see: Goher et al. (2008); Ribas et al. (1999); Liu et al. (2007); Cano et al. (2005); Abu-Youssef et al. (2000); Bose et al. (2004); Mautner et al. (2010); Meyer et al. (2005); Gao et al. (2004).

Experimental

Crystal data

• [Cd(N₃)₂(C₁₂H₈N₂)]

• M_r = 376.67

• Monoclinic, C 2/c

• a = 19.4591 (17) Å

• b = 10.2988 (6) Å

• c = 6.8151 (6) Å

• β = 106.033 (4)°

• V = 1312.66 (18) ų

• Z = 4

• Mo Kα radiation

• μ = 1.67 mm⁻¹

• T = 293 K

• 0.30 × 0.20 × 0.18 mm

Data collection

• Rigaku Mercury CCD diffractometer

• Absorption correction: multi-scan (CrystalClear; Rigaku, 2002) T_min = 0.774, T_max = 1.000

• 4185 measured reflections

• 1217 independent reflections

• 1133 reflections with I > 2σ(I)

• R_int = 0.023

Refinement

• R[F² > 2σ(F²)] = 0.020

• wR(F²) = 0.056

• S = 1.05

• 1217 reflections

• 96 parameters

• H-atom parameters constrained

• Δρ_max = 0.78 e Å⁻³

• Δρ_min = −0.48 e Å⁻³

Data collection: CrystalClear (Rigaku, 2002); cell refinement: CrystalClear; data reduction: CrystalClear; 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.

Supporting information

S1. Comment

Many compounds with uncommon magnetic properties have been widely investigated by using azido ligand, resulting from its rich coordination fashions (Ribas et al., 1999; Gao et al., 2004). The azido ligand exhibits a variety of bridging modes such as bi-dentate end-on (EO) and end-to-end (EE) bridging fashions (Liu et al., 2007; Cano et al., 2005; Goher et al., 2008; Mautner et al., 2010). A number of compounds with various structures have been obtained by introducing auxiliary ligands to the metal-azido system (Abu-Youssef et al., 2000; Bose et al., 2004; Meyer et al., 2005). The present example shows an infinite wavelike chain compound with 1,10-phenanthroline as an auxiliary ligand, [Cd(N₃)₂(C₁₂H₈N₂)], in which azido ligand adopts the EO mode.

The asymmetric unit of the title compound contains half a Cd^II ion, one azido ion and half a 1,10-phenanthroline molecule (Fig. 1). The Cd^II ion exhibits a distorted octahedral geometry, coordinated by one chelating 1,10-phenanthroline ligand and four azido ligands with the end-on (EO) mode. The distances of Cd—N vary from 2.306 (2) to 2.411 (3) Å . The azido ligands doubly bridge neighbouring Cd^II centers in the EO fashion, yielding an infinite wave-like Cd^II-azido chain along the c direction with the shortest Cd···Cd separation being 3.764 (3) Å.

The adjacent Cd^II-azido chains are mediated by interchained π-π stacking interactions between the aromatic rings of 1,10-phenanthroline molecules, which arrange in the opposite direction alternatively. The centroid-to-centroid distance between the central rings of the phenanthroline is 3.408 (2)Å and the centroid-to-plane distance is 3.28 Å leading to a slippage of 0.936Å. This π-π stacking builts up a 2-D supramolecular layer parallel to the bc plane (Fig. 2).

Related literature

For the structures of related metal-azido compounds, see: Goher et al. (2008); Ribas et al. (1999); Liu et al. (2007); Cano et al. (2005); Abu-Youssef et al. (2000); Bose et al. (2004); Mautner et al. (2010); Meyer et al. (2005); Gao et al. (2004).

S2. Experimental

A mixture of Cd(NO₃)₂.4H₂O (0.308 g, 1.00 mmol), NaN₃ (0.065 g, 1.00 mmol), Na(3-cba) (0.085 g, 0.50 mmol 3-Hcba = 3-cyanobenzoate acid), 1,10-phenanthroline (0.099 g, 0.50 mmol) and H₂O (8 ml) was placed in a Teflon-lined stainless container, and then heated at 453 K for 2 days, after cooled to room temperature for 2 days. Pale-yellow prism-shaped crystals of the title compound were obtained. IR peaks (KBr, cm^-1): 2053 s, 2037 s h, 1589 w, 1515 w, 1425 w, 1333 w, 1284 w, 846 m, 772 w, 727 m, 656 w. A strong band around 2053 cm^-1 indicates the presence of the azido group.

S3. Refinement

Hydrogen atoms were allowed to ride on their respective parent atoms with C—H distances of 0.93 Å, and were included in the refinement with isotropic displacement parameters U_iso(H) = 1.2U_eq(C).

Computing details

Data collection: CrystalClear (Rigaku, 2002); cell refinement: CrystalClear (Rigaku, 2002); data reduction: CrystalClear (Rigaku, 2002); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures

	Fig. 1. View of the title compound with the atom labeling scheme. Ellipsoids are drawn at the 30% probability level. H atoms have been omitted for clarity.[Symmetry codes: (i) -x+1, y, -z+1/2; (ii) -x+1, -y+2, -z; (iii) x, -y+2, z+1/2; (iv) x, -y+2, z-1/2].
	Fig. 2. View of the 2-D layer structure of the title compound formed by 1-D Cd^II-azido chains linked through π-π stacking interactions (black dotted lines) between symetry related 1,10-phenanthroline molecules. Hydrogen atoms have been omitted for clarity.

catena-Poly[di-µ_1,1-azido-(1,10-phenanthroline)cadmium(II)]

Crystal data

[Cd(N3)2(C12H8N2)]	F(000) = 736
Mr = 376.67	Dx = 1.906 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 1622 reflections
a = 19.4591 (17) Å	θ = 2.3–27.5°
b = 10.2988 (6) Å	µ = 1.67 mm^−1
c = 6.8151 (6) Å	T = 293 K
β = 106.033 (4)°	Prism, pale-yellow
V = 1312.66 (18) Å^3	0.30 × 0.20 × 0.18 mm
Z = 4

Data collection

Rigaku Mercury CCD diffractometer	1217 independent reflections
Radiation source: fine-focus sealed tube	1133 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.023
Detector resolution: 13.6612 pixels mm^-1	θmax = 25.5°, θmin = 3.6°
CCD_Profile_fitting scans	h = −23→22
Absorption correction: multi-scan (CrystalClear; Rigaku, 2002)	k = −12→12
Tmin = 0.774, Tmax = 1.000	l = −8→8
4185 measured reflections

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) = 0.056	H-atom parameters constrained
S = 1.05	w = 1/[σ^2(Fo^2) + (0.0373P)^2 + 0.2202P] where P = (Fo^2 + 2Fc^2)/3
1217 reflections	(Δ/σ)max = 0.001
96 parameters	Δρmax = 0.78 e Å^−3
0 restraints	Δρmin = −0.48 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 > 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	0.5000	0.922344 (19)	0.2500	0.03485 (12)
N1	0.43055 (13)	1.0473 (2)	−0.0103 (3)	0.0446 (5)
N2	0.37375 (13)	1.0889 (2)	−0.0144 (4)	0.0459 (6)
N3	0.31894 (16)	1.1315 (4)	−0.0167 (6)	0.0898 (10)
N11	0.43063 (10)	0.73525 (19)	0.1345 (3)	0.0367 (4)
C11	0.36250 (14)	0.7349 (3)	0.0214 (4)	0.0488 (6)
H11A	0.3404	0.8140	−0.0213	0.059*
C12	0.32340 (16)	0.6220 (4)	−0.0352 (5)	0.0587 (8)
H12A	0.2758	0.6260	−0.1114	0.070*
C13	0.35523 (17)	0.5055 (3)	0.0218 (4)	0.0551 (8)
H13A	0.3293	0.4291	−0.0144	0.066*
C14	0.42742 (16)	0.5003 (2)	0.1357 (4)	0.0447 (6)
C15	0.46270 (13)	0.6200 (2)	0.1908 (3)	0.0344 (5)
C16	0.46560 (18)	0.3819 (3)	0.1969 (4)	0.0552 (8)
H16A	0.4420	0.3032	0.1619	0.066*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cd1	0.03961 (17)	0.03359 (16)	0.02969 (16)	0.000	0.00680 (11)	0.000
N1	0.0461 (13)	0.0517 (11)	0.0384 (12)	0.0101 (11)	0.0156 (10)	0.0139 (10)
N2	0.0417 (14)	0.0477 (13)	0.0439 (13)	0.0009 (10)	0.0047 (10)	−0.0005 (9)
N3	0.0428 (16)	0.116 (3)	0.105 (3)	0.0208 (18)	0.0108 (16)	−0.008 (2)
N11	0.0368 (10)	0.0410 (11)	0.0332 (10)	0.0009 (9)	0.0109 (8)	−0.0043 (8)
C11	0.0405 (13)	0.0601 (17)	0.0449 (14)	0.0015 (13)	0.0099 (11)	−0.0113 (13)
C12	0.0430 (15)	0.084 (2)	0.0481 (16)	−0.0126 (16)	0.0112 (13)	−0.0179 (16)
C13	0.0651 (19)	0.0630 (18)	0.0434 (15)	−0.0282 (16)	0.0257 (14)	−0.0187 (13)
C14	0.0678 (18)	0.0436 (14)	0.0314 (12)	−0.0137 (12)	0.0282 (13)	−0.0088 (10)
C15	0.0436 (13)	0.0385 (11)	0.0241 (11)	−0.0021 (11)	0.0146 (10)	−0.0024 (9)
C16	0.099 (2)	0.0354 (11)	0.0409 (16)	−0.0135 (14)	0.0363 (15)	−0.0077 (11)

Geometric parameters (Å, º)

Cd1—N1^i	2.303 (2)	C11—C12	1.385 (5)
Cd1—N1	2.303 (2)	C11—H11A	0.9300
Cd1—N11	2.3596 (19)	C12—C13	1.357 (5)
Cd1—N11^i	2.3596 (19)	C12—H12A	0.9300
Cd1—N1^ii	2.411 (2)	C13—C14	1.406 (4)
Cd1—N1^iii	2.411 (2)	C13—H13A	0.9300
N1—N2	1.179 (3)	C14—C15	1.410 (4)
N1—Cd1^ii	2.411 (2)	C14—C16	1.429 (4)
N2—N3	1.149 (4)	C15—C15^i	1.453 (5)
N11—C11	1.337 (3)	C16—C16^i	1.335 (7)
N11—C15	1.347 (3)	C16—H16A	0.9300
N1^i—Cd1—N1	112.07 (12)	C11—N11—Cd1	125.41 (18)
N1^i—Cd1—N11	150.83 (8)	C15—N11—Cd1	116.58 (15)
N1—Cd1—N11	92.25 (8)	N11—C11—C12	122.9 (3)
N1^i—Cd1—N11^i	92.25 (8)	N11—C11—H11A	118.5
N1—Cd1—N11^i	150.83 (8)	C12—C11—H11A	118.5
N11—Cd1—N11^i	70.51 (9)	C13—C12—C11	119.4 (3)
N1^i—Cd1—N1^ii	97.46 (8)	C13—C12—H12A	120.3
N1—Cd1—N1^ii	74.05 (9)	C11—C12—H12A	120.3
N11—Cd1—N1^ii	104.83 (8)	C12—C13—C14	119.9 (3)
N11^i—Cd1—N1^ii	87.47 (7)	C12—C13—H13A	120.0
N1^i—Cd1—N1^iii	74.05 (9)	C14—C13—H13A	120.0
N1—Cd1—N1^iii	97.46 (8)	C13—C14—C15	116.9 (3)
N11—Cd1—N1^iii	87.47 (7)	C13—C14—C16	123.6 (3)
N11^i—Cd1—N1^iii	104.83 (8)	C15—C14—C16	119.5 (3)
N1^ii—Cd1—N1^iii	165.09 (11)	N11—C15—C14	122.8 (2)
N2—N1—Cd1	124.66 (19)	N11—C15—C15^i	118.13 (13)
N2—N1—Cd1^ii	129.35 (18)	C14—C15—C15^i	119.09 (16)
Cd1—N1—Cd1^ii	105.95 (9)	C16^i—C16—C14	121.41 (17)
N3—N2—N1	178.8 (3)	C16^i—C16—H16A	119.3
C11—N11—C15	118.0 (2)	C14—C16—H16A	119.3

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