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Acta Crystallogr Sect E Struct Rep Online

Acta Cryst. E

Acta Crystallographica Section E: Structure Reports Online

1600-5368

International Union of Crystallography

21836832

3151894

aa2014

10.1107/S1600536811024792

ACSEBH

S1600536811024792

Metal-Organic Papers

Bis(2-propyl-1H-imidazol-3-ium) bis(pyridine-2,6-dicarboxylato-κ³ O ²,N,O ⁶)cadmate(II)

(C₆H₁₁N₂)₂[Cd(C₇H₃NO₄)₂]

Dong

Gui-Ying

a*Liu

Tong-Fei

aHe

Cui-Hong

aDeng

Xiao-Chen

bShi

Xiao-Ge

baCollege of Chemical Engineering, Hebei United University, Tangshan 063009, People’s Republic of ChinabQian’an College, Hebei United University, Tangshan 063009, People’s Republic of China

Correspondence e-mail: tsdgying@126.com

0172011

3062011

67Pt 7

e110700

m1007m100706620112362011

2011

This is an open-access article distributed under the terms of the Creative Commons Attribution Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.

A full version of this article is available from Crystallography Journals Online.

The title salt, (C₆H₁₁N₂)₂[Cd(C₇H₃NO₄)₂], displays a discrete mononuclear structure, in which the central Cd^II atom is six-coordinated in a distorted octahedral coordination geometry by two N and four O atoms from two different pyridine-2,6-dicarboxylate anions in an O ²,N,O ⁶-tridentate chelation mode. The crystal packing is stabilized by N—H⋯O hydrogen bonds and π–π interactions [centroid–centroid distance = 3.576 (5) Å].

Related literature

For background to and the biological activity of pyridine-2,6-dicarboxylic acid, see: Hay et al. (2003 ▶). For related complexes, see: Dong et al. (2006 ▶); Guerriero et al. (1987 ▶); Kjell et al. (1993 ▶); Abboud et al. (1998 ▶).

Experimental<sec id="sec2.1.1"><title>Crystal data

(C₆H₁₁N₂)₂[Cd(C₇H₃NO₄)₂]

M _r = 664.95

Monoclinic,

a = 19.928 (4) Å

b = 9.5038 (19) Å

c = 15.073 (3) Å

β = 109.90 (3)°

V = 2684.2 (11) Å³

Z = 4

Mo Kα radiation

μ = 0.88 mm⁻¹

T = 295 K

0.22 × 0.12 × 0.08 mm

Data collection

Bruker SMART CCD area-detector diffractometer

Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.796, T _max = 0.808

11223 measured reflections

2364 independent reflections

2238 reflections with I > 2σ(I)

R _int = 0.034

Refinement

R[F ² > 2σ(F ²)] = 0.031

wR(F ²) = 0.065

S = 1.19

2364 reflections

186 parameters

H-atom parameters constrained

Δρ_max = 0.26 e Å⁻³

Δρ_min = −0.46 e Å⁻³

Data collection: <italic>SMART</italic> (Bruker, 1998<xref ref-type="bibr" rid="bb2"> ▶</xref>); cell refinement: <italic>SAINT</italic> (Bruker, 1998<xref ref-type="bibr" rid="bb2"> ▶</xref>); data reduction: <italic>SAINT</italic>; program(s) used to solve structure: <italic>SHELXS97</italic> (Sheldrick, 2008<xref ref-type="bibr" rid="bb8"> ▶</xref>); program(s) used to refine structure: <italic>SHELXL97</italic> (Sheldrick, 2008<xref ref-type="bibr" rid="bb8"> ▶</xref>); molecular graphics: <italic>SHELXTL</italic> (Sheldrick, 2008<xref ref-type="bibr" rid="bb8"> ▶</xref>); software used to prepare material for publication: <italic>SHELXTL</italic>.</sec></sec><sec sec-type="supplementary-material"><title>Supplementary Material

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536811024792/aa2014sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811024792/aa2014Isup2.hkl

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

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: AA2014).

The authors thank Hebei United University for supporting this work.

supplementary crystallographic information Comment

The pyridine-2,6-dicarboxylic (dipicolinic) acid is now recognized to be a major component of bacterial spores, which is used in a variety of processes as an enzyme inhibitor, plant preservative and food sanitizer (Hay et al. 2003). Pyridine-2,6-dicarboxylate has proved to be a versatile ligand with N,O-chelation and adopts diverse coordination modes (Guerriero et al., 1987; Kjell et al., 1993; Abboud et al., 1998; Dong et al.,2006). Recent efforts of our laboratory to synthesize coordination polymers with pyridine-2,6-dicarboxylic acid and 2-propylimidazole with transition metals resulted in the synthesis of the title complex (I).

In the title compound, the Cd^II is octahedrally coordinated by two tridentate dipicolinate ligands via their O and N atoms. In the crystal structure, adjacent molecules are linked via strong N—H···O hydrogen bonds into chains parallel to the b axis, see Fig. 2. Also there are π-π interactions between the centroids of adjacent pyridine rings. For Cg1 (the centroid of ring N1,C1—C5) and Cg1^a (ring N1^a,C1^a—C5^a) [symmetry code (a):-x,-y,-z + 1), the centroid–centroid distance is 3.576 (5)Å and the dihedral angle is 12.43 (3)°, this may further stabilize the structure.

Experimental

A mixture of cadmium(II) nitrate tetrahydrate (308.49 mg, 1 mmol) was added to a slightly basic (pH > 8) solution of pyridine-2,6-dicarboxylic acid (334 mg, 2 mmol), followed by the addition of 2-propylimidazole (440 mg, 4 mmol) with stirring. The reaction mixture was filtered and the filtrate was allowed to stay at room temperature. Colourless prism-shaped crystals were obtained after one week (yield: 0.132 g, 20%). Analysis for C₂₆H₂₈CdN₆O₈ (%): calculated C 46.96, H 4.24,N 12.64; found C 46.85, H 4.13 N 12.57.

FiguresFig. 1.

Fig. 1. The molecular structure of (I), showing displacement ellipsoids at the 30% probability level. Symmetry code: (i) -x, y, 0.5 - z.

Fig. 2.

A partial packing diagram of the title compound. Hydrogen bonds are shown as dashed lines and H atoms not involved in hydrogen bonding are omitted.

Crystal data

(C₆H₁₁N₂)₂[Cd(C₇H₃NO₄)₂]	F(000) = 1352
M_r = 664.95	D_x = 1.645 Mg m⁻³
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 5638 reflections
a = 19.928 (4) Å	θ = 22.4–4.6°
b = 9.5038 (19) Å	µ = 0.88 mm⁻¹
c = 15.073 (3) Å	T = 295 K
β = 109.90 (3)°	Prism, colourless
V = 2684.2 (11) Å³	0.22 × 0.12 × 0.08 mm
Z = 4

Data collection

Bruker SMART CCD area-detector diffractometer	2364 independent reflections
Radiation source: fine–focus sealed tube	2238 reflections with I > 2σ(I)
graphite	R_int = 0.034
φ and ω scans	θ_max = 25.0°, θ_min = 3.5°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −23→23
T_min = 0.796, T_max = 0.808	k = −11→11
11223 measured reflections	l = −17→17

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)] = 0.031	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.065	H-atom parameters constrained
S = 1.19	w = 1/[σ²(F_o²) + (0.0218P)² + 4.3339P] where P = (F_o² + 2F_c²)/3
2364 reflections	(Δ/σ)_max < 0.001
186 parameters	Δρ_max = 0.26 e Å⁻³
0 restraints	Δρ_min = −0.46 e Å⁻³

Special details

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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 (Å2)

	x	y	z	U_iso*/U_eq
Cd1	0.0000	0.07339 (3)	0.2500	0.03025 (11)
O1	0.09384 (11)	−0.0821 (2)	0.31049 (13)	0.0428 (5)
C7	0.13072 (14)	−0.0697 (3)	0.39623 (19)	0.0301 (6)
N1	0.04450 (10)	0.0993 (2)	0.40666 (14)	0.0221 (5)
O3	−0.06932 (10)	0.2362 (2)	0.29862 (13)	0.0400 (5)
O2	0.18879 (10)	−0.1286 (2)	0.43686 (14)	0.0413 (5)
O4	−0.07871 (12)	0.3529 (3)	0.42064 (15)	0.0513 (6)
C6	−0.05008 (14)	0.2656 (3)	0.3843 (2)	0.0309 (6)
C5	0.10172 (13)	0.0254 (3)	0.45517 (17)	0.0228 (5)
C1	0.01417 (13)	0.1878 (3)	0.44944 (18)	0.0243 (6)
C4	0.13092 (14)	0.0374 (3)	0.55192 (18)	0.0298 (6)
H4A	0.1713	−0.0139	0.5856	0.036*
C3	0.09920 (15)	0.1269 (3)	0.59761 (18)	0.0349 (7)
H3A	0.1173	0.1349	0.6630	0.042*
C2	0.04064 (14)	0.2043 (3)	0.54622 (18)	0.0321 (6)
H2A	0.0193	0.2667	0.5760	0.039*
N3	0.33043 (12)	0.0315 (2)	0.29967 (17)	0.0340 (6)
H3B	0.3571	−0.0311	0.3360	0.041*
C9	0.24342 (15)	0.1779 (3)	0.2381 (2)	0.0357 (7)
H9A	0.2019	0.2307	0.2254	0.043*
N2	0.29048 (11)	0.1827 (2)	0.18995 (16)	0.0313 (5)
H2B	0.2866	0.2357	0.1422	0.038*
C10	0.26839 (15)	0.0829 (3)	0.3068 (2)	0.0379 (7)
H10A	0.2476	0.0569	0.3511	0.045*
C8	0.34294 (14)	0.0927 (3)	0.2285 (2)	0.0316 (6)
C11	0.40311 (17)	0.0637 (4)	0.1952 (3)	0.0531 (9)
H11A	0.4345	−0.0051	0.2365	0.064*
H11B	0.4303	0.1495	0.1986	0.064*
C12	0.3781 (3)	0.0082 (5)	0.0936 (3)	0.0786 (14)
H12A	0.3508	0.0811	0.0517	0.094*
H12B	0.4196	−0.0118	0.0760	0.094*
C13	0.3335 (2)	−0.1215 (5)	0.0797 (3)	0.0729 (13)
H13A	0.3195	−0.1505	0.0149	0.109*
H13B	0.2917	−0.1021	0.0956	0.109*
H13C	0.3605	−0.1951	0.1195	0.109*

Atomic displacement parameters (Å2)

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Cd1	0.03459 (18)	0.03409 (18)	0.01739 (15)	0.000	0.00275 (11)	0.000
O1	0.0528 (13)	0.0463 (12)	0.0258 (11)	0.0206 (11)	0.0090 (9)	−0.0040 (9)
C7	0.0329 (15)	0.0278 (14)	0.0306 (15)	0.0010 (13)	0.0123 (12)	0.0042 (12)
N1	0.0216 (11)	0.0243 (12)	0.0198 (11)	−0.0003 (9)	0.0062 (9)	0.0008 (9)
O3	0.0346 (11)	0.0486 (13)	0.0298 (11)	0.0154 (10)	0.0019 (9)	0.0016 (9)
O2	0.0328 (11)	0.0433 (12)	0.0431 (12)	0.0159 (10)	0.0071 (9)	−0.0023 (10)
O4	0.0512 (14)	0.0585 (15)	0.0436 (13)	0.0309 (12)	0.0154 (11)	−0.0012 (11)
C6	0.0260 (14)	0.0309 (15)	0.0352 (16)	0.0036 (12)	0.0095 (12)	0.0034 (13)
C5	0.0215 (13)	0.0229 (13)	0.0233 (13)	−0.0009 (10)	0.0066 (10)	0.0028 (10)
C1	0.0243 (13)	0.0244 (13)	0.0255 (13)	0.0000 (11)	0.0101 (11)	−0.0002 (11)
C4	0.0261 (14)	0.0337 (16)	0.0245 (14)	0.0010 (12)	0.0021 (11)	0.0051 (12)
C3	0.0371 (16)	0.0478 (18)	0.0173 (13)	−0.0029 (14)	0.0062 (12)	−0.0017 (12)
C2	0.0349 (16)	0.0370 (17)	0.0268 (14)	−0.0008 (13)	0.0136 (12)	−0.0059 (12)
N3	0.0331 (13)	0.0281 (13)	0.0395 (14)	0.0027 (10)	0.0107 (11)	0.0019 (11)
C9	0.0265 (14)	0.0336 (16)	0.0462 (18)	0.0023 (12)	0.0112 (13)	−0.0047 (14)
N2	0.0296 (12)	0.0268 (12)	0.0373 (13)	−0.0007 (10)	0.0114 (10)	0.0020 (10)
C10	0.0362 (16)	0.0394 (17)	0.0421 (17)	−0.0022 (14)	0.0186 (13)	−0.0046 (15)
C8	0.0252 (14)	0.0254 (15)	0.0439 (17)	−0.0039 (12)	0.0115 (12)	−0.0034 (13)
C11	0.0419 (18)	0.0431 (19)	0.087 (3)	0.0057 (16)	0.0383 (19)	0.0133 (19)
C12	0.111 (4)	0.076 (3)	0.081 (3)	0.046 (3)	0.075 (3)	0.034 (2)
C13	0.092 (3)	0.076 (3)	0.048 (2)	0.037 (3)	0.021 (2)	−0.006 (2)

Geometric parameters (Å, °)

Cd1—N1	2.235 (2)	C2—H2A	0.9300
Cd1—N1ⁱ	2.235 (2)	N3—C8	1.316 (4)
Cd1—O1	2.313 (2)	N3—C10	1.368 (4)
Cd1—O1ⁱ	2.313 (2)	N3—H3B	0.8600
Cd1—O3ⁱ	2.351 (2)	C9—C10	1.336 (4)
Cd1—O3	2.351 (2)	C9—N2	1.368 (4)
O1—C7	1.256 (3)	C9—H9A	0.9300
C7—O2	1.243 (3)	N2—C8	1.323 (3)
C7—C5	1.513 (4)	N2—H2B	0.8600
N1—C1	1.324 (3)	C10—H10A	0.9300
N1—C5	1.326 (3)	C8—C11	1.475 (4)
O3—C6	1.247 (3)	C11—C12	1.534 (6)
O4—C6	1.236 (3)	C11—H11A	0.9700
C6—C1	1.515 (4)	C11—H11B	0.9700
C5—C4	1.379 (4)	C12—C13	1.492 (6)
C1—C2	1.381 (4)	C12—H12A	0.9700
C4—C3	1.376 (4)	C12—H12B	0.9700
C4—H4A	0.9300	C13—H13A	0.9600
C3—C2	1.374 (4)	C13—H13B	0.9600
C3—H3A	0.9300	C13—H13C	0.9600

N1—Cd1—N1ⁱ	167.37 (11)	C2—C3—H3A	120.2
N1—Cd1—O1	71.16 (7)	C3—C2—C1	118.7 (3)
N1ⁱ—Cd1—O1	117.61 (7)	C3—C2—H2A	120.6
N1—Cd1—O1ⁱ	117.61 (7)	C1—C2—H2A	120.6
N1ⁱ—Cd1—O1ⁱ	71.16 (7)	C8—N3—C10	109.5 (2)
O1—Cd1—O1ⁱ	100.59 (11)	C8—N3—H3B	125.3
N1—Cd1—O3ⁱ	101.12 (7)	C10—N3—H3B	125.3
N1ⁱ—Cd1—O3ⁱ	70.27 (7)	C10—C9—N2	107.0 (3)
O1—Cd1—O3ⁱ	93.52 (8)	C10—C9—H9A	126.5
O1ⁱ—Cd1—O3ⁱ	141.21 (7)	N2—C9—H9A	126.5
N1—Cd1—O3	70.27 (7)	C8—N2—C9	109.1 (2)
N1ⁱ—Cd1—O3	101.12 (7)	C8—N2—H2B	125.5
O1—Cd1—O3	141.21 (7)	C9—N2—H2B	125.5
O1ⁱ—Cd1—O3	93.52 (8)	C9—C10—N3	106.7 (3)
O3ⁱ—Cd1—O3	97.69 (11)	C9—C10—H10A	126.6
C7—O1—Cd1	117.19 (17)	N3—C10—H10A	126.6
O2—C7—O1	125.8 (3)	N3—C8—N2	107.7 (2)
O2—C7—C5	117.2 (2)	N3—C8—C11	126.6 (3)
O1—C7—C5	117.0 (2)	N2—C8—C11	125.7 (3)
C1—N1—C5	121.1 (2)	C8—C11—C12	112.3 (3)
C1—N1—Cd1	120.09 (16)	C8—C11—H11A	109.2
C5—N1—Cd1	118.80 (16)	C12—C11—H11A	109.2
C6—O3—Cd1	117.65 (17)	C8—C11—H11B	109.2
O4—C6—O3	125.7 (3)	C12—C11—H11B	109.2
O4—C6—C1	117.2 (2)	H11A—C11—H11B	107.9
O3—C6—C1	117.1 (2)	C13—C12—C11	113.6 (3)
N1—C5—C4	120.9 (2)	C13—C12—H12A	108.9
N1—C5—C7	114.9 (2)	C11—C12—H12A	108.9
C4—C5—C7	124.2 (2)	C13—C12—H12B	108.9
N1—C1—C2	120.9 (2)	C11—C12—H12B	108.9
N1—C1—C6	114.8 (2)	H12A—C12—H12B	107.7
C2—C1—C6	124.3 (2)	C12—C13—H13A	109.5
C3—C4—C5	118.7 (2)	C12—C13—H13B	109.5
C3—C4—H4A	120.7	H13A—C13—H13B	109.5
C5—C4—H4A	120.7	C12—C13—H13C	109.5
C4—C3—C2	119.7 (2)	H13A—C13—H13C	109.5
C4—C3—H3A	120.2	H13B—C13—H13C	109.5

Symmetry codes: (i) −x, y, −z+1/2.

Hydrogen-bond geometry (Å, °)

D—H···A	D—H	H···A	D···A	D—H···A
N2—H2B···O2ⁱⁱ	0.86	1.93	2.753 (3)	160
N3—H3B···O4ⁱⁱⁱ	0.86	1.84	2.690 (3)	173

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

References

Abboud, K. A., Xu, C. & Drago, R. S. (1998). Acta Cryst. C54, 1270–1273.

Bruker (1998). SMART and SAINT Bruker AXS Inc., Madison, Wisconsin, USA.

Dong, G.-Y., Cui, G.-H. & Wang, S.-C. (2006). Acta Cryst. E62, m606–m607.

Guerriero, P., Casellato, U., Sitran, S., Vigato, P. A. & Graziani, R. (1987). Inorg. Chim. Acta, 133, 337–345.

Hay, M. P., Anderson, R. F., Ferry, D. M., Wilson, W. R. & Denny, W. A. (2003). J. Med. Chem. 46, 5533–5545.

Kjell, H., Martin, L., Goran, S. & Jorgen, A. (1993). Acta Chem. Scand. 47, 449–455.

Sheldrick, G. M. (1996). SADABS University of Göttingen, Germany.

Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.

Table 1Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N2—H2B⋯O2ⁱ	0.86	1.93	2.753 (3)	160
N3—H3B⋯O4ⁱⁱ	0.86	1.84	2.690 (3)	173

Symmetry codes: (i) ; (ii) .