metal-organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

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Bis(2-propyl-1H-imidazol-3-ium) bis­­(pyridine-2,6-di­carboxyl­ato-κ3O2,N,O6)cadmate(II)

aCollege of Chemical Engineering, Hebei United University, Tangshan 063009, People's Republic of China, and bQian'an College, Hebei United University, Tangshan 063009, People's Republic of China
*Correspondence e-mail: tsdgying@126.com

(Received 6 June 2011; accepted 23 June 2011; online 30 June 2011)

The title salt, (C6H11N2)2[Cd(C7H3NO4)2], displays a discrete mononuclear structure, in which the central CdII 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 O2,N,O6-tridentate chelation mode. The crystal packing is stabilized by N—H⋯O hydrogen bonds and ππ 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[Hay, M. P., Anderson, R. F., Ferry, D. M., Wilson, W. R. & Denny, W. A. (2003). J. Med. Chem. 46, 5533-5545.]). For related complexes, see: Dong et al. (2006[Dong, G.-Y., Cui, G.-H. & Wang, S.-C. (2006). Acta Cryst. E62, m606-m607.]); Guerriero et al. (1987[Guerriero, P., Casellato, U., Sitran, S., Vigato, P. A. & Graziani, R. (1987). Inorg. Chim. Acta, 133, 337-345.]); Kjell et al. (1993[Kjell, H., Martin, L., Goran, S. & Jorgen, A. (1993). Acta Chem. Scand. 47, 449-455.]); Abboud et al. (1998[Abboud, K. A., Xu, C. & Drago, R. S. (1998). Acta Cryst. C54, 1270-1273.]).

[Scheme 1]

Experimental

Crystal data
  • (C6H11N2)2[Cd(C7H3NO4)2]

  • Mr = 664.95

  • Monoclinic, C 2/c

  • 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[Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.]) Tmin = 0.796, Tmax = 0.808

  • 11223 measured reflections

  • 2364 independent reflections

  • 2238 reflections with I > 2σ(I)

  • Rint = 0.034

Refinement
  • R[F2 > 2σ(F2)] = 0.031

  • wR(F2) = 0.065

  • S = 1.19

  • 2364 reflections

  • 186 parameters

  • H-atom parameters constrained

  • Δρmax = 0.26 e Å−3

  • Δρmin = −0.46 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA 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) [-x+{\script{1\over 2}}, y+{\script{1\over 2}}, -z+{\script{1\over 2}}]; (ii) [x+{\script{1\over 2}}, y-{\script{1\over 2}}, z].

Data collection: SMART (Bruker, 1998[Bruker (1998). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 1998[Bruker (1998). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); software used to prepare material for publication: SHELXTL.

Supporting information


Comment top

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 CdII 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 Cg1a (ring N1a,C1a—C5a) [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.

Related literature top

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 top

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.

Refinement top

H atoms were placed in calculated positions, with N—H = 0.86 Å; C—H = 0.97 Å for methyl H-atoms and C—H = 0.93 Å for other H-atoms and refined in a riding model with Uiso(H) = 1.5Ueq(C) for methyl H-atoms and Uiso(H) = 1.2Ueq(C, N) for other atoms.

Computing details top

Data collection: SMART (Bruker, 1998); cell refinement: SAINT (Bruker, 1998); data reduction: SAINT (Bruker, 1998); 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 top
[Figure 1] Fig. 1. Fig. 1. The molecular structure of (I), showing displacement ellipsoids at the 30% probability level. Symmetry code: (i) -x, y, 0.5 - z.
[Figure 2] 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.
Bis(2-propyl-1H-imidazol-3-ium) bis(pyridine-2,6-dicarboxylato-κ3O2,N,O6)cadmate(II) top
Crystal data top
(C6H11N2)2[Cd(C7H3NO4)2]F(000) = 1352
Mr = 664.95Dx = 1.645 Mg m3
Monoclinic, C2/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2ycCell parameters from 5638 reflections
a = 19.928 (4) Åθ = 22.4–4.6°
b = 9.5038 (19) ŵ = 0.88 mm1
c = 15.073 (3) ÅT = 295 K
β = 109.90 (3)°Prism, colourless
V = 2684.2 (11) Å30.22 × 0.12 × 0.08 mm
Z = 4
Data collection top
Bruker SMART CCD area-detector
diffractometer
2364 independent reflections
Radiation source: fine–focus sealed tube2238 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.034
ϕ and ω scansθmax = 25.0°, θmin = 3.5°
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
h = 2323
Tmin = 0.796, Tmax = 0.808k = 1111
11223 measured reflectionsl = 1717
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.031Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.065H-atom parameters constrained
S = 1.19 w = 1/[σ2(Fo2) + (0.0218P)2 + 4.3339P]
where P = (Fo2 + 2Fc2)/3
2364 reflections(Δ/σ)max < 0.001
186 parametersΔρmax = 0.26 e Å3
0 restraintsΔρmin = 0.46 e Å3
Crystal data top
(C6H11N2)2[Cd(C7H3NO4)2]V = 2684.2 (11) Å3
Mr = 664.95Z = 4
Monoclinic, C2/cMo Kα radiation
a = 19.928 (4) ŵ = 0.88 mm1
b = 9.5038 (19) ÅT = 295 K
c = 15.073 (3) Å0.22 × 0.12 × 0.08 mm
β = 109.90 (3)°
Data collection top
Bruker SMART CCD area-detector
diffractometer
2364 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
2238 reflections with I > 2σ(I)
Tmin = 0.796, Tmax = 0.808Rint = 0.034
11223 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0310 restraints
wR(F2) = 0.065H-atom parameters constrained
S = 1.19Δρmax = 0.26 e Å3
2364 reflectionsΔρmin = 0.46 e Å3
186 parameters
Special details top

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) top
xyzUiso*/Ueq
Cd10.00000.07339 (3)0.25000.03025 (11)
O10.09384 (11)0.0821 (2)0.31049 (13)0.0428 (5)
C70.13072 (14)0.0697 (3)0.39623 (19)0.0301 (6)
N10.04450 (10)0.0993 (2)0.40666 (14)0.0221 (5)
O30.06932 (10)0.2362 (2)0.29862 (13)0.0400 (5)
O20.18879 (10)0.1286 (2)0.43686 (14)0.0413 (5)
O40.07871 (12)0.3529 (3)0.42064 (15)0.0513 (6)
C60.05008 (14)0.2656 (3)0.3843 (2)0.0309 (6)
C50.10172 (13)0.0254 (3)0.45517 (17)0.0228 (5)
C10.01417 (13)0.1878 (3)0.44944 (18)0.0243 (6)
C40.13092 (14)0.0374 (3)0.55192 (18)0.0298 (6)
H4A0.17130.01390.58560.036*
C30.09920 (15)0.1269 (3)0.59761 (18)0.0349 (7)
H3A0.11730.13490.66300.042*
C20.04064 (14)0.2043 (3)0.54622 (18)0.0321 (6)
H2A0.01930.26670.57600.039*
N30.33043 (12)0.0315 (2)0.29967 (17)0.0340 (6)
H3B0.35710.03110.33600.041*
C90.24342 (15)0.1779 (3)0.2381 (2)0.0357 (7)
H9A0.20190.23070.22540.043*
N20.29048 (11)0.1827 (2)0.18995 (16)0.0313 (5)
H2B0.28660.23570.14220.038*
C100.26839 (15)0.0829 (3)0.3068 (2)0.0379 (7)
H10A0.24760.05690.35110.045*
C80.34294 (14)0.0927 (3)0.2285 (2)0.0316 (6)
C110.40311 (17)0.0637 (4)0.1952 (3)0.0531 (9)
H11A0.43450.00510.23650.064*
H11B0.43030.14950.19860.064*
C120.3781 (3)0.0082 (5)0.0936 (3)0.0786 (14)
H12A0.35080.08110.05170.094*
H12B0.41960.01180.07600.094*
C130.3335 (2)0.1215 (5)0.0797 (3)0.0729 (13)
H13A0.31950.15050.01490.109*
H13B0.29170.10210.09560.109*
H13C0.36050.19510.11950.109*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cd10.03459 (18)0.03409 (18)0.01739 (15)0.0000.00275 (11)0.000
O10.0528 (13)0.0463 (12)0.0258 (11)0.0206 (11)0.0090 (9)0.0040 (9)
C70.0329 (15)0.0278 (14)0.0306 (15)0.0010 (13)0.0123 (12)0.0042 (12)
N10.0216 (11)0.0243 (12)0.0198 (11)0.0003 (9)0.0062 (9)0.0008 (9)
O30.0346 (11)0.0486 (13)0.0298 (11)0.0154 (10)0.0019 (9)0.0016 (9)
O20.0328 (11)0.0433 (12)0.0431 (12)0.0159 (10)0.0071 (9)0.0023 (10)
O40.0512 (14)0.0585 (15)0.0436 (13)0.0309 (12)0.0154 (11)0.0012 (11)
C60.0260 (14)0.0309 (15)0.0352 (16)0.0036 (12)0.0095 (12)0.0034 (13)
C50.0215 (13)0.0229 (13)0.0233 (13)0.0009 (10)0.0066 (10)0.0028 (10)
C10.0243 (13)0.0244 (13)0.0255 (13)0.0000 (11)0.0101 (11)0.0002 (11)
C40.0261 (14)0.0337 (16)0.0245 (14)0.0010 (12)0.0021 (11)0.0051 (12)
C30.0371 (16)0.0478 (18)0.0173 (13)0.0029 (14)0.0062 (12)0.0017 (12)
C20.0349 (16)0.0370 (17)0.0268 (14)0.0008 (13)0.0136 (12)0.0059 (12)
N30.0331 (13)0.0281 (13)0.0395 (14)0.0027 (10)0.0107 (11)0.0019 (11)
C90.0265 (14)0.0336 (16)0.0462 (18)0.0023 (12)0.0112 (13)0.0047 (14)
N20.0296 (12)0.0268 (12)0.0373 (13)0.0007 (10)0.0114 (10)0.0020 (10)
C100.0362 (16)0.0394 (17)0.0421 (17)0.0022 (14)0.0186 (13)0.0046 (15)
C80.0252 (14)0.0254 (15)0.0439 (17)0.0039 (12)0.0115 (12)0.0034 (13)
C110.0419 (18)0.0431 (19)0.087 (3)0.0057 (16)0.0383 (19)0.0133 (19)
C120.111 (4)0.076 (3)0.081 (3)0.046 (3)0.075 (3)0.034 (2)
C130.092 (3)0.076 (3)0.048 (2)0.037 (3)0.021 (2)0.006 (2)
Geometric parameters (Å, º) top
Cd1—N12.235 (2)C2—H2A0.9300
Cd1—N1i2.235 (2)N3—C81.316 (4)
Cd1—O12.313 (2)N3—C101.368 (4)
Cd1—O1i2.313 (2)N3—H3B0.8600
Cd1—O3i2.351 (2)C9—C101.336 (4)
Cd1—O32.351 (2)C9—N21.368 (4)
O1—C71.256 (3)C9—H9A0.9300
C7—O21.243 (3)N2—C81.323 (3)
C7—C51.513 (4)N2—H2B0.8600
N1—C11.324 (3)C10—H10A0.9300
N1—C51.326 (3)C8—C111.475 (4)
O3—C61.247 (3)C11—C121.534 (6)
O4—C61.236 (3)C11—H11A0.9700
C6—C11.515 (4)C11—H11B0.9700
C5—C41.379 (4)C12—C131.492 (6)
C1—C21.381 (4)C12—H12A0.9700
C4—C31.376 (4)C12—H12B0.9700
C4—H4A0.9300C13—H13A0.9600
C3—C21.374 (4)C13—H13B0.9600
C3—H3A0.9300C13—H13C0.9600
N1—Cd1—N1i167.37 (11)C2—C3—H3A120.2
N1—Cd1—O171.16 (7)C3—C2—C1118.7 (3)
N1i—Cd1—O1117.61 (7)C3—C2—H2A120.6
N1—Cd1—O1i117.61 (7)C1—C2—H2A120.6
N1i—Cd1—O1i71.16 (7)C8—N3—C10109.5 (2)
O1—Cd1—O1i100.59 (11)C8—N3—H3B125.3
N1—Cd1—O3i101.12 (7)C10—N3—H3B125.3
N1i—Cd1—O3i70.27 (7)C10—C9—N2107.0 (3)
O1—Cd1—O3i93.52 (8)C10—C9—H9A126.5
O1i—Cd1—O3i141.21 (7)N2—C9—H9A126.5
N1—Cd1—O370.27 (7)C8—N2—C9109.1 (2)
N1i—Cd1—O3101.12 (7)C8—N2—H2B125.5
O1—Cd1—O3141.21 (7)C9—N2—H2B125.5
O1i—Cd1—O393.52 (8)C9—C10—N3106.7 (3)
O3i—Cd1—O397.69 (11)C9—C10—H10A126.6
C7—O1—Cd1117.19 (17)N3—C10—H10A126.6
O2—C7—O1125.8 (3)N3—C8—N2107.7 (2)
O2—C7—C5117.2 (2)N3—C8—C11126.6 (3)
O1—C7—C5117.0 (2)N2—C8—C11125.7 (3)
C1—N1—C5121.1 (2)C8—C11—C12112.3 (3)
C1—N1—Cd1120.09 (16)C8—C11—H11A109.2
C5—N1—Cd1118.80 (16)C12—C11—H11A109.2
C6—O3—Cd1117.65 (17)C8—C11—H11B109.2
O4—C6—O3125.7 (3)C12—C11—H11B109.2
O4—C6—C1117.2 (2)H11A—C11—H11B107.9
O3—C6—C1117.1 (2)C13—C12—C11113.6 (3)
N1—C5—C4120.9 (2)C13—C12—H12A108.9
N1—C5—C7114.9 (2)C11—C12—H12A108.9
C4—C5—C7124.2 (2)C13—C12—H12B108.9
N1—C1—C2120.9 (2)C11—C12—H12B108.9
N1—C1—C6114.8 (2)H12A—C12—H12B107.7
C2—C1—C6124.3 (2)C12—C13—H13A109.5
C3—C4—C5118.7 (2)C12—C13—H13B109.5
C3—C4—H4A120.7H13A—C13—H13B109.5
C5—C4—H4A120.7C12—C13—H13C109.5
C4—C3—C2119.7 (2)H13A—C13—H13C109.5
C4—C3—H3A120.2H13B—C13—H13C109.5
Symmetry code: (i) x, y, z+1/2.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N2—H2B···O2ii0.861.932.753 (3)160
N3—H3B···O4iii0.861.842.690 (3)173
Symmetry codes: (ii) x+1/2, y+1/2, z+1/2; (iii) x+1/2, y1/2, z.

Experimental details

Crystal data
Chemical formula(C6H11N2)2[Cd(C7H3NO4)2]
Mr664.95
Crystal system, space groupMonoclinic, C2/c
Temperature (K)295
a, b, c (Å)19.928 (4), 9.5038 (19), 15.073 (3)
β (°) 109.90 (3)
V3)2684.2 (11)
Z4
Radiation typeMo Kα
µ (mm1)0.88
Crystal size (mm)0.22 × 0.12 × 0.08
Data collection
DiffractometerBruker SMART CCD area-detector
diffractometer
Absorption correctionMulti-scan
(SADABS; Sheldrick, 1996)
Tmin, Tmax0.796, 0.808
No. of measured, independent and
observed [I > 2σ(I)] reflections
11223, 2364, 2238
Rint0.034
(sin θ/λ)max1)0.595
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.031, 0.065, 1.19
No. of reflections2364
No. of parameters186
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.26, 0.46

Computer programs: SMART (Bruker, 1998), SAINT (Bruker, 1998), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N2—H2B···O2i0.861.932.753 (3)160
N3—H3B···O4ii0.861.842.690 (3)173
Symmetry codes: (i) x+1/2, y+1/2, z+1/2; (ii) x+1/2, y1/2, z.
 

Acknowledgements

The authors thank Hebei United University for supporting this work.

References

First citationAbboud, K. A., Xu, C. & Drago, R. S. (1998). Acta Cryst. C54, 1270–1273.  Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
First citationBruker (1998). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationDong, G.-Y., Cui, G.-H. & Wang, S.-C. (2006). Acta Cryst. E62, m606–m607.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationGuerriero, P., Casellato, U., Sitran, S., Vigato, P. A. & Graziani, R. (1987). Inorg. Chim. Acta, 133, 337–345.  CSD CrossRef CAS Web of Science Google Scholar
First citationHay, M. P., Anderson, R. F., Ferry, D. M., Wilson, W. R. & Denny, W. A. (2003). J. Med. Chem. 46, 5533–5545.  Web of Science CrossRef PubMed CAS Google Scholar
First citationKjell, H., Martin, L., Goran, S. & Jorgen, A. (1993). Acta Chem. Scand. 47, 449–455.  Google Scholar
First citationSheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.  Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar

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