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Acta Crystallogr Sect E Struct Rep Online. 2010 June 1; 66(Pt 6): m705–m706.
Published online 2010 May 22. doi:  10.1107/S1600536810017915
PMCID: PMC2979651

Poly[bis­(1H-imidazole)bis­(μ2-1H-imidazolido)bis­(μ2-7-oxabicyclo­[2.2.1]heptane-2,3-dicarboxyl­ato)trizinc(II)]

Abstract

The title polymer, [Zn3(C8H8O5)2(C3H3N2)2(C3H4N2)2]n, was formed by the reaction of zinc acetate with imidazole and 7-oxabicyclo­[2.2.1]heptane-2,3-dicarboxylic anhydride (norcan­tharidine). One of the two crystallographically unique ZnII atoms is four-coordinated by three N atoms of three imidazole ligands, two of which are deprotonated, and by one carboxyl­ate O atom of the demethyl­cantharate anion. The second ZnII atom is situated on an inversion centre and is six-coordinated by the bridging O atoms of two symmetry-related demethyl­cantharate anions and by four carboxyl­ate O atoms of the corresponding carboxyl­ate groups. The polymeric crystal structure is additionally stabilized by N—H(...)O hydrogen bonding between the imidazole ligands and carboxyl­ate O atoms.

Related literature

7-Oxabicyclo­[2.2.1]heptane-2,3-dicarboxylic anhydride (nor­can­tharidin) is a lower toxicity anti­cancer drug, see: Shimi et al. (1982 [triangle]). For cobalt complexes of norcantharidin, see: Wang et al. (1988 [triangle]) and for those including imidazole ligands, see: Furenlid et al. (1986 [triangle]); Zhu et al. (2003 [triangle]).

An external file that holds a picture, illustration, etc.
Object name is e-66-0m705-scheme1.jpg

Experimental

Crystal data

  • [Zn3(C8H8O5)2(C3H3N2)2(C3H4N2)2]
  • M r = 834.71
  • Monoclinic, An external file that holds a picture, illustration, etc.
Object name is e-66-0m705-efi1.jpg
  • a = 7.9993 (1) Å
  • b = 22.3923 (2) Å
  • c = 9.7586 (1) Å
  • β = 112.633 (1)°
  • V = 1613.37 (3) Å3
  • Z = 2
  • Mo Kα radiation
  • μ = 2.28 mm−1
  • T = 296 K
  • 0.28 × 0.17 × 0.09 mm

Data collection

  • Bruker APEXII CCD diffractometer
  • Absorption correction: multi-scan (SADABS; Sheldrick, 1996 [triangle]) T min = 0.629, T max = 0.822
  • 13439 measured reflections
  • 3714 independent reflections
  • 3197 reflections with I > 2σ(I)
  • R int = 0.023

Refinement

  • R[F 2 > 2σ(F 2)] = 0.024
  • wR(F 2) = 0.060
  • S = 1.03
  • 3714 reflections
  • 223 parameters
  • H-atom parameters constrained
  • Δρmax = 0.36 e Å−3
  • Δρmin = −0.28 e Å−3

Data collection: APEX2 (Bruker, 2006 [triangle]); cell refinement: SAINT (Bruker, 2006 [triangle]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 [triangle]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 [triangle]); molecular graphics: SHELXTL (Sheldrick, 2008 [triangle]); software used to prepare material for publication: SHELXL97.

Table 1
Selected bond lengths (Å)
Table 2
Hydrogen-bond geometry (Å, °)

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536810017915/wm2332sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810017915/wm2332Isup2.hkl

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

Acknowledgments

The authors acknowledge financial support from the Natural Science Foundation of Zhejiang Province, China (grant No. Y407301).

supplementary crystallographic information

Comment

7-oxabicyclo[2,2,1] heptane-2,3-dicarboxylic anhydride (norcantharidin) derived from cantharidin is a lower toxicity anticancer drug (Shimi et al., 1982). Imidazole is reputed as biocatalyst and biological ligand. Several cobalt complexes of norcantharidin (Wang et al., 1988) and of imidazole (Furenlid et al., 1986; Zhu et al., 2003) have been reported previously.

In the structure of the title compound, the Zn1(II) cation is four-coordinated by three nitrogen atoms of three imidazoles ligands, two of which are deprotonated, and by one carboxylate oxygen atom of the demethylcantharate anion. The deprotonated imidazole rings are responsible for bridging neighbouring Zn1 atoms. The Zn2(II) cation is located on a crystallographic centre of inversion. Two bridge oxygen atoms of two symmetry-related demethylcantharate anions and four carboxylate oxygen atoms give rise to a slightly distorted octahedral ZnO6 coordination environment. Each demethylcantharate anion adopts simultaneously a bridging coordination mode (O2 towards Zn1, O4 towards Zn2) and a monodentate coordination mode (through O5 towards Zn2).

The crystal lattice is stabilized through N—H···O hydrogen bonds between the uncoordinated nitrogen atom (N4) of the imidazole molecule and one of the carboxylate oxygen atoms (O3) of the demethylcantharate anion.

Experimental

7-oxabicyclo[2,2,1] heptane-2,3-dicarboxylic anhydride, zinc acetate and imidazole were dissolved in 15 mL distilled water. The mixture was sealed in a 25 mL Teflon-lined stainless vessel and heated at 443 K for 3 d, then cooled slowly to room temperature. Crystals suitable for X-ray diffraction were obtained.

Refinement

The H atoms bonded to C and N atoms were positioned geometrically and refined using a riding model [aromatic C—H 0.93 Å, aliphatic C—H = 0.97 (2) Å and N—H = 0.86 Å with Uiso(H) = 1.2Ueq(C,N)].

Figures

Fig. 1.
A view of the molecule of the title compound showing the atom-labelling and connectivity of the ZnII atoms. Displacement ellipsoids drawn at the 30% probability level.

Crystal data

[Zn3(C8H8O5)2(C3H3N2)2(C3H4N2)2]F(000) = 848
Mr = 834.71Dx = 1.718 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 5397 reflections
a = 7.9993 (1) Åθ = 1.8–27.6°
b = 22.3923 (2) ŵ = 2.28 mm1
c = 9.7586 (1) ÅT = 296 K
β = 112.633 (1)°Block, colourless
V = 1613.37 (3) Å30.28 × 0.17 × 0.09 mm
Z = 2

Data collection

Bruker APEXII CCD diffractometer3714 independent reflections
Radiation source: fine-focus sealed tube3197 reflections with I > 2σ(I)
graphiteRint = 0.023
ω scansθmax = 27.6°, θmin = 1.8°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)h = −10→10
Tmin = 0.629, Tmax = 0.822k = −29→28
13439 measured reflectionsl = −12→12

Refinement

Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.024Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.060H-atom parameters constrained
S = 1.03w = 1/[σ2(Fo2) + (0.0306P)2 + 0.4382P] where P = (Fo2 + 2Fc2)/3
3714 reflections(Δ/σ)max = 0.001
223 parametersΔρmax = 0.36 e Å3
0 restraintsΔρmin = −0.28 e Å3

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 (Å2)

xyzUiso*/Ueq
Zn10.02705 (3)0.327653 (8)0.68480 (2)0.02488 (7)
Zn20.00000.50001.00000.02427 (8)
C10.5856 (3)0.35035 (11)0.8423 (3)0.0508 (6)
H1A0.70150.34150.84760.061*
C20.4334 (3)0.31994 (10)0.7673 (3)0.0471 (5)
H2A0.42590.28600.71030.057*
C30.3601 (3)0.39293 (9)0.8744 (2)0.0391 (5)
H3A0.29430.41960.90730.047*
C4−0.1719 (3)0.18968 (8)0.8571 (2)0.0333 (4)
H4A−0.24510.15650.84880.040*
C5−0.1783 (3)0.22588 (8)0.7447 (2)0.0325 (4)
H5A−0.25660.22180.64590.039*
C60.0280 (3)0.25794 (8)0.94487 (19)0.0293 (4)
H6A0.12060.28101.01100.035*
C7−0.1093 (2)0.44234 (7)0.70651 (18)0.0222 (3)
C8−0.1796 (2)0.50314 (7)0.64085 (19)0.0230 (3)
H8A−0.23750.50010.53250.028*
C9−0.3146 (2)0.52910 (8)0.70277 (19)0.0267 (4)
H9A−0.39370.49910.71980.032*
C10−0.4169 (3)0.58168 (8)0.6063 (2)0.0364 (4)
H10A−0.52170.59270.62770.044*
H10B−0.45550.57260.50150.044*
C11−0.2716 (3)0.63123 (8)0.6539 (2)0.0395 (5)
H11A−0.24650.64590.57020.047*
H11B−0.30780.66440.70030.047*
C12−0.1090 (3)0.59822 (8)0.7649 (2)0.0296 (4)
H12A−0.01770.62480.83360.036*
C13−0.0311 (2)0.55369 (7)0.68508 (19)0.0250 (4)
H13A−0.02820.57220.59500.030*
C140.1603 (2)0.53377 (8)0.78551 (19)0.0265 (4)
N1−0.0501 (2)0.26968 (6)0.80047 (16)0.0281 (3)
N2−0.0394 (2)0.20990 (6)0.98546 (16)0.0288 (3)
N30.2899 (2)0.34675 (7)0.78774 (18)0.0333 (4)
N40.5372 (2)0.39636 (8)0.9085 (2)0.0429 (4)
H4B0.60870.42320.96320.051*
O1−0.19478 (17)0.55896 (5)0.83772 (13)0.0271 (3)
O2−0.09952 (19)0.40346 (5)0.61684 (13)0.0326 (3)
O30.2753 (2)0.52710 (8)0.73430 (17)0.0515 (4)
O4−0.06572 (18)0.43224 (5)0.84191 (13)0.0293 (3)
O50.19131 (16)0.52692 (6)0.92484 (13)0.0299 (3)

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
Zn10.03053 (12)0.02231 (11)0.02322 (11)−0.00257 (8)0.01193 (9)−0.00100 (7)
Zn20.02831 (15)0.02813 (15)0.01822 (14)−0.00145 (11)0.01100 (12)−0.00224 (10)
C10.0314 (11)0.0607 (14)0.0607 (15)−0.0008 (10)0.0180 (11)−0.0062 (12)
C20.0400 (12)0.0476 (13)0.0559 (14)0.0009 (9)0.0209 (11)−0.0142 (10)
C30.0339 (10)0.0342 (10)0.0435 (12)0.0002 (8)0.0085 (9)−0.0071 (9)
C40.0360 (10)0.0285 (9)0.0353 (11)−0.0069 (8)0.0135 (9)0.0026 (8)
C50.0348 (10)0.0339 (10)0.0254 (9)−0.0060 (8)0.0077 (8)0.0002 (7)
C60.0355 (10)0.0247 (9)0.0267 (9)−0.0021 (7)0.0107 (8)0.0007 (7)
C70.0217 (8)0.0222 (8)0.0228 (9)−0.0034 (6)0.0088 (7)−0.0027 (6)
C80.0265 (9)0.0228 (8)0.0185 (8)−0.0016 (6)0.0075 (7)−0.0007 (6)
C90.0256 (9)0.0266 (9)0.0275 (9)−0.0022 (7)0.0096 (7)−0.0005 (7)
C100.0303 (10)0.0353 (10)0.0400 (11)0.0077 (8)0.0095 (9)0.0041 (8)
C110.0435 (12)0.0266 (10)0.0465 (12)0.0070 (8)0.0154 (10)0.0055 (8)
C120.0342 (10)0.0217 (8)0.0334 (10)−0.0031 (7)0.0134 (8)−0.0021 (7)
C130.0287 (9)0.0253 (8)0.0229 (8)−0.0028 (7)0.0121 (7)0.0023 (6)
C140.0271 (9)0.0272 (9)0.0270 (9)−0.0059 (7)0.0124 (8)−0.0009 (7)
N10.0341 (8)0.0252 (7)0.0249 (8)−0.0016 (6)0.0114 (7)0.0028 (6)
N20.0376 (9)0.0254 (8)0.0256 (8)0.0013 (6)0.0148 (7)0.0035 (6)
N30.0301 (8)0.0309 (8)0.0371 (9)−0.0032 (7)0.0110 (7)−0.0046 (7)
N40.0319 (9)0.0396 (9)0.0461 (11)−0.0091 (7)0.0028 (8)−0.0045 (8)
O10.0316 (7)0.0272 (6)0.0250 (6)0.0010 (5)0.0136 (5)−0.0020 (5)
O20.0497 (8)0.0243 (6)0.0235 (6)0.0059 (5)0.0137 (6)−0.0031 (5)
O30.0368 (8)0.0864 (12)0.0406 (9)0.0114 (8)0.0249 (7)0.0152 (8)
O40.0439 (8)0.0233 (6)0.0203 (6)0.0005 (5)0.0120 (6)−0.0004 (5)
O50.0258 (6)0.0419 (7)0.0226 (6)−0.0049 (5)0.0099 (5)−0.0012 (5)

Geometric parameters (Å, °)

Zn1—O21.9570 (12)C6—H6A0.9300
Zn1—N11.9686 (14)C7—O41.251 (2)
Zn1—N2i1.9944 (14)C7—O21.2578 (19)
Zn1—N31.9968 (16)C7—C81.518 (2)
Zn2—O5ii2.0266 (12)C8—C91.540 (2)
Zn2—O52.0266 (12)C8—C131.576 (2)
Zn2—O42.0819 (12)C8—H8A0.9800
Zn2—O4ii2.0819 (12)C9—O11.459 (2)
Zn2—O1ii2.1862 (12)C9—C101.533 (2)
Zn2—O12.1862 (12)C9—H9A0.9800
C1—C21.340 (3)C10—C111.543 (3)
C1—N41.350 (3)C10—H10A0.9700
C1—H1A0.9300C10—H10B0.9700
C2—N31.376 (3)C11—C121.525 (3)
C2—H2A0.9300C11—H11A0.9700
C3—N31.317 (2)C11—H11B0.9700
C3—N41.327 (3)C12—O11.457 (2)
C3—H3A0.9300C12—C131.537 (2)
C4—C51.349 (3)C12—H12A0.9800
C4—N21.369 (2)C13—C141.533 (2)
C4—H4A0.9300C13—H13A0.9800
C5—N11.371 (2)C14—O31.213 (2)
C5—H5A0.9300C14—O51.294 (2)
C6—N11.329 (2)N2—Zn1iii1.9944 (14)
C6—N21.330 (2)N4—H4B0.8600
O2—Zn1—N1122.06 (6)C10—C9—C8109.78 (15)
O2—Zn1—N2i97.25 (6)O1—C9—H9A113.8
N1—Zn1—N2i104.86 (6)C10—C9—H9A113.8
O2—Zn1—N3106.98 (6)C8—C9—H9A113.8
N1—Zn1—N3110.76 (7)C9—C10—C11101.84 (15)
N2i—Zn1—N3114.52 (7)C9—C10—H10A111.4
O5ii—Zn2—O5180.000 (1)C11—C10—H10A111.4
O5ii—Zn2—O492.34 (5)C9—C10—H10B111.4
O5—Zn2—O487.66 (5)C11—C10—H10B111.4
O5ii—Zn2—O4ii87.66 (5)H10A—C10—H10B109.3
O5—Zn2—O4ii92.34 (5)C12—C11—C10101.71 (15)
O4—Zn2—O4ii180.0C12—C11—H11A111.4
O5ii—Zn2—O1ii89.15 (5)C10—C11—H11A111.4
O5—Zn2—O1ii90.85 (5)C12—C11—H11B111.4
O4—Zn2—O1ii90.17 (4)C10—C11—H11B111.4
O4ii—Zn2—O1ii89.83 (4)H11A—C11—H11B109.3
O5ii—Zn2—O190.85 (5)O1—C12—C11101.88 (15)
O5—Zn2—O189.15 (5)O1—C12—C13102.39 (13)
O4—Zn2—O189.83 (4)C11—C12—C13110.85 (16)
O4ii—Zn2—O190.17 (4)O1—C12—H12A113.5
O1ii—Zn2—O1180.0C11—C12—H12A113.5
C2—C1—N4106.4 (2)C13—C12—H12A113.5
C2—C1—H1A126.8C14—C13—C12111.41 (14)
N4—C1—H1A126.8C14—C13—C8115.37 (13)
C1—C2—N3109.4 (2)C12—C13—C8101.21 (13)
C1—C2—H2A125.3C14—C13—H13A109.5
N3—C2—H2A125.3C12—C13—H13A109.5
N3—C3—N4110.88 (18)C8—C13—H13A109.5
N3—C3—H3A124.6O3—C14—O5123.32 (17)
N4—C3—H3A124.6O3—C14—C13120.10 (16)
C5—C4—N2108.61 (16)O5—C14—C13116.54 (15)
C5—C4—H4A125.7C6—N1—C5104.69 (15)
N2—C4—H4A125.7C6—N1—Zn1127.96 (13)
C4—C5—N1108.57 (16)C5—N1—Zn1126.56 (12)
C4—C5—H5A125.7C6—N2—C4104.75 (14)
N1—C5—H5A125.7C6—N2—Zn1iii130.16 (12)
N1—C6—N2113.37 (16)C4—N2—Zn1iii125.09 (12)
N1—C6—H6A123.3C3—N3—C2105.22 (17)
N2—C6—H6A123.3C3—N3—Zn1126.68 (14)
O4—C7—O2122.91 (15)C2—N3—Zn1127.52 (14)
O4—C7—C8121.03 (15)C3—N4—C1108.14 (17)
O2—C7—C8116.06 (15)C3—N4—H4B125.9
C7—C8—C9112.03 (14)C1—N4—H4B125.9
C7—C8—C13114.24 (14)C12—O1—C996.04 (12)
C9—C8—C13100.96 (13)C12—O1—Zn2112.31 (10)
C7—C8—H8A109.8C9—O1—Zn2114.50 (9)
C9—C8—H8A109.8C7—O2—Zn1121.81 (11)
C13—C8—H8A109.8C7—O4—Zn2122.65 (10)
O1—C9—C10102.25 (14)C14—O5—Zn2123.34 (11)
O1—C9—C8102.16 (13)
N4—C1—C2—N3−0.5 (3)C1—C2—N3—C30.3 (3)
N2—C4—C5—N1−0.1 (2)C1—C2—N3—Zn1171.94 (17)
O4—C7—C8—C9−42.3 (2)O2—Zn1—N3—C338.44 (19)
O2—C7—C8—C9137.10 (16)N1—Zn1—N3—C3−96.74 (18)
O4—C7—C8—C1371.7 (2)N2i—Zn1—N3—C3144.95 (17)
O2—C7—C8—C13−108.87 (17)O2—Zn1—N3—C2−131.53 (18)
C7—C8—C9—O186.39 (15)N1—Zn1—N3—C293.29 (19)
C13—C8—C9—O1−35.59 (15)N2i—Zn1—N3—C2−25.0 (2)
C7—C8—C9—C10−165.65 (14)N3—C3—N4—C1−0.4 (3)
C13—C8—C9—C1072.37 (16)C2—C1—N4—C30.5 (3)
O1—C9—C10—C1133.06 (18)C11—C12—O1—C957.35 (15)
C8—C9—C10—C11−74.84 (18)C13—C12—O1—C9−57.40 (14)
C9—C10—C11—C122.0 (2)C11—C12—O1—Zn2176.96 (11)
C10—C11—C12—O1−36.52 (18)C13—C12—O1—Zn262.21 (13)
C10—C11—C12—C1371.83 (19)C10—C9—O1—C12−55.89 (15)
O1—C12—C13—C14−88.49 (16)C8—C9—O1—C1257.76 (14)
C11—C12—C13—C14163.49 (15)C10—C9—O1—Zn2−173.78 (11)
O1—C12—C13—C834.66 (16)C8—C9—O1—Zn2−60.13 (13)
C11—C12—C13—C8−73.36 (17)O5ii—Zn2—O1—C12170.75 (10)
C7—C8—C13—C140.5 (2)O5—Zn2—O1—C12−9.25 (10)
C9—C8—C13—C14120.96 (15)O4—Zn2—O1—C12−96.91 (10)
C7—C8—C13—C12−119.84 (15)O4ii—Zn2—O1—C1283.09 (10)
C9—C8—C13—C120.57 (16)O5ii—Zn2—O1—C9−81.07 (11)
C12—C13—C14—O3−140.91 (18)O5—Zn2—O1—C998.93 (11)
C8—C13—C14—O3104.4 (2)O4—Zn2—O1—C911.27 (11)
C12—C13—C14—O536.7 (2)O4ii—Zn2—O1—C9−168.73 (11)
C8—C13—C14—O5−77.90 (19)O4—C7—O2—Zn1−11.7 (2)
N2—C6—N1—C50.4 (2)C8—C7—O2—Zn1168.88 (11)
N2—C6—N1—Zn1−169.85 (12)N1—Zn1—O2—C761.89 (16)
C4—C5—N1—C6−0.2 (2)N2i—Zn1—O2—C7174.51 (14)
C4—C5—N1—Zn1170.27 (13)N3—Zn1—O2—C7−67.06 (15)
O2—Zn1—N1—C6−105.18 (16)O2—C7—O4—Zn2159.29 (13)
N2i—Zn1—N1—C6146.15 (16)C8—C7—O4—Zn2−21.3 (2)
N3—Zn1—N1—C622.12 (17)O5ii—Zn2—O4—C7124.12 (14)
O2—Zn1—N1—C586.57 (16)O5—Zn2—O4—C7−55.88 (14)
N2i—Zn1—N1—C5−22.11 (17)O1ii—Zn2—O4—C7−146.73 (14)
N3—Zn1—N1—C5−146.14 (15)O1—Zn2—O4—C733.27 (14)
N1—C6—N2—C4−0.5 (2)O3—C14—O5—Zn2−150.62 (16)
N1—C6—N2—Zn1iii179.67 (12)C13—C14—O5—Zn231.8 (2)
C5—C4—N2—C60.3 (2)O4—Zn2—O5—C1447.74 (14)
C5—C4—N2—Zn1iii−179.80 (13)O4ii—Zn2—O5—C14−132.26 (14)
N4—C3—N3—C20.1 (2)O1ii—Zn2—O5—C14137.88 (14)
N4—C3—N3—Zn1−171.69 (14)O1—Zn2—O5—C14−42.12 (14)

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

Hydrogen-bond geometry (Å, °)

D—H···AD—HH···AD···AD—H···A
N4—H4B···O5iv0.861.912.756 (2)167

Symmetry codes: (iv) −x+1, −y+1, −z+2.

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: WM2332).

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