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Acta Crystallogr Sect E Struct Rep Online. 2010 September 1; 66(Pt 9): o2206.
Published online 2010 August 4. doi:  10.1107/S1600536810029314
PMCID: PMC3007933

Diisopropyl pyrazine-2,5-dicarboxyl­ate

Abstract

The mol­ecule of the title compound, C12H16N2O4, is located on an inversion center. The carboxyl­ate groups are twisted slightly with respect to the pyrazine ring, making a dihedral angle of 6.4 (3)°.

Related literature

For related structures, see: Cockriel et al. (2008 [triangle]); Vishweshwar et al. (2004 [triangle]).

An external file that holds a picture, illustration, etc.
Object name is e-66-o2206-scheme1.jpg

Experimental

Crystal data

  • C12H16N2O4
  • M r = 252.27
  • Monoclinic, An external file that holds a picture, illustration, etc.
Object name is e-66-o2206-efi1.jpg
  • a = 4.7804 (1) Å
  • b = 15.6842 (3) Å
  • c = 9.1877 (2) Å
  • β = 104.227 (2)°
  • V = 667.74 (2) Å3
  • Z = 2
  • Mo Kα radiation
  • μ = 0.10 mm−1
  • T = 296 K
  • 0.44 × 0.20 × 0.09 mm

Data collection

  • Bruker P4 diffractometer
  • 10015 measured reflections
  • 1361 independent reflections
  • 969 reflections with I > 2σ(I)
  • R int = 0.028

Refinement

  • R[F 2 > 2σ(F 2)] = 0.048
  • wR(F 2) = 0.148
  • S = 1.07
  • 1361 reflections
  • 84 parameters
  • H-atom parameters constrained
  • Δρmax = 0.22 e Å−3
  • Δρmin = −0.16 e Å−3

Data collection: XSCANS (Bruker, 1999 [triangle]); cell refinement: XSCANS; data reduction: SHELXTL (Sheldrick, 2008 [triangle]); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 [triangle]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 [triangle]); molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536810029314/dn2583sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810029314/dn2583Isup2.hkl

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

Acknowledgments

We are grateful for financial support from the National Science Foundation of Fujian Province of China (No. E0610017, 2003 F006).

supplementary crystallographic information

Comment

The molecule of the title compound is is organized around inversion center (Fig. 1). The carboxylate group are slightly twisted with respect to the pyrazine ring making a dihedral angle of 6.4 (3)°.The carboxyl C—O and C═ O bonds are normal, while the bond angle of C—N═C are slightly smaller than those in pyrazine-2,5-dicarboxylic acid dihydrate (Vishweshwar et al.,2004). The angle C3—O1—C4 of 117.60 (14) is larger compared to the value of 115.04 (16) in Pyrazine-2,5-dicarboxylic acid dimethyl ester (Cockriel et al., 2008). The atoms of O(1) to C(5) may be considered to control the molecular packing through intermolecular hydrophobic interaction of the isopropyl groups. The crystal structure is stabilized via van der Waals forces.

Experimental

The title compound was synthesized by dissolving 2,5-pyrazinedicarboxylic acid (200 mg,11.9 mmol)in 200 ml 2-propanol, while stirring 2 ml concentrated H2SO4 was added slowly.The solution was left to reflux for 12 h, then distillation under reduced pressure until no solution to outflow after filtered.The solution was made neutral with Na2CO3(aq), extracted with 30 ml e thyl acetate.Orange crystals of the title compound would be grew by slow evaporating at room temperature after five days.

Refinement

The C-bound H atoms were included in the riding model approximation with C—H=0.93, all these H atoms included in the final refinement. The Uiso of each H atom = 1.2Ueq(C). The Ueq of C4 is regular. The checkcif considers the Ueq of C4 is low, this is because it is lower compared with the C5 and C6.

Figures

Fig. 1.
Molecular view of the title compound with the atom labeling scheme. Ellipsoids are drawn at the 30% probability level. [Symmetry code: (A) -x+1, -y+1, -z+1].

Crystal data

C12H16N2O4F(000) = 268
Mr = 252.27Dx = 1.255 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 1552 reflections
a = 4.7804 (1) Åθ = 2.6–27.7°
b = 15.6842 (3) ŵ = 0.10 mm1
c = 9.1877 (2) ÅT = 296 K
β = 104.227 (2)°Block, orange
V = 667.74 (2) Å30.44 × 0.20 × 0.09 mm
Z = 2

Data collection

Bruker P4 diffractometer969 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.028
graphiteθmax = 26.4°, θmin = 2.6°
Detector resolution: 0 pixels mm-1h = −5→5
ω scansk = 0→19
10015 measured reflectionsl = 0→11
1361 independent reflections

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)] = 0.048Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.148H-atom parameters constrained
S = 1.07w = 1/[σ2(Fo2) + (0.0658P)2 + 0.1415P] where P = (Fo2 + 2Fc2)/3
1361 reflections(Δ/σ)max < 0.001
84 parametersΔρmax = 0.22 e Å3
0 restraintsΔρmin = −0.16 e Å3

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 (Å2)

xyzUiso*/Ueq
O10.2207 (3)0.61807 (8)0.76556 (16)0.0760 (5)
O20.0875 (4)0.48234 (10)0.7742 (2)0.0932 (6)
N10.4741 (4)0.58450 (9)0.54265 (18)0.0671 (5)
C10.3667 (4)0.52028 (10)0.6052 (2)0.0563 (5)
C20.6071 (4)0.56289 (12)0.4371 (2)0.0683 (5)
H2A0.68580.60580.38980.082*
C30.2104 (4)0.53794 (12)0.7251 (2)0.0625 (5)
C40.0807 (5)0.64177 (14)0.8860 (2)0.0803 (6)
H4A−0.07480.60110.88640.096*
C5−0.0461 (8)0.72695 (18)0.8468 (4)0.1229 (11)
H5A−0.14750.74430.92000.184*
H5B−0.17810.72490.74940.184*
H5C0.10460.76720.84540.184*
C60.2971 (8)0.6359 (3)1.0299 (3)0.1457 (15)
H6A0.20500.64371.11080.219*
H6B0.44030.67951.03460.219*
H6C0.38770.58091.03840.219*

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
O10.0981 (11)0.0603 (8)0.0829 (9)−0.0050 (7)0.0476 (8)−0.0104 (6)
O20.1167 (13)0.0701 (9)0.1115 (13)−0.0127 (8)0.0640 (11)−0.0055 (8)
N10.0815 (11)0.0508 (8)0.0747 (10)−0.0003 (7)0.0303 (8)−0.0029 (7)
C10.0563 (10)0.0523 (9)0.0600 (10)0.0013 (7)0.0139 (8)−0.0013 (7)
C20.0830 (13)0.0535 (10)0.0758 (12)−0.0043 (9)0.0334 (11)−0.0006 (9)
C30.0650 (11)0.0580 (10)0.0671 (11)0.0028 (8)0.0209 (9)0.0002 (8)
C40.1000 (16)0.0706 (12)0.0855 (15)−0.0042 (11)0.0519 (13)−0.0096 (10)
C50.173 (3)0.0914 (18)0.124 (2)0.0344 (19)0.075 (2)−0.0047 (16)
C60.141 (3)0.231 (4)0.0736 (17)0.040 (3)0.0424 (18)0.000 (2)

Geometric parameters (Å, °)

O1—C31.308 (2)C4—C51.475 (4)
O1—C41.474 (2)C4—H4A0.9800
O2—C31.200 (2)C5—H5A0.9600
N1—C11.324 (2)C5—H5B0.9600
N1—C21.327 (2)C5—H5C0.9600
C1—C2i1.376 (2)C6—H6A0.9600
C1—C31.500 (3)C6—H6B0.9600
C2—H2A0.9300C6—H6C0.9600
C4—C61.468 (4)
C3—O1—C4117.61 (15)O1—C4—H4A108.9
C1—N1—C2115.43 (15)C5—C4—H4A108.9
N1—C1—C2i121.76 (17)C4—C5—H5A109.5
N1—C1—C3119.62 (15)C4—C5—H5B109.5
C2i—C1—C3118.62 (16)H5A—C5—H5B109.5
N1—C2—C1i122.82 (17)C4—C5—H5C109.5
N1—C2—H2A118.6H5A—C5—H5C109.5
C1i—C2—H2A118.6H5B—C5—H5C109.5
O2—C3—O1125.35 (18)C4—C6—H6A109.5
O2—C3—C1121.35 (17)C4—C6—H6B109.5
O1—C3—C1113.29 (16)H6A—C6—H6B109.5
C6—C4—O1108.1 (2)C4—C6—H6C109.5
C6—C4—C5115.6 (3)H6A—C6—H6C109.5
O1—C4—C5106.28 (18)H6B—C6—H6C109.5
C6—C4—H4A108.9
N1—C1—C3—O1−6.0 (3)

Symmetry codes: (i) −x+1, −y+1, −z+1.

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: DN2583).

References

  • Bruker (1999). XSCANS Bruker AXS Inc., Madison, Wisconsin, USA.
  • Cockriel, D. L., McClain, J. M., Patel, K. C., Ullom, R., Hasley, T. R., Archibald, S. J. & Hubin, T. J. (2008). Inorg. Chem. Commun.11, 1–4.
  • Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. [PubMed]
  • Vishweshwar, P., Babu, N. J., Nangia, A., Mason, S. A., Puschmann, H., Mondal, R. & Howard, J. A. K. (2004). J. Phys. Chem. A, 108, 9406–9416.

Articles from Acta Crystallographica Section E: Structure Reports Online are provided here courtesy of International Union of Crystallography