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organic compounds
| CRYSTALLOGRAPHIC COMMUNICATIONS |
accessDiisopropyl pyrazine-2,5-dicarboxylate
aCollege of Materials Science and Engineering, Huaqiao University, Xiamen, Fujian, 361021, People's Republic of China
*Correspondence e-mail: wws@hqu.edu.cn
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)°.
![[Scheme 1]](dn2583scheme1.gif)
Experimental
Crystal data
|
Data collection: XSCANS (Bruker, 1999![[Bruker (1999). XSCANS. Bruker AXS Inc., Madison, Wisconsin, USA.]](../../../../../../logos/arrows/e_arr.gif "Bruker (1999). XSCANS. Bruker AXS Inc., Madison, Wisconsin, USA.")
); cell XSCANS; data reduction: SHELXTL (Sheldrick, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.
Supporting information
contains datablocks global, I. DOI: https://doi.org/10.1107/S1600536810029314/dn2583sup1.cif
Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536810029314/dn2583Isup2.hkl
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.
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 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.
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 of the isopropyl groups. The is stabilized via van der Waals forces.
For related structures, see: Cockriel et al. (2008); Vishweshwar et al. (2004).
Data collection: XSCANS (Bruker, 1999); cell XSCANS (Bruker, 1999; data reduction: SHELXTL (Sheldrick, 2008); 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).
![[Figure 1]](./dn2583fig1thm.gif) | 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]. |
| C12H16N2O4 | F(000) = 268 |
| Mr = 252.27 | Dx = 1.255 Mg m−3 |
| Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
| Hall symbol: -P 2ybc | Cell parameters from 1552 reflections |
| a = 4.7804 (1) Å | θ = 2.6–27.7° |
| b = 15.6842 (3) Å | µ = 0.10 mm−1 |
| c = 9.1877 (2) Å | T = 296 K |
| β = 104.227 (2)° | Block, orange |
| V = 667.74 (2) Å3 | 0.44 × 0.20 × 0.09 mm |
| Z = 2 |
| Bruker P4 diffractometer | 969 reflections with I > 2σ(I) |
| Radiation source: fine-focus sealed tube | Rint = 0.028 |
| Graphite monochromator | θmax = 26.4°, θmin = 2.6° |
| Detector resolution: 0 pixels mm-1 | h = −5→5 |
| ω scans | k = 0→19 |
| 10015 measured reflections | l = 0→11 |
| 1361 independent reflections |
| 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)] = 0.048 | Hydrogen site location: inferred from neighbouring sites |
| wR(F2) = 0.148 | H-atom parameters constrained |
| S = 1.07 | w = 1/[σ2(Fo2) + (0.0658P)2 + 0.1415P] where P = (Fo2 + 2Fc2)/3 |
| 1361 reflections | (Δ/σ)max < 0.001 |
| 84 parameters | Δρmax = 0.22 e Å−3 |
| 0 restraints | Δρmin = −0.16 e Å−3 |
| C12H16N2O4 | V = 667.74 (2) Å3 |
| Mr = 252.27 | Z = 2 |
| Monoclinic, P21/c | Mo Kα radiation |
| a = 4.7804 (1) Å | µ = 0.10 mm−1 |
| b = 15.6842 (3) Å | T = 296 K |
| c = 9.1877 (2) Å | 0.44 × 0.20 × 0.09 mm |
| β = 104.227 (2)° |
| Bruker P4 diffractometer | 969 reflections with I > 2σ(I) |
| 10015 measured reflections | Rint = 0.028 |
| 1361 independent reflections |
| R[F2 > 2σ(F2)] = 0.048 | 0 restraints |
| wR(F2) = 0.148 | H-atom parameters constrained |
| S = 1.07 | Δρmax = 0.22 e Å−3 |
| 1361 reflections | Δρmin = −0.16 e Å−3 |
| 84 parameters |
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. |
| x | y | z | Uiso*/Ueq | ||
| O1 | 0.2207 (3) | 0.61807 (8) | 0.76556 (16) | 0.0760 (5) | |
| O2 | 0.0875 (4) | 0.48234 (10) | 0.7742 (2) | 0.0932 (6) | |
| N1 | 0.4741 (4) | 0.58450 (9) | 0.54265 (18) | 0.0671 (5) | |
| C1 | 0.3667 (4) | 0.52028 (10) | 0.6052 (2) | 0.0563 (5) | |
| C2 | 0.6071 (4) | 0.56289 (12) | 0.4371 (2) | 0.0683 (5) | |
| H2A | 0.6858 | 0.6058 | 0.3898 | 0.082* | |
| C3 | 0.2104 (4) | 0.53794 (12) | 0.7251 (2) | 0.0625 (5) | |
| C4 | 0.0807 (5) | 0.64177 (14) | 0.8860 (2) | 0.0803 (6) | |
| H4A | −0.0748 | 0.6011 | 0.8864 | 0.096* | |
| C5 | −0.0461 (8) | 0.72695 (18) | 0.8468 (4) | 0.1229 (11) | |
| H5A | −0.1475 | 0.7443 | 0.9200 | 0.184* | |
| H5B | −0.1781 | 0.7249 | 0.7494 | 0.184* | |
| H5C | 0.1046 | 0.7672 | 0.8454 | 0.184* | |
| C6 | 0.2971 (8) | 0.6359 (3) | 1.0299 (3) | 0.1457 (15) | |
| H6A | 0.2050 | 0.6437 | 1.1108 | 0.219* | |
| H6B | 0.4403 | 0.6795 | 1.0346 | 0.219* | |
| H6C | 0.3877 | 0.5809 | 1.0384 | 0.219* |
| U11 | U22 | U33 | U12 | U13 | U23 | |
| O1 | 0.0981 (11) | 0.0603 (8) | 0.0829 (9) | −0.0050 (7) | 0.0476 (8) | −0.0104 (6) |
| O2 | 0.1167 (13) | 0.0701 (9) | 0.1115 (13) | −0.0127 (8) | 0.0640 (11) | −0.0055 (8) |
| N1 | 0.0815 (11) | 0.0508 (8) | 0.0747 (10) | −0.0003 (7) | 0.0303 (8) | −0.0029 (7) |
| C1 | 0.0563 (10) | 0.0523 (9) | 0.0600 (10) | 0.0013 (7) | 0.0139 (8) | −0.0013 (7) |
| C2 | 0.0830 (13) | 0.0535 (10) | 0.0758 (12) | −0.0043 (9) | 0.0334 (11) | −0.0006 (9) |
| C3 | 0.0650 (11) | 0.0580 (10) | 0.0671 (11) | 0.0028 (8) | 0.0209 (9) | 0.0002 (8) |
| C4 | 0.1000 (16) | 0.0706 (12) | 0.0855 (15) | −0.0042 (11) | 0.0519 (13) | −0.0096 (10) |
| C5 | 0.173 (3) | 0.0914 (18) | 0.124 (2) | 0.0344 (19) | 0.075 (2) | −0.0047 (16) |
| C6 | 0.141 (3) | 0.231 (4) | 0.0736 (17) | 0.040 (3) | 0.0424 (18) | 0.000 (2) |
| O1—C3 | 1.308 (2) | C4—C5 | 1.475 (4) |
| O1—C4 | 1.474 (2) | C4—H4A | 0.9800 |
| O2—C3 | 1.200 (2) | C5—H5A | 0.9600 |
| N1—C1 | 1.324 (2) | C5—H5B | 0.9600 |
| N1—C2 | 1.327 (2) | C5—H5C | 0.9600 |
| C1—C2i | 1.376 (2) | C6—H6A | 0.9600 |
| C1—C3 | 1.500 (3) | C6—H6B | 0.9600 |
| C2—H2A | 0.9300 | C6—H6C | 0.9600 |
| C4—C6 | 1.468 (4) | ||
| C3—O1—C4 | 117.61 (15) | O1—C4—H4A | 108.9 |
| C1—N1—C2 | 115.43 (15) | C5—C4—H4A | 108.9 |
| N1—C1—C2i | 121.76 (17) | C4—C5—H5A | 109.5 |
| N1—C1—C3 | 119.62 (15) | C4—C5—H5B | 109.5 |
| C2i—C1—C3 | 118.62 (16) | H5A—C5—H5B | 109.5 |
| N1—C2—C1i | 122.82 (17) | C4—C5—H5C | 109.5 |
| N1—C2—H2A | 118.6 | H5A—C5—H5C | 109.5 |
| C1i—C2—H2A | 118.6 | H5B—C5—H5C | 109.5 |
| O2—C3—O1 | 125.35 (18) | C4—C6—H6A | 109.5 |
| O2—C3—C1 | 121.35 (17) | C4—C6—H6B | 109.5 |
| O1—C3—C1 | 113.29 (16) | H6A—C6—H6B | 109.5 |
| C6—C4—O1 | 108.1 (2) | C4—C6—H6C | 109.5 |
| C6—C4—C5 | 115.6 (3) | H6A—C6—H6C | 109.5 |
| O1—C4—C5 | 106.28 (18) | H6B—C6—H6C | 109.5 |
| C6—C4—H4A | 108.9 | ||
| N1—C1—C3—O1 | −6.0 (3) |
| Symmetry code: (i) −x+1, −y+1, −z+1. |
Experimental details
| Crystal data | |
| Chemical formula | C12H16N2O4 |
| Mr | 252.27 |
| Crystal system, space group | Monoclinic, P21/c |
| Temperature (K) | 296 |
| a, b, c (Å) | 4.7804 (1), 15.6842 (3), 9.1877 (2) |
| β (°) | 104.227 (2) |
| V (Å3) | 667.74 (2) |
| Z | 2 |
| Radiation type | Mo Kα |
| µ (mm−1) | 0.10 |
| Crystal size (mm) | 0.44 × 0.20 × 0.09 |
| Data collection | |
| Diffractometer | Bruker P4 |
| Absorption correction | – |
| No. of measured, independent and observed [I > 2σ(I)] reflections | 10015, 1361, 969 |
| Rint | 0.028 |
| (sin θ/λ)max (Å−1) | 0.625 |
| Refinement | |
| R[F2 > 2σ(F2)], wR(F2), S | 0.048, 0.148, 1.07 |
| No. of reflections | 1361 |
| No. of parameters | 84 |
| H-atom treatment | H-atom parameters constrained |
| Δρmax, Δρmin (e Å−3) | 0.22, −0.16 |
Computer programs: XSCANS (Bruker, 1999), XSCANS (Bruker, 1999, SHELXTL (Sheldrick, 2008), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008).
Acknowledgements
We are grateful for financial support from the National Science Foundation of Fujian Province of China (No. E0610017, 2003 F006).
References
Bruker (1999). XSCANS. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
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. Web of Science CSD CrossRef CAS Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
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. Web of Science CSD CrossRef CAS Google Scholar
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| CRYSTALLOGRAPHIC COMMUNICATIONS |
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.