Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807049483/pk2054sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536807049483/pk2054Isup2.hkl |
CCDC reference: 667339
Key indicators
- Single-crystal X-ray study
- T = 95 K
- Mean (C-C) = 0.003 Å
- R factor = 0.044
- wR factor = 0.102
- Data-to-parameter ratio = 14.4
checkCIF/PLATON results
No syntax errors found
Alert level C PLAT250_ALERT_2_C Large U3/U1 Ratio for Average U(i,j) Tensor .... 2.30 PLAT250_ALERT_2_C Large U3/U1 Ratio for Average U(i,j) Tensor .... 2.07 PLAT333_ALERT_2_C Large Average Benzene C-C Dist. C1 -C3_a 1.44 Ang. PLAT333_ALERT_2_C Large Average Benzene C-C Dist. C4 -C6_b 1.44 Ang. PLAT335_ALERT_2_C Large Benzene C-C Range ....... C4 -C6_b 0.16 Ang.
0 ALERT level A = In general: serious problem 0 ALERT level B = Potentially serious problem 5 ALERT level C = Check and explain 0 ALERT level G = General alerts; check 0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data 5 ALERT type 2 Indicator that the structure model may be wrong or deficient 0 ALERT type 3 Indicator that the structure quality may be low 0 ALERT type 4 Improvement, methodology, query or suggestion 0 ALERT type 5 Informative message, check
Single crystals were obtained by slow evaporation from a methanol solution of chloranilic acid (99 mg) and quinoxaline (63 mg).
O-bound H atoms were found in a difference Fourier map and refined isotropically (refined distances given in Table 1). C-bound H atoms were positioned geometrically (C—H = 0.95 Å) and refined as riding, with Uiso(H) = 1.2Ueq(C).
The title compound was prepared in order to extend our study on D-H···A hydrogen bonding (D = N, O, or C; A = N, O or Cl) in amine–chloranilic acid 1:1 and 2:1 systems (Gotoh et al., 2006).
The asymmetric unit contains one quinoxaline molecule and two half chloranilic acid molecules. No acid-base interaction involving a proton transfer is observed between the quinoxaline and the chloranilic acid. In the crystal structure, the quinoxaline and the chloranilic acid are linked alternately through two kinds of O—H···N hydrogen bonds to form a zigzag chain running along the [201] direction (Fig. 1). Similar chain structures have been observed in the related compounds containing the pyrazine unit, i.e., pyrazine–chloranilic acid (1/1) (Ishida & Kashino, 1999), phenazine–chloranilic acid (1/1) (Horiuchi et al., 2005; Gotoh et al., 2007) and tetramethylpyrazine–chloranilic acid (1/1) (Prager et al., 2005, 2006). The chains are stacked along the a axis, forming a layer extending parallel to the (010) plane (Fig. 2). The layers are further linked by C—H···O hydrogen bonds.
For related literature, see: Gotoh et al. (2006, 2007); Horiuchi et al. (2005); Ishida & Kashino (1999); Prager et al. (2005, 2006).
Data collection: PROCESS-AUTO (Rigaku/MSC, 2004); cell refinement: PROCESS-AUTO (Rigaku/MSC, 2004); data reduction: CrystalStructure (Rigaku/MSC, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: CrystalStructure (Rigaku/MSC, 2004).
C8H6N2·C6H2Cl2O4 | Z = 2 |
Mr = 339.13 | F(000) = 344.00 |
Triclinic, P1 | Dx = 1.707 Mg m−3 |
Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71075 Å |
a = 3.7963 (3) Å | Cell parameters from 6043 reflections |
b = 7.7760 (7) Å | θ = 3.1–27.5° |
c = 22.4830 (14) Å | µ = 0.51 mm−1 |
α = 93.444 (3)° | T = 95 K |
β = 94.338 (3)° | Plate, orange |
γ = 92.322 (4)° | 0.48 × 0.43 × 0.10 mm |
V = 659.92 (9) Å3 |
Rigaku R-AXIS RAPID diffractometer | 2314 reflections with I > 2σ(I) |
Detector resolution: 10.00 pixels mm-1 | Rint = 0.066 |
ω scans | θmax = 27.5°, θmin = 3.1° |
Absorption correction: multi-scan (ABSCOR; Higashi, 1995) | h = −4→4 |
Tmin = 0.776, Tmax = 0.950 | k = −10→10 |
6457 measured reflections | l = −28→29 |
2974 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)] = 0.044 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.102 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.00 | w = 1/[σ2(Fo2) + (0.0337P)2] where P = (Fo2 + 2Fc2)/3 |
2974 reflections | (Δ/σ)max = 0.001 |
207 parameters | Δρmax = 0.41 e Å−3 |
0 restraints | Δρmin = −0.66 e Å−3 |
C8H6N2·C6H2Cl2O4 | γ = 92.322 (4)° |
Mr = 339.13 | V = 659.92 (9) Å3 |
Triclinic, P1 | Z = 2 |
a = 3.7963 (3) Å | Mo Kα radiation |
b = 7.7760 (7) Å | µ = 0.51 mm−1 |
c = 22.4830 (14) Å | T = 95 K |
α = 93.444 (3)° | 0.48 × 0.43 × 0.10 mm |
β = 94.338 (3)° |
Rigaku R-AXIS RAPID diffractometer | 2974 independent reflections |
Absorption correction: multi-scan (ABSCOR; Higashi, 1995) | 2314 reflections with I > 2σ(I) |
Tmin = 0.776, Tmax = 0.950 | Rint = 0.066 |
6457 measured reflections |
R[F2 > 2σ(F2)] = 0.044 | 0 restraints |
wR(F2) = 0.102 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.00 | Δρmax = 0.41 e Å−3 |
2974 reflections | Δρmin = −0.66 e Å−3 |
207 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 | ||
Cl1 | 0.71248 (15) | 0.13239 (7) | −0.05495 (2) | 0.01197 (14) | |
Cl2 | 0.30454 (15) | 0.15380 (7) | 0.54442 (2) | 0.01202 (14) | |
O1 | 1.0774 (4) | 0.4141 (2) | −0.11448 (6) | 0.0123 (3) | |
O2 | 0.6729 (4) | 0.2726 (2) | 0.06970 (6) | 0.0123 (4) | |
O3 | −0.0320 (4) | 0.4309 (2) | 0.61393 (6) | 0.0124 (4) | |
O4 | 0.3146 (4) | 0.2776 (2) | 0.42231 (6) | 0.0120 (4) | |
N1 | 0.6017 (5) | 0.3172 (2) | 0.18738 (7) | 0.0092 (4) | |
N2 | 0.4432 (5) | 0.3263 (2) | 0.30786 (7) | 0.0088 (4) | |
C1 | 1.0353 (6) | 0.4490 (3) | −0.06137 (8) | 0.0074 (4) | |
C2 | 0.8644 (6) | 0.3303 (3) | −0.02377 (8) | 0.0077 (4) | |
C3 | 0.8287 (6) | 0.3768 (3) | 0.03447 (8) | 0.0084 (4) | |
C4 | −0.0157 (6) | 0.4576 (3) | 0.56123 (8) | 0.0083 (4) | |
C5 | 0.1411 (6) | 0.3397 (3) | 0.51849 (8) | 0.0080 (4) | |
C6 | 0.1634 (6) | 0.3792 (3) | 0.46131 (8) | 0.0082 (4) | |
C7 | 0.4737 (6) | 0.4533 (3) | 0.21394 (9) | 0.0105 (4) | |
H7 | 0.4338 | 0.5520 | 0.1918 | 0.013* | |
C8 | 0.3932 (6) | 0.4577 (3) | 0.27438 (9) | 0.0100 (4) | |
H8 | 0.2997 | 0.5592 | 0.2914 | 0.012* | |
C9 | 0.5850 (6) | 0.1841 (3) | 0.28184 (8) | 0.0077 (4) | |
C10 | 0.6588 (6) | 0.0413 (3) | 0.31613 (9) | 0.0114 (4) | |
H10 | 0.6112 | 0.0446 | 0.3571 | 0.014* | |
C11 | 0.7991 (6) | −0.1021 (3) | 0.29023 (9) | 0.0129 (5) | |
H11 | 0.8500 | −0.1977 | 0.3133 | 0.015* | |
C12 | 0.8687 (6) | −0.1080 (3) | 0.22886 (9) | 0.0132 (5) | |
H12 | 0.9628 | −0.2085 | 0.2112 | 0.016* | |
C13 | 0.8022 (6) | 0.0286 (3) | 0.19491 (9) | 0.0111 (4) | |
H13 | 0.8501 | 0.0228 | 0.1540 | 0.013* | |
C14 | 0.6621 (6) | 0.1784 (3) | 0.22068 (8) | 0.0082 (4) | |
H2 | 0.669 (8) | 0.311 (4) | 0.1043 (12) | 0.018 (7)* | |
H4 | 0.338 (14) | 0.312 (7) | 0.388 (2) | 0.110 (19)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Cl1 | 0.0151 (3) | 0.0100 (3) | 0.0103 (3) | −0.0034 (2) | 0.00261 (18) | −0.00259 (17) |
Cl2 | 0.0171 (3) | 0.0093 (3) | 0.0107 (3) | 0.0050 (2) | 0.00351 (18) | 0.00301 (17) |
O1 | 0.0168 (9) | 0.0148 (9) | 0.0057 (7) | −0.0014 (7) | 0.0041 (6) | 0.0002 (5) |
O2 | 0.0203 (10) | 0.0120 (9) | 0.0047 (7) | −0.0050 (7) | 0.0051 (6) | 0.0007 (5) |
O3 | 0.0185 (9) | 0.0134 (9) | 0.0063 (7) | 0.0027 (7) | 0.0049 (6) | 0.0020 (5) |
O4 | 0.0194 (9) | 0.0112 (9) | 0.0066 (7) | 0.0054 (7) | 0.0056 (6) | 0.0000 (5) |
N1 | 0.0077 (10) | 0.0131 (10) | 0.0068 (8) | −0.0019 (8) | 0.0021 (6) | 0.0004 (6) |
N2 | 0.0097 (10) | 0.0097 (10) | 0.0073 (8) | 0.0009 (7) | 0.0024 (6) | −0.0003 (6) |
C1 | 0.0052 (11) | 0.0109 (11) | 0.0063 (9) | 0.0005 (8) | 0.0009 (7) | 0.0017 (7) |
C2 | 0.0085 (11) | 0.0069 (11) | 0.0077 (9) | −0.0011 (8) | 0.0017 (7) | 0.0001 (7) |
C3 | 0.0071 (11) | 0.0095 (11) | 0.0088 (10) | −0.0012 (9) | 0.0011 (7) | 0.0031 (7) |
C4 | 0.0074 (11) | 0.0096 (11) | 0.0075 (9) | −0.0020 (8) | 0.0011 (7) | −0.0008 (7) |
C5 | 0.0095 (11) | 0.0062 (11) | 0.0085 (10) | 0.0018 (8) | 0.0002 (7) | 0.0014 (7) |
C6 | 0.0084 (11) | 0.0083 (11) | 0.0076 (10) | −0.0009 (8) | 0.0024 (7) | −0.0018 (7) |
C7 | 0.0086 (11) | 0.0106 (11) | 0.0126 (10) | −0.0008 (9) | 0.0011 (8) | 0.0025 (7) |
C8 | 0.0100 (11) | 0.0086 (11) | 0.0115 (10) | 0.0009 (9) | 0.0022 (8) | −0.0003 (7) |
C9 | 0.0071 (11) | 0.0099 (11) | 0.0060 (9) | −0.0011 (8) | 0.0008 (7) | −0.0005 (7) |
C10 | 0.0135 (12) | 0.0113 (12) | 0.0099 (10) | 0.0016 (9) | 0.0026 (7) | 0.0016 (7) |
C11 | 0.0133 (12) | 0.0096 (12) | 0.0161 (11) | 0.0002 (9) | 0.0013 (8) | 0.0027 (8) |
C12 | 0.0108 (12) | 0.0114 (12) | 0.0172 (11) | 0.0008 (9) | 0.0043 (8) | −0.0039 (8) |
C13 | 0.0072 (11) | 0.0140 (12) | 0.0115 (10) | −0.0018 (9) | 0.0028 (7) | −0.0034 (7) |
C14 | 0.0053 (11) | 0.0107 (12) | 0.0084 (10) | −0.0019 (8) | 0.0015 (7) | −0.0013 (7) |
Cl1—C2 | 1.711 (2) | C4—C6ii | 1.508 (3) |
Cl2—C5 | 1.713 (2) | C5—C6 | 1.348 (3) |
O1—C1 | 1.232 (2) | C6—C4ii | 1.508 (3) |
O2—C3 | 1.321 (2) | C7—C8 | 1.414 (3) |
O2—H2 | 0.82 (3) | C7—H7 | 0.9500 |
O3—C4 | 1.221 (2) | C8—H8 | 0.9500 |
O4—C6 | 1.324 (2) | C9—C10 | 1.415 (3) |
O4—H4 | 0.85 (5) | C9—C14 | 1.426 (3) |
N1—C7 | 1.313 (3) | C10—C11 | 1.372 (3) |
N1—C14 | 1.367 (3) | C10—H10 | 0.9500 |
N2—C8 | 1.316 (3) | C11—C12 | 1.423 (3) |
N2—C9 | 1.368 (3) | C11—H11 | 0.9500 |
C1—C2 | 1.455 (3) | C12—C13 | 1.365 (3) |
C1—C3i | 1.505 (3) | C12—H12 | 0.9500 |
C2—C3 | 1.356 (3) | C13—C14 | 1.411 (3) |
C3—C1i | 1.505 (3) | C13—H13 | 0.9500 |
C4—C5 | 1.464 (3) | ||
C3—O2—H2 | 114 (2) | N1—C7—H7 | 118.9 |
C6—O4—H4 | 119 (4) | C8—C7—H7 | 118.9 |
C7—N1—C14 | 117.54 (16) | N2—C8—C7 | 122.4 (2) |
C8—N2—C9 | 116.86 (17) | N2—C8—H8 | 118.8 |
O1—C1—C2 | 123.3 (2) | C7—C8—H8 | 118.8 |
O1—C1—C3i | 117.76 (19) | N2—C9—C10 | 119.65 (17) |
C2—C1—C3i | 118.89 (17) | N2—C9—C14 | 120.90 (18) |
C3—C2—C1 | 120.2 (2) | C10—C9—C14 | 119.45 (19) |
C3—C2—Cl1 | 121.46 (17) | C11—C10—C9 | 119.96 (18) |
C1—C2—Cl1 | 118.33 (15) | C11—C10—H10 | 120.0 |
O2—C3—C2 | 121.7 (2) | C9—C10—H10 | 120.0 |
O2—C3—C1i | 117.37 (17) | C10—C11—C12 | 120.2 (2) |
C2—C3—C1i | 120.91 (19) | C10—C11—H11 | 119.9 |
O3—C4—C5 | 123.53 (19) | C12—C11—H11 | 119.9 |
O3—C4—C6ii | 118.54 (18) | C13—C12—C11 | 121.0 (2) |
C5—C4—C6ii | 117.93 (17) | C13—C12—H12 | 119.5 |
C6—C5—C4 | 120.83 (19) | C11—C12—H12 | 119.5 |
C6—C5—Cl2 | 121.59 (17) | C12—C13—C14 | 119.89 (18) |
C4—C5—Cl2 | 117.55 (14) | C12—C13—H13 | 120.1 |
O4—C6—C5 | 122.0 (2) | C14—C13—H13 | 120.1 |
O4—C6—C4ii | 116.79 (17) | N1—C14—C13 | 120.32 (17) |
C5—C6—C4ii | 121.19 (18) | N1—C14—C9 | 120.20 (19) |
N1—C7—C8 | 122.10 (19) | C13—C14—C9 | 119.48 (19) |
O1—C1—C2—C3 | 179.6 (2) | C9—N2—C8—C7 | 1.3 (3) |
C3i—C1—C2—C3 | 0.1 (3) | N1—C7—C8—N2 | 0.4 (4) |
O1—C1—C2—Cl1 | −0.3 (3) | C8—N2—C9—C10 | 177.4 (2) |
C3i—C1—C2—Cl1 | −179.79 (16) | C8—N2—C9—C14 | −2.1 (3) |
C1—C2—C3—O2 | 179.54 (18) | N2—C9—C10—C11 | 179.6 (2) |
Cl1—C2—C3—O2 | −0.6 (3) | C14—C9—C10—C11 | −0.8 (3) |
C1—C2—C3—C1i | −0.1 (4) | C9—C10—C11—C12 | −0.4 (4) |
Cl1—C2—C3—C1i | 179.78 (16) | C10—C11—C12—C13 | 0.9 (4) |
O3—C4—C5—C6 | −177.5 (2) | C11—C12—C13—C14 | 0.0 (3) |
C6ii—C4—C5—C6 | 2.3 (4) | C7—N1—C14—C13 | −179.5 (2) |
O3—C4—C5—Cl2 | 0.8 (3) | C7—N1—C14—C9 | 0.3 (3) |
C6ii—C4—C5—Cl2 | −179.44 (16) | C12—C13—C14—N1 | 178.6 (2) |
C4—C5—C6—O4 | 177.7 (2) | C12—C13—C14—C9 | −1.2 (3) |
Cl2—C5—C6—O4 | −0.5 (3) | N2—C9—C14—N1 | 1.3 (3) |
C4—C5—C6—C4ii | −2.3 (4) | C10—C9—C14—N1 | −178.2 (2) |
Cl2—C5—C6—C4ii | 179.43 (17) | N2—C9—C14—C13 | −178.8 (2) |
C14—N1—C7—C8 | −1.1 (3) | C10—C9—C14—C13 | 1.6 (3) |
Symmetry codes: (i) −x+2, −y+1, −z; (ii) −x, −y+1, −z+1. |
D—H···A | D—H | H···A | D···A | D—H···A |
O2—H2···N1 | 0.82 (3) | 1.90 (3) | 2.683 (2) | 159 (3) |
O2—H2···O1i | 0.82 (3) | 2.30 (3) | 2.687 (2) | 110 (2) |
O4—H4···N2 | 0.84 (5) | 1.89 (5) | 2.701 (2) | 163 (5) |
O4—H4···O3ii | 0.84 (5) | 2.35 (5) | 2.691 (2) | 105 (4) |
C7—H7···O1iii | 0.95 | 2.54 | 3.191 (3) | 126 |
C8—H8···O3ii | 0.95 | 2.43 | 3.048 (3) | 123 |
C10—H10···Cl2iv | 0.95 | 2.78 | 3.560 (2) | 140 |
C11—H11···O3iv | 0.95 | 2.59 | 3.538 (3) | 173 |
Symmetry codes: (i) −x+2, −y+1, −z; (ii) −x, −y+1, −z+1; (iii) −x+1, −y+1, −z; (iv) −x+1, −y, −z+1. |
Experimental details
Crystal data | |
Chemical formula | C8H6N2·C6H2Cl2O4 |
Mr | 339.13 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 95 |
a, b, c (Å) | 3.7963 (3), 7.7760 (7), 22.4830 (14) |
α, β, γ (°) | 93.444 (3), 94.338 (3), 92.322 (4) |
V (Å3) | 659.92 (9) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.51 |
Crystal size (mm) | 0.48 × 0.43 × 0.10 |
Data collection | |
Diffractometer | Rigaku R-AXIS RAPID |
Absorption correction | Multi-scan (ABSCOR; Higashi, 1995) |
Tmin, Tmax | 0.776, 0.950 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 6457, 2974, 2314 |
Rint | 0.066 |
(sin θ/λ)max (Å−1) | 0.649 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.044, 0.102, 1.00 |
No. of reflections | 2974 |
No. of parameters | 207 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.41, −0.66 |
Computer programs: PROCESS-AUTO (Rigaku/MSC, 2004), CrystalStructure (Rigaku/MSC, 2004), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), ORTEP-3 (Farrugia, 1997).
D—H···A | D—H | H···A | D···A | D—H···A |
O2—H2···N1 | 0.82 (3) | 1.90 (3) | 2.683 (2) | 159 (3) |
O2—H2···O1i | 0.82 (3) | 2.30 (3) | 2.687 (2) | 110 (2) |
O4—H4···N2 | 0.84 (5) | 1.89 (5) | 2.701 (2) | 163 (5) |
O4—H4···O3ii | 0.84 (5) | 2.35 (5) | 2.691 (2) | 105 (4) |
C7—H7···O1iii | 0.95 | 2.54 | 3.191 (3) | 126 |
C8—H8···O3ii | 0.95 | 2.43 | 3.048 (3) | 123 |
C10—H10···Cl2iv | 0.95 | 2.78 | 3.560 (2) | 140 |
C11—H11···O3iv | 0.95 | 2.59 | 3.538 (3) | 173 |
Symmetry codes: (i) −x+2, −y+1, −z; (ii) −x, −y+1, −z+1; (iii) −x+1, −y+1, −z; (iv) −x+1, −y, −z+1. |
The title compound was prepared in order to extend our study on D-H···A hydrogen bonding (D = N, O, or C; A = N, O or Cl) in amine–chloranilic acid 1:1 and 2:1 systems (Gotoh et al., 2006).
The asymmetric unit contains one quinoxaline molecule and two half chloranilic acid molecules. No acid-base interaction involving a proton transfer is observed between the quinoxaline and the chloranilic acid. In the crystal structure, the quinoxaline and the chloranilic acid are linked alternately through two kinds of O—H···N hydrogen bonds to form a zigzag chain running along the [201] direction (Fig. 1). Similar chain structures have been observed in the related compounds containing the pyrazine unit, i.e., pyrazine–chloranilic acid (1/1) (Ishida & Kashino, 1999), phenazine–chloranilic acid (1/1) (Horiuchi et al., 2005; Gotoh et al., 2007) and tetramethylpyrazine–chloranilic acid (1/1) (Prager et al., 2005, 2006). The chains are stacked along the a axis, forming a layer extending parallel to the (010) plane (Fig. 2). The layers are further linked by C—H···O hydrogen bonds.