organic compounds
6,7-Dichloro-2,3-bis(pyridin-2-yl)quinoxaline
aDepartment of Chemistry & Biochemistry, Central Connecticut State University, New Britain, CT 06053, USA
*Correspondence e-mail: crundwellg@mail.ccsu.edu
The title compound, C18H10Cl2N4, synthesized by the condensation reaction between 4,5-dichlorobenzene-1,2-diamine and 1,2-di(pyridin-2-yl)ethane-1,2-dione in boiling acetic acid, has a nearly planar quinoxaline moiety [maximum deviation = 0.070 (1) Å] whose mean plane makes dihedral angles of 40.51 (2) and 39.29 (3)° with the pyridine rings. Within the there are no classical hydrogen bonds. Molecules in the structure pack with π–π stacking contacts between the quinoxaline units and nearby pyridine rings with an intercentroid distance of 3.7676 (9) Å.
Keywords: crystal structure; quinoxaline.
CCDC reference: 1041827
1. Related literature
For the synthesis of the title compound, see: Imeri et al. (2013). For the structures of similar compounds, see: Woźniak (1991); Rasmussen et al. (1990); Crundwell et al. (2010, 2014); Jaso et al. (2005); Bu et al. (2001); Cantalupo et al. (2010); Crundwell (2013).
2. Experimental
2.1. Crystal data
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2.3. Refinement
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Data collection: CrysAlis CCD (Oxford Diffraction, 2009); cell CrysAlis RED (Oxford Diffraction, 2009); data reduction: CrysAlis RED; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2009); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).
Supporting information
CCDC reference: 1041827
10.1107/S2056989015000055/hg5423sup1.cif
contains datablocks I, New_Global_Publ_Block. DOI:Structure factors: contains datablock I. DOI: 10.1107/S2056989015000055/hg5423Isup2.hkl
Supporting information file. DOI: 10.1107/S2056989015000055/hg5423Isup3.cml
The title compound was synthesized in a manner similar to related compounds Imeri et al. (2013). To a 50 ml round bottom flask equipped with a reflux condenser was combined 0.2685 g (1.265 mmol) 1,2-di(pyridin-2-yl)ethane-1,2-dione, 0.3445 g (1.946 mmol) 4,5-dichlorobenzene-1,2-diamine and 20 ml glacial acetic acid. The resulting mixture was heated to reflux for 24 h. After this time, the resulting solution was poured over ice. The resulting beige solid was filtered and recrystallized from methanol, which produced 0.299 g of the title compound as a shiny, beige solid (67%). Rf 0.36 (SiO2, ethyl acetate); m.p. 468 K; IR (ATR-FTIR) 3077, 3046, 3008, 1585, 1474, 1391, 1341, 1278, 1110, 1078, 1002, 965, 860, 790, 743, 599, 547 cm-1; 1H NMR (300 MHz, CDCl3) δ 8.38 (s, 2H), 8.38 (dt, 2H J = 5, 1 Hz), 8.00 (dt, 2H, J = 8, 1 Hz), 7.87 (td, 2H, J = 8, 1 Hz), 7.29 (td, 2H, J = 5, 1 Hz); 13C NMR (300 MHz, CDCl3) δ 156.87, 153.53, 148.58, 139.84, 136.74, 135.10, 129.97, 124.17, 123.29; UV/Vis (CH2Cl2; λmax (logε)) 348 nm (12668), 275 nm (24188) 253 nm (43604); MS calculated for C18H10Cl2N4: M+: 352, measured: 352.
Carbon-bound H-atoms were placed in calculated positions (C—H = 0.93 Å) and were included in the
in the riding model approximation, with Uiso(H) = 1.2Ueq(C).Data collection: CrysAlis CCD (Oxford Diffraction, 2009); cell
CrysAlis RED (Oxford Diffraction, 2009); data reduction: CrysAlis RED (Oxford Diffraction, 2009); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2009); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).Fig. 1. A view of the title compound (Spek, 2009). Displacement ellipsoids are drawn at the 50% probability level. |
C18H10Cl2N4 | Dx = 1.498 Mg m−3 |
Mr = 353.20 | Melting point: 468 K |
Orthorhombic, Pbca | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ac 2ab | Cell parameters from 9283 reflections |
a = 7.1921 (5) Å | θ = 3.8–34.6° |
b = 18.072 (3) Å | µ = 0.42 mm−1 |
c = 24.093 (4) Å | T = 110 K |
V = 3131.6 (8) Å3 | Needle, brown |
Z = 8 | 0.23 × 0.12 × 0.09 mm |
F(000) = 1440 |
Oxford Diffraction Xcalibur, Sapphire3 diffractometer | 6227 independent reflections |
Radiation source: fine-focus sealed tube | 3818 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.031 |
Detector resolution: 16.1790 pixels mm-1 | θmax = 34.7°, θmin = 4.0° |
ω scans | h = −10→11 |
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2009) | k = −27→27 |
Tmin = 0.971, Tmax = 1.000 | l = −36→12 |
24047 measured 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)] = 0.034 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.086 | H-atom parameters constrained |
S = 0.90 | w = 1/[σ2(Fo2) + (0.0479P)2] where P = (Fo2 + 2Fc2)/3 |
6227 reflections | (Δ/σ)max = 0.002 |
217 parameters | Δρmax = 0.45 e Å−3 |
0 restraints | Δρmin = −0.24 e Å−3 |
C18H10Cl2N4 | V = 3131.6 (8) Å3 |
Mr = 353.20 | Z = 8 |
Orthorhombic, Pbca | Mo Kα radiation |
a = 7.1921 (5) Å | µ = 0.42 mm−1 |
b = 18.072 (3) Å | T = 110 K |
c = 24.093 (4) Å | 0.23 × 0.12 × 0.09 mm |
Oxford Diffraction Xcalibur, Sapphire3 diffractometer | 6227 independent reflections |
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2009) | 3818 reflections with I > 2σ(I) |
Tmin = 0.971, Tmax = 1.000 | Rint = 0.031 |
24047 measured reflections |
R[F2 > 2σ(F2)] = 0.034 | 0 restraints |
wR(F2) = 0.086 | H-atom parameters constrained |
S = 0.90 | Δρmax = 0.45 e Å−3 |
6227 reflections | Δρmin = −0.24 e Å−3 |
217 parameters |
Experimental. Carbon-bound H-atoms were placed in calculated positions (C—H = 0.93 Å) and were included in the refinement in the riding model approximation, with Uiso(H) = 1.2Ueq(C). |
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. |
x | y | z | Uiso*/Ueq | ||
Cl2 | 0.32732 (4) | 0.426900 (14) | 1.127570 (12) | 0.02132 (7) | |
Cl1 | 0.47814 (4) | 0.573896 (15) | 1.184200 (12) | 0.02235 (7) | |
N1 | 0.40209 (13) | 0.70156 (5) | 0.99845 (4) | 0.01556 (18) | |
C6 | 0.41314 (16) | 0.57361 (6) | 1.11493 (5) | 0.0160 (2) | |
N2 | 0.22634 (13) | 0.57626 (5) | 0.95171 (4) | 0.01546 (18) | |
C14 | 0.15721 (15) | 0.64197 (6) | 0.86826 (5) | 0.0142 (2) | |
N4 | 0.06670 (13) | 0.70481 (5) | 0.85634 (4) | 0.0180 (2) | |
N3 | 0.45961 (14) | 0.75394 (5) | 0.86134 (4) | 0.0178 (2) | |
C3 | 0.29491 (15) | 0.57490 (5) | 1.00477 (5) | 0.0144 (2) | |
C5 | 0.34195 (15) | 0.50820 (6) | 1.09007 (5) | 0.0160 (2) | |
C15 | 0.16747 (16) | 0.58249 (6) | 0.83174 (5) | 0.0174 (2) | |
H15 | 0.2258 | 0.5387 | 0.8422 | 0.021* | |
C1 | 0.34541 (15) | 0.70080 (5) | 0.94668 (5) | 0.0143 (2) | |
C2 | 0.24614 (15) | 0.63859 (5) | 0.92372 (5) | 0.0144 (2) | |
C7 | 0.42943 (15) | 0.63766 (6) | 1.08503 (5) | 0.0162 (2) | |
H7 | 0.4772 | 0.6801 | 1.1015 | 0.019* | |
C9 | 0.39540 (15) | 0.76674 (5) | 0.91270 (5) | 0.0146 (2) | |
C4 | 0.28220 (15) | 0.50930 (6) | 1.03626 (5) | 0.0166 (2) | |
H4 | 0.2330 | 0.4667 | 1.0204 | 0.020* | |
C18 | −0.01188 (17) | 0.70972 (6) | 0.80610 (5) | 0.0210 (2) | |
H18 | −0.0776 | 0.7526 | 0.7976 | 0.025* | |
C8 | 0.37327 (15) | 0.63874 (6) | 1.02907 (5) | 0.0149 (2) | |
C11 | 0.41978 (16) | 0.89793 (6) | 0.90239 (5) | 0.0188 (2) | |
H11 | 0.4055 | 0.9458 | 0.9159 | 0.023* | |
C10 | 0.37737 (16) | 0.83738 (5) | 0.93523 (5) | 0.0169 (2) | |
H10 | 0.3376 | 0.8437 | 0.9716 | 0.020* | |
C16 | 0.08919 (17) | 0.58966 (6) | 0.77953 (5) | 0.0211 (2) | |
H16 | 0.0971 | 0.5513 | 0.7539 | 0.025* | |
C13 | 0.50436 (16) | 0.81321 (6) | 0.83081 (5) | 0.0198 (2) | |
H13 | 0.5518 | 0.8054 | 0.7954 | 0.024* | |
C12 | 0.48406 (16) | 0.88553 (6) | 0.84893 (5) | 0.0196 (2) | |
H12 | 0.5130 | 0.9250 | 0.8257 | 0.024* | |
C17 | −0.00125 (16) | 0.65502 (6) | 0.76609 (5) | 0.0222 (2) | |
H17 | −0.0533 | 0.6619 | 0.7311 | 0.027* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Cl2 | 0.02666 (15) | 0.01669 (12) | 0.02059 (14) | −0.00209 (10) | −0.00040 (11) | 0.00626 (11) |
Cl1 | 0.03104 (16) | 0.02148 (13) | 0.01452 (13) | −0.00167 (11) | −0.00438 (11) | 0.00270 (11) |
N1 | 0.0188 (5) | 0.0130 (4) | 0.0149 (5) | −0.0012 (3) | 0.0003 (4) | −0.0006 (3) |
C6 | 0.0167 (5) | 0.0180 (5) | 0.0132 (5) | 0.0002 (4) | −0.0012 (4) | 0.0006 (4) |
N2 | 0.0191 (4) | 0.0133 (4) | 0.0140 (4) | −0.0002 (3) | −0.0001 (4) | −0.0006 (3) |
C14 | 0.0160 (5) | 0.0131 (4) | 0.0136 (5) | −0.0023 (4) | 0.0001 (4) | −0.0005 (4) |
N4 | 0.0206 (5) | 0.0163 (4) | 0.0170 (5) | 0.0008 (4) | −0.0022 (4) | −0.0002 (4) |
N3 | 0.0221 (5) | 0.0158 (4) | 0.0157 (5) | −0.0014 (4) | 0.0004 (4) | −0.0007 (4) |
C3 | 0.0161 (5) | 0.0133 (4) | 0.0138 (5) | −0.0004 (4) | 0.0004 (4) | −0.0007 (4) |
C5 | 0.0168 (5) | 0.0138 (5) | 0.0174 (5) | 0.0016 (4) | 0.0020 (4) | 0.0027 (4) |
C15 | 0.0207 (5) | 0.0145 (5) | 0.0169 (5) | −0.0035 (4) | 0.0017 (4) | −0.0011 (4) |
C1 | 0.0167 (5) | 0.0115 (4) | 0.0148 (5) | 0.0007 (4) | 0.0008 (4) | −0.0011 (4) |
C2 | 0.0169 (5) | 0.0132 (4) | 0.0133 (5) | −0.0001 (4) | 0.0018 (4) | −0.0016 (4) |
C7 | 0.0178 (5) | 0.0155 (5) | 0.0154 (5) | −0.0018 (4) | −0.0002 (4) | −0.0017 (4) |
C9 | 0.0161 (5) | 0.0129 (4) | 0.0148 (5) | −0.0005 (4) | −0.0019 (4) | 0.0004 (4) |
C4 | 0.0195 (5) | 0.0131 (5) | 0.0172 (6) | −0.0013 (4) | 0.0001 (4) | −0.0014 (4) |
C18 | 0.0218 (6) | 0.0210 (5) | 0.0203 (6) | 0.0008 (5) | −0.0029 (5) | 0.0020 (5) |
C8 | 0.0169 (5) | 0.0134 (4) | 0.0143 (5) | −0.0001 (4) | 0.0005 (4) | −0.0003 (4) |
C11 | 0.0194 (6) | 0.0126 (5) | 0.0245 (6) | −0.0005 (4) | −0.0029 (5) | 0.0000 (4) |
C10 | 0.0190 (5) | 0.0149 (5) | 0.0167 (6) | −0.0006 (4) | −0.0009 (4) | −0.0022 (4) |
C16 | 0.0263 (6) | 0.0211 (5) | 0.0158 (6) | −0.0070 (5) | 0.0019 (5) | −0.0050 (4) |
C13 | 0.0232 (6) | 0.0202 (5) | 0.0160 (6) | −0.0021 (4) | 0.0005 (5) | 0.0021 (4) |
C12 | 0.0215 (6) | 0.0165 (5) | 0.0208 (6) | −0.0029 (4) | −0.0020 (5) | 0.0050 (4) |
C17 | 0.0235 (6) | 0.0275 (6) | 0.0155 (6) | −0.0074 (5) | −0.0045 (5) | 0.0012 (5) |
Cl2—C5 | 1.7281 (11) | C1—C2 | 1.4420 (15) |
Cl1—C6 | 1.7332 (12) | C1—C9 | 1.4897 (15) |
N1—C1 | 1.3124 (14) | C7—C8 | 1.4075 (15) |
N1—C8 | 1.3697 (14) | C7—H7 | 0.9300 |
C6—C7 | 1.3685 (15) | C9—C10 | 1.3934 (14) |
C6—C5 | 1.4207 (15) | C4—H4 | 0.9300 |
N2—C2 | 1.3206 (13) | C18—C17 | 1.3828 (17) |
N2—C3 | 1.3703 (15) | C18—H18 | 0.9300 |
C14—N4 | 1.3402 (13) | C11—C10 | 1.3843 (15) |
C14—C15 | 1.3912 (15) | C11—C12 | 1.3869 (17) |
C14—C2 | 1.4826 (16) | C11—H11 | 0.9300 |
N4—C18 | 1.3390 (15) | C10—H10 | 0.9300 |
N3—C13 | 1.3386 (14) | C16—C17 | 1.3869 (17) |
N3—C9 | 1.3411 (15) | C16—H16 | 0.9300 |
C3—C8 | 1.4112 (14) | C13—C12 | 1.3856 (16) |
C3—C4 | 1.4107 (15) | C13—H13 | 0.9300 |
C5—C4 | 1.3658 (16) | C12—H12 | 0.9300 |
C15—C16 | 1.3841 (17) | C17—H17 | 0.9300 |
C15—H15 | 0.9300 | ||
C1—N1—C8 | 117.15 (9) | N3—C9—C1 | 116.88 (9) |
C7—C6—C5 | 120.84 (11) | C10—C9—C1 | 119.77 (10) |
C7—C6—Cl1 | 118.78 (8) | C5—C4—C3 | 120.16 (10) |
C5—C6—Cl1 | 120.38 (8) | C5—C4—H4 | 119.9 |
C2—N2—C3 | 116.93 (9) | C3—C4—H4 | 119.9 |
N4—C14—C15 | 123.03 (10) | N4—C18—C17 | 124.02 (11) |
N4—C14—C2 | 115.94 (9) | N4—C18—H18 | 118.0 |
C15—C14—C2 | 121.03 (10) | C17—C18—H18 | 118.0 |
C18—N4—C14 | 117.06 (10) | N1—C8—C3 | 120.97 (10) |
C13—N3—C9 | 116.86 (9) | N1—C8—C7 | 118.94 (10) |
N2—C3—C8 | 121.07 (9) | C3—C8—C7 | 120.05 (10) |
N2—C3—C4 | 119.58 (9) | C10—C11—C12 | 118.46 (10) |
C8—C3—C4 | 119.33 (10) | C10—C11—H11 | 120.8 |
C4—C5—C6 | 120.10 (10) | C12—C11—H11 | 120.8 |
C4—C5—Cl2 | 119.30 (8) | C11—C10—C9 | 118.77 (11) |
C6—C5—Cl2 | 120.59 (9) | C11—C10—H10 | 120.6 |
C16—C15—C14 | 118.74 (10) | C9—C10—H10 | 120.6 |
C16—C15—H15 | 120.6 | C15—C16—C17 | 118.86 (11) |
C14—C15—H15 | 120.6 | C15—C16—H16 | 120.6 |
N1—C1—C2 | 121.77 (9) | C17—C16—H16 | 120.6 |
N1—C1—C9 | 116.03 (9) | N3—C13—C12 | 123.81 (11) |
C2—C1—C9 | 122.16 (10) | N3—C13—H13 | 118.1 |
N2—C2—C1 | 121.50 (10) | C12—C13—H13 | 118.1 |
N2—C2—C14 | 116.67 (9) | C13—C12—C11 | 118.69 (10) |
C1—C2—C14 | 121.82 (9) | C13—C12—H12 | 120.7 |
C6—C7—C8 | 119.43 (10) | C11—C12—H12 | 120.7 |
C6—C7—H7 | 120.3 | C18—C17—C16 | 118.17 (11) |
C8—C7—H7 | 120.3 | C18—C17—H17 | 120.9 |
N3—C9—C10 | 123.33 (10) | C16—C17—H17 | 120.9 |
C15—C14—N4—C18 | −1.81 (16) | N1—C1—C9—N3 | 135.70 (11) |
C2—C14—N4—C18 | 178.80 (10) | C2—C1—C9—N3 | −42.28 (15) |
C2—N2—C3—C8 | 3.50 (15) | N1—C1—C9—C10 | −43.17 (15) |
C2—N2—C3—C4 | −178.38 (10) | C2—C1—C9—C10 | 138.85 (11) |
C7—C6—C5—C4 | −2.44 (17) | C6—C5—C4—C3 | 1.47 (17) |
Cl1—C6—C5—C4 | 176.69 (9) | Cl2—C5—C4—C3 | −179.29 (8) |
C7—C6—C5—Cl2 | 178.33 (9) | N2—C3—C4—C5 | −176.88 (10) |
Cl1—C6—C5—Cl2 | −2.54 (13) | C8—C3—C4—C5 | 1.27 (16) |
N4—C14—C15—C16 | 3.48 (17) | C14—N4—C18—C17 | −1.49 (17) |
C2—C14—C15—C16 | −177.17 (10) | C1—N1—C8—C3 | 3.28 (15) |
C8—N1—C1—C2 | 3.95 (15) | C1—N1—C8—C7 | −179.04 (10) |
C8—N1—C1—C9 | −174.03 (9) | N2—C3—C8—N1 | −7.34 (16) |
C3—N2—C2—C1 | 3.71 (15) | C4—C3—C8—N1 | 174.53 (10) |
C3—N2—C2—C14 | −174.77 (9) | N2—C3—C8—C7 | 175.00 (10) |
N1—C1—C2—N2 | −7.87 (16) | C4—C3—C8—C7 | −3.13 (16) |
C9—C1—C2—N2 | 169.99 (10) | C6—C7—C8—N1 | −175.51 (10) |
N1—C1—C2—C14 | 170.53 (10) | C6—C7—C8—C3 | 2.19 (17) |
C9—C1—C2—C14 | −11.61 (15) | C12—C11—C10—C9 | −1.98 (17) |
N4—C14—C2—N2 | 136.57 (10) | N3—C9—C10—C11 | 2.96 (17) |
C15—C14—C2—N2 | −42.83 (15) | C1—C9—C10—C11 | −178.25 (10) |
N4—C14—C2—C1 | −41.91 (14) | C14—C15—C16—C17 | −1.84 (17) |
C15—C14—C2—C1 | 138.69 (11) | C9—N3—C13—C12 | −1.45 (17) |
C5—C6—C7—C8 | 0.57 (17) | N3—C13—C12—C11 | 2.30 (18) |
Cl1—C6—C7—C8 | −178.57 (9) | C10—C11—C12—C13 | −0.46 (17) |
C13—N3—C9—C10 | −1.23 (17) | N4—C18—C17—C16 | 2.97 (18) |
C13—N3—C9—C1 | 179.95 (10) | C15—C16—C17—C18 | −1.16 (17) |
Experimental details
Crystal data | |
Chemical formula | C18H10Cl2N4 |
Mr | 353.20 |
Crystal system, space group | Orthorhombic, Pbca |
Temperature (K) | 110 |
a, b, c (Å) | 7.1921 (5), 18.072 (3), 24.093 (4) |
V (Å3) | 3131.6 (8) |
Z | 8 |
Radiation type | Mo Kα |
µ (mm−1) | 0.42 |
Crystal size (mm) | 0.23 × 0.12 × 0.09 |
Data collection | |
Diffractometer | Oxford Diffraction Xcalibur, Sapphire3 diffractometer |
Absorption correction | Multi-scan (CrysAlis RED; Oxford Diffraction, 2009) |
Tmin, Tmax | 0.971, 1.000 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 24047, 6227, 3818 |
Rint | 0.031 |
(sin θ/λ)max (Å−1) | 0.800 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.034, 0.086, 0.90 |
No. of reflections | 6227 |
No. of parameters | 217 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.45, −0.24 |
Computer programs: CrysAlis CCD (Oxford Diffraction, 2009), CrysAlis RED (Oxford Diffraction, 2009), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), PLATON (Spek, 2009), SHELXTL (Sheldrick, 2008).
Cl2—C5 | 1.7281 (11) | C3—C8 | 1.4112 (14) |
Cl1—C6 | 1.7332 (12) | C3—C4 | 1.4107 (15) |
N1—C1 | 1.3124 (14) | C5—C4 | 1.3658 (16) |
N1—C8 | 1.3697 (14) | C15—C16 | 1.3841 (17) |
C6—C7 | 1.3685 (15) | C1—C2 | 1.4420 (15) |
C6—C5 | 1.4207 (15) | C1—C9 | 1.4897 (15) |
N2—C2 | 1.3206 (13) | C7—C8 | 1.4075 (15) |
N2—C3 | 1.3703 (15) | C9—C10 | 1.3934 (14) |
C14—N4 | 1.3402 (13) | C18—C17 | 1.3828 (17) |
C14—C15 | 1.3912 (15) | C18—H18 | 0.9300 |
C14—C2 | 1.4826 (16) | C11—C10 | 1.3843 (15) |
N4—C18 | 1.3390 (15) | C11—C12 | 1.3869 (17) |
N3—C13 | 1.3386 (14) | C16—C17 | 1.3869 (17) |
N3—C9 | 1.3411 (15) | C13—C12 | 1.3856 (16) |
C1—N1—C8 | 117.15 (9) | C2—C1—C9 | 122.16 (10) |
C7—C6—C5 | 120.84 (11) | N2—C2—C1 | 121.50 (10) |
C7—C6—Cl1 | 118.78 (8) | N2—C2—C14 | 116.67 (9) |
C5—C6—Cl1 | 120.38 (8) | C1—C2—C14 | 121.82 (9) |
C2—N2—C3 | 116.93 (9) | C6—C7—C8 | 119.43 (10) |
N4—C14—C15 | 123.03 (10) | N3—C9—C10 | 123.33 (10) |
N4—C14—C2 | 115.94 (9) | N3—C9—C1 | 116.88 (9) |
C15—C14—C2 | 121.03 (10) | C10—C9—C1 | 119.77 (10) |
C18—N4—C14 | 117.06 (10) | C5—C4—C3 | 120.16 (10) |
C13—N3—C9 | 116.86 (9) | N4—C18—C17 | 124.02 (11) |
N2—C3—C8 | 121.07 (9) | N1—C8—C3 | 120.97 (10) |
N2—C3—C4 | 119.58 (9) | N1—C8—C7 | 118.94 (10) |
C8—C3—C4 | 119.33 (10) | C3—C8—C7 | 120.05 (10) |
C4—C5—C6 | 120.10 (10) | C10—C11—C12 | 118.46 (10) |
C4—C5—Cl2 | 119.30 (8) | C11—C10—C9 | 118.77 (11) |
C6—C5—Cl2 | 120.59 (9) | C15—C16—C17 | 118.86 (11) |
C16—C15—C14 | 118.74 (10) | N3—C13—C12 | 123.81 (11) |
N1—C1—C2 | 121.77 (9) | C13—C12—C11 | 118.69 (10) |
N1—C1—C9 | 116.03 (9) | C18—C17—C16 | 118.17 (11) |
C15—C14—N4—C18 | −1.81 (16) | N1—C1—C9—N3 | 135.70 (11) |
C2—C14—N4—C18 | 178.80 (10) | C2—C1—C9—N3 | −42.28 (15) |
C2—N2—C3—C8 | 3.50 (15) | N1—C1—C9—C10 | −43.17 (15) |
C2—N2—C3—C4 | −178.38 (10) | C2—C1—C9—C10 | 138.85 (11) |
C7—C6—C5—C4 | −2.44 (17) | C6—C5—C4—C3 | 1.47 (17) |
Cl1—C6—C5—C4 | 176.69 (9) | Cl2—C5—C4—C3 | −179.29 (8) |
C7—C6—C5—Cl2 | 178.33 (9) | N2—C3—C4—C5 | −176.88 (10) |
Cl1—C6—C5—Cl2 | −2.54 (13) | C8—C3—C4—C5 | 1.27 (16) |
N4—C14—C15—C16 | 3.48 (17) | C14—N4—C18—C17 | −1.49 (17) |
C2—C14—C15—C16 | −177.17 (10) | C1—N1—C8—C3 | 3.28 (15) |
C8—N1—C1—C2 | 3.95 (15) | C1—N1—C8—C7 | −179.04 (10) |
C8—N1—C1—C9 | −174.03 (9) | N2—C3—C8—N1 | −7.34 (16) |
C3—N2—C2—C1 | 3.71 (15) | C4—C3—C8—N1 | 174.53 (10) |
C3—N2—C2—C14 | −174.77 (9) | N2—C3—C8—C7 | 175.00 (10) |
N1—C1—C2—N2 | −7.87 (16) | C4—C3—C8—C7 | −3.13 (16) |
C9—C1—C2—N2 | 169.99 (10) | C6—C7—C8—N1 | −175.51 (10) |
N1—C1—C2—C14 | 170.53 (10) | C6—C7—C8—C3 | 2.19 (17) |
C9—C1—C2—C14 | −11.61 (15) | C12—C11—C10—C9 | −1.98 (17) |
N4—C14—C2—N2 | 136.57 (10) | N3—C9—C10—C11 | 2.96 (17) |
C15—C14—C2—N2 | −42.83 (15) | C1—C9—C10—C11 | −178.25 (10) |
N4—C14—C2—C1 | −41.91 (14) | C14—C15—C16—C17 | −1.84 (17) |
C15—C14—C2—C1 | 138.69 (11) | C9—N3—C13—C12 | −1.45 (17) |
C5—C6—C7—C8 | 0.57 (17) | N3—C13—C12—C11 | 2.30 (18) |
Cl1—C6—C7—C8 | −178.57 (9) | C10—C11—C12—C13 | −0.46 (17) |
C13—N3—C9—C10 | −1.23 (17) | N4—C18—C17—C16 | 2.97 (18) |
C13—N3—C9—C1 | 179.95 (10) | C15—C16—C17—C18 | −1.16 (17) |
Acknowledgements
This research was funded by a CCSU–AAUP research grant and a CCSU Student-Faculty grant.
References
Bu, X.-H., Liu, H., Du, M., Wong, K. M.-C., Yam, V. W.-W. & Shionoya, M. (2001). Inorg. Chem. 40, 4143–4149. Web of Science CSD CrossRef PubMed CAS Google Scholar
Cantalupo, S. A., Crundwell, G. & Glagovich, N. (2010). Acta Cryst. E66, o2184. Web of Science CSD CrossRef IUCr Journals Google Scholar
Crundwell, G. (2013). Acta Cryst. E69, m164. Google Scholar
Crundwell, G., Cantalupo, S., Foss, P. C. D., McBurney, B., Kopp, K., Westcott, B. L., Updegraff, J. III, Zeller, M. & Hunter, A. D. (2014). Open J. Inorg. Chem. 4, 10–17. Google Scholar
Crundwell, G. & Glagovich, N. (2010). Acta Cryst. E66, o3042. Google Scholar
Imeri, A., Glagovich, N. M. & Crundwell, G. (2013). Acta Cryst. E69, o48. Google Scholar
Jaso, A., Zarranz, B., Aldana, I. & Monge, A. (2005). J. Med. Chem. 48, 2019–2025. Web of Science CrossRef PubMed CAS Google Scholar
Oxford Diffraction (2009). CrysAlis CCD,CrysAlis PRO, CrysAlis RED. Oxford Diffraction Ltd, Abington, England. Google Scholar
Rasmussen, S. C., Richter, M. M., Yi, E., Place, H. & Brewer, K. J. (1990). Inorg. Chem. 29, 3926–3932. CSD CrossRef CAS Web of Science Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Spek, A. L. (2009). Acta Cryst. D65, 148–155. Web of Science CrossRef CAS IUCr Journals Google Scholar
Woźniak, K. (1991). Acta Cryst. C47, 1761–1763. Google Scholar
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Quinoxalines, like the title compound C18H10Cl2N4, have interesting characteristics including antimicrobial activity (Jaso et al., 2005). Our interest in quinoxalines results from their simple synthesis, and the proclivity with which X-ray quality crystals can be grown (Imeri et al., 2013; Crundwell et al., 2010; Cantalupo et al., 2010; Wozniak, 1991). We have also found that quinoxalines make interesting ligands when combined with metals, especially silver(I) salts (Rasmussen et al., 1990; Bu et al., 2001; Crundwell, 2013; Crundwell et al., 2014).
The title compound, C18H10Cl2N4, has a nearly planar quinoxaline moiety (Fig. 1). The pyridine rings make angles of 40.52 (2)° and 39.32 (3)° with respect to the mean plane of the quinoxaline. All bond lengths and angles lie within expected values. Within the unit cell, there are no classical hydrogen bonds. The molecules pack in offset layers with closest contacts between quinoxalines and nearby pyridine rings.