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Acta Crystallogr Sect E Struct Rep Online. 2008 January 1; 64(Pt 1): o110–o111.
Published online 2007 December 6. doi:  10.1107/S1600536807033521
PMCID: PMC2915182

2,2,3,3′-Tetra­phenyl-7,7′-biquinoxaline

Abstract

In the crystal structure of the title compound, C40H26N4, mol­ecules reside on crystallographic centers of inversion and are linked via C—H(...)N inter­actions about inversion centers into one-dimensional chains: longer C—H(...)π(arene) inter­actions complete the inter­molecular inter­actions.

Related literature

For the synthesis of quinoxalines, see: Kowalski et al. (2006 [triangle]); Kou et al. (2006 [triangle]); Baek & Tan (2006 [triangle]). For applications of quinoxalines see: Mollegaard et al. (2000 [triangle]); Aldakov et al. (2005 [triangle]); Kaiwar et al. (1997 [triangle]); Anzenbacher et al. (2000 [triangle]). For related literature, see: Brown et al. (2004 [triangle]); Bruno et al. (2002 [triangle]); Gibson et al. (2006 [triangle]); Page et al. (1998 [triangle]); Pascal & Ho (1993 [triangle]); Salvatore et al. (2006 [triangle]); Simpson & Gordon (1995 [triangle]); Willett et al. (2001 [triangle]); Wozniak et al. (1993 [triangle]); Wu et al. (2002 [triangle]).

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Object name is e-64-0o110-scheme1.jpg

Experimental

Crystal data

  • C40H26N4
  • M r = 562.65
  • Triclinic, An external file that holds a picture, illustration, etc.
Object name is e-64-0o110-efi1.jpg
  • a = 5.70240 (10) Å
  • b = 9.9534 (2) Å
  • c = 12.9785 (3) Å
  • α = 105.3520 (10)°
  • β = 96.6170 (10)°
  • γ = 91.7510 (10)°
  • V = 704.19 (3) Å3
  • Z = 1
  • Cu Kα radiation
  • μ = 0.61 mm−1
  • T = 100 (2) K
  • 0.19 × 0.12 × 0.06 mm

Data collection

  • Bruker SMART APEXII CCD diffractometer
  • Absorption correction: numerical (SADABS; Sheldrick, 2004 [triangle]) T min = 0.893, T max = 0.964
  • 12179 measured reflections
  • 2429 independent reflections
  • 2156 reflections with I > 2σ(I)
  • R int = 0.033

Refinement

  • R[F 2 > 2σ(F 2)] = 0.033
  • wR(F 2) = 0.091
  • S = 1.06
  • 2429 reflections
  • 251 parameters
  • All H-atom parameters refined
  • Δρmax = 0.23 e Å−3
  • Δρmin = −0.18 e Å−3

Data collection: APEX2 (Bruker, 2004 [triangle]); cell refinement: SAINT-Plus (Bruker, 2004 [triangle]); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997 [triangle]); program(s) used to refine structure: XSHELL (Bruker, 2004 [triangle]); molecular graphics: ORTEP-3 (Farrugia, 1997 [triangle]); software used to prepare material for publication: SHELXL97 (Sheldrick, 1997 [triangle]).

Table 1
Hydrogen-bond geometry (Å, °)

Supplementary Material

Crystal structure: contains datablocks I, global, publication_text. DOI: 10.1107/S1600536807033521/gg2021sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536807033521/gg2021Isup2.hkl

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

Acknowledgments

EED acknowledges the National Science Foundation for primary support of this research (EPSCOR grant No. 450901). RDP is indebted to the NSF (CHE-0443345) and the College of William and Mary for the purchase of the X-ray diffractometer.

supplementary crystallographic information

Comment

Quinoxalines and their derivatives have received considerable attention in the past several years due to their electronic properties (Page et al., 1998; Simpson & Gordon, 1995), H-bonding ability (Pascal et al., 1993; Wozniak et al., 1993), and their capacity to coordinate to metals forming interesting three-dimensional structures (Wu et al., 2002; Willett et al., 2001). During our investigations, we have prepared a number of substituted quinoxalines and phenazines, some of which coordinate to metal salts forming novel structures (Dueno, et al., unpublished). Our current work involves the synthesis of new nitrogen heterocycles (Gibson, et al., 2006; Salvatore, et al., 2006) which may lead to novel three dimensional structures upon coordination to metal salts. Here, we report the crystal structure of 2,2',3,3'-Tetraphenyl-7,7'-biquinoxaline (I), (Figure 1).

The structure of (I) has bond distances and angles that are unexceptional, as all fall within ranges found in the literature for similar nitrogen heterocycles (Brown et al., 2004). The one molecule present in the asymmetric unit cell lies on an inversion center, so that half the molecule is related to its counterpart by symmetry (symmetry code, -x,-y,-z). As expected, the steric bulk of the phenyl substituents prevents them from being coplanar with the quinoxaline rings: the dihedral angle N2—C5—C15—C20 (phenyl ring 1) is 59.80 (11)°, and the dihedral angle N1—C4—C9—C10 (phenyl ring 2) is 25.98 (11)°. An interesting feature worth mentioning is that the two rings that make up the quinoxaline unit are not perfectly planar, for the angle between the N containing ring and the carbon-only ring is 3.50 (11)° (based on a least squares mean planes of N1—C4—C5—N2—C6—C3 and C1—C2—C3—C6—C7—C8). It is conceivable that this deviation from a planar structure is due to Van der Waals repulsion interactions between the aromatic substituents. Another interesting aspect of this molecule is that the packing diagram shows short contact interactions between phenyl substituents on one molecule and the quinoxaline ring of an adjacent molecule. Intermolecular distances range from 3.181 (2) Å (C10—C6) to 3.376 (2) Å (C11—C4), which suggests some degree of σ(CH)···π interaction (Figure 2).

Experimental

A 50 ml round-bottomed flask was charged with biphenyl-3,3',4,4'-tetramine (214 mg, 1 mmol), benzil (420 mg, 2 mmol), iodine (51 mg, 0.2 mmol), and acetonitrile (15 ml). The reaction was monitored by thin-layer chromatography until complete consumption of the starting materials (15 min). The resulting amber solution was concentrated to dryness under reduced pressure. The dark-brown crude product was then subjected to flash column chromatography using silica gel (eluent: 9:1 hexane–EtOAc) in order to remove residual iodine. The pale-yellow solution was evaporated to dryness under reduced pressure to give (I) (yield 0.413 mg, 74%), as a white powder (m.p. 573 K). This powder was then crystallized from a minimal amount of toluene, and afforded (I) as pale-yellow cubes.

Refinement

H atoms were placed in idealized positions (C—H = 0.96 – 1.00 A) and allowed to ride on their parent atoms with Uiso(H) = 1.2 Ueq(C).

Figures

Fig. 1.
ORTEP (Farrugia, 1997) drawing of (I). Displacement ellipsoids have been drawn at the 50% probability level. Unlabeled atoms are related to labeled atoms by symmetry (code –x,-y,-z). H atoms have been omitted for clarity.
Fig. 2.
Mercury (Bruno et al., 2002) packing diagram of (I) along the b axis showing short contact interactions.

Crystal data

C40H26N4Z = 1
Mr = 562.65F000 = 294
Triclinic, P1Dx = 1.327 Mg m3
Hall symbol: -P 1Cu Kα radiation λ = 1.54178 Å
a = 5.70240 (10) ÅCell parameters from 585 reflections
b = 9.9534 (2) Åθ = 3.6–67.0º
c = 12.9785 (3) ŵ = 0.61 mm1
α = 105.3520 (10)ºT = 100 (2) K
β = 96.6170 (10)ºBlock, colourless
γ = 91.7510 (10)º0.19 × 0.12 × 0.06 mm
V = 704.19 (3) Å3

Data collection

Bruker SMART APEXII CCD diffractometer2429 independent reflections
Radiation source: fine-focus sealed tube2156 reflections with I > 2σ(I)
Monochromator: graphiteRint = 0.033
T = 100(2) Kθmax = 67.0º
ω and ψ scansθmin = 3.6º
Absorption correction: numerical(SADABS; Sheldrick, 2004)h = −6→6
Tmin = 0.893, Tmax = 0.964k = −11→11
12179 measured reflectionsl = −15→15

Refinement

Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.033All H-atom parameters refined
wR(F2) = 0.091  w = 1/[σ2(Fo2) + (0.0496P)2 + 0.1323P] where P = (Fo2 + 2Fc2)/3
S = 1.06(Δ/σ)max < 0.001
2429 reflectionsΔρmax = 0.23 e Å3
251 parametersΔρmin = −0.18 e Å3
Primary atom site location: structure-invariant direct methodsExtinction correction: none

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
N10.51854 (16)0.85128 (10)0.69940 (8)0.0221 (2)
N20.23046 (17)0.60236 (10)0.64109 (8)0.0224 (2)
C10.03603 (19)0.94087 (11)0.52202 (9)0.0209 (3)
C20.2496 (2)0.94755 (12)0.58600 (9)0.0226 (3)
C30.31629 (19)0.83612 (11)0.62942 (9)0.0211 (3)
C40.57593 (19)0.74558 (12)0.73939 (9)0.0212 (3)
C50.43238 (19)0.61520 (12)0.70434 (9)0.0211 (3)
C60.1661 (2)0.71321 (12)0.60385 (9)0.0217 (3)
C7−0.0511 (2)0.70597 (12)0.53726 (9)0.0231 (3)
C8−0.1142 (2)0.81609 (12)0.49890 (9)0.0225 (3)
C90.79004 (19)0.77207 (11)0.82117 (9)0.0219 (3)
C100.9637 (2)0.87320 (12)0.81830 (10)0.0239 (3)
C111.1675 (2)0.90121 (13)0.89186 (10)0.0269 (3)
C121.2013 (2)0.82934 (13)0.97005 (10)0.0288 (3)
C131.0272 (2)0.73173 (13)0.97578 (10)0.0281 (3)
C140.8232 (2)0.70364 (12)0.90232 (10)0.0252 (3)
C150.49998 (19)0.48375 (11)0.73197 (9)0.0215 (3)
C160.7014 (2)0.41920 (12)0.69865 (9)0.0240 (3)
C170.7507 (2)0.29096 (12)0.71734 (10)0.0248 (3)
C180.6025 (2)0.22840 (12)0.77110 (9)0.0244 (3)
C190.4035 (2)0.29355 (13)0.80581 (10)0.0268 (3)
C200.3503 (2)0.42037 (12)0.78536 (10)0.0247 (3)
H20.361 (3)1.0290 (16)0.6039 (12)0.035 (4)*
H7−0.153 (3)0.6200 (16)0.5199 (12)0.035 (4)*
H8−0.267 (2)0.8096 (13)0.4535 (11)0.021 (3)*
H100.938 (2)0.9233 (14)0.7633 (11)0.026 (3)*
H111.287 (3)0.9694 (15)0.8870 (12)0.033 (4)*
H121.344 (3)0.8484 (16)1.0224 (12)0.036 (4)*
H131.048 (2)0.6786 (16)1.0312 (13)0.037 (4)*
H140.698 (3)0.6366 (16)0.9090 (12)0.033 (4)*
H160.807 (2)0.4646 (15)0.6621 (12)0.029 (3)*
H170.888 (2)0.2451 (14)0.6924 (11)0.023 (3)*
H180.640 (2)0.1387 (15)0.7834 (11)0.028 (3)*
H190.296 (2)0.2499 (15)0.8440 (12)0.033 (4)*
H200.210 (3)0.4660 (15)0.8084 (12)0.032 (4)*

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
N10.0212 (5)0.0209 (5)0.0245 (5)0.0010 (4)0.0015 (4)0.0073 (4)
N20.0241 (5)0.0195 (5)0.0240 (5)0.0010 (4)0.0019 (4)0.0070 (4)
C10.0227 (6)0.0196 (6)0.0205 (6)0.0010 (5)0.0037 (4)0.0052 (4)
C20.0228 (6)0.0193 (6)0.0258 (6)−0.0015 (5)0.0015 (4)0.0073 (5)
C30.0204 (6)0.0208 (6)0.0216 (6)0.0006 (5)0.0027 (4)0.0049 (4)
C40.0219 (6)0.0196 (5)0.0231 (6)0.0019 (4)0.0047 (4)0.0067 (4)
C50.0204 (5)0.0208 (6)0.0224 (6)0.0010 (4)0.0035 (4)0.0060 (4)
C60.0243 (6)0.0189 (5)0.0217 (6)0.0012 (5)0.0038 (4)0.0051 (4)
C70.0238 (6)0.0199 (6)0.0244 (6)−0.0024 (5)0.0005 (4)0.0053 (4)
C80.0224 (6)0.0217 (6)0.0227 (6)−0.0013 (5)0.0003 (4)0.0058 (4)
C90.0207 (6)0.0187 (5)0.0249 (6)0.0033 (4)0.0025 (4)0.0034 (4)
C100.0247 (6)0.0207 (6)0.0260 (6)0.0034 (5)0.0037 (5)0.0057 (5)
C110.0227 (6)0.0256 (6)0.0302 (7)−0.0002 (5)0.0041 (5)0.0036 (5)
C120.0224 (6)0.0343 (7)0.0261 (6)0.0014 (5)−0.0025 (5)0.0042 (5)
C130.0279 (6)0.0295 (6)0.0270 (6)0.0038 (5)0.0002 (5)0.0087 (5)
C140.0248 (6)0.0235 (6)0.0262 (6)0.0008 (5)0.0015 (5)0.0058 (5)
C150.0218 (6)0.0185 (5)0.0225 (6)−0.0011 (4)−0.0023 (4)0.0050 (4)
C160.0240 (6)0.0229 (6)0.0258 (6)0.0002 (5)0.0034 (5)0.0077 (5)
C170.0238 (6)0.0225 (6)0.0264 (6)0.0041 (5)0.0008 (5)0.0045 (5)
C180.0285 (6)0.0180 (5)0.0253 (6)0.0009 (5)−0.0048 (5)0.0069 (4)
C190.0260 (6)0.0259 (6)0.0310 (7)−0.0011 (5)0.0017 (5)0.0131 (5)
C200.0206 (6)0.0248 (6)0.0296 (6)0.0023 (5)0.0030 (5)0.0089 (5)

Geometric parameters (Å, °)

N1—C41.3245 (15)C10—H100.974 (14)
N1—C31.3613 (14)C11—C121.3880 (18)
N2—C51.3166 (15)C11—H110.966 (15)
N2—C61.3609 (15)C12—C131.3899 (18)
C1—C21.3819 (16)C12—H120.978 (15)
C1—C81.4301 (16)C13—C141.3870 (17)
C1—C1i1.488 (2)C13—H130.998 (15)
C2—C31.4141 (16)C14—H140.988 (15)
C2—H20.976 (15)C15—C161.3898 (17)
C3—C61.4129 (16)C15—C201.3936 (16)
C4—C51.4484 (16)C16—C171.3918 (16)
C4—C91.4900 (15)C16—H160.976 (14)
C5—C151.4955 (15)C17—C181.3865 (17)
C6—C71.4143 (16)C17—H170.962 (14)
C7—C81.3604 (16)C18—C191.3852 (18)
C7—H70.977 (15)C18—H180.973 (14)
C8—H80.986 (13)C19—C201.3922 (16)
C9—C141.3967 (17)C19—H190.990 (15)
C9—C101.4010 (16)C20—H200.971 (15)
C10—C111.3868 (17)
C4—N1—C3118.29 (10)C9—C10—H10118.5 (8)
C5—N2—C6117.97 (10)C12—C11—C10120.12 (11)
C2—C1—C8117.90 (10)C12—C11—H11120.4 (8)
C2—C1—C1i121.33 (13)C10—C11—H11119.4 (8)
C8—C1—C1i120.76 (12)C11—C12—C13119.59 (11)
C1—C2—C3121.34 (11)C11—C12—H12120.8 (9)
C1—C2—H2122.0 (8)C13—C12—H12119.6 (9)
C3—C2—H2116.6 (9)C14—C13—C12120.35 (11)
N1—C3—C6120.83 (10)C14—C13—H13118.8 (9)
N1—C3—C2119.57 (10)C12—C13—H13120.9 (9)
C6—C3—C2119.52 (10)C13—C14—C9120.67 (11)
N1—C4—C5120.22 (10)C13—C14—H14119.5 (8)
N1—C4—C9115.70 (10)C9—C14—H14119.8 (8)
C5—C4—C9124.07 (10)C16—C15—C20119.65 (10)
N2—C5—C4121.55 (10)C16—C15—C5120.82 (10)
N2—C5—C15114.09 (10)C20—C15—C5119.38 (10)
C4—C5—C15124.33 (10)C15—C16—C17119.93 (11)
N2—C6—C3120.68 (10)C15—C16—H16119.3 (8)
N2—C6—C7120.32 (10)C17—C16—H16120.8 (8)
C3—C6—C7118.99 (10)C18—C17—C16120.38 (11)
C8—C7—C6120.36 (11)C18—C17—H17119.8 (8)
C8—C7—H7121.6 (9)C16—C17—H17119.8 (8)
C6—C7—H7118.1 (9)C19—C18—C17119.78 (11)
C7—C8—C1121.85 (11)C19—C18—H18121.0 (8)
C7—C8—H8119.2 (7)C17—C18—H18119.2 (8)
C1—C8—H8119.0 (7)C18—C19—C20120.18 (11)
C14—C9—C10118.36 (11)C18—C19—H19120.6 (8)
C14—C9—C4123.20 (10)C20—C19—H19119.2 (8)
C10—C9—C4118.42 (10)C15—C20—C19120.05 (11)
C11—C10—C9120.85 (11)C15—C20—H20119.3 (8)
C11—C10—H10120.7 (8)C19—C20—H20120.7 (8)
C8—C1—C2—C3−1.34 (17)N1—C4—C9—C14152.27 (11)
C1i—C1—C2—C3178.88 (12)C5—C4—C9—C14−26.95 (17)
C4—N1—C3—C62.79 (16)N1—C4—C9—C10−25.98 (15)
C4—N1—C3—C2179.56 (10)C5—C4—C9—C10154.81 (11)
C1—C2—C3—N1−174.44 (10)C14—C9—C10—C112.26 (17)
C1—C2—C3—C62.37 (17)C4—C9—C10—C11−179.41 (10)
C3—N1—C4—C53.29 (16)C9—C10—C11—C12−0.35 (18)
C3—N1—C4—C9−175.95 (9)C10—C11—C12—C13−1.57 (19)
C6—N2—C5—C43.88 (16)C11—C12—C13—C141.55 (19)
C6—N2—C5—C15−174.05 (9)C12—C13—C14—C90.41 (18)
N1—C4—C5—N2−6.97 (17)C10—C9—C14—C13−2.28 (17)
C9—C4—C5—N2172.21 (10)C4—C9—C14—C13179.47 (10)
N1—C4—C5—C15170.75 (10)N2—C5—C15—C16115.78 (12)
C9—C4—C5—C15−10.07 (17)C4—C5—C15—C16−62.09 (15)
C5—N2—C6—C32.27 (16)N2—C5—C15—C20−59.79 (14)
C5—N2—C6—C7−178.84 (10)C4—C5—C15—C20122.33 (12)
N1—C3—C6—N2−5.86 (17)C20—C15—C16—C170.92 (17)
C2—C3—C6—N2177.37 (10)C5—C15—C16—C17−174.64 (10)
N1—C3—C6—C7175.23 (10)C15—C16—C17—C18−1.36 (18)
C2—C3—C6—C7−1.54 (16)C16—C17—C18—C190.39 (17)
N2—C6—C7—C8−179.17 (10)C17—C18—C19—C201.01 (18)
C3—C6—C7—C8−0.26 (17)C16—C15—C20—C190.46 (18)
C6—C7—C8—C11.31 (18)C5—C15—C20—C19176.09 (10)
C2—C1—C8—C7−0.51 (17)C18—C19—C20—C15−1.44 (18)
C1i—C1—C8—C7179.27 (13)

Symmetry codes: (i) −x, −y+2, −z+1.

Hydrogen-bond geometry (Å, °)

D—H···AD—HH···AD···AD—H···A
C2—H2···C18ii0.977 (15)2.722 (15)3.5521 (16)143.1 (12)
C7—H7···N2iii0.979 (15)2.593 (16)3.3635 (15)135.6 (11)
C10—H10···C3iv0.974 (13)2.935 (12)3.2994 (15)103.4 (8)
C10—H10···C6iv0.974 (13)2.974 (13)3.1801 (15)93.1 (8)
C11—H11···N1iv0.963 (15)2.893 (14)3.3233 (14)108.3 (10)
C12—H12···C18v0.975 (15)2.959 (15)3.6146 (16)125.6 (10)
C13—H13···C18v0.999 (15)2.978 (15)3.6141 (16)122.5 (10)
C16—H16···N2iv0.978 (14)2.815 (14)3.7256 (14)155.2 (11)
C17—H17···C1vi0.969 (13)2.993 (14)3.7019 (16)131.0 (9)
C17—H17···C8vi0.969 (13)2.860 (14)3.6338 (15)137.5 (9)
C18—H18···N1vii0.975 (14)2.808 (14)3.6217 (14)141.5 (10)

Symmetry codes: (ii) x, y+1, z; (iii) −x, −y+1, −z+1; (iv) x+1, y, z; (v) −x+2, −y+1, −z+2; (vi) −x+1, −y+1, −z+1; (vii) x, y−1, z.

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: GG2021).

References

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