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

Dueno, E.E.; Gibson, R.J.P.; Salvatore, R.N.; Pike, R.D.; Zambrano, C.H.

doi:10.1107/S1600536807033521

organic compounds

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ISSN: 2056-9890

Volume 64| Part 1| January 2008| Pages o110-o111

https://doi.org/10.1107/S1600536807033521

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

Eric E. Dueno,^a ^* Ricky Joseph Paul Gibson,^a Ralph Nicholas Salvatore,^a Robert D. Pike ^b and Cesar H. Zambrano ^c

^aDepartment of Chemistry, Eastern Kentucky University, 521 Lancaster Avenue, Richmond, KY 40475, USA, ^bDepartment of Chemistry, The College of William and Mary, PO Box 8795, Williamsburg, VA 23187-8795, USA, and ^cDepartamento de Quimica, Universidad San Francisco de Quito, Pampite & Robles - Cumbaya, Quito, Ecuador
^*Correspondence e-mail: eric.dueno@eku.edu

(Received 29 June 2007; accepted 9 July 2007; online 6 December 2007)

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

Experimental

Crystal data

C₄₀H₂₆N₄
M_r = 562.65
Triclinic, $[P \overline 1]$
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 ) 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[F² > 2σ(F²)] = 0.033
wR(F²) = 0.091
S = 1.06
2429 reflections
251 parameters
All H-atom parameters refined
Δρ_max = 0.23 e Å⁻³
Δρ_min = −0.18 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C2—H2⋯C18ⁱ	0.977 (15)	2.722 (15)	3.5521 (16)	143.1 (12)
C7—H7⋯N2ⁱⁱ	0.979 (15)	2.593 (16)	3.3635 (15)	135.6 (11)
C10—H10⋯C3ⁱⁱⁱ	0.974 (13)	2.935 (12)	3.2994 (15)	103.4 (8)
C10—H10⋯C6ⁱⁱⁱ	0.974 (13)	2.974 (13)	3.1801 (15)	93.1 (8)
C11—H11⋯N1ⁱⁱⁱ	0.963 (15)	2.893 (14)	3.3233 (14)	108.3 (10)
C12—H12⋯C18^iv	0.975 (15)	2.959 (15)	3.6146 (16)	125.6 (10)
C13—H13⋯C18^iv	0.999 (15)	2.978 (15)	3.6141 (16)	122.5 (10)
C16—H16⋯N2ⁱⁱⁱ	0.978 (14)	2.815 (14)	3.7256 (14)	155.2 (11)
C17—H17⋯C1^v	0.969 (13)	2.993 (14)	3.7019 (16)	131.0 (9)
C17—H17⋯C8^v	0.969 (13)	2.860 (14)	3.6338 (15)	137.5 (9)
C18—H18⋯N1^vi	0.975 (14)	2.808 (14)	3.6217 (14)	141.5 (10)
Symmetry codes: (i) x, y+1, z; (ii) -x, -y+1, -z+1; (iii) x+1, y, z; (iv) -x+2, -y+1, -z+2; (v) -x+1, -y+1, -z+1; (vi) x, y-1, z.

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

Supporting information

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

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536807033521/gg2021Isup2.hkl

checkCIF report

Comment top

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).

Related literature top

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

Experimental top

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.

Structure description top

no drafts

Computing details top

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

Figures top

	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.

2,2,3,3'-Tetraphenyl-7,7'-biquinoxaline top

Crystal data top

C₄₀H₂₆N₄	Z = 1
M_r = 562.65	F(000) = 294
Triclinic, P1	D_x = 1.327 Mg m⁻³
Hall symbol: -P 1	Cu Kα radiation, λ = 1.54178 Å
a = 5.7024 (1) Å	Cell parameters from 585 reflections
b = 9.9534 (2) Å	θ = 3.6–67.0°
c = 12.9785 (3) Å	µ = 0.61 mm⁻¹
α = 105.352 (1)°	T = 100 K
β = 96.617 (1)°	Block, colourless
γ = 91.751 (1)°	0.19 × 0.12 × 0.06 mm
V = 704.19 (3) Å³

Data collection top

Bruker SMART APEXII CCD diffractometer	2429 independent reflections
Radiation source: fine-focus sealed tube	2156 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.033
ω and ψ scans	θ_max = 67.0°, θ_min = 3.6°
Absorption correction: numerical (SADABS; Sheldrick, 2004)	h = −6→6
T_min = 0.893, T_max = 0.964	k = −11→11
12179 measured reflections	l = −15→15

Refinement top

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)] = 0.033	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.091	All H-atom parameters refined
S = 1.06	w = 1/[σ²(F_o²) + (0.0496P)² + 0.1323P] where P = (F_o² + 2F_c²)/3
2429 reflections	(Δ/σ)_max < 0.001
251 parameters	Δρ_max = 0.23 e Å⁻³
0 restraints	Δρ_min = −0.18 e Å⁻³

Crystal data top

C₄₀H₂₆N₄	γ = 91.751 (1)°
M_r = 562.65	V = 704.19 (3) Å³
Triclinic, P1	Z = 1
a = 5.7024 (1) Å	Cu Kα radiation
b = 9.9534 (2) Å	µ = 0.61 mm⁻¹
c = 12.9785 (3) Å	T = 100 K
α = 105.352 (1)°	0.19 × 0.12 × 0.06 mm
β = 96.617 (1)°

Data collection top

Bruker SMART APEXII CCD diffractometer	2429 independent reflections
Absorption correction: numerical (SADABS; Sheldrick, 2004)	2156 reflections with I > 2σ(I)
T_min = 0.893, T_max = 0.964	R_int = 0.033
12179 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.033	0 restraints
wR(F²) = 0.091	All H-atom parameters refined
S = 1.06	Δρ_max = 0.23 e Å⁻³
2429 reflections	Δρ_min = −0.18 e Å⁻³
251 parameters

Special details top

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) top

	x	y	z	U_iso*/U_eq
N1	0.51854 (16)	0.85128 (10)	0.69940 (8)	0.0221 (2)
N2	0.23046 (17)	0.60236 (10)	0.64109 (8)	0.0224 (2)
C1	0.03603 (19)	0.94087 (11)	0.52202 (9)	0.0209 (3)
C2	0.2496 (2)	0.94755 (12)	0.58600 (9)	0.0226 (3)
C3	0.31629 (19)	0.83612 (11)	0.62942 (9)	0.0211 (3)
C4	0.57593 (19)	0.74558 (12)	0.73939 (9)	0.0212 (3)
C5	0.43238 (19)	0.61520 (12)	0.70434 (9)	0.0211 (3)
C6	0.1661 (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)
C9	0.79004 (19)	0.77207 (11)	0.82117 (9)	0.0219 (3)
C10	0.9637 (2)	0.87320 (12)	0.81830 (10)	0.0239 (3)
C11	1.1675 (2)	0.90121 (13)	0.89186 (10)	0.0269 (3)
C12	1.2013 (2)	0.82934 (13)	0.97005 (10)	0.0288 (3)
C13	1.0272 (2)	0.73173 (13)	0.97578 (10)	0.0281 (3)
C14	0.8232 (2)	0.70364 (12)	0.90232 (10)	0.0252 (3)
C15	0.49998 (19)	0.48375 (11)	0.73197 (9)	0.0215 (3)
C16	0.7014 (2)	0.41920 (12)	0.69865 (9)	0.0240 (3)
C17	0.7507 (2)	0.29096 (12)	0.71734 (10)	0.0248 (3)
C18	0.6025 (2)	0.22840 (12)	0.77110 (9)	0.0244 (3)
C19	0.4035 (2)	0.29355 (13)	0.80581 (10)	0.0268 (3)
C20	0.3503 (2)	0.42037 (12)	0.78536 (10)	0.0247 (3)
H2	0.361 (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)*
H10	0.938 (2)	0.9233 (14)	0.7633 (11)	0.026 (3)*
H11	1.287 (3)	0.9694 (15)	0.8870 (12)	0.033 (4)*
H12	1.344 (3)	0.8484 (16)	1.0224 (12)	0.036 (4)*
H13	1.048 (2)	0.6786 (16)	1.0312 (13)	0.037 (4)*
H14	0.698 (3)	0.6366 (16)	0.9090 (12)	0.033 (4)*
H16	0.807 (2)	0.4646 (15)	0.6621 (12)	0.029 (3)*
H17	0.888 (2)	0.2451 (14)	0.6924 (11)	0.023 (3)*
H18	0.640 (2)	0.1387 (15)	0.7834 (11)	0.028 (3)*
H19	0.296 (2)	0.2499 (15)	0.8440 (12)	0.033 (4)*
H20	0.210 (3)	0.4660 (15)	0.8084 (12)	0.032 (4)*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
N1	0.0212 (5)	0.0209 (5)	0.0245 (5)	0.0010 (4)	0.0015 (4)	0.0073 (4)
N2	0.0241 (5)	0.0195 (5)	0.0240 (5)	0.0010 (4)	0.0019 (4)	0.0070 (4)
C1	0.0227 (6)	0.0196 (6)	0.0205 (6)	0.0010 (5)	0.0037 (4)	0.0052 (4)
C2	0.0228 (6)	0.0193 (6)	0.0258 (6)	−0.0015 (5)	0.0015 (4)	0.0073 (5)
C3	0.0204 (6)	0.0208 (6)	0.0216 (6)	0.0006 (5)	0.0027 (4)	0.0049 (4)
C4	0.0219 (6)	0.0196 (5)	0.0231 (6)	0.0019 (4)	0.0047 (4)	0.0067 (4)
C5	0.0204 (5)	0.0208 (6)	0.0224 (6)	0.0010 (4)	0.0035 (4)	0.0060 (4)
C6	0.0243 (6)	0.0189 (5)	0.0217 (6)	0.0012 (5)	0.0038 (4)	0.0051 (4)
C7	0.0238 (6)	0.0199 (6)	0.0244 (6)	−0.0024 (5)	0.0005 (4)	0.0053 (4)
C8	0.0224 (6)	0.0217 (6)	0.0227 (6)	−0.0013 (5)	0.0003 (4)	0.0058 (4)
C9	0.0207 (6)	0.0187 (5)	0.0249 (6)	0.0033 (4)	0.0025 (4)	0.0034 (4)
C10	0.0247 (6)	0.0207 (6)	0.0260 (6)	0.0034 (5)	0.0037 (5)	0.0057 (5)
C11	0.0227 (6)	0.0256 (6)	0.0302 (7)	−0.0002 (5)	0.0041 (5)	0.0036 (5)
C12	0.0224 (6)	0.0343 (7)	0.0261 (6)	0.0014 (5)	−0.0025 (5)	0.0042 (5)
C13	0.0279 (6)	0.0295 (6)	0.0270 (6)	0.0038 (5)	0.0002 (5)	0.0087 (5)
C14	0.0248 (6)	0.0235 (6)	0.0262 (6)	0.0008 (5)	0.0015 (5)	0.0058 (5)
C15	0.0218 (6)	0.0185 (5)	0.0225 (6)	−0.0011 (4)	−0.0023 (4)	0.0050 (4)
C16	0.0240 (6)	0.0229 (6)	0.0258 (6)	0.0002 (5)	0.0034 (5)	0.0077 (5)
C17	0.0238 (6)	0.0225 (6)	0.0264 (6)	0.0041 (5)	0.0008 (5)	0.0045 (5)
C18	0.0285 (6)	0.0180 (5)	0.0253 (6)	0.0009 (5)	−0.0048 (5)	0.0069 (4)
C19	0.0260 (6)	0.0259 (6)	0.0310 (7)	−0.0011 (5)	0.0017 (5)	0.0131 (5)
C20	0.0206 (6)	0.0248 (6)	0.0296 (6)	0.0023 (5)	0.0030 (5)	0.0089 (5)

Geometric parameters (Å, º) top

N1—C4	1.3245 (15)	C10—H10	0.974 (14)
N1—C3	1.3613 (14)	C11—C12	1.3880 (18)
N2—C5	1.3166 (15)	C11—H11	0.966 (15)
N2—C6	1.3609 (15)	C12—C13	1.3899 (18)
C1—C2	1.3819 (16)	C12—H12	0.978 (15)
C1—C8	1.4301 (16)	C13—C14	1.3870 (17)
C1—C1ⁱ	1.488 (2)	C13—H13	0.998 (15)
C2—C3	1.4141 (16)	C14—H14	0.988 (15)
C2—H2	0.976 (15)	C15—C16	1.3898 (17)
C3—C6	1.4129 (16)	C15—C20	1.3936 (16)
C4—C5	1.4484 (16)	C16—C17	1.3918 (16)
C4—C9	1.4900 (15)	C16—H16	0.976 (14)
C5—C15	1.4955 (15)	C17—C18	1.3865 (17)
C6—C7	1.4143 (16)	C17—H17	0.962 (14)
C7—C8	1.3604 (16)	C18—C19	1.3852 (18)
C7—H7	0.977 (15)	C18—H18	0.973 (14)
C8—H8	0.986 (13)	C19—C20	1.3922 (16)
C9—C14	1.3967 (17)	C19—H19	0.990 (15)
C9—C10	1.4010 (16)	C20—H20	0.971 (15)
C10—C11	1.3868 (17)

C4—N1—C3	118.29 (10)	C9—C10—H10	118.5 (8)
C5—N2—C6	117.97 (10)	C12—C11—C10	120.12 (11)
C2—C1—C8	117.90 (10)	C12—C11—H11	120.4 (8)
C2—C1—C1ⁱ	121.33 (13)	C10—C11—H11	119.4 (8)
C8—C1—C1ⁱ	120.76 (12)	C11—C12—C13	119.59 (11)
C1—C2—C3	121.34 (11)	C11—C12—H12	120.8 (9)
C1—C2—H2	122.0 (8)	C13—C12—H12	119.6 (9)
C3—C2—H2	116.6 (9)	C14—C13—C12	120.35 (11)
N1—C3—C6	120.83 (10)	C14—C13—H13	118.8 (9)
N1—C3—C2	119.57 (10)	C12—C13—H13	120.9 (9)
C6—C3—C2	119.52 (10)	C13—C14—C9	120.67 (11)
N1—C4—C5	120.22 (10)	C13—C14—H14	119.5 (8)
N1—C4—C9	115.70 (10)	C9—C14—H14	119.8 (8)
C5—C4—C9	124.07 (10)	C16—C15—C20	119.65 (10)
N2—C5—C4	121.55 (10)	C16—C15—C5	120.82 (10)
N2—C5—C15	114.09 (10)	C20—C15—C5	119.38 (10)
C4—C5—C15	124.33 (10)	C15—C16—C17	119.93 (11)
N2—C6—C3	120.68 (10)	C15—C16—H16	119.3 (8)
N2—C6—C7	120.32 (10)	C17—C16—H16	120.8 (8)
C3—C6—C7	118.99 (10)	C18—C17—C16	120.38 (11)
C8—C7—C6	120.36 (11)	C18—C17—H17	119.8 (8)
C8—C7—H7	121.6 (9)	C16—C17—H17	119.8 (8)
C6—C7—H7	118.1 (9)	C19—C18—C17	119.78 (11)
C7—C8—C1	121.85 (11)	C19—C18—H18	121.0 (8)
C7—C8—H8	119.2 (7)	C17—C18—H18	119.2 (8)
C1—C8—H8	119.0 (7)	C18—C19—C20	120.18 (11)
C14—C9—C10	118.36 (11)	C18—C19—H19	120.6 (8)
C14—C9—C4	123.20 (10)	C20—C19—H19	119.2 (8)
C10—C9—C4	118.42 (10)	C15—C20—C19	120.05 (11)
C11—C10—C9	120.85 (11)	C15—C20—H20	119.3 (8)
C11—C10—H10	120.7 (8)	C19—C20—H20	120.7 (8)

C8—C1—C2—C3	−1.34 (17)	N1—C4—C9—C14	152.27 (11)
C1ⁱ—C1—C2—C3	178.88 (12)	C5—C4—C9—C14	−26.95 (17)
C4—N1—C3—C6	2.79 (16)	N1—C4—C9—C10	−25.98 (15)
C4—N1—C3—C2	179.56 (10)	C5—C4—C9—C10	154.81 (11)
C1—C2—C3—N1	−174.44 (10)	C14—C9—C10—C11	2.26 (17)
C1—C2—C3—C6	2.37 (17)	C4—C9—C10—C11	−179.41 (10)
C3—N1—C4—C5	3.29 (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—C4	3.88 (16)	C11—C12—C13—C14	1.55 (19)
C6—N2—C5—C15	−174.05 (9)	C12—C13—C14—C9	0.41 (18)
N1—C4—C5—N2	−6.97 (17)	C10—C9—C14—C13	−2.28 (17)
C9—C4—C5—N2	172.21 (10)	C4—C9—C14—C13	179.47 (10)
N1—C4—C5—C15	170.75 (10)	N2—C5—C15—C16	115.78 (12)
C9—C4—C5—C15	−10.07 (17)	C4—C5—C15—C16	−62.09 (15)
C5—N2—C6—C3	2.27 (16)	N2—C5—C15—C20	−59.79 (14)
C5—N2—C6—C7	−178.84 (10)	C4—C5—C15—C20	122.33 (12)
N1—C3—C6—N2	−5.86 (17)	C20—C15—C16—C17	0.92 (17)
C2—C3—C6—N2	177.37 (10)	C5—C15—C16—C17	−174.64 (10)
N1—C3—C6—C7	175.23 (10)	C15—C16—C17—C18	−1.36 (18)
C2—C3—C6—C7	−1.54 (16)	C16—C17—C18—C19	0.39 (17)
N2—C6—C7—C8	−179.17 (10)	C17—C18—C19—C20	1.01 (18)
C3—C6—C7—C8	−0.26 (17)	C16—C15—C20—C19	0.46 (18)
C6—C7—C8—C1	1.31 (18)	C5—C15—C20—C19	176.09 (10)
C2—C1—C8—C7	−0.51 (17)	C18—C19—C20—C15	−1.44 (18)
C1ⁱ—C1—C8—C7	179.27 (13)

Symmetry code: (i) −x, −y+2, −z+1.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C2—H2···C18ⁱⁱ	0.977 (15)	2.722 (15)	3.5521 (16)	143.1 (12)
C7—H7···N2ⁱⁱⁱ	0.979 (15)	2.593 (16)	3.3635 (15)	135.6 (11)
C10—H10···C3^iv	0.974 (13)	2.935 (12)	3.2994 (15)	103.4 (8)
C10—H10···C6^iv	0.974 (13)	2.974 (13)	3.1801 (15)	93.1 (8)
C11—H11···N1^iv	0.963 (15)	2.893 (14)	3.3233 (14)	108.3 (10)
C12—H12···C18^v	0.975 (15)	2.959 (15)	3.6146 (16)	125.6 (10)
C13—H13···C18^v	0.999 (15)	2.978 (15)	3.6141 (16)	122.5 (10)
C16—H16···N2^iv	0.978 (14)	2.815 (14)	3.7256 (14)	155.2 (11)
C17—H17···C1^vi	0.969 (13)	2.993 (14)	3.7019 (16)	131.0 (9)
C17—H17···C8^vi	0.969 (13)	2.860 (14)	3.6338 (15)	137.5 (9)
C18—H18···N1^vii	0.975 (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.

Experimental details

Crystal data
Chemical formula	C₄₀H₂₆N₄
M_r	562.65
Crystal system, space group	Triclinic, P1
Temperature (K)	100
a, b, c (Å)	5.7024 (1), 9.9534 (2), 12.9785 (3)
α, β, γ (°)	105.352 (1), 96.617 (1), 91.751 (1)
V (Å³)	704.19 (3)
Z	1
Radiation type	Cu Kα
µ (mm⁻¹)	0.61
Crystal size (mm)	0.19 × 0.12 × 0.06

Data collection
Diffractometer	Bruker SMART APEXII CCD
Absorption correction	Numerical (SADABS; Sheldrick, 2004)
T_min, T_max	0.893, 0.964
No. of measured, independent and observed [I > 2σ(I)] reflections	12179, 2429, 2156
R_int	0.033
(sin θ/λ)_max (Å⁻¹)	0.597

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.033, 0.091, 1.06
No. of reflections	2429
No. of parameters	251
H-atom treatment	All H-atom parameters refined
Δρ_max, Δρ_min (e Å⁻³)	0.23, −0.18

Computer programs: APEX2 (Bruker, 2004), SAINT-Plus (Bruker, 2004), SAINT-Plus, SHELXS97 (Sheldrick, 1997), XSHELL (Bruker, 2004), ORTEP-3 (Farrugia, 1997), SHELXL97 (Sheldrick, 1997).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C2—H2···C18ⁱ	0.977 (15)	2.722 (15)	3.5521 (16)	143.1 (12)
C7—H7···N2ⁱⁱ	0.979 (15)	2.593 (16)	3.3635 (15)	135.6 (11)
C10—H10···C3ⁱⁱⁱ	0.974 (13)	2.935 (12)	3.2994 (15)	103.4 (8)
C10—H10···C6ⁱⁱⁱ	0.974 (13)	2.974 (13)	3.1801 (15)	93.1 (8)
C11—H11···N1ⁱⁱⁱ	0.963 (15)	2.893 (14)	3.3233 (14)	108.3 (10)
C12—H12···C18^iv	0.975 (15)	2.959 (15)	3.6146 (16)	125.6 (10)
C13—H13···C18^iv	0.999 (15)	2.978 (15)	3.6141 (16)	122.5 (10)
C16—H16···N2ⁱⁱⁱ	0.978 (14)	2.815 (14)	3.7256 (14)	155.2 (11)
C17—H17···C1^v	0.969 (13)	2.993 (14)	3.7019 (16)	131.0 (9)
C17—H17···C8^v	0.969 (13)	2.860 (14)	3.6338 (15)	137.5 (9)
C18—H18···N1^vi	0.975 (14)	2.808 (14)	3.6217 (14)	141.5 (10)

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

Acknowledgements

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.

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