2,3-Bis(thio­phen-3-yl)quinoxaline

Abstract

In the title compound, C₁₆H₁₀N₂S₂, the thienyl rings are inclined to one another by 62.71 (10)°, and are inclined by 63.94 (8) and 21.35 (8)° to the quinoline mean plane [maximum deviation = 0.031 (2) Å]. In the crystal, the mol­ecules pack in a herringbone pattern, with π–π stacking inter­actions [centroid–centroid distances = 3.7381 (15) and 3.7268 (15) Å].

Related literature  

For the synthesis of the title compound, and the crystal structure of the 2,3-di(thio­phen-2-yl)quinoxaline analogue, see: Crundwell et al. (2003 ▶). For the structure of a similar compound, see: Cantalupo et al. (2010 ▶).

Experimental  

Crystal data  

• C₁₆H₁₀N₂S₂

• M _r = 294.38

• Monoclinic,

• a = 15.966 (2) Å

• b = 5.5741 (15) Å

• c = 15.629 (4) Å

• β = 98.25 (2)°

• V = 1376.5 (6) ų

• Z = 4

• Mo Kα radiation

• μ = 0.38 mm⁻¹

• T = 293 K

• 0.45 × 0.44 × 0.39 mm

Data collection  

• Oxford Diffraction Xcalibur Sapphire3 diffractometer

• Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2009 ▶) T _min = 0.731, T _max = 1.000

• 30279 measured reflections

• 4745 independent reflections

• 2660 reflections with I > 2σ(I)

• R _int = 0.087

Refinement  

• R[F ² > 2σ(F ²)] = 0.057

• wR(F ²) = 0.183

• S = 0.92

• 4745 reflections

• 181 parameters

• H-atom parameters constrained

• Δρ_max = 0.44 e Å⁻³

• Δρ_min = −0.50 e Å⁻³

Data collection: CrysAlis CCD (Oxford Diffraction, 2009 ▶); cell refinement: 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 ▶).

Supplementary Material

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

supplementary crystallographic information

Comment

In the title compound, Fig. 1, the quinoxaline moiety is flat, with a dihedral angle involving rings N1/N2/C1-C3/C8 and C3-C8 of 1.71 (9) °, and the two thienyl rings, S1/C9-C12 and S2/C13-C16, are inclined to the quinoxaline mean plane by 63.94 (8) and 21.35 (8) °, respectively. All bond lengths and angles fall within the typical ranges found in similar compounds (Cantalupo et al., 2010; Crundwell et al., 2003).

In the crystal, molecules pack in a herringbone pattern with π···π intermolecular contacts of 3.7381 (15) and 3.7268 (15) Å, for Cg1···Cg1ⁱ and Cg2···Cg3ⁱⁱ, respectively [where Cg1 is ring S1/C9-C12; Cg2 is ring S2/C13-C16; Cg3 is ring N1/N2/C1-C3/C8; symmetry codes: (i) -x+1, -y+1, -z; (ii) x, y+1, z].

Experimental

The title compound was prepared and purified according to literature methods (Crundwell et al., 2003). Equal mole amounts of o-phenylenediamine (1.62 g, 15.0 mmol) and 3,3'-thenil (3.33 g, 15.0 mmol) were dissolved in 95% ethanol and heated in an Erlenmeyer flask in a hot water bath. Recrystallization of the crude product from boiling ethanol sufficiently purified the quinoxaline product as a pale white solid (3.71 g, 12.6 mmol; 84% yield; M.p. 403 K). Spectroscopic data for the title compound are available in the archived CIF.

Refinement

Hydrogen atoms were included in calculated positions and included in the refinement in the riding motion approximation: C-H = 0.93 Å with U_iso = 1.2U_eq(C).

Figures

Fig. 1.

A view of the molecular structure of the title compound, with atom labelling. Displacement ellipsoids are drawn at the 50% probability level.

Crystal data

C16H10N2S2	F(000) = 608
Mr = 294.38	Dx = 1.420 Mg m−3
Monoclinic, P21/c	Melting point: 406 K
Hall symbol: -P 2ybc	Mo Kα radiation, λ = 0.71073 Å
a = 15.966 (2) Å	Cell parameters from 3293 reflections
b = 5.5741 (15) Å	θ = 4.1–33.0°
c = 15.629 (4) Å	µ = 0.38 mm−1
β = 98.25 (2)°	T = 293 K
V = 1376.5 (6) Å3	Block, white
Z = 4	0.45 × 0.44 × 0.39 mm

Data collection

Oxford Diffraction Xcalibur Sapphire3 diffractometer	4745 independent reflections
Radiation source: fine-focus sealed tube	2660 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.087
Detector resolution: 16.1790 pixels mm-1	θmax = 32.5°, θmin = 4.2°
ω scans	h = −23→23
Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2009)	k = −8→8
Tmin = 0.731, Tmax = 1.000	l = −23→23
30279 measured reflections

Refinement

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)] = 0.057	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.183	H-atom parameters constrained
S = 0.92	w = 1/[σ2(Fo2) + (0.1124P)2] where P = (Fo2 + 2Fc2)/3
4745 reflections	(Δ/σ)max = 0.001
181 parameters	Δρmax = 0.44 e Å−3
0 restraints	Δρmin = −0.50 e Å−3

Special details

Experimental. Spectroscopic data for the title compound: 1H NMR (300 MHz, (CD3)2CO) d 8.088 (m, 1H), 7.840 (m, 1H), 7.678 (dd, 1H),7.539 (dd, 1H), 7.331 (dd, 1H); 13C NMR (300 MHz,CDCl3) d 148.81, 140.86, 140.51, 129.88, 128.90, 128.60, 127.02, 125.50.

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 (Ų)

	x	y	z	Uiso*/Ueq
N1	0.29116 (9)	0.2491 (3)	−0.02718 (9)	0.0397 (3)
C1	0.29649 (11)	0.4316 (3)	0.02698 (11)	0.0360 (4)
C2	0.22246 (11)	0.5650 (3)	0.04216 (11)	0.0373 (4)
N2	0.14724 (10)	0.5169 (3)	−0.00197 (10)	0.0423 (4)
C3	0.14154 (11)	0.3343 (4)	−0.06015 (11)	0.0406 (4)
C4	0.06234 (12)	0.2759 (4)	−0.10817 (13)	0.0531 (5)
H4	0.0146	0.3653	−0.1010	0.064*
C5	0.05559 (14)	0.0887 (4)	−0.16501 (14)	0.0586 (6)
H5	0.0034	0.0525	−0.1970	0.070*
C6	0.12757 (15)	−0.0510 (4)	−0.17559 (14)	0.0543 (5)
H6	0.1222	−0.1786	−0.2143	0.065*
C7	0.20477 (13)	0.0005 (4)	−0.12934 (13)	0.0466 (5)
H7	0.2516	−0.0929	−0.1361	0.056*
C8	0.21308 (11)	0.1952 (3)	−0.07156 (11)	0.0391 (4)
C9	0.43076 (12)	0.3380 (4)	0.12458 (12)	0.0478 (5)
H9	0.4125	0.1877	0.1400	0.057*
C10	0.38308 (11)	0.4901 (3)	0.07058 (11)	0.0367 (4)
C11	0.42746 (12)	0.7043 (4)	0.05750 (12)	0.0469 (5)
H11	0.4048	0.8291	0.0220	0.056*
C12	0.50766 (12)	0.7072 (4)	0.10303 (14)	0.0535 (5)
H12	0.5458	0.8328	0.1019	0.064*
S1	0.52814 (3)	0.45345 (12)	0.16120 (4)	0.0617 (2)
C13	0.28349 (12)	0.7946 (4)	0.17905 (12)	0.0453 (4)
H13	0.3306	0.6973	0.1940	0.054*
C14	0.22447 (11)	0.7587 (3)	0.10719 (11)	0.0387 (4)
C15	0.15839 (13)	0.9348 (4)	0.10173 (13)	0.0459 (5)
H15	0.1122	0.9381	0.0581	0.055*
C16	0.17121 (12)	1.1020 (4)	0.16974 (13)	0.0439 (4)
H16	0.1355	1.2304	0.1765	0.053*
S2	0.26067 (4)	1.03661 (12)	0.23738 (4)	0.0598 (2)

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
N1	0.0331 (7)	0.0495 (9)	0.0355 (7)	−0.0031 (6)	0.0019 (6)	−0.0029 (7)
C1	0.0306 (8)	0.0450 (10)	0.0321 (8)	−0.0010 (7)	0.0028 (6)	0.0029 (7)
C2	0.0324 (8)	0.0463 (11)	0.0324 (8)	−0.0016 (7)	0.0020 (6)	0.0040 (7)
N2	0.0338 (8)	0.0528 (10)	0.0387 (8)	−0.0007 (6)	0.0000 (6)	0.0033 (7)
C3	0.0352 (9)	0.0495 (11)	0.0353 (8)	−0.0035 (8)	−0.0007 (7)	0.0041 (8)
C4	0.0373 (10)	0.0663 (14)	0.0523 (11)	−0.0016 (9)	−0.0054 (8)	−0.0031 (10)
C5	0.0437 (11)	0.0759 (16)	0.0515 (12)	−0.0120 (10)	−0.0088 (9)	−0.0036 (11)
C6	0.0559 (12)	0.0628 (14)	0.0414 (10)	−0.0125 (10)	−0.0028 (9)	−0.0093 (10)
C7	0.0445 (10)	0.0530 (12)	0.0418 (10)	−0.0057 (8)	0.0043 (8)	−0.0053 (8)
C8	0.0346 (8)	0.0497 (11)	0.0322 (8)	−0.0066 (7)	0.0019 (6)	0.0027 (8)
C9	0.0388 (10)	0.0525 (12)	0.0490 (11)	−0.0023 (8)	−0.0045 (8)	0.0020 (9)
C10	0.0306 (8)	0.0470 (10)	0.0322 (8)	−0.0010 (7)	0.0030 (6)	−0.0044 (7)
C11	0.0424 (10)	0.0518 (12)	0.0461 (10)	−0.0055 (8)	0.0049 (8)	0.0037 (9)
C12	0.0373 (10)	0.0597 (13)	0.0635 (13)	−0.0132 (9)	0.0076 (9)	−0.0124 (11)
S1	0.0398 (3)	0.0779 (5)	0.0612 (4)	0.0005 (2)	−0.0134 (2)	−0.0057 (3)
C13	0.0437 (10)	0.0523 (11)	0.0398 (9)	0.0014 (9)	0.0052 (7)	−0.0036 (9)
C14	0.0358 (8)	0.0446 (10)	0.0368 (8)	−0.0011 (7)	0.0092 (7)	0.0008 (7)
C15	0.0408 (10)	0.0519 (12)	0.0462 (10)	0.0024 (8)	0.0104 (8)	0.0049 (9)
C16	0.0397 (9)	0.0428 (10)	0.0518 (11)	0.0044 (8)	0.0154 (8)	0.0022 (8)
S2	0.0572 (4)	0.0705 (4)	0.0532 (3)	−0.0039 (3)	0.0130 (3)	−0.0152 (3)

Geometric parameters (Å, º)

N1—C1	1.318 (2)	C9—C10	1.351 (3)
N1—C8	1.370 (2)	C9—S1	1.7040 (19)
C1—C2	1.445 (2)	C9—H9	0.9300
C1—C10	1.487 (2)	C10—C11	1.418 (3)
C2—N2	1.324 (2)	C11—C12	1.373 (3)
C2—C14	1.480 (2)	C11—H11	0.9300
N2—C3	1.359 (2)	C12—S1	1.688 (2)
C3—C8	1.413 (3)	C12—H12	0.9300
C3—C4	1.413 (2)	C13—C14	1.373 (2)
C4—C5	1.365 (3)	C13—S2	1.697 (2)
C4—H4	0.9300	C13—H13	0.9300
C5—C6	1.417 (3)	C14—C15	1.435 (3)
C5—H5	0.9300	C15—C16	1.406 (3)
C6—C7	1.367 (3)	C15—H15	0.9300
C6—H6	0.9300	C16—S2	1.690 (2)
C7—C8	1.406 (3)	C16—H16	0.9300
C7—H7	0.9300
C1—N1—C8	117.70 (15)	C10—C9—S1	112.20 (16)
N1—C1—C2	121.58 (16)	C10—C9—H9	123.9
N1—C1—C10	115.70 (15)	S1—C9—H9	123.9
C2—C1—C10	122.72 (16)	C9—C10—C11	111.71 (17)
N2—C2—C1	120.83 (17)	C9—C10—C1	123.50 (17)
N2—C2—C14	115.76 (16)	C11—C10—C1	124.71 (16)
C1—C2—C14	123.41 (15)	C12—C11—C10	112.53 (18)
C2—N2—C3	117.98 (16)	C12—C11—H11	123.7
N2—C3—C8	121.18 (16)	C10—C11—H11	123.7
N2—C3—C4	119.79 (17)	C11—C12—S1	111.33 (16)
C8—C3—C4	118.99 (18)	C11—C12—H12	124.3
C5—C4—C3	120.2 (2)	S1—C12—H12	124.3
C5—C4—H4	119.9	C12—S1—C9	92.21 (10)
C3—C4—H4	119.9	C14—C13—S2	112.35 (15)
C4—C5—C6	120.42 (19)	C14—C13—H13	123.8
C4—C5—H5	119.8	S2—C13—H13	123.8
C6—C5—H5	119.8	C13—C14—C15	111.18 (18)
C7—C6—C5	120.5 (2)	C13—C14—C2	127.79 (17)
C7—C6—H6	119.7	C15—C14—C2	121.00 (17)
C5—C6—H6	119.7	C16—C15—C14	112.50 (18)
C6—C7—C8	119.8 (2)	C16—C15—H15	123.8
C6—C7—H7	120.1	C14—C15—H15	123.8
C8—C7—H7	120.1	C15—C16—S2	110.37 (15)
N1—C8—C7	119.34 (17)	C15—C16—H16	124.8
N1—C8—C3	120.58 (17)	S2—C16—H16	124.8
C7—C8—C3	120.08 (16)	C16—S2—C13	93.60 (10)