2-(4-Fluoro­phen­yl)quinoxaline

Abstract

In the title compound, C₁₄H₉FN₂, the dihedral angle between the benzene ring and the quinoxaline ring system is 22.2 (3)°. Any aromatic π–π stacking in the crystal must be very weak, with a minimum centroid–centroid separation of 3.995 (2) Å.

Related literature  

For background to the applications of quinoxaline derivatives, see: Lindsley et al. (2005 ▶); Dailey et al. (2001 ▶).

Experimental  

Crystal data  

• C₁₄H₉FN₂

• M _r = 224.23

• Monoclinic,

• a = 24.249 (13) Å

• b = 3.7925 (19) Å

• c = 22.609 (13) Å

• β = 91.866 (9)°

• V = 2078.2 (19) ų

• Z = 8

• Mo Kα radiation

• μ = 0.10 mm⁻¹

• T = 113 K

• 0.20 × 0.18 × 0.10 mm

Data collection  

• Rigaku Saturn724 CCD diffractometer

• Absorption correction: multi-scan (CrystalClear; Rigaku, 2008 ▶) T _min = 0.981, T _max = 0.990

• 9711 measured reflections

• 2454 independent reflections

• 1797 reflections with I > 2σ(I)

• R _int = 0.032

Refinement  

• R[F ² > 2σ(F ²)] = 0.036

• wR(F ²) = 0.109

• S = 1.01

• 2454 reflections

• 154 parameters

• H-atom parameters constrained

• Δρ_max = 0.25 e Å⁻³

• Δρ_min = −0.22 e Å⁻³

Data collection: CrystalClear (Rigaku, 2008 ▶); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Supplementary material file. DOI: 10.1107/S1600536812017771/hb6725Isup3.cml

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

supplementary crystallographic information

Comment

Quinoxaline and its derivatives are an important class of nitrogen-containing heterocycles displaying both biologial activities (Lindsley et al., 2005) and technological applications (Dailey et al., 2001). Here, we report the synthesis and crystal structure of the title compound (Fig. 1).

In the title compound, C₁₄H₉FN₂, the dihedral angle between the benzene ring and the quinoxaline ring is 22.2 (3)°.

Experimental

A solution of benzene-1,2-diamine (1.5 mmol) and 2-(4-fluorophenyl)-2-oxoacetaldehyde monohydrate (1.5 mmol) in EtOH (10 ml) was stirred at room temperature for 0.5 h. After completion of the reaction (monitored by TLC or HPLC), the precipitated solid was collected by filtration and dried to afford the pure product. Or after completion of the reaction, water was added to the reaction mixture and filtered to afford the product. When necessary, the product was recrystallized from ethanol/water. Colourless prisms were grown by slow evaporation of a solution in chloroform/ethanol (1:1).

Refinement

H atoms were placed in calculated positions (C—H = 0.95 Å) and refined as riding with U_iso(H) = 1.2U_eq(C).

Figures

Fig. 1.

The molecular structure of the title compound, showing 30% probability displacement ellipsoids for the non-hydrogen atoms.

Crystal data

C14H9FN2	F(000) = 928
Mr = 224.23	Dx = 1.433 Mg m−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
a = 24.249 (13) Å	Cell parameters from 3509 reflections
b = 3.7925 (19) Å	θ = 1.7–27.9°
c = 22.609 (13) Å	µ = 0.10 mm−1
β = 91.866 (9)°	T = 113 K
V = 2078.2 (19) Å3	Prism, colorless
Z = 8	0.20 × 0.18 × 0.10 mm

Data collection

Rigaku Saturn724 CCD diffractometer	2454 independent reflections
Radiation source: rotating anode	1797 reflections with I > 2σ(I)
Multilayer monochromator	Rint = 0.032
Detector resolution: 14.22 pixels mm-1	θmax = 27.9°, θmin = 1.7°
ω and φ scans	h = −31→31
Absorption correction: multi-scan (CrystalClear; Rigaku, 2008)	k = −4→4
Tmin = 0.981, Tmax = 0.990	l = −29→29
9711 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)] = 0.036	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.109	H-atom parameters constrained
S = 1.01	w = 1/[σ2(Fo2) + (0.0692P)2] where P = (Fo2 + 2Fc2)/3
2454 reflections	(Δ/σ)max = 0.001
154 parameters	Δρmax = 0.25 e Å−3
0 restraints	Δρmin = −0.22 e Å−3

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 (Ų)

	x	y	z	Uiso*/Ueq
F1	0.46580 (3)	0.67692 (19)	1.18737 (3)	0.0321 (2)
N1	0.39311 (3)	0.1470 (2)	0.93164 (4)	0.0184 (2)
N2	0.28374 (3)	−0.1127 (2)	0.93193 (4)	0.0213 (2)
C1	0.36818 (4)	0.0119 (3)	0.88147 (4)	0.0182 (2)
C2	0.39774 (4)	−0.0011 (3)	0.82863 (5)	0.0216 (3)
H2	0.4347	0.0813	0.8283	0.026*
C3	0.37306 (5)	−0.1322 (3)	0.77801 (5)	0.0238 (3)
H3	0.3931	−0.1408	0.7426	0.029*
C4	0.31805 (5)	−0.2552 (3)	0.77785 (5)	0.0246 (3)
H4	0.3013	−0.3434	0.7423	0.030*
C5	0.28877 (4)	−0.2481 (3)	0.82842 (5)	0.0226 (3)
H5	0.2519	−0.3332	0.8280	0.027*
C6	0.31319 (4)	−0.1147 (3)	0.88123 (5)	0.0189 (2)
C7	0.30886 (4)	0.0153 (3)	0.97928 (5)	0.0205 (2)
H7	0.2895	0.0180	1.0152	0.025*
C8	0.36398 (4)	0.1514 (3)	0.97994 (5)	0.0175 (2)
C9	0.38994 (4)	0.2927 (3)	1.03511 (4)	0.0173 (2)
C10	0.35866 (4)	0.4178 (3)	1.08148 (5)	0.0204 (3)
H10	0.3195	0.4132	1.0779	0.025*
C11	0.38416 (5)	0.5485 (3)	1.13269 (5)	0.0217 (3)
H11	0.3630	0.6352	1.1642	0.026*
C12	0.44101 (5)	0.5499 (3)	1.13683 (5)	0.0217 (3)
C13	0.47352 (4)	0.4309 (3)	1.09221 (5)	0.0220 (3)
H13	0.5126	0.4356	1.0963	0.026*
C14	0.44741 (4)	0.3042 (3)	1.04120 (5)	0.0193 (2)
H14	0.4690	0.2235	1.0096	0.023*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
F1	0.0308 (4)	0.0440 (5)	0.0213 (4)	−0.0068 (3)	−0.0033 (3)	−0.0063 (3)
N1	0.0176 (4)	0.0186 (5)	0.0190 (4)	−0.0001 (4)	0.0009 (3)	0.0012 (4)
N2	0.0164 (4)	0.0220 (5)	0.0256 (5)	−0.0004 (4)	0.0011 (4)	0.0017 (4)
C1	0.0184 (5)	0.0157 (5)	0.0204 (5)	0.0005 (4)	−0.0014 (4)	0.0015 (4)
C2	0.0208 (5)	0.0212 (6)	0.0228 (6)	−0.0016 (4)	0.0017 (4)	0.0009 (4)
C3	0.0282 (6)	0.0227 (6)	0.0206 (5)	0.0005 (5)	0.0023 (4)	0.0004 (5)
C4	0.0279 (6)	0.0225 (6)	0.0229 (6)	0.0010 (5)	−0.0066 (4)	−0.0017 (5)
C5	0.0183 (5)	0.0208 (6)	0.0284 (6)	0.0000 (4)	−0.0045 (5)	−0.0002 (5)
C6	0.0180 (5)	0.0152 (5)	0.0233 (5)	0.0018 (4)	−0.0011 (4)	0.0023 (4)
C7	0.0164 (5)	0.0225 (6)	0.0226 (5)	−0.0002 (4)	0.0021 (4)	0.0026 (4)
C8	0.0156 (5)	0.0161 (6)	0.0207 (5)	0.0020 (4)	0.0002 (4)	0.0031 (4)
C9	0.0177 (5)	0.0159 (5)	0.0182 (5)	−0.0010 (4)	0.0007 (4)	0.0034 (4)
C10	0.0163 (5)	0.0224 (6)	0.0227 (5)	0.0008 (4)	0.0022 (4)	0.0032 (4)
C11	0.0245 (5)	0.0228 (6)	0.0183 (5)	0.0011 (5)	0.0050 (4)	0.0013 (4)
C12	0.0260 (5)	0.0221 (6)	0.0169 (5)	−0.0035 (4)	−0.0024 (4)	0.0007 (4)
C13	0.0176 (5)	0.0247 (6)	0.0235 (5)	−0.0008 (4)	−0.0010 (4)	0.0018 (5)
C14	0.0176 (5)	0.0196 (6)	0.0208 (5)	0.0007 (4)	0.0027 (4)	0.0012 (4)

Geometric parameters (Å, º)

F1—C12	1.3617 (13)	C5—H5	0.9500
N1—C8	1.3198 (14)	C7—C8	1.4325 (15)
N1—C1	1.3676 (14)	C7—H7	0.9500
N2—C7	1.3078 (15)	C8—C9	1.4792 (16)
N2—C6	1.3703 (14)	C9—C14	1.3966 (15)
C1—C2	1.4138 (16)	C9—C10	1.3969 (15)
C1—C6	1.4171 (16)	C10—C11	1.3864 (16)
C2—C3	1.3676 (16)	C10—H10	0.9500
C2—H2	0.9500	C11—C12	1.3787 (17)
C3—C4	1.4131 (17)	C11—H11	0.9500
C3—H3	0.9500	C12—C13	1.3764 (16)
C4—C5	1.3656 (16)	C13—C14	1.3835 (15)
C4—H4	0.9500	C13—H13	0.9500
C5—C6	1.4095 (16)	C14—H14	0.9500
C8—N1—C1	117.21 (9)	C8—C7—H7	118.3
C7—N2—C6	116.44 (10)	N1—C8—C7	120.74 (10)
N1—C1—C2	119.44 (10)	N1—C8—C9	118.54 (10)
N1—C1—C6	121.36 (10)	C7—C8—C9	120.71 (9)
C2—C1—C6	119.20 (10)	C14—C9—C10	118.67 (10)
C3—C2—C1	119.98 (11)	C14—C9—C8	119.37 (9)
C3—C2—H2	120.0	C10—C9—C8	121.96 (10)
C1—C2—H2	120.0	C11—C10—C9	120.66 (10)
C2—C3—C4	120.63 (10)	C11—C10—H10	119.7
C2—C3—H3	119.7	C9—C10—H10	119.7
C4—C3—H3	119.7	C12—C11—C10	118.41 (10)
C5—C4—C3	120.52 (10)	C12—C11—H11	120.8
C5—C4—H4	119.7	C10—C11—H11	120.8
C3—C4—H4	119.7	F1—C12—C13	118.89 (10)
C4—C5—C6	120.05 (10)	F1—C12—C11	118.13 (10)
C4—C5—H5	120.0	C13—C12—C11	122.98 (10)
C6—C5—H5	120.0	C12—C13—C14	117.86 (10)
N2—C6—C5	119.65 (10)	C12—C13—H13	121.1
N2—C6—C1	120.73 (10)	C14—C13—H13	121.1
C5—C6—C1	119.61 (10)	C13—C14—C9	121.40 (10)
N2—C7—C8	123.50 (10)	C13—C14—H14	119.3
N2—C7—H7	118.3	C9—C14—H14	119.3
C8—N1—C1—C2	−179.57 (9)	C1—N1—C8—C9	179.40 (9)
C8—N1—C1—C6	0.65 (15)	N2—C7—C8—N1	−1.44 (17)
N1—C1—C2—C3	−179.32 (10)	N2—C7—C8—C9	179.95 (10)
C6—C1—C2—C3	0.47 (16)	N1—C8—C9—C14	−21.66 (15)
C1—C2—C3—C4	0.10 (17)	C7—C8—C9—C14	156.99 (10)
C2—C3—C4—C5	−0.63 (17)	N1—C8—C9—C10	157.91 (10)
C3—C4—C5—C6	0.56 (17)	C7—C8—C9—C10	−23.44 (16)
C7—N2—C6—C5	−179.90 (10)	C14—C9—C10—C11	−0.46 (16)
C7—N2—C6—C1	0.90 (15)	C8—C9—C10—C11	179.97 (10)
C4—C5—C6—N2	−179.19 (10)	C9—C10—C11—C12	−0.40 (16)
C4—C5—C6—C1	0.02 (16)	C10—C11—C12—F1	−179.66 (10)
N1—C1—C6—N2	−1.55 (16)	C10—C11—C12—C13	0.72 (17)
C2—C1—C6—N2	178.67 (9)	F1—C12—C13—C14	−179.76 (9)
N1—C1—C6—C5	179.25 (9)	C11—C12—C13—C14	−0.15 (18)
C2—C1—C6—C5	−0.53 (15)	C12—C13—C14—C9	−0.76 (16)
C6—N2—C7—C8	0.53 (16)	C10—C9—C14—C13	1.06 (16)
C1—N1—C8—C7	0.76 (15)	C8—C9—C14—C13	−179.36 (9)