A second monoclinic modification of phenyl quinoxalin-2-yl ether

Abstract

The two aromatic systems in the title compound, C₁₄H₁₀N₂O, enclose a dihedral angle of 77.9 (1)°, and the C—O—C inter-ring bond angle is 117.6 (1)°.

Related literature

Another polymorph of this compound has recently been described in the C2/c space group; see Hassan et al. (2008 ▶).

Experimental

Crystal data

• C₁₄H₁₀N₂O

• M _r = 222.24

• Monoclinic,

• a = 7.9447 (2) Å

• b = 6.5169 (1) Å

• c = 20.2992 (5) Å

• β = 91.983 (1)°

• V = 1050.36 (4) ų

• Z = 4

• Mo Kα radiation

• μ = 0.09 mm⁻¹

• T = 100 (2) K

• 0.40 × 0.20 × 0.10 mm

Data collection

• Bruker SMART APEX diffractometer

• Absorption correction: none

• 7016 measured reflections

• 2398 independent reflections

• 1960 reflections with I > 2σ(I)

• R _int = 0.021

Refinement

• R[F ² > 2σ(F ²)] = 0.037

• wR(F ²) = 0.114

• S = 1.03

• 2398 reflections

• 154 parameters

• H-atom parameters constrained

• Δρ_max = 0.33 e Å⁻³

• Δρ_min = −0.23 e Å⁻³

Data collection: APEX2 (Bruker, 2007 ▶); cell refinement: SAINT (Bruker, 2007 ▶); data reduction: SAINT ; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: X-SEED (Barbour, 2001 ▶); software used to prepare material for publication: publCIF (Westrip, 2008 ▶).

Supplementary Material

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

supplementary crystallographic information

Comment

The compound was recently described in the C2/c space group with the two aromatic substituents in C₁₄H₁₀N₂O enclosing a dihedral angle of 63.8 (1)°. The bond angle at oxygen measures to 118.2 (1)° (Hassan et al., 2008). In the P2₁/n modification described herein (Scheme I, Fig. 1), the two aromatic systems show a dihedral angle of 77.9 (1)° and they subtend an angle of 117.6 (1)° at oxygen.

Experimental

The monoclinic modification was obtained when the C2/c modification of quinoxalinyl phenyl ether was recrystallized from ethanol in the presence of a small quantity of manganese acetate. Slow evaporation of the solvent gave colorless crystals mixed with unchanged manganese acetate.

Refinement

Carbon-bound H-atoms were placed in calculated positions (C—H 0.95 Å) and were included in the refinement in the riding model approximation, with U(H) fixed at 1.2U(C).

Figures

Fig. 1.

Thermal ellipsoid plot (Barbour, 2001) of C14H10N2O at the 70% probability level; hydrogen atoms are drawn as spheres of arbitrary radius.

Crystal data

C14H10N2O	F(000) = 464
Mr = 222.24	Dx = 1.405 Mg m−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 2712 reflections
a = 7.9447 (2) Å	θ = 2.7–28.4°
b = 6.5169 (1) Å	µ = 0.09 mm−1
c = 20.2992 (5) Å	T = 100 K
β = 91.983 (1)°	Block, colorless
V = 1050.36 (4) Å3	0.40 × 0.20 × 0.10 mm
Z = 4

Data collection

Bruker SMART APEX diffractometer	1960 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.021
graphite	θmax = 27.5°, θmin = 2.0°
ω scans	h = −10→9
7016 measured reflections	k = −8→8
2398 independent reflections	l = −26→26

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)] = 0.037	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.114	H-atom parameters constrained
S = 1.03	w = 1/[σ2(Fo2) + (0.0648P)2 + 0.2602P] where P = (Fo2 + 2Fc2)/3
2398 reflections	(Δ/σ)max = 0.001
154 parameters	Δρmax = 0.33 e Å−3
0 restraints	Δρmin = −0.23 e Å−3

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
O1	0.34884 (10)	0.24973 (13)	0.66577 (4)	0.0189 (2)
N1	0.58503 (12)	0.26591 (14)	0.60174 (5)	0.0150 (2)
N2	0.35723 (12)	0.23610 (14)	0.49088 (5)	0.0153 (2)
C1	0.45193 (13)	0.28653 (19)	0.72247 (5)	0.0170 (3)
C2	0.44960 (15)	0.48057 (19)	0.74939 (6)	0.0199 (3)
H2	0.3836	0.5863	0.7292	0.024*
C3	0.54551 (15)	0.5187 (2)	0.80653 (6)	0.0233 (3)
H3	0.5461	0.6519	0.8255	0.028*
C4	0.64037 (15)	0.3635 (2)	0.83596 (6)	0.0232 (3)
H4	0.7066	0.3906	0.8749	0.028*
C5	0.63876 (15)	0.1689 (2)	0.80870 (6)	0.0242 (3)
H5	0.7029	0.0622	0.8293	0.029*
C6	0.54360 (15)	0.1286 (2)	0.75122 (6)	0.0219 (3)
H6	0.5419	−0.0047	0.7323	0.026*
C7	0.42352 (15)	0.25028 (16)	0.60650 (5)	0.0148 (2)
C8	0.30741 (14)	0.23391 (17)	0.55103 (6)	0.0158 (3)
H8	0.1905	0.2211	0.5586	0.019*
C9	0.52855 (14)	0.25143 (16)	0.48299 (5)	0.0139 (2)
C10	0.59172 (15)	0.25296 (17)	0.41912 (5)	0.0160 (3)
H10	0.5161	0.2467	0.3819	0.019*
C11	0.76232 (15)	0.26345 (17)	0.41025 (6)	0.0174 (3)
H11	0.8043	0.2630	0.3670	0.021*
C12	0.87492 (15)	0.27483 (18)	0.46528 (6)	0.0179 (3)
H12	0.9927	0.2808	0.4589	0.021*
C13	0.81557 (14)	0.27741 (18)	0.52800 (6)	0.0167 (3)
H13	0.8925	0.2878	0.5647	0.020*
C14	0.64163 (14)	0.26477 (16)	0.53833 (5)	0.0141 (2)

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
O1	0.0148 (4)	0.0292 (5)	0.0127 (4)	−0.0019 (3)	0.0008 (3)	−0.0024 (3)
N1	0.0146 (5)	0.0160 (5)	0.0144 (5)	0.0003 (3)	−0.0008 (4)	−0.0002 (3)
N2	0.0155 (5)	0.0137 (5)	0.0166 (5)	0.0004 (3)	−0.0011 (4)	−0.0005 (4)
C1	0.0119 (5)	0.0277 (6)	0.0116 (5)	−0.0025 (4)	0.0025 (4)	0.0000 (4)
C2	0.0208 (6)	0.0237 (6)	0.0153 (5)	−0.0008 (5)	0.0014 (4)	0.0026 (4)
C3	0.0253 (6)	0.0276 (7)	0.0170 (6)	−0.0061 (5)	0.0017 (5)	−0.0019 (5)
C4	0.0160 (6)	0.0396 (8)	0.0140 (5)	−0.0056 (5)	0.0002 (4)	0.0014 (5)
C5	0.0164 (6)	0.0368 (7)	0.0195 (6)	0.0047 (5)	0.0025 (4)	0.0076 (5)
C6	0.0199 (6)	0.0262 (7)	0.0199 (6)	0.0018 (5)	0.0042 (4)	−0.0001 (5)
C7	0.0168 (5)	0.0137 (5)	0.0139 (5)	0.0000 (4)	0.0014 (4)	−0.0007 (4)
C8	0.0134 (5)	0.0162 (6)	0.0177 (6)	0.0003 (4)	−0.0005 (4)	−0.0009 (4)
C9	0.0146 (5)	0.0113 (5)	0.0158 (6)	0.0011 (4)	−0.0008 (4)	0.0001 (4)
C10	0.0188 (6)	0.0148 (6)	0.0142 (5)	0.0015 (4)	−0.0024 (4)	0.0002 (4)
C11	0.0200 (6)	0.0186 (6)	0.0138 (5)	0.0017 (4)	0.0030 (4)	0.0013 (4)
C12	0.0147 (5)	0.0195 (6)	0.0196 (6)	0.0009 (4)	0.0023 (4)	0.0011 (4)
C13	0.0145 (5)	0.0192 (6)	0.0161 (6)	0.0009 (4)	−0.0020 (4)	0.0007 (4)
C14	0.0158 (6)	0.0121 (5)	0.0142 (5)	0.0007 (4)	−0.0002 (4)	0.0005 (4)

Geometric parameters (Å, °)

O1—C7	1.3598 (14)	C5—H5	0.9500
O1—C1	1.4099 (13)	C6—H6	0.9500
N1—C7	1.2941 (15)	C7—C8	1.4346 (15)
N1—C14	1.3781 (14)	C8—H8	0.9500
N2—C8	1.2966 (15)	C9—C10	1.4066 (15)
N2—C9	1.3796 (15)	C9—C14	1.4165 (16)
C1—C2	1.3780 (17)	C10—C11	1.3751 (16)
C1—C6	1.3786 (17)	C10—H10	0.9500
C2—C3	1.3880 (16)	C11—C12	1.4086 (16)
C2—H2	0.9500	C11—H11	0.9500
C3—C4	1.3847 (18)	C12—C13	1.3730 (15)
C3—H3	0.9500	C12—H12	0.9500
C4—C5	1.383 (2)	C13—C14	1.4073 (16)
C4—H4	0.9500	C13—H13	0.9500
C5—C6	1.3931 (17)
C7—O1—C1	117.58 (9)	O1—C7—C8	113.94 (10)
C7—N1—C14	115.20 (10)	N2—C8—C7	121.96 (11)
C8—N2—C9	116.40 (10)	N2—C8—H8	119.0
C2—C1—C6	122.08 (11)	C7—C8—H8	119.0
C2—C1—O1	117.68 (10)	N2—C9—C10	119.51 (10)
C6—C1—O1	120.14 (11)	N2—C9—C14	120.90 (10)
C1—C2—C3	118.77 (11)	C10—C9—C14	119.59 (10)
C1—C2—H2	120.6	C11—C10—C9	120.38 (10)
C3—C2—H2	120.6	C11—C10—H10	119.8
C4—C3—C2	120.30 (12)	C9—C10—H10	119.8
C4—C3—H3	119.8	C10—C11—C12	120.04 (11)
C2—C3—H3	119.8	C10—C11—H11	120.0
C5—C4—C3	119.98 (11)	C12—C11—H11	120.0
C5—C4—H4	120.0	C13—C12—C11	120.46 (11)
C3—C4—H4	120.0	C13—C12—H12	119.8
C4—C5—C6	120.32 (12)	C11—C12—H12	119.8
C4—C5—H5	119.8	C12—C13—C14	120.53 (10)
C6—C5—H5	119.8	C12—C13—H13	119.7
C1—C6—C5	118.53 (12)	C14—C13—H13	119.7
C1—C6—H6	120.7	N1—C14—C13	119.52 (10)
C5—C6—H6	120.7	N1—C14—C9	121.50 (10)
N1—C7—O1	122.03 (10)	C13—C14—C9	118.98 (11)
N1—C7—C8	124.02 (11)
C7—O1—C1—C2	100.70 (12)	O1—C7—C8—N2	178.65 (10)
C7—O1—C1—C6	−82.79 (13)	C8—N2—C9—C10	179.47 (10)
C6—C1—C2—C3	1.36 (17)	C8—N2—C9—C14	−0.26 (15)
O1—C1—C2—C3	177.79 (10)	N2—C9—C10—C11	−178.53 (10)
C1—C2—C3—C4	−0.52 (17)	C14—C9—C10—C11	1.21 (16)
C2—C3—C4—C5	−0.52 (18)	C9—C10—C11—C12	−0.64 (16)
C3—C4—C5—C6	0.77 (18)	C10—C11—C12—C13	−0.59 (17)
C2—C1—C6—C5	−1.11 (17)	C11—C12—C13—C14	1.22 (17)
O1—C1—C6—C5	−177.45 (10)	C7—N1—C14—C13	−178.90 (10)
C4—C5—C6—C1	0.02 (17)	C7—N1—C14—C9	1.19 (15)
C14—N1—C7—O1	−179.82 (10)	C12—C13—C14—N1	179.46 (10)
C14—N1—C7—C8	−0.37 (15)	C12—C13—C14—C9	−0.63 (16)
C1—O1—C7—N1	5.91 (15)	N2—C9—C14—N1	−0.94 (16)
C1—O1—C7—C8	−173.59 (10)	C10—C9—C14—N1	179.33 (10)
C9—N2—C8—C7	1.10 (15)	N2—C9—C14—C13	179.15 (10)
N1—C7—C8—N2	−0.84 (17)	C10—C9—C14—C13	−0.58 (15)