2,4,5-Tris(pyridin-4-yl)-4,5-dihydro-1,3-oxazole.

In the title compound, C(18)H(14)N(4)O, the mol-ecules are disordered about a crystallographic twofold axis, leading to 50:50 disorder of the O- and N-atom sites within the oxazole ring. As a consequence, symmetry-related oxazole C-N and C-O bonds are averaged. The oxazole ring makes a dihedral angle of 6.920 (1)° with the pyridyl ring in the 2-position and 60.960 (2)° with the pyridyl rings in the 4- and 5-positions.

Related literature

For background to the synthesis of oxazoles see: Graham (2010 ▶); Aspinall et al. (2011 ▶). For the use of pyridyl­oxazole ligands in the construction of metal-organic complexes see: Bettencourt-Dias et al. (2010 ▶, 2012 ▶). For the use of tripyridyl ligands in the construction of metal-organic coordination complexes and polymers, see: Campos-Gaxiola et al. (2007 ▶, 2008 ▶, 2010 ▶); Liang et al. (2008 ▶, 2009 ▶); Yang et al. (2010 ▶); Chen et al. (2011 ▶).

Experimental

Crystal data

C18H14N4O

M = 302.33

Orthorhombic,

a = 15.9777 (13) Å

b = 11.4504 (9) Å

c = 7.7573 (6) Å

V = 1419.21 (19) Å3

Z = 4

Mo Kα radiation

μ = 0.09 mm−1

T = 293 K

0.43 × 0.38 × 0.34 mm

Data collection

Bruker SMART CCD area-detector diffractometer

Absorption correction: multi-scan (SADABS; Bruker, 2001 ▶) T min = 0.962, T max = 0.969

12571 measured reflections

1254 independent reflections

1107 reflections with I > 2σ(I)

R int = 0.030

Refinement

R[F 2 > 2σ(F 2)] = 0.039

wR(F 2) = 0.107

S = 1.07

1254 reflections

106 parameters

H-atom parameters constrained

Δρmax = 0.16 e Å−3

Δρmin = −0.23 e Å−3

Data collection: SMART (Bruker, 2000 ▶); cell refinement: SAINT-Plus (Bruker, 2001 ▶); data reduction: SAINT-Plus; 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.

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536812022611/pk2402sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812022611/pk2402Isup2.hkl

Supplementary material file. DOI: 10.1107/S1600536812022611/pk2402Isup3.cml

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

C18H14N4O	F(000) = 632
Mr = 302.33	Dx = 1.415 Mg m−3
Orthorhombic, Pbcn	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2n 2ab	Cell parameters from 5620 reflections
a = 15.9777 (13) Å	θ = 2.2–28.3°
b = 11.4504 (9) Å	µ = 0.09 mm−1
c = 7.7573 (6) Å	T = 293 K
V = 1419.21 (19) Å3	Rectangular prism, colorless
Z = 4	0.43 × 0.38 × 0.34 mm

Bruker SMART CCD area-detector diffractometer	1254 independent reflections
Radiation source: fine-focus sealed tube	1107 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.030
φ and ω scans	θmax = 25.0°, θmin = 2.2°
Absorption correction: multi-scan (SADABS; Bruker, 2001)	h = −19→19
Tmin = 0.962, Tmax = 0.969	k = −13→13
12571 measured reflections	l = −9→9

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)] = 0.039	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.107	H-atom parameters constrained
S = 1.07	w = 1/[σ2(Fo2) + (0.0526P)2 + 0.3873P] where P = (Fo2 + 2Fc2)/3
1254 reflections	(Δ/σ)max < 0.001
106 parameters	Δρmax = 0.16 e Å−3
0 restraints	Δρmin = −0.23 e Å−3

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.

	x	y	z	Uiso*/Ueq	Occ. (<1)
C1	0.5000	0.86189 (17)	0.2500	0.0382 (5)
N1	0.44050 (7)	0.80349 (9)	0.17275 (14)	0.0380 (3)	0.50
O1	0.44050 (7)	0.80349 (9)	0.17275 (14)	0.0380 (3)	0.50
C2	0.45914 (8)	0.68010 (11)	0.19468 (17)	0.0327 (3)
H2	0.4713	0.6458	0.0817	0.039*
N2	0.5000	1.23405 (16)	0.2500	0.0507 (5)
N3	0.25339 (8)	0.49131 (13)	0.42490 (18)	0.0509 (4)
C3	0.5000	0.99035 (17)	0.2500	0.0327 (4)
C4	0.43313 (9)	1.05212 (13)	0.18356 (19)	0.0405 (4)
H4	0.3870	1.0136	0.1374	0.049*
C5	0.43658 (11)	1.17225 (14)	0.1875 (2)	0.0480 (4)
H5	0.3911	1.2131	0.1431	0.058*
C6	0.38645 (8)	0.61604 (12)	0.27474 (18)	0.0334 (3)
C7	0.31909 (9)	0.67265 (13)	0.34906 (19)	0.0406 (4)
H7	0.3168	0.7538	0.3508	0.049*
C8	0.25525 (9)	0.60737 (15)	0.4207 (2)	0.0487 (4)
H8	0.2105	0.6474	0.4694	0.058*
C9	0.31870 (10)	0.43864 (13)	0.3541 (2)	0.0500 (4)
H9	0.3197	0.3574	0.3560	0.060*
C10	0.38510 (9)	0.49502 (13)	0.2781 (2)	0.0423 (4)
H10	0.4287	0.4524	0.2295	0.051*

	U11	U22	U33	U12	U13	U23
C1	0.0407 (12)	0.0313 (10)	0.0426 (11)	0.000	0.0142 (9)	0.000
N1	0.0352 (6)	0.0292 (6)	0.0495 (7)	−0.0013 (4)	−0.0024 (5)	0.0045 (5)
O1	0.0352 (6)	0.0292 (6)	0.0495 (7)	−0.0013 (4)	−0.0024 (5)	0.0045 (5)
C2	0.0306 (7)	0.0276 (7)	0.0399 (7)	0.0015 (6)	0.0005 (6)	−0.0017 (6)
N2	0.0645 (13)	0.0313 (9)	0.0562 (12)	0.000	0.0062 (10)	0.000
N3	0.0354 (7)	0.0536 (8)	0.0637 (9)	−0.0076 (6)	−0.0014 (6)	0.0109 (7)
C3	0.0340 (10)	0.0289 (10)	0.0352 (10)	0.000	0.0077 (8)	0.000
C4	0.0365 (8)	0.0394 (8)	0.0456 (9)	−0.0001 (6)	0.0006 (6)	−0.0014 (7)
C5	0.0526 (9)	0.0391 (8)	0.0523 (9)	0.0118 (7)	0.0019 (7)	0.0053 (7)
C6	0.0289 (7)	0.0326 (7)	0.0387 (7)	−0.0005 (6)	−0.0048 (6)	−0.0003 (6)
C7	0.0322 (8)	0.0360 (8)	0.0536 (9)	0.0030 (6)	−0.0006 (7)	0.0008 (7)
C8	0.0296 (8)	0.0565 (10)	0.0602 (10)	0.0049 (7)	0.0043 (7)	0.0032 (8)
C9	0.0430 (9)	0.0354 (8)	0.0717 (11)	−0.0077 (7)	−0.0053 (8)	0.0049 (7)
C10	0.0342 (7)	0.0329 (7)	0.0598 (9)	−0.0008 (6)	0.0004 (7)	−0.0039 (7)

C1—N1	1.3077 (14)	C3—C4i	1.3811 (18)
C1—O1i	1.3077 (14)	C4—C5	1.377 (2)
C1—C3	1.471 (3)	C4—H4	0.9300
N1—C2	1.4539 (17)	C5—H5	0.9300
C2—C6	1.5076 (19)	C6—C7	1.382 (2)
C2—C2i	1.563 (3)	C6—C10	1.386 (2)
C2—H2	0.9800	C7—C8	1.381 (2)
N2—C5	1.3277 (19)	C7—H7	0.9300
N2—C5i	1.3277 (19)	C8—H8	0.9300
N3—C9	1.324 (2)	C9—C10	1.375 (2)
N3—C8	1.330 (2)	C9—H9	0.9300
C3—C4	1.3811 (18)	C10—H10	0.9300
N1—C1—O1i	118.50 (17)	N2—C5—C4	124.82 (15)
N1—C1—C3	120.75 (9)	N2—C5—H5	117.6
O1i—C1—C3	120.75 (9)	C4—C5—H5	117.6
N1i—C1—C3	120.75 (9)	C7—C6—C10	116.67 (13)
C1—N1—C2	107.12 (12)	C7—C6—C2	122.92 (12)
N1—C2—C6	111.30 (11)	C10—C6—C2	120.41 (12)
N1—C2—C2i	103.62 (7)	C8—C7—C6	119.27 (14)
C6—C2—C2i	114.67 (12)	C8—C7—H7	120.4
N1—C2—H2	109.0	C6—C7—H7	120.4
C6—C2—H2	109.0	N3—C8—C7	124.56 (15)
C2i—C2—H2	109.0	N3—C8—H8	117.7
C5—N2—C5i	115.59 (19)	C7—C8—H8	117.7
C9—N3—C8	115.29 (13)	N3—C9—C10	124.89 (14)
C4—C3—C4i	118.38 (19)	N3—C9—H9	117.6
C4—C3—C1	120.81 (9)	C10—C9—H9	117.6
C4i—C3—C1	120.81 (9)	C9—C10—C6	119.31 (14)
C5—C4—C3	118.19 (15)	C9—C10—H10	120.3
C5—C4—H4	120.9	C6—C10—H10	120.3
C3—C4—H4	120.9
O1i—C1—N1—C2	−0.62 (6)	C3—C4—C5—N2	0.4 (2)
N1i—C1—N1—C2	−0.62 (6)	N1—C2—C6—C7	−12.42 (18)
C3—C1—N1—C2	179.38 (6)	C2i—C2—C6—C7	104.78 (14)
C1—N1—C2—C6	125.19 (10)	N1—C2—C6—C10	168.25 (12)
C1—N1—C2—C2i	1.45 (15)	C2i—C2—C6—C10	−74.55 (15)
N1—C1—C3—C4	6.47 (9)	C10—C6—C7—C8	−0.2 (2)
O1i—C1—C3—C4	−173.53 (9)	C2—C6—C7—C8	−179.56 (13)
N1i—C1—C3—C4	−173.53 (9)	C9—N3—C8—C7	0.1 (2)
N1—C1—C3—C4i	−173.53 (9)	C6—C7—C8—N3	0.3 (2)
O1i—C1—C3—C4i	6.47 (9)	C8—N3—C9—C10	−0.7 (3)
N1i—C1—C3—C4i	6.47 (9)	N3—C9—C10—C6	0.8 (3)
C4i—C3—C4—C5	−0.17 (10)	C7—C6—C10—C9	−0.3 (2)
C1—C3—C4—C5	179.83 (10)	C2—C6—C10—C9	179.05 (14)
C5i—N2—C5—C4	−0.19 (11)