2,4,6-Tri-p-tolyl­pyridine

In the title compound, C₂₆H₂₃N, the complete molecule is generated by crystallographic mirror symmetry, with the N atom and four C atoms lying on the reflection plane. The dihedral angles between the pyridine ring and pendant benzene rings are 2.9 (1), 14.1 (1) and 14.1 (1)°. Neighbouring mol­ecules are stabilized through inter­molecular π–π inter­actions along the c axis [centroid-to-centroid distance = 3.804 (2) Å], forming one-dimensional chains.

Related literature

For the syntheses of related 2,4,6-triaryl­pyridine compounds, see: Hou et al. (2005); Huang et al. (2005); Tewari et al. (1981); Yang et al. (2005).

Experimental

Crystal data

• C₂₆H₂₃N

• M_r = 349.45

• Orthorhombic, P n m a

• a = 15.337 (5) Å

• b = 20.778 (7) Å

• c = 6.322 (2) Å

• V = 2014.8 (11) ų

• Z = 4

• Mo Kα radiation

• μ = 0.07 mm⁻¹

• T = 295 K

• 0.24 × 0.16 × 0.15 mm

Data collection

• Bruker SMART APEX area-detector diffractometer

• Absorption correction: multi-scan (SADABS; Sheldrick, 1996) T_min = 0.975, T_max = 0.986

• 7912 measured reflections

• 2037 independent reflections

• 924 reflections with I > 2σ(I)

• R_int = 0.067

Refinement

• R[F² > 2σ(F²)] = 0.139

• wR(F²) = 0.342

• S = 1.26

• 2037 reflections

• 132 parameters

• 47 restraints

• H-atom parameters constrained

• Δρ_max = 0.27 e Å⁻³

• Δρ_min = −0.20 e Å⁻³

Data collection: SMART (Bruker, 2002); cell refinement: SAINT (Bruker, 2002); data reduction: SAINT; 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.

Supporting information

S1. Comment

2,4,6-Triarylpyridines are used as good building blocks in supramolecular chemistry because of their stacking ability, directional H-bonding and coordination, and which have also been prepared by many procedures (Hou et al., 2005; Huang et al., 2005; Tewari et al., 1981; Yang et al., 2005). We here reported the synthesis and crystal structure of 2,4,6-tri-p-tolylpyridine.

As shown in Fig.1, the title compound is a neutral organic molecule with a mirror symmetry through the methyl C15 atom and N1 atom of the central pyridine. The central pyridine is almost coplanar with the C_11-14 benzene ring with a dihedral angle of 2.9 (1) °, however, which form bigger dihedral angles of 14.1 (1) ° with the other two outer benzene rings, thus the whole molecule is nonplanar. In the crystal packing, neighboring molecules form intermolecular π–π interactions with the centroid- to-centroid distances of 3.804 (2) Å to give a one-dimensional chain along the c-axis.

Related literature

For the related synthesis of 2,4,6-triarylpyridine compounds, see: Hou et al. (2005); Huang et al. (2005); Tewari et al. (1981); Yang et al. (2005).

S2. Experimental

The title compound was synthesized with a modified procedure (Yang et al., 2005). A mixture of 5-tri-p-tolyl-pentane-1,5-dione (1.85 g, 5 mmol), ammonium acetate (3.85 g, 50 mmol) and ethanol (60 mL) was refluxed for 20 h. Upon cooling to room temperature, a precipitate was filtered, washed with ethanol/water (1:1) and dried to afford the product, purified by column chromatography on silica with petroleum/ethyl acetate. A white solid was obtained and was further recrystallized from ethanol to give colourless crystals [yield: 0.85 g, 48.6%].

S3. Refinement

The carbon-bound H atoms were placed at calculated positions (C—H = 0.93 and 0.96 Å) and refined as riding, with U(H) = 1.2U_eq(C) for benzenel H atoms, and C—H = 0.96 Å and U_iso = 1.5U_eq (C) for methyl H atoms.

Computing details

Data collection: SMART (Bruker, 2002); cell refinement: SAINT (Bruker, 2002); data reduction: SAINT (Bruker, 2002); 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 (Sheldrick, 2008).

Figures

Fig. 1. The title molecule with displacement ellipsoids drawn at the 30% probability level, and H atoms as spheres of arbitrary radius.

2,4,6-Tri-p-tolylpyridine

Crystal data

C26H23N	F(000) = 744
Mr = 349.45	Dx = 1.152 Mg m^−3
Orthorhombic, Pnma	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2n	Cell parameters from 562 reflections
a = 15.337 (5) Å	θ = 2.7–22.4°
b = 20.778 (7) Å	µ = 0.07 mm^−1
c = 6.322 (2) Å	T = 295 K
V = 2014.8 (11) Å^3	Prism, colourless
Z = 4	0.24 × 0.16 × 0.15 mm

Data collection

Bruker SMART APEX area-detector diffractometer	2037 independent reflections
Radiation source: fine-focus sealed tube	924 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.067
ϕ and ω scans	θmax = 26.0°, θmin = 2.0°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −17→18
Tmin = 0.975, Tmax = 0.986	k = −20→25
7912 measured reflections	l = −7→5

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.139	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.342	H-atom parameters constrained
S = 1.26	w = 1/[σ^2(Fo^2) + (0.0923P)^2 + 1.1054P] where P = (Fo^2 + 2Fc^2)/3
2037 reflections	(Δ/σ)max < 0.001
132 parameters	Δρmax = 0.27 e Å^−3
47 restraints	Δρmin = −0.20 e Å^−3

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 > 2sigma(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	Occ. (<1)
C1	0.4178 (6)	0.5536 (4)	0.7562 (16)	0.180 (4)
H1A	0.4197	0.5501	0.9076	0.270*
H1B	0.3776	0.5869	0.7165	0.270*
H1C	0.4749	0.5639	0.7038	0.270*
C2	0.3882 (5)	0.4900 (4)	0.6625 (15)	0.139 (3)
C3	0.3948 (6)	0.4331 (5)	0.7686 (15)	0.158 (3)
H3	0.4171	0.4334	0.9053	0.190*
C4	0.3696 (5)	0.3750 (4)	0.6812 (13)	0.143 (3)
H4	0.3750	0.3378	0.7624	0.172*
C5	0.3376 (4)	0.3699 (4)	0.4833 (11)	0.098 (2)
C6	0.3283 (6)	0.4267 (5)	0.3786 (13)	0.139 (3)
H6	0.3050	0.4261	0.2428	0.167*
C7	0.3522 (6)	0.4853 (4)	0.4650 (15)	0.163 (4)
H7	0.3435	0.5226	0.3866	0.196*
C8	0.3116 (4)	0.3075 (3)	0.3878 (9)	0.0859 (18)
C9	0.2622 (3)	0.3058 (2)	0.2112 (8)	0.0646 (14)
H9	0.2455	0.3443	0.1479	0.077*
N1	0.3373 (5)	0.2500	0.4758 (13)	0.123 (3)
C10	0.2366 (5)	0.2500	0.1249 (12)	0.075 (2)
C11	0.1802 (4)	0.2500	−0.0662 (12)	0.0673 (19)
C12	0.1525 (4)	0.3049 (3)	−0.1594 (11)	0.107 (2)
H12	0.1713	0.3442	−0.1057	0.128*
C13	0.0972 (5)	0.3044 (3)	−0.3317 (11)	0.121 (2)
H13	0.0794	0.3438	−0.3873	0.145*
C14	0.0676 (6)	0.2500	−0.4240 (15)	0.103 (3)
C15	0.0081 (6)	0.2500	−0.6115 (15)	0.133 (3)
H15A	0.0335	0.2753	−0.7227	0.199*	0.50
H15B	−0.0472	0.2681	−0.5722	0.199*	0.50
H15C	−0.0001	0.2066	−0.6600	0.199*	0.50

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.158 (7)	0.165 (7)	0.217 (9)	0.049 (6)	−0.066 (7)	−0.093 (7)
C2	0.111 (5)	0.149 (7)	0.157 (7)	0.030 (5)	−0.054 (5)	−0.053 (5)
C3	0.153 (5)	0.181 (7)	0.141 (6)	−0.015 (5)	−0.063 (5)	−0.029 (5)
C4	0.142 (5)	0.165 (6)	0.122 (5)	−0.027 (4)	−0.049 (5)	−0.006 (5)
C5	0.074 (4)	0.142 (5)	0.078 (4)	0.003 (4)	−0.022 (3)	−0.008 (4)
C6	0.157 (7)	0.141 (7)	0.119 (7)	0.036 (6)	−0.052 (5)	−0.024 (6)
C7	0.186 (9)	0.132 (7)	0.171 (9)	0.057 (6)	−0.061 (8)	−0.042 (6)
C8	0.063 (3)	0.120 (5)	0.075 (4)	0.002 (4)	0.002 (3)	0.001 (4)
C9	0.054 (3)	0.080 (3)	0.060 (3)	0.011 (3)	−0.013 (3)	−0.001 (3)
N1	0.089 (6)	0.180 (9)	0.098 (6)	0.000	0.011 (5)	0.000
C10	0.055 (4)	0.103 (6)	0.065 (5)	0.000	0.011 (4)	0.000
C11	0.060 (4)	0.076 (5)	0.066 (5)	0.000	−0.002 (4)	0.000
C12	0.119 (5)	0.092 (4)	0.110 (5)	−0.002 (4)	−0.037 (4)	0.003 (4)
C13	0.114 (5)	0.141 (6)	0.108 (5)	0.004 (4)	−0.038 (4)	0.031 (4)
C14	0.078 (5)	0.152 (7)	0.079 (5)	0.000	−0.020 (4)	0.000
C15	0.098 (6)	0.216 (9)	0.085 (6)	0.000	−0.022 (5)	0.000

Geometric parameters (Å, º)

C1—C2	1.518 (10)	C9—C10	1.340 (6)
C1—H1A	0.9600	C9—H9	0.9300
C1—H1B	0.9600	N1—C8^i	1.375 (5)
C1—H1C	0.9600	C10—C9^i	1.340 (6)
C2—C3	1.361 (8)	C10—C11	1.486 (10)
C2—C7	1.369 (8)	C11—C12^i	1.352 (6)
C3—C4	1.384 (10)	C11—C12	1.352 (6)
C3—H3	0.9300	C12—C13	1.381 (8)
C4—C5	1.348 (9)	C12—H12	0.9300
C4—H4	0.9300	C13—C14	1.352 (6)
C5—C6	1.361 (9)	C13—H13	0.9300
C5—C8	1.484 (8)	C14—C13^i	1.352 (6)
C6—C7	1.384 (9)	C14—C15	1.495 (12)
C6—H6	0.9300	C15—H15A	0.9600
C7—H7	0.9300	C15—H15B	0.9600
C8—C9	1.350 (7)	C15—H15C	0.9600
C8—N1	1.375 (5)
C2—C1—H1A	109.5	N1—C8—C5	121.1 (6)
C2—C1—H1B	109.5	C10—C9—C8	121.5 (6)
H1A—C1—H1B	109.5	C10—C9—H9	119.2
C2—C1—H1C	109.5	C8—C9—H9	119.2
H1A—C1—H1C	109.5	C8^i—N1—C8	120.6 (9)
H1B—C1—H1C	109.5	C9—C10—C9^i	119.8 (7)
C3—C2—C7	114.7 (9)	C9—C10—C11	120.1 (4)
C3—C2—C1	122.7 (8)	C9^i—C10—C11	120.1 (4)
C7—C2—C1	122.6 (9)	C12^i—C11—C12	115.0 (8)
C2—C3—C4	122.7 (8)	C12^i—C11—C10	122.5 (4)
C2—C3—H3	118.7	C12—C11—C10	122.5 (4)
C4—C3—H3	118.7	C11—C12—C13	122.1 (6)
C5—C4—C3	122.7 (9)	C11—C12—H12	118.9
C5—C4—H4	118.6	C13—C12—H12	118.9
C3—C4—H4	118.6	C14—C13—C12	123.5 (7)
C4—C5—C6	114.9 (8)	C14—C13—H13	118.2
C4—C5—C8	123.0 (7)	C12—C13—H13	118.2
C6—C5—C8	122.1 (6)	C13—C14—C13^i	113.6 (9)
C5—C6—C7	122.9 (8)	C13—C14—C15	123.2 (4)
C5—C6—H6	118.5	C13^i—C14—C15	123.2 (4)
C7—C6—H6	118.5	C14—C15—H15A	109.5
C2—C7—C6	122.0 (9)	C14—C15—H15B	109.5
C2—C7—H7	119.0	H15A—C15—H15B	109.5
C6—C7—H7	119.0	C14—C15—H15C	109.5
C9—C8—N1	118.2 (7)	H15A—C15—H15C	109.5
C9—C8—C5	120.6 (5)	H15B—C15—H15C	109.5
C7—C2—C3—C4	1.9 (14)	C5—C8—C9—C10	−178.7 (6)
C1—C2—C3—C4	−178.5 (8)	C9—C8—N1—C8^i	−1.3 (11)
C2—C3—C4—C5	0.8 (15)	C5—C8—N1—C8^i	178.9 (5)
C3—C4—C5—C6	−2.7 (12)	C8—C9—C10—C9^i	−1.8 (10)
C3—C4—C5—C8	179.1 (7)	C8—C9—C10—C11	178.3 (5)
C4—C5—C6—C7	1.8 (12)	C9—C10—C11—C12^i	−179.9 (6)
C8—C5—C6—C7	180.0 (7)	C9^i—C10—C11—C12^i	0.2 (10)
C3—C2—C7—C6	−2.8 (14)	C9—C10—C11—C12	−0.2 (10)
C1—C2—C7—C6	177.6 (8)	C9^i—C10—C11—C12	179.9 (6)
C5—C6—C7—C2	1.0 (15)	C12^i—C11—C12—C13	2.5 (12)
C4—C5—C8—C9	164.8 (6)	C10—C11—C12—C13	−177.3 (6)
C6—C5—C8—C9	−13.2 (10)	C11—C12—C13—C14	−1.3 (12)
C4—C5—C8—N1	−15.4 (10)	C12—C13—C14—C13^i	0.0 (15)
C6—C5—C8—N1	166.6 (7)	C12—C13—C14—C15	−179.6 (8)
N1—C8—C9—C10	1.5 (9)

Symmetry code: (i) x, −y+1/2, z.