9-Ethyl-3-(imidazo[1,2-a]pyrimidin-3-yl)-9H-carbazole

Huang, P.-H.; Chen, G.-J.; Wen, Y.-S.

doi:10.1107/S1600536808038300

organic compounds

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ISSN: 2056-9890

Volume 64| Part 12| December 2008| Page o2407

doi:10.1107/S1600536808038300

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9-Ethyl-3-(imidazo[1,2-a]pyrimidin-3-yl)-9H-carbazole

Ping-Hsin Huang,^a ^* Guan-Ji Chen ^b and Yuh-Sheng Wen ^b

^aInstitute of Chemistry, Academia Sinica, Nankang, Taipei, Taiwan, and Cardinal Tien College of Healthcare and Management, Taipei, Taiwan, and ^bInstitute of Chemistry, Academia Sinica, Nankang, Taipei, Taiwan
^*Correspondence e-mail: pshuang@ctcn.edu.tw

(Received 29 October 2008; accepted 17 November 2008; online 22 November 2008)

The title compound, C₂₀H₁₆N₄, is a precursor for the production of electron-transporting and -emitting materials. The bond lengths and angles in this compound are normal. In the crystal structure, there are no significant hydrogen-bonding interactions or π–π stacking interactions between molecules.

Related literature

For general background to the use of small organic molecules or organic polymers as electroluminescent materials, see: Burroughes et al. (1990 ); Tang & VanSlyke (1987 ).

Experimental

Crystal data

C₂₀H₁₆N₄
M_r = 312.37
Monoclinic, P 2₁ /c
a = 13.9106 (3) Å
b = 9.3187 (2) Å
c = 12.9047 (3) Å
β = 112.712 (1)°
V = 1543.10 (6) Å³
Z = 4
Mo Kα radiation
μ = 0.08 mm⁻¹
T = 100.0 (1) K
0.36 × 0.32 × 0.28 mm

Data collection

Bruker SMART CCD area-detector diffractometer
Absorption correction: none
11748 measured reflections
2717 independent reflections
1991 reflections with I > 2σ(I)
R_int = 0.033

Refinement

R[F² > 2σ(F²)] = 0.030
wR(F²) = 0.072
S = 0.91
2717 reflections
218 parameters
H-atom parameters constrained
Δρ_max = 0.19 e Å⁻³
Δρ_min = −0.19 e Å⁻³

Data collection: SMART (Bruker, 2001 ); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ); software used to prepare material for publication: WinGX (Farrugia, 1999 ).

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808038300/ww2131sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536808038300/ww2131Isup2.hkl

checkCIF report

Comment top

The application of organic electroluminescent (OEL) in flatpanel displays using small organic molecules or organic polymers has been intensively pursued after the reports by Kodak's team (Tang & VanSlyke, 1987) and Cambridge's group (Burroughes et al., 1990). The molecular structure of is shown in Fig. 1. The dihedral angle between the imidazole (P2) and phenyl ring of carbazole (P3) is 34.63 (8)°. Furthermore, the dihedral angles are 4.64 (8)°, 0.90 (8)° and 0.97 (8)° for P1/P2, P3/P4 and P4/P5, respectively.

Related literature top

For related literature, see: Burroughes et al. (1990); Tang & VanSlyke (1987).

Experimental top

The compound was synthesized by the following procedure. Imidazo[1,2-a]pyrimidine hydrobromide (2.0 g, 0.01 mol), 3-bromo-9-ethyl-9H-carbazole (4.6 g, 1.15 eq), Pd(PPh₃)₄ (0.23 g, 0.02 eq), K₂CO₃ (2.8 g, 2 eq), and N,N-dimethylformamide (5 ml) were charged in a two-necked flask kept under nitrogen. The mixture was heated to reflux for 48 h. After cooling, it was quenched with 5 ml of water. The solvent was removed under vacuum and the residue was extracted with dichloromethane/water. The organic layer was dried over MgSO₄ and filtered. Evaporation of the solvent left a brown residue that was chromatographed through silica gel using dichloromethane/hexane (19:1) mixture as eluant. The compound was obtained as yellow solid in 37% yield. FW:312.4;FAB MS: m/e 313.3 (M⁺ + H). ¹H NMR (CDCl₃, δ/ ppm): 8.68 (dd, 1H, J = 6.8 Hz, J = 1.8 Hz), 8.57 (dd, 1H, J = 3.9 Hz, J = 1.9 Hz), 8.21 (s, 1H), 8.11 (d, 1H, J = 7.8 Hz), 7.92 (s, 1H), 7.59–7.49 (m, 3H), 7.45 (d, 1H, J = 8.1 Hz), 7.26(t, 1H, J = 7.3 Hz), 6.89 (dd, 1H, J = 6.8 Hz, J = 4.0 Hz).

Computing details top

Data collection: SMART (Bruker, 2001); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT (Bruker, 2001); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures top

	Fig. 1. A molecular structure of (I) with 30% probability displacement ellipsoids, showing the atom-numbering scheme employed.
	Fig. 2. The formation of the title compound.

9-Ethyl-3-(imidazo[1,2-a]pyrimidin-3-yl)-9H-carbazole top

Crystal data top

C₂₀H₁₆N₄	F(000) = 656
M_r = 312.37	D_x = 1.345 Mg m⁻³ D_m = 1.345 Mg m⁻³ D_m measured by not measured
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 3698 reflections
a = 13.9106 (3) Å	θ = 2.7–30.2°
b = 9.3187 (2) Å	µ = 0.08 mm⁻¹
c = 12.9047 (3) Å	T = 100 K
β = 112.712 (1)°	Prism, yellow
V = 1543.10 (6) Å³	0.36 × 0.32 × 0.28 mm
Z = 4

Data collection top

Bruker SMART CCD area-detector diffractometer	1991 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	R_int = 0.033
Graphite monochromator	θ_max = 25.0°, θ_min = 1.6°
ω and ϕ scans	h = −16→16
11748 measured reflections	k = −11→11
2717 independent reflections	l = −15→15

Refinement top

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F² > 2σ(F²)] = 0.030	H-atom parameters constrained
wR(F²) = 0.072	w = 1/[σ²(F_o²) + (0.0416P)²] where P = (F_o² + 2F_c²)/3
S = 0.91	(Δ/σ)_max = 0.001
2717 reflections	Δρ_max = 0.19 e Å⁻³
218 parameters	Δρ_min = −0.19 e Å⁻³
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0063 (8)

Crystal data top

C₂₀H₁₆N₄	V = 1543.10 (6) Å³
M_r = 312.37	Z = 4
Monoclinic, P2₁/c	Mo Kα radiation
a = 13.9106 (3) Å	µ = 0.08 mm⁻¹
b = 9.3187 (2) Å	T = 100 K
c = 12.9047 (3) Å	0.36 × 0.32 × 0.28 mm
β = 112.712 (1)°

Data collection top

Bruker SMART CCD area-detector diffractometer	1991 reflections with I > 2σ(I)
11748 measured reflections	R_int = 0.033
2717 independent reflections

Refinement top

R[F² > 2σ(F²)] = 0.030	0 restraints
wR(F²) = 0.072	H-atom parameters constrained
S = 0.91	Δρ_max = 0.19 e Å⁻³
2717 reflections	Δρ_min = −0.19 e Å⁻³
218 parameters

Special details top

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 (Å²) top

	x	y	z	U_iso*/U_eq
N4	1.35147 (8)	0.58921 (11)	0.45030 (9)	0.0200 (3)
N3	0.96458 (8)	0.19984 (11)	0.66711 (9)	0.0225 (3)
N1	0.85050 (8)	0.05126 (11)	0.51971 (9)	0.0209 (3)
N2	0.98239 (8)	0.20433 (11)	0.50125 (8)	0.0166 (3)
C17	1.37034 (10)	0.48850 (14)	0.38158 (10)	0.0196 (3)
C16	1.43492 (10)	0.49764 (15)	0.32235 (11)	0.0256 (3)
H16	1.4741	0.5797	0.3258	0.031*
C14	1.43902 (10)	0.38125 (15)	0.25828 (11)	0.0279 (4)
H14	1.4817	0.3852	0.2179	0.033*
C13	1.38043 (10)	0.25737 (15)	0.25257 (11)	0.0253 (3)
H13	1.3845	0.1805	0.2085	0.030*
C12	1.31683 (10)	0.24836 (14)	0.31163 (11)	0.0210 (3)
H12	1.2784	0.1656	0.3081	0.025*
C11	1.31059 (9)	0.36437 (13)	0.37670 (10)	0.0179 (3)
C10	1.25171 (9)	0.39349 (13)	0.44510 (10)	0.0166 (3)
C9	1.17866 (9)	0.31495 (13)	0.47090 (10)	0.0171 (3)
H9	1.1602	0.2230	0.4422	0.021*
C8	1.13349 (9)	0.37494 (13)	0.53988 (10)	0.0171 (3)
C7	1.16524 (10)	0.51203 (13)	0.58548 (10)	0.0195 (3)
H7	1.1364	0.5503	0.6336	0.023*
C24	1.23750 (10)	0.59182 (14)	0.56155 (10)	0.0203 (3)
H24	1.2575	0.6824	0.5927	0.024*
C23	1.27953 (9)	0.53254 (13)	0.48938 (10)	0.0180 (3)
C18	1.39561 (10)	0.73286 (13)	0.47180 (11)	0.0248 (3)
H18A	1.4685	0.7281	0.4827	0.030*
H18B	1.3919	0.7690	0.5406	0.030*
C19	1.33998 (11)	0.83644 (15)	0.37712 (12)	0.0305 (4)
H19A	1.3718	0.9294	0.3954	0.046*
H19B	1.2680	0.8430	0.3668	0.046*
H19C	1.3449	0.8025	0.3091	0.046*
C6	1.04213 (10)	0.29149 (14)	0.66997 (11)	0.0223 (3)
H6	1.0810	0.3451	0.7331	0.027*
C4	0.92857 (10)	0.14710 (13)	0.56400 (10)	0.0181 (3)
C1	0.82339 (10)	0.02090 (13)	0.41227 (11)	0.0214 (3)
H1	0.7709	−0.0464	0.3802	0.026*
C2	0.86906 (10)	0.08412 (13)	0.34325 (11)	0.0205 (3)
H2	0.8445	0.0624	0.2671	0.025*
C3	0.94900 (10)	0.17667 (13)	0.38901 (10)	0.0184 (3)
H3	0.9804	0.2203	0.3453	0.022*
C5	1.05729 (10)	0.29722 (13)	0.57133 (10)	0.0173 (3)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
N4	0.0182 (6)	0.0194 (6)	0.0212 (6)	−0.0032 (5)	0.0064 (5)	0.0020 (5)
N3	0.0221 (6)	0.0286 (7)	0.0179 (6)	−0.0029 (5)	0.0090 (5)	−0.0014 (5)
N1	0.0186 (6)	0.0214 (6)	0.0225 (7)	−0.0001 (5)	0.0076 (5)	0.0002 (5)
N2	0.0167 (6)	0.0193 (6)	0.0148 (6)	0.0011 (5)	0.0071 (5)	0.0008 (5)
C17	0.0145 (7)	0.0257 (8)	0.0166 (7)	0.0018 (6)	0.0038 (6)	0.0037 (6)
C16	0.0167 (7)	0.0315 (8)	0.0279 (8)	−0.0014 (6)	0.0077 (7)	0.0065 (7)
C14	0.0189 (8)	0.0413 (9)	0.0273 (8)	0.0068 (7)	0.0131 (7)	0.0075 (7)
C13	0.0199 (8)	0.0338 (9)	0.0225 (8)	0.0065 (7)	0.0087 (6)	0.0006 (7)
C12	0.0164 (7)	0.0244 (8)	0.0205 (7)	0.0019 (6)	0.0054 (6)	0.0029 (6)
C11	0.0138 (7)	0.0219 (7)	0.0161 (7)	0.0021 (6)	0.0038 (6)	0.0032 (6)
C10	0.0151 (7)	0.0194 (7)	0.0130 (7)	0.0022 (6)	0.0030 (6)	0.0023 (6)
C9	0.0178 (7)	0.0164 (7)	0.0145 (7)	−0.0006 (6)	0.0033 (6)	0.0006 (6)
C8	0.0159 (7)	0.0206 (7)	0.0129 (7)	0.0015 (6)	0.0034 (6)	0.0021 (6)
C7	0.0207 (7)	0.0228 (7)	0.0146 (7)	0.0040 (6)	0.0065 (6)	0.0006 (6)
C24	0.0219 (7)	0.0167 (7)	0.0181 (7)	0.0001 (6)	0.0032 (6)	−0.0008 (6)
C23	0.0157 (7)	0.0200 (7)	0.0158 (7)	0.0007 (6)	0.0033 (6)	0.0050 (6)
C18	0.0229 (8)	0.0214 (8)	0.0284 (8)	−0.0050 (6)	0.0081 (6)	0.0026 (6)
C19	0.0288 (9)	0.0284 (8)	0.0367 (9)	0.0029 (7)	0.0152 (7)	0.0085 (7)
C6	0.0211 (7)	0.0286 (8)	0.0171 (7)	−0.0035 (6)	0.0072 (6)	−0.0041 (6)
C4	0.0184 (7)	0.0213 (7)	0.0166 (7)	0.0019 (6)	0.0090 (6)	0.0031 (6)
C1	0.0180 (7)	0.0207 (7)	0.0229 (8)	0.0011 (6)	0.0051 (6)	−0.0020 (6)
C2	0.0192 (7)	0.0238 (8)	0.0165 (7)	0.0020 (6)	0.0048 (6)	−0.0021 (6)
C3	0.0188 (7)	0.0226 (8)	0.0141 (7)	0.0045 (6)	0.0068 (6)	0.0013 (6)
C5	0.0160 (7)	0.0193 (7)	0.0157 (7)	0.0008 (6)	0.0049 (6)	−0.0014 (6)

Geometric parameters (Å, º) top

N4—C17	1.3841 (16)	C10—C23	1.4088 (17)
N4—C23	1.3871 (15)	C9—C8	1.3898 (16)
N4—C18	1.4541 (15)	C9—H9	0.9300
N3—C4	1.3222 (16)	C8—C7	1.4045 (17)
N3—C6	1.3652 (16)	C8—C5	1.4646 (17)
N1—C1	1.3194 (15)	C7—C24	1.3778 (17)
N1—C4	1.3508 (16)	C7—H7	0.9300
N2—C3	1.3640 (15)	C24—C23	1.3911 (17)
N2—C5	1.3874 (15)	C24—H24	0.9300
N2—C4	1.4031 (15)	C18—C19	1.5143 (18)
C17—C16	1.3889 (17)	C18—H18A	0.9700
C17—C11	1.4115 (17)	C18—H18B	0.9700
C16—C14	1.3782 (18)	C19—H19A	0.9600
C16—H16	0.9300	C19—H19B	0.9600
C14—C13	1.3986 (18)	C19—H19C	0.9600
C14—H14	0.9300	C6—C5	1.3693 (16)
C13—C12	1.3752 (17)	C6—H6	0.9300
C13—H13	0.9300	C1—C2	1.4074 (17)
C12—C11	1.3920 (17)	C1—H1	0.9300
C12—H12	0.9300	C2—C3	1.3499 (18)
C11—C10	1.4429 (16)	C2—H2	0.9300
C10—C9	1.3929 (16)	C3—H3	0.9300

C17—N4—C23	108.46 (10)	C8—C7—H7	118.8
C17—N4—C18	125.16 (10)	C7—C24—C23	117.87 (12)
C23—N4—C18	126.29 (11)	C7—C24—H24	121.1
C4—N3—C6	104.37 (10)	C23—C24—H24	121.1
C1—N1—C4	116.31 (11)	N4—C23—C24	129.87 (12)
C3—N2—C5	132.23 (10)	N4—C23—C10	109.06 (10)
C3—N2—C4	120.15 (11)	C24—C23—C10	121.07 (11)
C5—N2—C4	107.14 (10)	N4—C18—C19	112.72 (11)
N4—C17—C16	129.35 (12)	N4—C18—H18A	109.0
N4—C17—C11	109.28 (10)	C19—C18—H18A	109.0
C16—C17—C11	121.37 (12)	N4—C18—H18B	109.0
C14—C16—C17	117.86 (13)	C19—C18—H18B	109.0
C14—C16—H16	121.1	H18A—C18—H18B	107.8
C17—C16—H16	121.1	C18—C19—H19A	109.5
C16—C14—C13	121.53 (13)	C18—C19—H19B	109.5
C16—C14—H14	119.2	H19A—C19—H19B	109.5
C13—C14—H14	119.2	C18—C19—H19C	109.5
C12—C13—C14	120.51 (13)	H19A—C19—H19C	109.5
C12—C13—H13	119.7	H19B—C19—H19C	109.5
C14—C13—H13	119.7	N3—C6—C5	113.76 (11)
C13—C12—C11	119.36 (12)	N3—C6—H6	123.1
C13—C12—H12	120.3	C5—C6—H6	123.1
C11—C12—H12	120.3	N3—C4—N1	127.00 (11)
C12—C11—C17	119.38 (11)	N3—C4—N2	111.12 (11)
C12—C11—C10	134.22 (12)	N1—C4—N2	121.88 (11)
C17—C11—C10	106.39 (11)	N1—C1—C2	124.03 (12)
C9—C10—C23	119.86 (11)	N1—C1—H1	118.0
C9—C10—C11	133.33 (12)	C2—C1—H1	118.0
C23—C10—C11	106.80 (10)	C3—C2—C1	119.18 (12)
C8—C9—C10	119.59 (12)	C3—C2—H2	120.4
C8—C9—H9	120.2	C1—C2—H2	120.4
C10—C9—H9	120.2	C2—C3—N2	118.06 (12)
C9—C8—C7	119.17 (12)	C2—C3—H3	121.0
C9—C8—C5	122.22 (11)	N2—C3—H3	121.0
C7—C8—C5	118.54 (11)	C6—C5—N2	103.61 (10)
C24—C7—C8	122.38 (12)	C6—C5—C8	131.65 (12)
C24—C7—H7	118.8	N2—C5—C8	124.72 (11)

Experimental details

Crystal data
Chemical formula	C₂₀H₁₆N₄
M_r	312.37
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	100
a, b, c (Å)	13.9106 (3), 9.3187 (2), 12.9047 (3)
β (°)	112.712 (1)
V (Å³)	1543.10 (6)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.08
Crystal size (mm)	0.36 × 0.32 × 0.28

Data collection
Diffractometer	Bruker SMART CCD area-detector diffractometer
Absorption correction	–
No. of measured, independent and observed [I > 2σ(I)] reflections	11748, 2717, 1991
R_int	0.033
(sin θ/λ)_max (Å⁻¹)	0.595

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.030, 0.072, 0.91
No. of reflections	2717
No. of parameters	218
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.19, −0.19

Computer programs: SMART (Bruker, 2001), SAINT (Bruker, 2001), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 1997), WinGX (Farrugia, 1999).

Acknowledgements

This work was partially supported by the Institute of Chemistry, Academia Sinica, and Cardinal Tien College of Healthcare and Management.

References

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