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

Ping-Hsin Huang; Guan-Ji Chen; Yuh-Sheng Wen

doi:10.1107/S1600536808038300

. 2008 Nov 22;64(Pt 12):o2407. doi: 10.1107/S1600536808038300

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

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

PMCID: PMC2959935 PMID: 21581376

Abstract

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 ▶). graphic file with name e-64-o2407-scheme1.jpg

Experimental

Crystal data

C₂₀H₁₆N₄
M _r = 312.37
Monoclinic,
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[F ² > 2σ(F ²)] = 0.030
wR(F ²) = 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 ▶).

Supplementary Material

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

e-64-o2407-sup1.cif^{(17KB, cif)}

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

e-64-o2407-Isup2.hkl^{(130.7KB, hkl)}

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

Acknowledgments

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

supplementary crystallographic information

Comment

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.

Experimental

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).