Research Article: 9-Ethynyl-9H-carbazole

Date Published: March 01, 2012

Publisher: International Union of Crystallography

Author(s): Hideyuki Tabata, Tsunehisa Okuno.


The title compound, C14H9N, is the second crystallographically characterized example of an ynamine with an H atom in the C-terminal position. There are two independent mol­ecules (A and B) in the asymmetric unit. The structures of both mol­ecules are essentially planar (r.m.s. deviation = 0.0312 and 0.0152 Å). The N—Csp bond lengths are 1.353 (4) and 1.350 (4) Å, and those of the acetyl­ene bonds are 1.189 (4) and 1.190 (4) Å. The Csp—H bond lengths are 0.95 (5) and 0.97 (4) Å. These geometries are consistent with those of the previously reported ynamine characterized by crystallography. In the crystal, the mol­ecules stack along the c axis, forming two kinds of columnar structures. The acetyl­ene C atoms of mol­ecule A have a short contact [3.341 (4) Å and 3.396 (4) Å] with an adjacent mol­ecule A at the C—C bond of the fused part, which originates in π–π stacking inter­action; no remarkable spatial contact is recognized within the stacking of mol­ecule B.

Partial Text

For the preparation of the title compound, see: Cuniberti et al. (1996 ▶). For the related structure of a diacetyl­ene compound having 9-carbazolyl groups at both ends, see: Mayerle & Flandera (1978 ▶). For the related structure of an ynamine compound that carrys an H atom at an acetyl­ene terminal, see: Tabata & Okuno (2011 ▶). For related structures of ynamine compounds, see: Galli et al. (1988 ▶, 1989 ▶); Okuno et al. (2006 ▶); Tabata et al. (2012 ▶).