9-Ethynyl-9H-carbazole

The title compound, C(14)H(9)N, 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—C(sp) 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 C(sp)—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.