β-Carboline (norharman).

The structure of β-carboline, also called norharman (systematic name: 9H-pyrido[3,4-b]indole), C(11)H(8)N(2), has been determined at 110 K. Norharman is prevalent in the environment and the human body and is of wide biological interest. The structure exhibits intermolecular N-H···N hydrogen bonding, which results in a one-dimensional herringbone motif. The three rings of the norharman molecule collectively result in a C-shaped curvature of 3.19 (13)° parallel to the long axis. The diffraction data show shorter pyridyl C-C bonds than those reported at the STO-3G level of theory.