4-(1-2,3-Dihydro-naphtho-[1,8-][1,3,2]di-aza-borinin-2-yl)-1-ethylpyridin-1-ium iodide.

The title compound, CHBNI, is a type of di-aza-borinane featuring substitution at the 1, 2, and 3 positions of the nitro-gen-boron six-membered heterocycle. The organic mol-ecule has a planar structure, the dihedral angle between the pyridyl ring and the fused ring system being 3.46 (4)°. In the crystal, mol-ecules are stacked in a head-to-tail manner. The iodide ion makes close contacts with three organic mol-ecules and supports the alternating stack.