4-(Phenyldiazenyl)naphthalen-1-amine and its hydrochloride

The crystal structures of 4-(phenyldiazenyl)naphthalen-1-amine, C16H13N3, ( I), and its hydrochloride, (4-aminonaphthalen-1-yl)phenyldiazenium chloride , C16H14N3+. Cl-, (II), have been determined from X-ray single-crystal and powder data, respectively. The effect of the crystal environment on the mol ecular electronic structure was analysed on the AM1 level. One of the two s ymmetry-independent molecules in (I) is involved in intermolecular hydrogen bonding, so that its dipole moment is twice as large as that of the other molecule. The cations in (II) form stacks along [100], with the Cl- anions forming hydrogen bonds to all three H atoms attached to N atoms.