organic compounds
In 5,8-dimethoxy-1-naphthoic acid, C13H12O4, hydrogen bonding is of the cyclic dimer type. The acid H atom is modelled as being distributed equally over two sites. In addition to the conventional hydrogen bonds there are three significantly attractive C—HO interactions. The dihedral angle between the naphthalene core plane and the carboxyl plane is 80.0 (1)°. In methyl 5,8-dimethoxy-1-naphthoate, C14H14O4, there are no conventional hydrogen bonds but there are three significantly attractive C—HO interactions. With the exception of the C-O distances in the carboxyl groups, the molecular geometries of the acid and the ester are quite similar.