research papers
An X-ray analysis employing two-dimensional Fourier methods has established the crystal structure of adenine hydrochloride. The purine molecule is planar, and the intramolecular bond distances are in general agreement with those found in the pyrimidine molecule. Hydrogen bonds linking a purine molecule to chlorine atoms and to water molecules, and short van der Waals contacts with other purine molecules, lie approximately in the plane of the molecule.