Abstract
A crystal and molecular structure determination of the transition metal-nucleotide complex, Ni(imp)(H2O)5,2H2O shows that the octahedral nickel ion is co-ordinated to the N(7) atom of the hypoxanthine unit and to five water molecules and that hydrogen bonding occurs between two of the co-ordinated water molecules and two of the phosphate oxygen atoms; the structure previously proposed is shown to be incorrect.