The main aim of this study was to investigate the co-ordination chemistry of certain antivirally active derivatives of 2 alpha hydroxybenzylbenzimidazole and some inactive 2 substituted benzimidazoles with cobalt(II) and nickel(II) salts, with a view to correlating virus inhibitory activity with chelation properties. In the case of the parent compound, 2 alpha hydroxybenzylbenzimidazole, its co-ordination chemistry with some copper(II) salts has been investigated. A number of complexes have been prepared and attempts made to deduce their structures from their electronic spectral, magnetic and infrared spectral data. All the ligands except 2 alpha methoxybenzylbenzimidazole and 2 alpha hydroxyphenylbenzimidazole were found to chelate very readily, doing so through their unsaturated nitrogen atom and oxygen atom. 2 alpha methoxybenzylbenzimidazole,while not as ready to chelate as the other compounds, is nevertheless capable of doing sof as is evident from its nickel complexes. With 2 alpha hydroxyphenylbenzimidazole chelation is uncommon, the ligand either bridging or bonding monodentately. In those complexes in which it is bridging, peculiar magnetic properties are observed. The differences in the co-ordination chemistry of the various ligands have in most cases been explained in terms of steric effects. In the case of 2 alpha hydroxyphenylbenzimidazole its difference in co-ordination chemistry to the other compounds is probably due mainly to electronic factors. The behaviour of 2 alpha hydroxybenzylbenzimidazole with copper(II) salts is interesting in that it chelates less readily with these than with cobalt(II) or nickel(II) salts. Several of the copper complexes have very interesting magnetic properties. Finally, the correlation between antiviral activity and chelation properties is discussed.