5-Amino-2,9-dimethyl-1,10-phenanthroline-oligonucleotide conjugates have been synthesized. A 2'-O-methyl octaribonucleotide carrying a 2'-aminoethoxymethyl linker in a central position was produced. Reaction of the aminoneocuproine phenyl carbamate with the fully deprotected oligonucleotide in aqueous solution gave virtually quantitative conversion into the conjugate. Preliminary cleavage studies in presence of zinc ions show nuclease activity towards RNA targets.