New methods for functionalizing biologically important molecules using triosmium metal clusters.

This perspective report summarizes recent work on the interactions of the triosmium clusters of general formula Os(3)(CO)(9)(μ(3)-η(2)-L-H)(μ-H) (L = bicyclic benzoheterocycle) with DNA and proteins. The early work focused on how the structure of the benzoheterocycle influenced the binding of the cluster to plasmid DNA, albumin and the inhibition of telomerase. Later, selective binding of the triosmium clusters to guanine was targeted using a range of alkylating functionalities. In connection with these efforts some very recent unpublished work will be presented. Suggestions for future directions in this area and a summary of the problems and difficulties encountered will be discussed.