Segmented multitopic ligands constructed from bipyrimidine, phenanthroline, and terpyridine modules

Starting from bromo-substituted 2,2′-bipyrimidine or 1,10-phenanthroline building blocks, the preparation in a first step of ethynyl grafted molecules allows the production in a second step of multitopic ligands by cross-coupling with difunctionalised chelating molecules. Various combinations allow the interconnection of bipyrimidine to terpyridine, pyrene, or phenanthroline fragments. When two alkyne functions are present, a simple protocol gives a large variety of linear or bent ligands with an increasing number of nitrogen atoms. It was also possible to construct a linear complex capped at the periphery by ruthenium(II) centers and retaining an uncomplexed phenanthroline fragment in its core.