Luminescence properties and redox behavior of Ru(II) molecular racks

The absorption spectra, luminescence properties, and redox behavior of Ru(II) molecular racks are reviewed, together with the same properties of closely related systems, including homo- (Fe(II)) and hetero-metallic (Fe(II)/Ru(II) and Fe(II)/Os(II)) molecular grids and their mononuclear Ru(II) and Os(II) precursors, and bis-dirhodium(II, II) molecular racks. The systems discussed are based on polytopic molecular strands made of poly(pyridine-pyrimidine), poly(naphthyridine-pyrimidine), and poly(hydrazone-pyrimidine/pyrazine) subunits. Linearly-arranged systems based on tris-terpyridine molecular strands are also reported for completeness. The results indicate that the title species are quite promising multicomponent systems for the development of functional supramolecular systems, with particular regards towards the design of nano-organized species featuring information storage functions, molecular wire-type behavior, and light-harvesting antennae properties.