Among the most challenging subjects facing chemists today are catalysis and solar energy conversion. The former involves bond activation and transformation, while the latter deals with the excited states of chromophores, electron-hole separation and catalysis. All of these subjects are being addressed in the Eisenberg laboratory using chemistry based mainly on the platinum group elements.

With regard to solar energy conversion, new photochemically active complexes are studied with respect to their excited state properties, their ability to promote hydrogen generation from water (such as that done by 1) and their incorporation into two- and three-component systems for photoinduced charge separation (PICS). In photosynthesis including the energy storing splitting of water, PICS is the key initial process from which all other steps emanate. The structure of a recently constructed three-component system is shown as 2 with a platinum chromophore, a benzamide donor and a pyridinium acceptor.

Other projects relating to the luminescence behavior of metal complexes concerns the use of such systems as dopant emitters in electroluminescent or OLED flat panel displays and the development of new luminescent gold and platinum complexes for possible application as chemosensors. The compounds being investigated give evidence of "metallophilic" interactions in the solid state which in turn affect their photoluminescence. Efforts to design systems in which such interactions are stabilized in solution in order to yield detectable emission are being pursued.

For catalysis, new electrophilic systems based on Ir(III) such as 3 have been developed, and in a collaborative project, shown to promote electrocyclizations and tandem reaction sequences based on them. Current studies are directed to making these reactions enantioselective and expanding the scope of the tandem sequences.

Finally, hydrogen addition reactions are being examined using parahydrogen induced polarization (PHIP), a fascinating spin effect that allows species in small concentrations such as reaction intermediates in hydrogenation and hydroformylation catalysis to be observed directly by NMR spectroscopy. Recent studies have allowed characterization of model intermediates in hydroformylation.