The Virginia Tech chemistry research group that has been creating molecular complexes that use solar energy to produce hydrogen from water has added an additional capacity to their supramolecule.

Karen Brewer, professor of chemistry, explains that the new, more robust molecules still harness light and covert it to chemical energy by splitting water to produce hydrogen. “What is different is the way the systems function. It is a three part molecule. The first part is a light absorber, harnessing visible and UV light. The second part is an electron reservoir. The third part is the catalysis to make hydrogen from water.” All of these sub-units are coupled into one large supramolecular assembly.

She said the new molecules are expected to enhance efficiency. “It is a different kind of energy production reaction – not married to hydrogen but linked to whatever catalyst is selected. For example, we can conceivably use carbon dioxide to produce methanol or other reduced forms of carbon dioxide.”

The new molecular complex can also bind to DNA, providing applications in another Brewer group project – light-activated drug delivery to disease sites.

The paper, “Coupling Ru or Os light absorbers to reactive Pt complexes: Excited state reactivity and DNA photocleavage” (INOR 1200), will be presented by Ran Miao of Zhangzhou City, China, a Ph.D. student in chemistry at Virginia Tech. Co-authors are chemistry graduate students David F. Zigler of Sterling, Illinois, and Jared Brown of Salem, Va., and Brewer.

Miao will present details of the synthesis of the compound. Aspects of the design will also be presented in a poster, “Designing mixed-metal supramolecular assemblies as photochemical molecular devices: Applications in solar hydrogen production” (INOR 305)during the Energy and Environmental Inorganic Chemistry Poster session. Authors are Virginia Tech Shamindri M. Arachchige, post-doctoral associate in chemistry at Virginia Tech; Ph.D. students Mark Elvington of Blacksburg, Va., and Jared Brown, and Brewer.