Green Chemistry

The realization in the latter part of the 20th century that many syntheses practiced on a large scale were detrimental to the environment led to a movement towards reshaping the science of organic synthesis. The problems are particularly acute in the area of oxidation chemistry. Thus, the approach taken in this research is motivated or “pulled” by societal considerations that demand environmentally benign and sustainable solutions for oxidative synthetic transformations in organic chemistry; broadly speaking this means the selective oxidation of hydrocarbons such as alkanes, alkenes and aromatics and other functionalized organic compounds, for example alcohols or sulfides. The choice of this specific area of scientific pursuit is “scientifically pushed” by the realization that our mechanistic understanding of catalytic oxidation involving simple environmentally benign oxygen donors such as molecular oxygen (O2) or nitrous oxide (N2O) among others is often very lacking especially when compared to other classical catalytic research areas such as hydrogenation.
The goal of obtaining viable synthetic “green” procedures requires new catalysts capable of activation of oxidants that will lead to new selective transformations that will then fulfill the requirements of “green chemistry”. The success of this venture is dependent on mechanistic understanding and also design of practical catalytic methodologies for the eventual realization of new catalytic reactions. Indeed, we attempt to stress these latter two aspects throughout our investigations. Much of the research in selective oxidation area is through the use of new catalysts, which contain inorganic polyoxometalates as key components. The atypical use of these intrinsically inorganic catalysts as opposed to the more common use of coordination compounds, has presented us both with new challenges and opportunities generally not envisioned in more traditional transition complex mediated transformations.

A polyhedral representation of a “sandwich” type polyoxometalate that catalyzes oxidation reactions.