Challenges in Molecular Energy Research

Serena DeBeer, Maurice van Gastel, Eckhard Bill, Shengfa Ye, Taras Petrenko, Dimitrios A. Pantazis, Frank Neese 

The relevant processes all involve the activation of small, largely inert molecules. The most important elementary processes are summarized by the following six reactions  

Reaction (1) is one of the most elementary chemical reactions and is of central importance for energy research as it provides H2, which either serves as a fuel by itself or acts as a precursor for further reduction reactions (e.g. in the activation of O2, CO2, and N2 - reactions [3], [4], and [6]). Ideally, the protons and electrons required for 

The aim of this book is to summarize the state of the art of the efforts within individual chemical subdisciplines toward achieving the common goals associated with energy research. By bringing together the various communities, this will hopefully develop into an internal joint research effort that benefits from cross-fertilization. In this chapter, we will focus on the biological and molecular aspects of energy research. 

2 Modern Spectroscopy and Quantum Chemistry as a Means to Decipher Reaction Mechanisms 

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Unraveling the individual molecular interactions in these very complex photosystems is a challenging focus of current research, particularly since the demand for alternative energy sources has become critical in the past few years. Progress in this area is hampered, however, due to the extreme complexity of the natural systems coupled with the fact that the synthesis of biomimetic porphyrin models is quite challenging. Experimental... 

The proper theoretical study of core-hole excited states has been one of the most challenging problems in molecular quantum mechanics. The difficulty stems from the fact that these states lie above the continuum part of the spectra, and their attainment as high-energy roots in an ordinary configuration interaction calculation is impossible [46]. However, core-hole excited states play an important role in the identification of chemical species by X-ray based spectroscopic techniques. Additionally, there are many interesting effects that are particular to this region of the spectra and their study are the object of active research [47]. 

By observation and better understanding of these sophisticated biological processes, the design of multiporphyrinic species capable of performing energy and electron transfer has been both stimulated and facilitated, leading to one of the major areas of research in molecular electronics in terms of activity and publications. In terms of applicability, the synthetic systems face two challenges. 

A fascinating but challenging issue in molecular reaction dynamics is the characterization of reactive resonances in elementary chemical reactions. Since Liu and co-workers experimentally demonstrated the existence of the reactive resonances in the polyatomic reactions of F -f CH4/CHD3/CD4, research interest on the polyatomic reaction of F -I- CH4 and its isotope variants has continued to grow. On the theoretical side and for understanding the reaction mechanism, some attention is focused on the construction of a 12-dimensional ground potential energy surface of the polyatomic system while some is on implementation of dynamical (both QCT and quantum) calculations. ... 

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