Intimate interplay of theory and experiments in model catalysis

We briefly summarize our joint effort to understand catalytic reactions on the model catalyst RuO₂(1 1 0) on the atomic scale, applying state-of-the-art density functional theory calculations and surface chemical characterizations in parallel. This intimate theory/experiment interplay allows us to gain new and deep insights into a catalytic system under investigation and to save recourses such as experimental and computing time as well as (wo)man power. Here we illustrate the utility of this intimate theory/experiment approach with a variety of recent examples related to the extraordinary activity of RuO₂. The identification of RuO₂(1 1 0) as the catalytically active state in the oxidation of CO on Ru(0 0 0 1) (Science 287 (2000) 1474) triggered a paradigm shift in model catalysis from the view of a rigid catalyst towards a structural and chemically flexible catalyst which adapts itself to the reaction conditions.     

Die Kerze

In this paper we discuss the physical chemistry of the candle light, which has shown to encompass thermodynamics, chemical kinetics, transport processes and quantum chemistry and physics. In a candle light all states of matter (solid, liquid, gas and plasma) are present. Solid wax is molten by the heat radiation of the flame and subsequently pumped through the wick by capillary forces to the interior of the flame, where the liquid wax is evaporated and ignited. Oxygen cannot penetrate deeply into the flame so that inside the flame reducing reaction conditions prevail. In the flame the wax molecules are pyrolized to small molecule fragments (including ions: plasma), which are the starting point for building up poly‐aromatic rings and finally soot particles. The almond‐shape of the candle light is the result of convection of the hot air around the flame. The candle light serves as a flow reactor with luminous effect where molecular oxygen from the atmosphere oxidized ultimately the wax molecules to CO₂ and water. Only a very small percentage (0.5 %) of the released heat in the combustion reaction is transformed into visible light, rendering the candle light an incredibly inefficient albeit romantic light source.     

Renewability is not Enough: Recent Advances in the Sustainable Synthesis of Biomass‐Derived Monomers and Polymers

Taking advantage of the structural diversity of different biomass resources, recent efforts were directed towards the synthesis of renewable monomers and polymers, either for the substitution of petroleum‐based resources or for the design of novel polymers. Not only the use of biomass, but also the development of sustainable chemical approaches is a crucial aspect for the production of sustainable materials. This review discusses the recent examples of chemical modifications and polymerizations of abundant biomass resources with a clear focus on the sustainability of the described processes. Topics such as synthetic methodology, catalysis, and development of new solvent systems or greener alternative reagents are addressed. The chemistry of vegetable oil derivatives, terpenes, lignin, carbohydrates, and sugar‐based platform chemicals was selected to highlight the trends in the active field of a sustainable use of renewable resources.     

First insights into the electronic properties of a Cu(II) center embedded in the PN3 cap of a calix[6]arene-based ligand

The first metal complex based on the calix[6]PN3 cryptand is described. The solid-state and solution studies show a 5-coordinate Cu(II) center due to its coordination to the PN3 cap and to an exchangeable guest molecule. Spectroscopic and electrochemical studies evidence surprising properties of the metal ion, which are tentatively assigned to the unusual P-Cu(II) bond enforced by the cryptand.