What is the most significant result of this study? Attempts to mimic metalloenzymes teach us about catalysis, and the lessons learnt find widespread application in an umber of chemical disciplines, including process engineering. Our catechol oxidase models show an unprecedented dependence of their reactivity on the method of oxygen administration:w hen going beyond the limits of homogeneously distributed reactants, by administering surplus dioxygen periodically during catalytic turnover, we observed reactivities increasing by factors of five to ten, in comparison with the well-established conditions of dioxygen saturation. This observation is not limited to our new system. Reference experiments with systems taken from the literature suggest that the effect, which is of interest in the context of reactive bubbly flows, is general, but has hitherto gone unnoticed. What was the inspiration for this cover design? When we were invited to submit ad esign, we took inspiration from the fact that the browning of cut fruit is effected by copper-and oxygen-dependent oxygenases, leading to melanine pigments, which are polymeric ortho-quinone derivatives. An abstract rendering of our dinuclear copper(II) complexes is shown in the foreground at left. In our cover art, as till life by Gabriele Endres, the browning of the half-eaten apple in the foreground denotes the enhanced reaction of our model substrate, ac atechol, under oxygen-enriched conditions, as provided by ab ubbly flow of oxygen. What other topics are you working on at the moment? We are interested in the activation of dioxygen and its exploitation as an environmentally benign, or green, oxidant, using bioinspired transition-metal complexes of tailor-made ligands. Our "workhorse" metal ions are iron and copper,i nt heir various oxidation states, and we are currently making our first forays into the coordination chemistry of manganese. Our ligands are polypodal, including tetra-and pentadentate ligands, as in the present work, or extended -tripodal hexadentate, as in recent spin-state dynamics studies. The former chelators shield am ajor part of the metal-coordination sphere, focusing the reactivity on one or two "labile" coordination sites. The coordinative strain of all these claw-like ligands can also be varied, enabling investigations, in which distortions of the coordination sphere and their influence on complex reactivity and spin multiplicity,c an be studied in isolation (and with reference to the concept of the entatic state). Invited for the cover of this issue is the group of Gerald Hçrner and Andreas Grohmann at the Technical University of Berlin. The image depicts that the browning of cut fruit is effected by copper-and oxygen-dependent oxygenases, leading to mela-nine pigments, which are polymeric ortho-quinone derivatives.R ead the full text of the article at