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Due to the unique advantages of light weight, flexibility, stretchability and biocompatibility, organic solar cells have great commercial application prospects in the fields of wearable and portable electronics. Based on miscibility and crystallinity considerations, Long Ye and co-workers proposed an effective strategy to simultaneously improve device efficiency, mechanical robustness, and stability of all-polymer organic solar cells by refining the aggregation and crystallization behaviors of polymerized Y-series acceptors. This work heralds a bright future of all-polymer systems for flexible wearable energy-harvesting applications. More details are discussed in the article by Ye et al. on page 159—166.

     

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The cover picture shows nanometer‐thin elastomeric membranes made from polyisobutene star polymers with ionic head groups. Spreading of the polymers onto a water surface yields fluid monolayers. These can be transferred to cover openings in solid substrates. After transfer, the ionic head groups aggregate, cross‐link the membrane, and thus give rise to elastomeric properties. For example applying a small overpressure from one side gives rise to comparatively large, reversible deformations. These elastomeric membranes could be used in micromechanical devices such as membrane pumps and valves. More details on these membranes are reported by F. Mallwitz and W. Goedel on pages 2645 ff.     

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The cover picture shows a rhodium catalyst (green) that is encapsulated by three porphyrin molecules (black; the van der Waals radii are shown in yellow). The hemispherical assembly is obtained by a self‐assembly process using readily available pyridylphosphane and zinc‐porphyrin building blocks. Its exclusive formation is based on selective coordination of the nitrogen atom to the zinc atom and the phosphane group to the rhodium center. The catalyst assemblies show a higher activity than the free rhodium catalyst in the rhodium‐catalyzed hydroformylation of 1‐octene, and the branched product is now the main product. In a similar way, the assembly of porphyrin building blocks to pyridylphosphane can regulate the performance of palladium catalysts in the Heck reaction. Further details about these catalyst assemblies can be found in the article by Reek et al. on p. 4271ff.     

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The cover picture shows in red the three‐dimensional structure of the Ras protein in a ribbon representation, with its β‐strands, α‐helices and connecting loops. The protein bound cofactor Guanosine triphosphate (guanine base up, phosphates down) is shown in a space‐filing model. Due to its central role in many signal transduction processes and since it is heart‐shaped, Ras has been called the beating heart of signal transduction (i.e. H. Bos, Utrecht).