Angewandte Chemie International Edition
© WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Cover Picture: Direct Decomposition of Nitrous Oxide to Nitrogen by In Situ Oxygen Removal with a Perovskite Membrane (Angew. Chem. Int. Ed. 16/2009)
Hollow fiber membranes from mixed-conducting perovskites can separate oxygen selectively from gas mixtures. Wall thicknesses as low as 150 μm can be obtained by a wet spinning process, and oxygen fluxes are thereby obtained that are relevant for technical applications. In their Communication on page 2983 ff., H. Wang, J. Caro and co-workers describe the complete decomposition of nitrous oxide with such membranes. This method offers new opportunities to reduce emissions of this greenhouse gas.
Also of Interest
The use of molecular complexes as catalysts for the oxidation of water is discussed by A. Llobet and co-workers in their Minireview on page 2842 ff. Initial attempts to generate supported molecular catalysts for this reaction are also presented.
In their Review on page 2854 ff., P. S. Baran, R. W. Hoffmann, and N. Z. Burns discuss an often-overlooked form of synthetic economy, namely redox economy: the use of as few redox steps as possible in the synthesis of a target molecule. Guidelines are given as to how the redox economy in multistep synthetic sequences can be improved.
X. Xu, Q. Liu and co-workers show in their Communication on page 2868 ff. that one C-N and three C-C bonds along with four adjacent stereocenters can be formed with excellent atom economy in the synthesis of pyrrolizidines.