• crown complexes;
  • lasso;
  • molecular switch;
  • self-entanglement;
  • rotaxanes


The sculpture “Man on a rolling stone” by the Danish artist Erik Heide is integrated into a C2-symmetric molecule as a model for a chiral organocatalyst, which can break the symmetry of anthracene aldehydes (to the left) and maleimides (to the right) and catalyze a highly enantioselective Diels–Alder reaction. For more details, see the Communication by K. A. Jørgensen et al. on page 2932 ff.

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Crystalline Polyoxometalate (POM) Isomers

There are many issues regarding how POMs assemble in solution, especially when additional hetero-metals are involved. However, research into such mechanisms by using solution-phase techniques is limited. In their Communication on page 2976 ff., L. Cronin et al. present a unique system, in which intermediate “meta-stable” crystals of new clusters temporarily crystallize out of solution and could be analyzed by using single-crystal X-ray crystallography. This insight combined with an unusual pair of final-product isomers allowed a mechanism of assembly to be proposed, which may allow the design of new transition-metal-substituted POM clusters.

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Hierarchical Nanospheres

A facile method has been designed for the large-scale production of hierarchical TiO2 nanorod spheres through deliberately adding TiCl3 into the reaction of resorcinol and formaldehyde. After calcination, the resultant TiO2 nanorod spheres exhibit high photocatalytic performances in eliminating contaminants and killing bacteria under UV or solar-light irradiation. This is of great significance in fabricating well-crystallized hierarchical TiO2 nanorod spheres for water purification. For more details, see the Full Paper by Z. Y. Liu, D. D. Delai et al. on page 3061 ff.

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