The additive-free synthesis of poly(phenylene oxides) by aerobic oxidation was achieved using a copper complex in a dendritic phenylazomethine structure. The outer shell composed of Schiff base units assists the catalytic function of the inner Cu complex moiety. It is important that the hybrid structure should be designed with a rigid architecture not to deactivate the catalytic center. Due to the rigid π-conjugating structure of the phenylazomethine dendrimer, the metal center can retain its fine conformation. This catalyst drastically decreased the total waste required to produce the PPO derivatives and provided a new approach to green polymerization.

Molecular shape recognition for larger guest molecules (typically over 1 nm) is a difficult task because it requires cooperativity within a wide three-dimensional nanospace coincidentally probing every molecular aspect (size, outline shape, flexibility and specific groups). Although the intelligent functions of proteins have fascinated many researchers, the reproduction by artificial molecules remains a significant challenge. Here we report the construction of large, well-defined cavities in macromolecular hosts. Through the use of semi-rigid dendritic phenylazomethine backbones, even subtle differences in the shapes of large guest molecules (up to B2 nm) may be discriminated by the cooperative mechanism. A conformationally fixed complex with the best-fitting guest is supported by a three-dimensional model based on a molecular simulation. Interestingly, the simulated cavity structure also predicts catalytic selectivity by a ruthenium porphyrin centre, demonstrating the high shape persistence and wide applicability of the cavity.

Sintered copper nano particles are being considered as alternatives to solder and/or sintered silver in different applications. Like for the alternatives, interpretation of accelerated fatigue test results does however require modeling, typically involving prediction of stresses and strains vs. time and temperature based on constitutive relations. This poses a challenge as the inelastic deformation properties depend strongly on both the initial particles and details of the processing, i.e. unlike for solder general constitutive relations are not possible. The present work provides a mechanistic description of the early transient creep of relevance in cycling, including effects of sintering parameters and subsequent oxidation. Inelastic deformation is dominated by diffusion, rather than dislocation motion. Generalized constitutive relations are provided to the extent that quantitative modeling of a specific structure only requires the measurement of a single creep curve for that.

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The inelastic deformation properties of sintered metal nanoparticle joints are complicated by the inherent nanocrystalline and nanoporous structures as well as by dislocation networks formed in sintering or under cyclic loading. Creep rates of sintered nanocopper structures were found to be dominated by the diffusion of individual atoms or vacancies, while dislocation motion remained negligible up to stresses far above those of practical interest. Rapid sintering of one material led to unstable structures the creep of which could be strongly reduced by subsequent annealing or aging. Longer sintering of another material led to more stable structures, but creep rates could still be strongly enhanced by subsequent work hardening in mild cycling.