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Fine-tuning of the ratio of two different states is important in controlling the structures and functions of crystalline materials. Here we report that clathrated guest molecules inside a tubular host crystal formed via halogen and hydrogen bonding exhibit reversible temperature-dependent orientational isomerisation in equilibrium. [ABSTRACT FROM AUTHOR]

Porous crystals with well‐defined active metal centers on the pore surface have high potential as heterogeneous metal catalysts. We have recently demonstrated that a porous molecular crystal, metal‐macrocycle framework (MMF), catalyzes olefin migration reactions by photoactivation of its PdIICl2 moieties exposed on the crystalline channel surface. Herein we report a mechanistic study of the photoinduced olefin migration reactions at the PdII active centers of MMF. Several experiments, including a deuterium scrambling study, revealed that olefin migration is catalyzed via an alkyl mechanism by in situ generated Pd−H species on the channel surface during photoirradiation. This proposed mechanism was further supported by DFT and ONIOM calculations. [ABSTRACT FROM AUTHOR]

Designing unique core–shell porous crystals is key to the development of anisotropically functionalised materials. Herein we report the facile preparation of a core–shell metal–macrocycle framework (MMF) containing continuous 1D-channels via an epitaxial growth procedure. Methyl orange loaded in the core was found to be anisotropically transported to the shell along the heterogeneously hybridised 1D-channels. [ABSTRACT FROM AUTHOR]

Porous crystals are excellent materials with potential spatial functions through molecular encapsulation within the pores. Co-encapsulation of multiple different molecules further expands their usability and designability. Herein we report the simultaneous arrangement of up to three different guest molecules, TTF (tetrathiafulvalene), ferrocene, and fluorene, on the pore surfaces of a porous crystalline metal-macrocycle framework (MMF). The position and orientation of adsorbed molecules arranged in the pore were determined by single-crystal X-ray diffraction analysis. The anchoring effect of hydrogen bonds between the hydroxy groups of the guest molecules and inter-guest cooperation and competition are significant factors in the adsorption behaviors of the guest molecules. This finding would serve as a design basis of multicomponent functionalized nanospaces for elaborate reactions that are realized in enzymes. [ABSTRACT FROM AUTHOR]

Keywords: mechanism; metallacycles; olefin migration; palladium; photoactivation EN mechanism metallacycles olefin migration palladium photoactivation 174 174 1 02/03/21 20210201 NES 210201 B One-dimensional crystalline channels b with well-defined active metal centers hold great potential as heterogeneous catalysts. Experimental and theoretical studies revealed that the olefin migration was catalyzed via an alkyl mechanism by in situ generated Pd-H species on the channel ceiling through photoirradiation. Mechanism, metallacycles, olefin migration, palladium, photoactivation. [Extracted from the article]