English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Understanding, controlling, and utilizing the flexibility of adsorbents are of great importance and difficulty. Analogous with conventional solid materials, downsizing to the nanoscale is emerging as a possible strategy for controlling the flexibility of porous coordination polymers (or metal-organic frameworks). We report a unique flexibility controllable by crystal size at the micrometer to submillimeter scale. Template removal transforms [Cu 2 (pypz) 2 ]·0.5 p -xylene (MAF-36, Hpypz = 4-(1 H -pyrazol-4-yl)pyridine) with one-dimensional channels to  α -[Cu 2 (pypz) 2 ] with discrete small cavities, and further heating gives a nonporous isomer  β -[Cu 2 (pypz) 2 ]. Both isomers can adsorb  p -xylene to give [Cu 2 (pypz) 2 ]·0.5 p -xylene, meaning the coexistence of guest-driven flexibility and shape-memory behavior. The phase transition temperature from  α -[Cu 2 (pypz) 2 ] to  β -[Cu 2 (pypz) 2 ] decreased from ~270°C to ~150°C by increasing the crystal size from the micrometer to the submillimeter scale, ca. 2-3 orders larger than those of other size-dependent behaviors. Single-crystal X-ray diffraction showed coordination bond reconstitution and chirality inversion mechanisms for the phase transition, which provides a sufficiently high energy barrier to stabilize the metastable phase without the need of downsizing to the nanoscale. By virtue of the crystalline molecular imprinting and gate-opening effects,  α -[Cu 2 (pypz) 2 ] and  β -[Cu 2 (pypz) 2 ] show unprecedentedly high  p -xylene selectivities of 16 and 51, respectively, as well as ultrafast adsorption kinetics (<2 minutes), for xylene isomers.

Flexibility of Metal-Organic Framework Tunable by Crystal Size at the Micrometer to Submillimeter Scale for Efficient Xylene Isomer Separation