A metamorphic inorganic framework that can be switched between eight single-crystalline states

Abstract

The design of highly flexible framework materials requires organic linkers, whereas inorganic materials are more robust but inflexible. Here, by using linkable inorganic rings made up of tungsten oxide (P8W48O184) building blocks, we synthesized an inorganic single crystal material that can undergo at least eight different crystal-to-crystal transformations, with gigantic crystal volume contraction and expansion changes ranging from −2,170 to +1,720 Å3 with no reduction in crystallinity. Not only does this material undergo the largest single crystal-to-single crystal volume transformation thus far reported (to the best of our knowledge), the system also shows conformational flexibility while maintaining robustness over several cycles in the reversible uptake and release of guest molecules switching the crystal between different metamorphic states. This material combines the robustness of inorganic materials with the flexibility of organic frameworks, thereby challenging the notion that flexible materials with robustness are mutually exclusive.

Cation‐Controlled Assembly of Polyoxotungstate‐Based Coordination Networks

“…All‐inorganic POM coordination networks, such as those shown in Figure , contain POM clusters connected solely through coordinative O–M–O (where M is generally a transition or lanthanide metal) bonds to form one‐dimensional chains, two‐dimensional sheets or three‐dimensionally connected extended solids . Such materials combine the all‐inorganic nature of zeolites with the coordination linkages of MOFs and thus represent an exciting class of materials for realizing and understanding design principles of tunable, molecule‐based metal oxides.…”

A zeolitic vanadotungstate family with structural diversity and ultrahigh porosity for catalysis

“…There are only a few examples of zeolitic transition metal oxides. The typical materials are porous frameworks based on ring-shaped [P 8 W 48 O 184 ] unit 14,15 , [MnV 13 O 38 ] unit 16 , and pentagon [Mo 6 O 21 ] units 17 . However, the current materials suffer from problems that include poor structural diversity, unopened micropores 18 , and low surface area and porosity 18,19 .…”

Physical and Electrochemical Modulation of Polyoxometalate Ionic Liquids via Organic Functionalization

“…Polyoxometalates (POMs) are discrete anionic metal oxide clusters with a variety of attractive properties, such as photosensitivity, redox activity, and high thermal and chemical stability These properties make POMs of potential interest in a range of applications including catalysis, electrical‐energy storage, and sensing, to name but a few. Hybrid organic/inorganic clusters are an increasingly important sub‐class of POMs,, in which a near‐limitless selection of organic groups can be incorporated through either weak electrostatic interactions (class I) or via direct covalent functionalization of the POM structure itself (class II) , .…”