Open framework materials (OFM) constitute a large and growing class of nanoporous crystalline structures that is attracting considerable attention for electronic device applications. This review summarizes the most recent reports concerning electronic devices enabled by either of the two primary categories of OFM, metal−organic frameworks (MOFs) and covalent−organic frameworks (COFs). Devices in which the OFM plays an active role (as opposed to acting only as a selective sorbent or filter) are the principal focus, with examples cited that include field-effect transistors, capacitors, memristors, and a wide variety of sensing architectures. As a brief tutorial, we also provide a concise summary of various methods of depositing or growing OFM on surfaces, as these are of crucial importance to the deployment of electronic OFM. Finally, we offer our perspective concerning future research directions, particularly regarding what in our view are the biggest challenges remaining to be addressed. On the basis of the literature discussed here, we conclude that OFM constitute a unique class of electronic materials with characteristics and advantages that are distinct from either conventional inorganic semiconductors or organic conductors. This suggests a bright future for these materials in applications such as edge computing, resistive switching, and mechanically flexible sensing and electronics. CONTENTSReview pubs.acs.org/CR

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Functional materials that respond to chemical or physical stimuli through reversible structural transformations are highly desirable for the integration into devices. Now, a new stable and flexible eightfold interpenetrated three‐dimensional (3D) metal–organic framework (MOF) is reported, [Zn(oba)(pip)]n (JUK‐8) based on 4,4′‐oxybis(benzenedicarboxylate) (oba) and 4‐pyridyl functionalized benzene‐1,3‐dicarbohydrazide (pip) linkers, featuring distinct switchability in response to guest molecules (H2O and CO2) or temperature. Single‐crystal X‐ray diffraction (SC‐XRD), combined with density functional theory (DFT) and grand canonical Monte Carlo (GCMC) simulations, reveal a unique breathing mechanism involving collective motions of eight mixed‐linker diamondoid subnetworks with only minor displacements between them. The pronounced stepwise volume change of JUK‐8 during water adsorption is used to construct an electron conducting composite film for resistive humidity sensing.

Complexation of iron(III) with the heterodonor chelating agent 3,5-di-tert-butylsalicylidene benzoylhydrazine, H2(3,5-tBu2)salbh, in the absence or presence of a base affords the complex cation [Fe{H(3,5-tBu2)salbh}2]+ or the neutral compound [Fe{H(3,5-tBu2)salbh}{(3,5-tBu2)salbh}], respectively, as revealed by single-crystal X-ray analyses. Such a synthetic and crystallographic demonstration of the coordination versatility of an aroylhydrazone toward iron is uncommon. The oxidation and spin states of the iron have been verified with magnetic and spectroscopic measurements.