Switching in Metal–Organic Frameworks

Abstract

In recent years, metal–organic frameworks (MOFs) have become an area of intense research interest because of their adjustable pores and nearly limitless structural diversity deriving from the design of different organic linkers and metal structural building units (SBUs). Among the recent great challenges for scientists include switchable MOFs and their corresponding applications. Switchable MOFs are a type of smart material that undergo distinct, reversible, chemical changes in their structure upon exposure to external stimuli, yielding interesting technological applicability. Although the process of switching shares similarities with flexibility, very limited studies have been devoted specifically to switching, while a fairly large amount of research and a number of Reviews have covered flexibility in MOFs. This Review focuses on the properties and general design of switchable MOFs. The switching activity has been delineated based on the cause of the switching: light, spin crossover (SCO), redox, temperature, and wettability.

Thermo- and light-triggered reversible interconversion of dysprosium–anthracene complexes and their responsive optical, magnetic and dielectric properties

“…5, inset). The enthalpy is estimated to be À47.8 kJ mol À1 per molecule, which is comparable to those for Dy III 2 ðdepma 2 Þ(NO 3 ) 6 (hmpa) 4 (À46.8 kJ mol À1 for both de-dimerization and conformation change of depma 2 ), 40 and 3 -bis(salicylideneimino)diethylenetriamine] (À42.4 kJ mol À1 ). 55 Fig .…”

“…Articial smart materials that possess switchable and cooperative multifunctionality have garnered considerable attention in recent years, owing to their wide application in switches, sensors, displays and memory devices. [1][2][3] The responsive dynamics of these materials oen involve two distinct states, which can be optical, magnetic, conductive and dielectric, that switch upon exposure to an external stimulus. [4][5][6][7] Among various types of multifunctional smart materials, metal-organic systems combining magnetism with optical [8][9][10][11][12] and/or dielectric [13][14][15][16] properties are of particular interest because of their importance in information storage and spintronic devices.…”

Photoresponsive porous materials

“…While the first approach is a reliable strategy and was widely used to fabricate photo-responsive functional porous materials, the latter strategy is more challenging but potentially leads to more robust and stable materials and therefore this review will be focused solely on the materials featuring photoswitches installed in the scaffold. The reader is referred also to other recent reviews on responsive porous materials [57][58][59][60][61][62] and molecular machines embedded in MOFs. 63 Figure 1 Illustration of three distinct modes of incorporation of a photoswitch in a solid material scaffold (a) as a guest in the pores, (b) pendant to the linker, (c) in the backbone of the linker.…”

Guest Modulated Spin States of Metal Complex Assemblies

“…[3] Coordination polymers (CPs) and metal-organic frameworks (MOFs; or porous coordination polymers, PCPs) -where metal ions are connected by organic linkers -frequently show extended network structures with actual or potential porosity; such materials have been demonstrated to be versatile functional materials. [4] To date, 1D, 2D and 3D CPs/MOFs systems with designed pores have been investigated for guest-adsorp-very often influence the structures of both discrete metallosupramolecular assemblies as well as those of coordination polymers/metal-organic frameworks (CPs/MOFs), providing a means for fine-tuning their magnetic behavior, including the switching of their spin states. In this minireview, we report recent progress in the development and investigation of magnetic materials of both the CP and MOF categories as well as of discrete complexes whose properties are modulated by guests.…”