Connecting Wires: Photoinduced Electronic Structure Modulation in Metal–Organic Frameworks

Abstract

Electronic structure modulation of metal–organic frameworks (MOFs) through the connection of linker “wires” as a function of an external stimulus is reported for the first time. The established correlation between MOF electronic properties and photoisomerization kinetics as well as changes in an absorption profile is unprecedented for extended well-defined structures containing coordinatively integrated photoresponsive linkers. The presented studies were carried out on both single crystal and bulk powder with preservation of framework integrity. An LED-containing electric circuit, in which the switching behavior was driven by the changes in MOF electronic profile, was built for visualization of experimental findings. The demonstrated concept could be used as a blueprint for development of stimuli-responsive materials with dynamically controlled electronic behavior.

Novel Photoactive Spirooxazine Based Switch@MOF Composite Materials

“…Therefore, it was the aim of the present work to synthesize and characterize different SPÀ O@MOF systems to examine the influence of the MOF hosts on the optical and photoswitching properties of the embedded spirooxazine molecules. Notably, the SPÀ O molecules will be non-covalently bound to the MOF framework rather than being attached to the MOF scaffold, [34][35][36] as a part of the linker backbone [35,[37][38][39][40] or as a substituent of the linker, [41][42][43][44][45][46][47][48][49][50] which necessarily leads to a high mobility of the dye molecules in the former. That way, host-guest and guest-guest interactions are expected to have an important impact on the photophysical properties of these composites, but on the other hand can be examined in an elegant way in these systems.…”

Metal–Organic Frameworks in Modern Physics: Highlights and Perspectives

“…Magnetic phase transitions between low spin and high spin states have also been observed at 20 K with coercive fields of 240 Oe. [98][99][100][101][102][103] The proton semiconductive hysteresis observed in the 3D MOF, Cu 2 (F 2 AzoBDC) 2 (dabco) (F 2 AzoBDC = (E)-2-((2,6-difluorophenyl)diazenyl)terephthalic acid; dabco = 1,4-Diazabicyclo[2.2.2]octane), is an indicator of such structural changes. This high bipolar reversible magnetization switching is different from the irreversible rotation of ferro/ferrimagnetic domains through the use of external magnetic fields.…”

“…[96] The 3D niccolite MOF mentioned earlier, [(CH 3 CH 2 ) 2 NH 2 ] [Fe III Fe II (HCOO) 6 ], also appeared to demonstrate magnetic hysteresis regulated by a thermal and magnetic state at low temperatures, [80] a phenomenon which is the response of the magnetization of Fe II and Fe III sublattices to external stimuli. [98] In general, this photoisomerisation process leads to conformation changes of the ligand, and modulates the electronic structure of MOFs and, therefore, their chemical, [98][99][100][101][102] optical, [103] and electrical [104] properties. [80] Mechanical hysteresis has been reported for some examples of 3D MOFs (e.g., rigid layers of Co/1,3,5-benzenetricarboxylate which are connected to each other with flexible and spherical dipyridyl linkers).…”

Light‐Controllable Ionic Conductivity in a Polymeric Ionic Liquid

“…[4][5][6] Surprisingly,combining the advantageous features of both materials classes through the development of smart PILs with light-controllable conductivity has lagged significantly behind other classes of electronic/ionic conducting materials. [7][8][9][10][11][12] Advances in tunable PILs would therefore enable cutting-edge applications based on photoconductive properties such as light-controlled electronic circuits [13][14][15] and wearable photodetectors. [16][17][18] To enable the development of stimuli-responsive PILs,we sought to design an ionic-liquid-based photoswitchable motif that could be incorporated into ap olymeric structure.W hile the incorporation of photo-responsive molecules in ionic liquid motifs has been previously reported, [19][20][21][22][23][24] incorporating these structures into PILs has yet to be demonstrated.…”