Site-Selective Photoswitching of Two Distinct Magnetic Chromophores in a Propeller-Like Molecule To Achieve Four Different Magnetic States

Abstract

Magnetic photoswitching is a highly important but relatively rare phenomenon for enabling optical writing/reading of the magnetic state of a molecule. In this work, an unprecedented site-selective double photoswitching is reported from the assembly of two different "photomagnetic chromophores" into a single hexanuclear molecule: namely, a spin-crossover Fe(II) center exhibiting light-induced excited spin state trapping (LIESST) and a photochemically active octacyanometalate(IV) unit. Four different magnetization levels are accessible through the appropriate combination of violet/red light and temperature, results that highlight the potential of photomagnetic molecules as future molecular memory cells.

Guest‐Dependent Pressure‐Induced Spin Crossover in FeII4[MIV(CN)8]2 (M=Mo, W) Cluster‐Based Material Showing Persistent Solvent‐Driven Structural Transformations

“…The pressuredependentg raduald ecrease of the c M T in the 300-80K range can be ascribed to the pressure-induced spin crossover (SCO) of ac ertain fraction of Fe II HS centres (S HS = 2) to the low-spin diamagnetic state (S LS = 0). The gradualand incomplete character of the SCO was observed previously for similar clusters, [33,34] Fe 4 grid compounds [52,53] and trigonal bipyramidal molecules. [54] Note that the shapes of the SCO curvesp resented in Figure 10 and Figure S16 are also affected by the gradual pressure drop inside the pressure cell (usually around0 .15 GPa in the 300- 50 Kr ange) due to the solidificationo ft he pressure transmitting medium Daphne 7373.…”

“…Among them, cyanido-bridged octahedral clusterso ft he general formula {[M1 II reveal photomagnetism, [28][29][30][31] {[Mn II (bpy) 2 ] 4 [Nb IV (CN) 8 ] 2 } [32] and {Mn II [33] presents spin crossover behaviour andp hotomagnetism related to the lightinduced excited spin state trapping effect (LIESST) at the Fe II centres,{ [Fe II (tmphen) 2 ] 4 [Mo IV (CN) 8 ] 2 } [34] presents site-selective photoswitching and {[Co II (tmphen) 2 ] 4 [Nb IV (CN) 8 ] 2 } [33] [35] demonstrate photomagnetic behaviour and single-crystal-to-single-crystal( SCSC)t ransformations-a rare phenomenon among discrete molecular systems. [36] TheS CSC transformations in the purely molecular Cd 4 Mo 2 and Cd 4 W 2 are relatedt ot he reversible release and sorption of water molecules by their crystals, resembling the behaviouro fs ome metal-organicf rameworks (MOFs).…”

Extremely low-frequency phonon material and its temperature- and photo-induced switching effects

“…Various functionalities such as magnetism, ionic conduction, and external-stimulation responsivity into the 2D metal-organic framework layers can be incorporated using lowfrequency phonon 2D layers to study the synergistic effects between these functionalities and the low-frequency optical phonons. For example, an effective way to switch the phonon frequency by external stimuli is to include external-stimuli responsive units such as spin-crossover, [59][60][61][62][63][64][65][66][67] charge-transfer, [56][57][58][68][69][70][71][72][73][74][75][76] and photo-isomerisation units, [77][78][79][80] into the framework. External-stimulation-tuneable THz or sub-THz phonon crystals may lead to the development of devices such as optical lters and optical shutters for THz or sub-THz lights.…”

Large Breathing Effect Induced by Water Sorption in the Exceptionally Stable Nonporous Non-MOF Crystalline Material

“…Magnetic susceptibility measurements were performed using a Quantum Design MPMS-3 Evercool magnetometer in magnetic fields up to 7 T for samples packed into Delrin sample holders. 114 The experimental data were corrected for the diamagnetism of the sample and the sample holder. Photomagnetic measurements were performed for samples placed between two layers of scotch tape and inserted into the plastic straw.…”