Combining organic photochromism with inorganic paramagnetism—optical tuning of the iron(ii) electronic structure

Abstract

The crystalline photochromism of a diarylethene pyridyl ligand is applied to the modulation of the electronic environment of a high-spin Fe(II) metal ion.

Structure Switching and Modulation of the Magnetic Properties in Diarylethene‐Bridged Metallosupramolecular Compounds by Controlled Coordination‐Driven Self‐Assembly

“…Additionally, the open form of diarylethene with heterocyclic aryl groups is known to exhibit two conformations with two rings adopting the mirror (o‐ L syn ) and C 2 (o‐ L anti ) symmetries. Regardless, as compared to the light‐control of open and closed ring isomers, the preparation of metal complexes involving o‐ L syn remains challenging …”

Photochromism of Diarylethene Molecules and Crystals: Memories, Switches, and Actuators

“…501−504 Photoinduced spin change was monitored for the Fe(II) complex with diarylethene ligand 294 (Scheme 31). 501 An increase in the magnetization was observed upon irradiation with 355 nm light due to the LD-LISC effect. Nihei et al 503 synthesized Fe(II) spin-crossover complex with a diarylethene moiety 295.…”

How to Switch Spin‐Crossover Metal Complexes at Constant Room Temperature

“…The very first attempts to achieve the LD‐LISC by a photoreaction at a diarylethene‐based ligand were independently made by Boillot and Garcia . Both groups provided evidence for photomagnetic effects in solids at room temperature.…”

“…Both groups provided evidence for photomagnetic effects in solids at room temperature. However, a ligand photocyclization within a molecular HS complex [Fe II ( 4 ) 4 (NCS) 2 ] (Scheme ), did not induce an anticipated HS→LS transition, but an unexpected increase of magnetization was observed instead . UV‐induced photocyclization in a similar, but polymeric compound {Fe II ( 5 ) 2 (NCS) 2 (MeOH) 2 } n (Scheme ) was suggested to result in a metal‐to‐ligand electron transfer …”