Field-induced spin phase transition in a Co complex

Switchable cobalt coordination polymers: Spin crossover and valence tautomerism

“…The reverse process can also be induced by irradiation with light of different wavelengths. Other methods of stimulating VT transitions in Cobalt-dioxolene systems include pressure, magnetic or electric field, irradiation with both soft and hard X-rays[49][50][51][52][53].…”

Investigation of cobalt (1,10-phenanthroline)-bis-(3,6-di-tert-butyl-o-benzosemiquinolate) by X-ray diffraction, IR and ESR spectroscopy, magnetochemistry, and precision calorimetry

“…is bidentate N donor ligand is mono or direduced forms of o quinone possible to synthesize compounds with a desired phase transition temperature (T 1/2 ); 2) the photodynamics of redox isomeric transitions was studied in detail, and methods for the detection and iden tification of the excited metastable state were examined; 6, 7 3) the influence of the composition of the complexes and the nature of the ligands on the hysteresis width in the temperature dependence of μ eff was analyzed; 8 4) based on the temperature dependence of the heat capacity, 9 it was shown that redox isomeric transforma tions are accompanied by the phase transition (λ transi tion), which can be induced also by electromagnetic radi ation, 10 pressure, 11 magnetic field, 12 and chemical action (pH), 13 the temperature and the energy of the transition being dependent on the nature of the o quinone ligand; 14, 15 5) new types of redox isomeric cobalt complexes, viz., mono o semiquinone complexes 16 and dinuclear mixed valence complexes, were synthesized; 17 6) nanosized redox isomeric cobalt complexes 18 and complexes immobilized on gold nanoparticles, 19 redox isomeric cobalt complexes with o semiquinone ligands having liquid crystalline properties, 20,21 and polymeric re dox isomeric cobalt complexes 22 were prepared; 7) the photo(thermo)mechanical effect was found for single crystal samples of the complex (bpy)Co(3,6 DBSQ) 2 . 1 This class of compounds has attracted great interest due primarily to the fact that these compounds show prom ise as new photoactive magnetic materials.…”

Large‐Amplitude Thermal Vibration‐Coupled Valence Tautomeric Transition Observed in a Conductive One‐Dimensional Rhodium–Dioxolene Complex

“…Valence tautomeric (VT) complexes derived from redox‐active ligands and metal centers, represented by metal‐dioxolene complexes, can take two valence isomers or redox isomers with different localized electronic structures exhibiting different physical properties [8] . VT transitions between these isomers accompanying intramolecular electron transfer can not only cause changes in the valence and spin states and radical formation and disappearance but also lead to interesting mixed‐valence states [9] and spin transitions, [2a–c, 10] and these features can be tuned by controlling the VT transitions by external stimuli, such as heat, [10a, f, g, 11] light, [1g, 10e, f, 12] X‐ray, [13] pressure, [3g] and electric [14] and magnetic fields [15] . Therefore, VT transitions are widely utilized as stimuli‐responsive, controllable functions on dynamic molecular crystals.…”