0000000000266679

AUTHOR

Andreas Vef

showing 2 related works from this author

Intersystem crossing in Fe(II) coordination compounds

1994

Fe(II) spin-crossover systems can be quantitatively converted from the low-spin (LS) to the high-spin (HS) state well below the thermal transition temperature by irradiating either into the metal-ligand charge transfer or d-d absorption bands, and even in low-spin systems a transient population of the HS state can be achieved. This fact can be made use of to determine HS → LS relaxation rate constants for a wide variety of Fe(II) spin-crossover and low-spin systems. The HS → LS relaxation shows strong deviations from an Arrhenius behaviour, with nearly temperature-independent tunnelling below ∼70 K and a thermally activated process above ∼100 K. The range of more than 12 orders of magnitude…

Arrhenius equationNuclear and High Energy Physicseducation.field_of_studyChemistryPopulationCondensed Matter PhysicsInternal conversion (chemistry)PhotochemistryMolecular physicsAtomic and Molecular Physics and OpticsVibronic couplingsymbols.namesakeIntersystem crossingReaction rate constantsymbolsRelaxation (physics)Physical and Theoretical ChemistryeducationQuantum tunnellingHyperfine Interactions
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Dynamics of spin state conversion processes in the solid state

1989

High spin (HS) ⇌ low spin (LS) conversions in transition metal complexes are nonradiative transitions between spin states. In this contribution, we present a study of the temperature and pressure dependence of the HS ⇌ LS intersystem crossing dynamics. For some iron(II) spin-crossover complexes, the rate constants were determined by line shape analysis of57Fe Mossbauer spectra. Their temperature dependence is described by an Arrhenius equation, their pressure dependence is interpreted within absolute rate theory. HS → LS conversion rates at low temperatures were determined from the relaxation of light-induced formation of HS states, monitored by optical spectroscopy. Deviations from a simpl…

Arrhenius equationNuclear and High Energy PhysicsSpin statesChemistryThermodynamicsCondensed Matter PhysicsAtomic and Molecular Physics and Opticssymbols.namesakeReaction rate constantIntersystem crossingTransition metalComputational chemistrysymbolsPhysical and Theoretical ChemistrySpectroscopyQuantum tunnellingShape analysis (digital geometry)Hyperfine Interactions
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