0000000000704147
AUTHOR
Hideo Ando
Innentitelbild: Bidirectional Chemo‐Switching of Spin State in a Microporous Framework (Angew. Chem. 26/2009)
Das chemische Schalten des Magnetismus in zwei Richtungen wurde in einem mikroporosen Koordinationspolymer mit Spin-Crossover-Einheiten beobachtet. M. Ohba, J. A. Real, S. Kitagawa und Mitarbeiter stellten in ihrer Zuschrift auf S. 4861 ff. magnetische Messungen vor, die belegen, dass die meisten Gastmolekule einen Ubergang des Netzwerks vom diamagnetischen Low-Spin- (rot) in den paramagnetischen High-Spin-Zustand (gelb) bewirken. Allein CS2 stabilisiert den Low-Spin-Zustand. Die induzierten Spinzustande werden auch nach Freisetzung der Gastspezies beibehalten.
A Switchable Molecular Rotator: Neutron Spectroscopy Study on a Polymeric Spin-Crossover Compound
A quasielastic neutron scattering and solid-state 2H NMR spectroscopy study of the polymeric spin-crossover compound {Fe(pyrazine)[Pt(CN) 4]} shows that the switching of the rotation of a molecular fragment-the pyrazine ligand-occurs in association with the change of spin state. The rotation switching was examined on a wide time scale (10 -13-10 -3 s) by both techniques, which clearly demonstrated the combination between molecular rotation and spin-crossover transition under external stimuli (temperature and chemical). The pyrazine rings are seen to perform a 4-fold jump motion about the coordinating nitrogen axis in the high-spin state. In the low-spin state, however, the motion is suppres…
Bidirectional Chemo-Switching of Spin State in a Microporous Framework
The ins and outs of spin: Using the microporous coordination polymer {Fe(pz)[Pt(CN)(4)]} (1, pz=pyrazine), incorporating spin-crossover subunits, two-directional magnetic chemo-switching is achieved at room temperature. In situ magnetic measurements following guest vapor injection show that most guest molecules transform 1 from the low-spin (LS) state to the high-spin (HS) state, whereas CS(2) uniquely causes the reverse HS-to-LS transition.
Inside Cover: Bidirectional Chemo-Switching of Spin State in a Microporous Framework (Angew. Chem. Int. Ed. 26/2009)
Bidirectional chemo-switching of magnetism occurs in a microporous coordination polymer containing spin-crossover subunits, as described by M. Ohba, J. A. Real, S. Kitagawa, and co-workers in their Communication on page 4767 ff. In situ magnetic measurements reveal that most guest molecules transform the framework spin state from diamagnetic low spin (red) to paramagnetic high spin (yellow), whereas the guest CS2 stabilizes the low-spin state. These induced spin states are retained as a memory effect after the release of the guest.