Mössbauer spectroscopy in molecular magnetism

Abstract

The aim of this paper is to highlight some selected research activities on molecular magnetic materials using Mössbauer spectroscopy as a technique carried out in our laboratory in recent years. The first part of the present article is devoted to the studies of the various magnetic interactions, metal-to-metal electrontransfer phenomenon, glass transition occurring in molecular magnetic materials, whereas the second part deals with the iron(II) high spin (S = 2)-low spin (S = 0) transition phenomenon occurring in some isoxazole ligand based iron(II) compounds as examples with unusually complicated spin transition behaviour. Also, an example of a dinuclear a spin crossover compound of iron(II) is described, where Mössbauer spectroscopy has most convincingly unraveled the mechanism of the spin transition process. Finally, an example from our most recent studies of spin crossover materials exhibiting both thermal spin crossover and liquid crystalline properties in the same temperature interval near room temperature will be presented.

Spin crossover in discrete polynuclear iron(ii) complexes

“…The most convenient way to quantify SCO is therefore variable temperature w M T (the product of molar magnetic susceptibility and temperature) measurements, which are routinely performed on modern SQUID, PPMS, or Versalab magnetometers. UV-vis, 9 IR, 11 Raman, 12 NMR, [13][14][15][16] Mössbauer, 17 and fluorescence 18 spectroscopies, as well as PXRD 19 and DSC, 20,21 can also be invaluable tools for monitoring SCO.…”