Polymorphism dependent light induced spin transition.

A photomagnetic study of orthorhombic and tetragonal low spin polymorphs of compound [Fe(L)2](BF4)2 revealed different properties and thermal stability of their metastable high spin states. Furthermore, the reversible thermally induced phase/spin transition between low spin and high spin orthorhombic phases was studied by variable temperature UV/VIS spectroscopy.