Polarization effects in homo-binuclear and trinuclear iron complexes

Polarization phenomena induced by adsorption and desorption of solvated molecules in a new class of homo-binuclear and trinuclear iron complexes were investigated by means of correlated TSDC and infrared (IR) absorption spectra. {[Fe(L)]}₂Fe(CN)₆Cl-4H₂O (where L is a bis(acylhydrazone) of 2,6-diacetylpyridine) shows a typical behavior: the TSDC bands occurring in the as-prepared pellet at ~180 and ~290 K disappear whenever the sample is stored in dynamic vacuum and a new one grows at ~155 K. The subsequent exposure to moist atmosphere causes a partial recovery of the spectrum, suggesting that loosely bound water molecules are responsible for the polarization phenomena. The adsorption and desorption kinetics analyzed by means of IR spectroscopy supported such a conclusion