The SPASIBA Force Field for Studying Iron-Tannins Interactions: Application to Fe3+/Fe2+ Catechol Complexes

The SPASIBA force field parameters have been obtained for Fe/Fe-Oxygen interactions occuring between non-heminic iron and hydroxyl groups of polyphenols found in tannins. These parameters were derived from normal modes analyses based on quantum chemical calculations using the Density Functional Theory (DFT). Four models involving complexation of iron with water ([Fe(H2O)6] , [Fe(H2O)6] ) and with cathechol molecules ([Fe(cat)2(H2O)2] , [Fe(cat)2(H2O)2] ) were studied using the Density Functional Theory and the B3LYP hybrid functional under high spin states of iron.