Ligand movement modulates the rate of proton transfer in reactions of [Fe4S4Cl4]2−

Abstract

Substitution of the first chloro-ligand in [Fe₄S₄Cl₄]²⁻ by 4-RC₆H₄S⁻ (R = CF₃, Cl, H, Me or MeO), in the presence of [H₂N(CH₂)₃CH₂]⁺, involves initial binding of thiolate, followed by protonation and finally chloride dissociation; the rate of protonation is facilitated by electron-withdrawing R-substituents indicating that Fe-thiolate bond length changes modulate proton transfer.