Reaction of Hydroxyfullerene with Metal Salts:  A Route to Remediation and Immobilization

Hydroxylated fullerene reacts rapidly and irreversibly (across a wide pH range) with Fe(NO₃)₃, Al(NO₃)₃, CaCl₂, CoCl₂, CuCl₂, KMnO₄, Ag(NO₃), and ZnCl₂ under ambient aqueous conditions to produce insoluble metal−hydroxyfullerene cross-linked polymers (M−fullerenol). Materials have been characterized by SEM, TEM, AFM, XPS, and UV−visible spectroscopy. Molecular mechanics calculations on the model systems, [Fe(C₆₀O₂)₂] and [Fe(C₆₀O₂)₃], show that both tetrahedral and octahedral coordination are possible. The rate of precipitation reaction is proportional to the concentration of both reagents. The interaction of hydroxyfullerenes with metals is an important issue with regard to waste treatment, fullerene exposure in the environment, and fullerene-based pharmaceutical agents.