Muonium kinetics and free radical formation in solutions of fullerenes.

摘要

The purpose of this research was to study the kinetics of the reaction of muonium with C60 in solution. The solubility of C60, which is poor in most organic solvents and negligible in water, has been one of the greatest impediments to study reactions and possible biological functions. The kinetics of the reaction of muonium with C60 in solution was investigated by transverse field muon spin resonance (TF-μSR).;The rate constant for the reaction of muonium with C60 in decalin was extracted from the magnetic field dependence of the C60Mu radical signal amplitude. The rate constant determined by this method was found to be 5.5(7) × 1010 M−1 s −1 at 25°C with an activation energy of 18 kJ mol −1. (Abstract shortened by UMI.).;From measurements of muonium decay rates in dilute solutions of C 60 in cyclohexane, the rate constant for the reaction of muonium with C60 was found to be 2.0(3) × 1011 M −1 s−1 at room temperature, in agreement with previous work. C60 is thought to form a true solution in cyclohexane. However, in water C60 forms sols—suspensions of C60 clusters.