Nuclear magnetic resonance study of fluorine exchange in the system

Abstract

p>Intermolecular fluorine exchange in the [Formula: see text] system has been studied by 31P nmr spectroscopy. The anion [Formula: see text] was prepared insitu from PhPF4 and KF in 18-crown-6, or from PhPF4 and [Formula: see text]. Exchange was found to be first-order in PhPF4, first-order in [Formula: see text], and slowed down by donor solvents such as acetonitrile, in support of a mechanism involving a fluorine-bridged intermediate. Experimental difficulties are probably due to HF impurities.