Magnetically sensitive non-polar exciplex: the perfluoronaphthalene–anthracene system

The complexation reaction between anthracene (AN) and perfluoronaphthalene (PFN) has been found to be magnetically sensitive. The various characteristics of magnetic field effect in the radical ion pair system, namely wavelength, field and dielectric constant dependence, were investigated. The mismatch between theoretically estimated and experimentally determined B1/2, has been ascribed to the out-of-plane floppy motion of the perfluoranaphthalene radical anion, which bestows a σ character on the latter thereby affecting the hyperfine coupling constant. The low magnetic sensitivity of this exciplex system has been ascribed to a combined effect of static complexation of AN-PFN and an out-of-plane butterfly motion of the PFN radical.