Isotropic and anisotropic magnetic field effect on the exciplex between all-s-trans-1,6-diphenylhexa-1,3,5-triene and 1,4-dicyanobenzene

The exciplex between all-s-trans-l,6-diphenyIhexa-l,3,5-triene and 1, 4;-di cyanobenzene exhibits both isotropic and anisotropic magnetic field effects (MFEs). The exciplex luminescence increases in the presence of a magnetic field. The maximum MFE occurs at the dielectric constant epsilon approximat e to 10, which confirms the importance of the charge-transfer characteristi cs of the exciplex, as observed previously (Aich, S.; Basu, S. J. Phys. Che m. A 1998, 102, 722). The wavelength dependence of the field effect proves the existence of two types of charge-transfer complexes with different stoi chiometries. The MFE is greater when the excitation light is polarized para llel to the field compared to that with the exitation light polarized perpe ndicular to the field. This observation signifies the presence of an anisot ropic MFE with this exciplex system.