Systems or molecular species showing two fluorescence bands. Several non-trivial molecular properties may be at the basis of a dual fluorescence, such as conformational equilibrium in the ground state and a mixture of excited states.
Trivial reason for dual @F02453@ is the coexistence of two independent @FT07380@.
PAC, 2007, 79, 293. 'Glossary of terms used in photochemistry, 3rd edition (IUPAC Recommendations 2006)' on page 327 (https://doi.org/10.1351/pac200779030293)