| Abstract: | The photophysical properties of mixed coaggregates containing 1,4-dicyanonaphthalene (DCN) and 1,3,5-triphenyl-2-pyrazoline (TPP) have been studied. The absorption spectra of mixed coaggregates indicate that a charge-transfer complex is not formed in the ground state between DCN and TPP. The fluorescence of TPP in the mixed coaggregates is quenched by DCN, accompanied with a broad and structureless emission at about 560 nm from an exciplex between DCN and TPP. The color of the emission from mixed coaggregates is tunable by changing the DCN content. The excited-state properties of the TPP-DCN molecule pair are investigated theoretically with a quantum chemistry method. The theoretical results have also confirmed that the broad emission at about 560 nm in the mixed coaggregates originates from the exciplex rather than from the charge-transfer complex. |
