부산대학교 도서관

Optical absorption and emission properties as well as fluorescence quenching via introduction of an additional unsaturated five‐membered ring in some azaacenes are investigated computationally. It is shown that non‐radiative decay via conical intersections or intersystem crossing is rather unlikely. Instead, the additional double bond alters the electronic structure of the first excited singlet state, turning it into a dark state with long lifetime and hence low fluorescence rate, that cannot be seen anymore with the naked eye. [ABSTRACT FROM AUTHOR]