Structure−property relationships for the nucleobase-containing π-conjugated oligomers have emerged from a combination
of experimental spectroscopic data and DFT calculations. The
absorption and emission properties, emission lifetimes, and
fluorescence quantum yields respond in understandable ways to
both nucleobase and π-backbone electronic structure. For
example, guanine-terminated derivatives (G-TBT-G and G-TTT-G) exhibit the most bathochromically shifted absorption,
consistent with the nucleobase’s good electron-donating
character compared to A and U. Despite having lower
HOMO−LUMO gaps, the fluorescence quantum yields and
lifetimes of the TBT-linked nucleobases are significantly
improved over the terthiophene (TTT) family